1,368 results
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2. Writing Papers with Four Hands - In Memory of Professor Matteo Caleo (1970-2022)
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Yuri Bozzi
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General Neuroscience - Published
- 2022
3. Expression of the neuropeptide Y Y1 receptor in the CNS of rat and of wild-type and Y1 receptor knock-out mice. Focus on immunohistochemical localization1<FN ID="FN1"><NO>1</NO>This paper is dedicated to our collaborator and coauthor, the late John H. Walsh, an excellent and generous scientist and a fine human being.</FN>
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Kopp, J., Xu, Z.-Q., Zhang, X., Pedrazzini, T., Herzog, H., Kresse, A., Wong, H., Walsh, J.H., and Hökfelt, T.
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NEUROPEPTIDE Y , *ETHYLENEDIAMINETETRAACETIC acid , *CENTRAL nervous system , *IMMUNOFLUORESCENCE - Abstract
The distribution of neuropeptide Y (NPY) Y1 receptor-like immunoreactivity (Y1R-LI) has been studied in detail in the CNS of rat using a rabbit polyclonal antibody against the C-terminal 13 amino acids of the rat receptor protein. The indirect immunofluorescence technique with tyramide signal amplification has been employed. For specificity and comparative reasons Y1 knock-out mice and wild-type controls were analyzed. The distribution of Y1R mRNA was also studied using in situ hybridization. A limited comparison between Y1R-LI and NPY-LI was carried out.A widespread and abundant distribution of Y1R-LI, predominantly in processes but also in cell bodies, was observed. In fact, Y1R-LI was found in most regions of the CNS with a similar distribution pattern between rat and wild-type mouse. This staining was specific in the sense that it was absent in adjacent sections following preadsorption of the antibody with 10−5 M of the antigenic peptide, and that it could not be observed in sections of the Y1 KO mouse. In contrast, the staining obtained with an N-terminally directed Y1R antiserum did not disappear, strongly suggesting unspecificity. In brief, very high levels of Y1R-LI were seen in the islands of Calleja, the anterior olfactory nucleus, the molecular layer of the dentate gyrus, parts of the habenula, the interpeduncular nucleus, the mammillary body, the spinal nucleus of the trigeminal, caudal part, the paratrigeminal nucleus, and superficial layers of the dorsal horn. High levels were found in most cortical areas, many thalamic nuclei, some subnuclei of the amygdaloid complex, the hypothalamus and the nucleus of the stria terminalis, the nucleus of the solitary tract, the parabrachial nucleus, and the inferior olive. Moderate levels of Y1R-LI were detected in the cornu Ammonis and the subicular complex, many septal, some thalamic and many brainstem regions. Y1R staining of processes, often fiber and/or dot-like, and occasional cell bodies was also seen in tracts, such as the lateral lemniscus, the rubrospinal tract and the spinal tract of the trigeminal. There was in general a good overlap between Y1R-LI and NPY-LI, but some exceptions were found. Thus, some areas had NPY innervation but apparently lacked Y1Rs, whereas in other regions Y1R-LI, but no or only few NPY-positive nerve endings could be detected.Our results demonstrate that NPY signalling through the Y1R is common in the rat (and mouse) CNS. Mostly the Y1R is postsynaptic but there are also presynaptic Y1Rs. Mostly there is a good match between NPY-releasing nerve endings and Y1Rs, but ‘volume transmission’ may be ‘needed’ in some regions. Finally, the importance of using proper control experiments for immunohistochemical studies on seven-transmembrane receptors is stressed. [Copyright &y& Elsevier]
- Published
- 2002
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4. Explaining neuronal membrane potentials: The Goldman equation vs. Lee’s TELC hypothesis
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Silverstein, Todd P.
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- 2025
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5. Unveiling the veil of adipokines: A meta-analysis and systematic review in amyotrophic lateral sclerosis.
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Abbasi, Hamid, Jourabchi-ghadim, Neda, Asgarzade, Ali, Mirshekari, Mobin, and Ebrahimi-Mameghani, Mehrangiz
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AMYOTROPHIC lateral sclerosis , *GHRELIN , *LEPTIN , *OLDER people , *SCIENCE databases , *ADIPOKINES - Abstract
• Clinical evidence indicates the key role of adipokines in amyotrophic lateral sclerosis (ALS) pathophysiology. • This study is the first meta -analysis and systematic review of case-control studies published comparing the serum levels of adipokines in ALS patients compared with control groups. • Although serum adiponectin levels were elevated in ALS patients, the association was not statistically significant, though a trend was noted in older individuals. • ALS patients exhibited significantly lower serum leptin levels compared to controls, indicating a potential role of leptin deficiency in ALS progression. • These findings suggest that targeting adipokine signaling pathways, especially leptin and ghrelin, could present new therapeutic possibilities for ALS patients. Adipokines are proposed to be associated with ALS progression through assorted pathways. Therefore, The present meta -analysis explored the link between various adipokines and ALS progression. International database like PubMed, Scopus, and Web of Science databases were searched to achieve eligible papers published before December 2023. The following PICO structure was utilized: Population (patients with ALS); Intervention (serum concentrations of ghrelin, leptin, and adiponectin), Comparison (with or without controls), and Outcome (ALS progression). the risk of bias of selected papers was assessed through the Newcastle-Ottawa Scale (NOS) tool. 11 out of 240 papers were selected for this study which were published between 2010 and 2024. Lower serum leptin concentrations were detected in the ALS compared to control groups (WMD: −0.91, 95% CI:-1.77, −0.05). Serum concentrations of adiponectin were higher in ALS compared to control groups (WMD: 0.41, 95% CI:-0.7, 0.89). Ultimately, The serum concentrations of ghrelin in the ALS groups were lower than control groups (WMD: −1.21, 95% CI: −2.95, 0.53). Our findings revealed that serum concentrations of ghrelin and leptin were higher in ALS patients compared to control, unlike adiponectin. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Forthcoming papers
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- 1976
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7. Forthcoming Papers
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- 1977
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8. Brain microdissection techniques. IBRO handbook series:Methods in the neurosciences (vol 2) A. C. Cuello (ed.) John Wiley & Sons (1983). 200pp., (Cloth) $46.00/£23.00; (Paper) $23.00/£11.30
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Starr, M.S., primary
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- 1983
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9. Pathways for Naturalistic Looking Behavior in Primate II. Superior Colliculus Integrates Parallel Top-down and Bottom-up Inputs.
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Veale, Richard and Takahashi, Mayu
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SUPERIOR colliculus , *NEURAL pathways , *GAZE , *CEREBRAL cortex , *SPINAL cord , *BASAL ganglia - Abstract
• Volitional signals for gaze control provided by multiple parallel pathways to the superior colliculus (88) • Interaction of sensory task-related signals within the multi-layered superior colliculus (79) • Convergence of bottom-up (world statistics) and top-down (goal and task) signals in the SC for gaze control (91) • Models of attention such as saliency map and their physiological basis (60) • Cerebral and subcortical inputs to control output signals for gaze in the SC (64) Volitional signals for gaze control are provided by multiple parallel pathways converging on the midbrain superior colliculus (SC), whose deeper layers output to the brainstem gaze circuits. In the first of two papers (Takahashi and Veale, 2023), we described the properties of gaze behavior of several species under both laboratory and natural conditions, as well as the current understanding of the brainstem and spinal cord circuits implementing gaze control in primate. In this paper, we review the parallel pathways by which sensory and task information reaches SC and how these sensory and task signals interact within SC's multilayered structure. This includes both bottom-up (world statistics) signals mediated by sensory cortex, association cortex, and subcortical structures, as well as top-down (goal and task) influences which arrive via either direct excitatory pathways from cerebral cortex, or via indirect basal ganglia relays resulting in inhibition or dis-inhibition as appropriate for alternative behaviors. Models of attention such as saliency maps serve as convenient frameworks to organize our understanding of both the separate computations of each neural pathway, as well as the interaction between the multiple parallel pathways influencing gaze. While the spatial interactions between gaze's neural pathways are relatively well understood, the temporal interactions between and within pathways will be an important area of future study, requiring both improved technical methods for measurement and improvement of our understanding of how temporal dynamics results in the observed spatiotemporal allocation of gaze. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Brain microdissection techniques. IBRO handbook series:Methods in the neurosciences (vol 2) A. C. Cuello (ed.) John Wiley & Sons (1983). 200pp., (Cloth) $46.00/£23.00; (Paper) $23.00/£11.30
- Author
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M.S. Starr
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Polymer science ,General Neuroscience ,media_common.quotation_subject ,Art ,Anatomy ,Microdissection ,media_common - Published
- 1983
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11. Pigs as a translational animal model for the study of peak alpha frequency.
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Mazhari-Jensen, Daniel Skak, Jensen, Winnie, Muhammadee Janjua, Taha Al, Meijs, Suzan, Nørgaard dos Santos Nielsen, Thomas Gomes, and Andreis, Felipe Rettore
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SENSORIMOTOR cortex , *NEUROBEHAVIORAL disorders , *GAUSSIAN distribution , *MEDICAL screening , *BIOMARKERS - Abstract
• Female Danish Landrace pigs were anesthetized while intracranial EEG was recorded. • 18/20 subjects produced clear peak alpha frequency (PAF) using the FOOOF algorithm. • 70% of spontaneous resting-state recording time contained PAF above the 1/f-activity. • PAF was approx. normally distributed ∼ 10 Hz and robust to µECoG and penetrating electrodes. • Future studies may elucidate the mechanisms of PAF and its implication as a biomarker. The most characteristic feature of the human electroencephalogram is the peak alpha frequency (PAF). While PAF has been proposed as a biomarker in several diseases and disorders, the disease mechanisms modulating PAF, as well as its physiological substrates, remain elusive. This has partly been due to challenges related to experimental manipulation and invasive procedures in human neuroscience, as well as the scarcity of animal models where PAF is consistently present in resting-state. With the potential inclusion of PAF in clinical screening and decision-making, advancing the mechanistic understanding of PAF is warranted. In this paper, we propose the female Danish Landrace pig as a suitable animal model to probe the mechanisms of PAF and its feature as a biomarker. We show that somatosensory alpha oscillations are present in anesthetized pigs using electrocorticography and intracortical electrodes located at the sensorimotor cortex. This was evident when looking at the time-domain as well as the spectral morphology of spontaneous recordings. We applied the FOOOF-algorithm to extract the spectral characteristics and implemented a robustness threshold for any periodic component. Using this conservative threshold, PAF was present in 18/20 pigs with a normal distribution of the peak frequency between 8–12 Hz, producing similar findings to human recordings. We show that PAF was present in 69.6 % of epochs of approximately six-minute-long resting-state recordings. In sum, we propose that the pig is a suitable candidate for investigating the neural mechanisms of PAF as a biomarker for disease and disorders such as pain, neuropsychiatric disorders, and response to pharmacotherapy. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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12. Clinical application of respiratory-gated auricular vagal afferent nerve stimulation.
- Author
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Han, Zhiyuan, Zhang, Cuicui, Cheng, Keling, Chen, Yunfang, Tang, Zhiqin, Chen, Lewen, Ni, Jun, and Wang, Zhiyong
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VAGUS nerve stimulation , *CHRONIC pain , *SOLITARY nucleus , *LOCUS coeruleus , *CENTRAL nervous system - Abstract
• The mechanism of action of RAVANS may enhance the targeting of taVNS to nucleus of the solitary tract(NTS) • RAVANS shows some therapeutic effect in chronic low back pain, depression, migraine, hypertension, cognitive impairment. • RAVANS has a potential therapeutic role in post-stroke dysphagia. • Further in-depth research is needed on the optimal parameter settings for RAVANS. Vagus nerve stimulation (VNS) has garnered significant attention as a promising bioelectronic therapy. In recent years, respiratory-gated auricular vagal afferent nerve stimulation (RAVANS), a novel non-invasive vagus nerve stimulation technique, has emerged. RAVANS integrates respiration with transcutaneous auricular vagus nerve stimulation (taVNS) and shares a similar mechanism of action to traditional VNS. Similar to conventional Vagus Nerve Stimulation (VNS), RAVANS may mitigate brain injury through three primary pathways: reducing neuronal apoptosis, modulating neurotransmitter release, and influencing inflammatory factor pathways. In this paper, we emphasize how RAVANS enhances the activation of nucleus of the solitary tract (NTS)and the locus coeruleus by regulating the monoaminergic and GABA systems through respiratory control. Additionally, it leverages the beneficial effects of respiration on the central nervous system. In this review, we delineate the potential mechanisms of action of RAVANS, provide a comprehensive overview of its clinical applications in chronic low back pain, migraine, depression, hypertension, and cognitive disorders. Furthermore, we offer future perspectives on optimizing the parameters of RAVANS and its application in post-stroke dysphagia. This will pave the way for new avenues in RAVANS research. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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13. Application of olfactory ensheathing cells in peripheral nerve injury and its complication with pathological pain.
- Author
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Ding, Lin, Hu, Dong-xia, Yang, Liu, and Zhang, Wen-jun
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PERIPHERAL nerve injuries , *NERVOUS system regeneration , *INJURY complications , *NERVOUS system injuries , *NERVE grafting , *NEUROGLIA - Abstract
• Comprehensively synthesize the functional features of OECs. • The function and mechanism of OECs in the repair of peripheral nerve injury were discussed. • Application of OECs in the treatment of pathological pain induced by peripheral nerve injury was discussed. Direct or indirect injury of peripheral nerve can lead to sensory and motor dysfunction, which can lead to pathological pain and seriously affect the quality of life and psychosomatic health of patients. While the internal repair function of the body after peripheral nerve injury is limited. Nerve regeneration is the key factor hindering the recovery of nerve function. At present, there is no effective treatment. Therefore, more and more attention have been paid to the development of foreground treatment to achieve functional recovery after peripheral nerve injury, including relief of pathological pain. Cell transplantation strategy is a therapeutic method with development potential in recent years, which can exert endogenous alternative repair by transplanting exogenous functional bioactive cells to the site of nerve injury. Olfactory ensheathing cells (OECs) are a special kind of glial cells, which have the characteristics of continuous renewal and survival. The mechanisms of promoting nerve regeneration and functional repair and relieving pathological pain by transplantation of OECs to peripheral nerve injury include secretion of a variety of neurotrophic factors, axonal regeneration and myelination, immune regulation, anti-inflammation, neuroprotection, promotion of vascular growth and improvement of inflammatory microenvironment around nerve injury. Different studies have shown that OECs combined with biomaterials have made some progress in the treatment of peripheral nerve injury and pathological pain. These biomaterials enhance the therapeutic effect of OECs. Therefore, the functional role of OECs in peripheral nerve injury and pathological pain was discussed in this paper. Although OECs are in the primary stage of exploration in the repair of peripheral nerve injury and the application of pain, but OECs transplantation may become a prospective therapeutic strategy for the treatment of peripheral nerve injury and pathological pain. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. The Crosstalk Between Immune Cells After Intracerebral Hemorrhage.
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Zhang, Bai-Wen, Sun, Ke-Han, Liu, Ting, and Zou, Wei
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CEREBRAL hemorrhage , *INTRACEREBRAL hematoma , *CEREBRAL edema , *THERAPEUTICS , *BRAIN injuries , *BLOOD volume - Abstract
[Display omitted] • This paper mainly discusses the cells based on the inflammatory mechanism to discuss their functions after ICH. • Microglia can interact with a wide range of cells, which is important for both disease development and treatment. • We believe that exploring multi-mechanism and multi-cell regulated drugs may be the future development trend. The inflammatory mechanism of intracerebral hemorrhage (ICH) has been widely studied, and it is believed that the regulation of this mechanism is of great significance to the prognosis. In the early stage of the acute phase of ICH, the release of a large number of inflammatory factors around the hematoma can recruit more inflammatory cells to infiltrate the area, further release inflammatory factors, cause an inflammatory cascade reaction, aggravate the volume of cerebral hematoma and edema and further destroy the blood–brain barrier (BBB), according to this, the crosstalk between cells may be of great significance in secondary brain injury (SBI). Because most of the cells recruited are inflammatory immune cells, this paper mainly discusses the cells based on the inflammatory mechanism to discuss their functions after ICH, we found that among the main cells inherent in the brain, glial cells account for the majority, of which microglia are the most widely studied and it can interact with a variety of cells, which is reflected in the literature researches on its pathogenesis and treatment. We believe that exploring multi-mechanism and multi-cell regulated drugs may be the future development trend, and the existing research, the comparison and unification of modeling methods, and the observation of long-term efficacy may be the first problem that researchers need to solve. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Cyclic AMP modulates but does not mediate the inhibition of [3H]norepinephrine release by activation of alpha-2 adrenergic receptors in cultured rat ganglion cells.
- Author
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Schwartz DD and Malik KU
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- Adrenergic alpha-Agonists pharmacology, Animals, Animals, Newborn, Brimonidine Tartrate, Cells, Cultured, Chromatography, Paper, Colforsin pharmacology, Cyclic AMP analogs & derivatives, Cyclic AMP pharmacology, Electric Stimulation, Ganglia, Sympathetic cytology, In Vitro Techniques, Norepinephrine analysis, Quinoxalines pharmacology, Radioimmunoassay, Rats, Rats, Sprague-Dawley, Thionucleotides pharmacology, Cyclic AMP physiology, Ganglia, Sympathetic metabolism, Norepinephrine metabolism, Receptors, Adrenergic, alpha metabolism
- Abstract
The purpose of this study was to determine whether a decrease in cyclic AMP accumulation mediates the inhibition of norepinephrine release in response to alpha-2 adrenergic receptor activation in cultured rat superior cervical ganglion cells. Superior cervical ganglia from neonatal rats were dissociated and cultured on collagen-coated plastic strips. Neurotransmitter release was assessed by measuring the fractional overflow of tritium in superfused cells prelabeled with [3H]norepinephrine. Intracellular cyclic AMP accumulation was measured using radioimmunoassay. Electrical field stimulation at 1 Hz, 30 pulses, 1 ms duration at 20 min intervals produced an increase in the fractional overflow of tritium that was composed predominantly of intact [3H]norepinephrine. The alpha-2 adrenergic receptor agonist UK-14,304 dose-dependently attenuated the increase in fractional tritium overflow elicited by electrical field stimulation. The adenylyl cyclase activator, forskolin, increased cyclic AMP accumulation in superior cervical ganglion cells and UK-14,304 dose-dependently inhibited forskolin-stimulated cyclic AMP accumulation. UK-14,304 had no effect on basal cyclic AMP accumulation or cyclic AMP accumulation during electrical field stimulation. Forskolin (1-10 microM) or the non-hydrolysable cAMP analog, 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate (1-100 microM), slightly increased basal and dose-dependently potentiated the increase in fractional tritium overflow in response to electrical stimulation. Despite enhancement by forskolin and 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate of fractional tritium overflow caused by electrical field stimulation, UK-14304 (1-10 microM) reduced release to a similar degree as that observed in the absence of forskolin or 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1993
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16. The mechanism of cancer-depression comorbidity.
- Author
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Huang, Jian-Wei, Cao, Cheng-An, Zheng, Wen-Han, Jia, Chao-Ran, Liu, Xin, Gao, Shuang-Qi, and Guo, Ying
- Subjects
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MENTAL depression , *CANCER patients , *ANXIETY , *WELL-being , *QUALITY of life - Abstract
• The high incidence of depression in cancer patients and its impact on their quality of life. • Summarizes the potential mechanisms of comorbidity between cancer and depression. • Provides discussion and analysis of potential treatments for depression. Cancer and depression are closely interrelated, particularly in patients with advanced cancer, who often present with comorbid anxiety and depression for various reasons. Recently, there has been a growing interest in the study of depression in cancer patients, with the aim of assessing the possible triggers, predictors, adverse events, and possible treatment options for depression in several common cancers. The objective of this narrative review is to synthesize the extant literature on the relationship between the occurrence and progression of depression in several common patient categories. The authors conducted a comprehensive review of 75 articles published in PubMed over the past five years. This review was further evaluated in the present paper. Ultimately, it was determined that depression is a prevalent and detrimental phenomenon among cancer patients, particularly those with advanced disease. Consequently, there is a pressing need to prioritize research and interventions aimed at improving the quality of life and psychosocial well-being of cancer patients, including those with advanced disease. The relationship between cancer and depression has been evolving dynamically in recent times. The current research findings indicate a strong association between cancer and depression. However, the direction of causality remains unclear. Focusing on depression in cancer patients may, therefore, be beneficial for these patients. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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17. EEG-VTTCNet: A loss joint training model based on the vision transformer and the temporal convolution network for EEG-based motor imagery classification.
- Author
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Shi, Xingbin, Li, Baojiang, Wang, Wenlong, Qin, Yuxin, Wang, Haiyan, and Wang, Xichao
- Subjects
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TRANSFORMER models , *MOTOR imagery (Cognition) , *BRAIN-computer interfaces , *TIME-varying networks , *FEATURE extraction - Abstract
• The increase of decoding precision of motor imaging EEG signal. • The hybrid TCN and ViT method achieves good results. • A shared convolution strategy and a dual-branching strategy. Brain-computer interface (BCI) is a technology that directly connects signals between the human brain and a computer or other external device. Motor imagery electroencephalographic (MI-EEG) signals are considered a promising paradigm for BCI systems, with a wide range of potential applications in medical rehabilitation, human–computer interaction, and virtual reality. Accurate decoding of MI-EEG signals poses a significant challenge due to issues related to the quality of the collected EEG data and subject variability. Therefore, developing an efficient MI-EEG decoding network is crucial and warrants research. This paper proposes a loss joint training model based on the vision transformer (VIT) and the temporal convolutional network (EEG-VTTCNet) to classify MI-EEG signals. To take advantage of multiple modules together, the EEG-VTTCNet adopts a shared convolution strategy and a dual-branching strategy. The dual-branching modules perform complementary learning and jointly train shared convolutional modules with better performance. We conducted experiments on the BCI Competition IV-2a and IV-2b datasets, and the proposed network outperformed the current state-of-the-art techniques with an accuracy of 84.58% and 90.94%, respectively, for the subject-dependent mode. In addition, we used t-SNE to visualize the features extracted by the proposed network, further demonstrating the effectiveness of the feature extraction framework. We also conducted extensive ablation and hyperparameter tuning experiments to construct a robust network architecture that can be well generalized. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Making Science Education More Accessible: A Case Study of TikTok's Utility as a Science Communication Tool.
- Author
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Rein, Ben
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SCIENTIFIC communication , *SCIENCE education , *SCIENTIFIC literacy , *SOCIAL media mobile apps , *SCIENTIFIC literature , *RECOMMENDER systems - Abstract
• Scientists can use social media apps to reach broad audiences with educational content. • On TikTok, only likes , shares , and viewer retention predicted the number of views videos received. • TikTok videos summarizing research papers received the highest viewer engagement. • 84% of users reported feeling more trustful of science/scientists after following. Social media has revolutionized science communication, allowing for rapid dissemination of science-related content to the public. In recent years, video platforms like TikTok and Instagram have implemented recommendation algorithms that track users' interests and suggest personalized videos. As a result, these apps have become powerful tools for public messaging, facilitating access to audiences that are naturally curious about science. In 2020 I began uploading educational science videos to TikTok which have collectively accumulated more than 48 million views and 8 million "likes." Here I present an analysis of video metrics collected from the TikTok app for a random sampling of 150 videos, searching for factors that predict the number of views a video receives and the level of viewer engagement. Videos with higher view counts were liked and shared at higher rates and sustained viewer attention for longer. Properties like hashtags, sounds, and effects did not significantly influence video views. Interestingly, videos summarizing research papers received the highest levels of engagement, potentially reflecting high demand from lay audiences who are traditionally unable to access scientific literature. Finally, I present survey data demonstrating that 84% of users report feeling more trustful of science & scientists after following this account. Although the generalizability of these findings is limited, the results offer insights into the factors that drive video performance on TikTok and how users engage with scientific content on social media. These findings may help science communicators more effectively reach wider audiences and promote science literacy in new and innovative ways. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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19. Glutamatergic input–output properties of thalamic astrocytes
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H.R. Parri and T.M. Pirttimaki
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Male ,Neuroscience(all) ,Gliotransmitter ,Glutamic Acid ,glutamate ,Biology ,Neurotransmission ,Synaptic Transmission ,somatosensory ,Synapse ,Cellular and Molecular Neuroscience ,03 medical and health sciences ,Glutamatergic ,Organ Culture Techniques ,0302 clinical medicine ,mGluR, metabotropic glutamate receptor ,TC, thalamocortical ,Lem, Lemniscal ,Tripartite synapse ,Animals ,[Ca2+]i, intracellular calcium ,Calcium Signaling ,Rats, Wistar ,SSP, spindle stimulation pattern ,NMDA-R, N-methyl-d-aspartate receptor ,030304 developmental biology ,VB, ventrobasal ,SIC ,Afferent Pathways ,Ventral Thalamic Nuclei ,0303 health sciences ,tripartite synapse ,General Neuroscience ,PSC, post synaptic current ,astrocytes ,Glutamate receptor ,CT, corticothalamic ,SIC, slow inward current ,GT, gliotransmission ,gliotransmission ,Rats ,Metabotropic glutamate receptor ,NMDA receptor ,Neuroscience ,030217 neurology & neurosurgery ,Research Paper - Abstract
Astrocytes in the somatosensory ventrobasal (VB) thalamus of rats respond to glutamatergic synaptic input with metabotropic glutamate receptor (mGluR) mediated intracellular calcium ([Ca2+]i) elevations. Astrocytes in the VB thalamus also release the gliotransmitter (GT) glutamate in a Ca2+-dependent manner. The tripartite synapse hypothesis posits that astrocytic [Ca2+]i elevations resulting from synaptic input releases gliotransmitters that then feedback to modify the synapse. Understanding the dynamics of this process and the conditions under which it occurs are therefore important steps in elucidating the potential roles and impact of GT release in particular brain activities. In this study, we investigated the relationship between VB thalamus afferent synaptic input and astrocytic glutamate release by recording N-methyl-d-aspartate (NMDA) receptor-mediated slow inward currents (SICs) elicited in neighboring neurons. We found that Lemniscal or cortical afferent stimulation, which can elicit astrocytic [Ca2+]i elevations, do not typically result in the generation of SICs in thalamocortical (TC) neurons. Rather, we find that the spontaneous emergence of SICs is largely resistant to acute afferent input. The frequency of SICs, however, is correlated to long-lasting afferent activity. In contrast to short-term stimulus-evoked GT release effects reported in other brain areas, astrocytes in the VB thalamus do not express a straightforward input–output relationship for SIC generation but exhibit integrative characteristics., Highlights ▶VB thalamus afferents were stimulated at a range of frequencies and durations to investigate the interaction of afferent input and astrocytic glutamate output. ▶Acute afferent activity does not result in the evoking of astrocyte glutamate-mediated slow inward currents. ▶Prolonged afferent activity, however, increases SIC frequency in a time-dependent manner. ▶VB thalamus astrocytes therefore exhibit integrative properties that modulate the rate of spontaneous glutamate release.
- Published
- 2012
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20. Spatio-temporal expression analysis of the calcium-binding protein calumenin in the rodent brain
- Author
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Matthias Kneussel, Frank F. Heisler, Ivan Milenkovic, Susanne Fehr, Werner Sieghart, M. Vasiljevic, and Torben J. Hausrat
- Subjects
bp, base pair ,PSD-95, post-synaptic density protein 95 ,Centrifugation ,brain development ,SV2, synaptic vesicle protein 2 ,Hippocampal formation ,Endoplasmic Reticulum ,Subgranular zone ,Mice ,cellular and subcellular distribution ,Neural Stem Cells ,Calcium-binding protein ,calcium-binding protein ,Tissue Distribution ,Cells, Cultured ,In Situ Hybridization ,GFP, green fluorescent protein ,Calcium signaling ,Neurons ,DIV, day in vitro ,General Neuroscience ,SGZ, subgranular zone ,Brain ,progenitor cells ,Immunohistochemistry ,glial cells ,Cell biology ,CREC, Cab45, reticulocalbin, ERC-55, calumenin ,medicine.anatomical_structure ,PSA-NCAM, poly-sialylated neural cell adhesion molecule ,symbols ,Electrophoresis, Polyacrylamide Gel ,Neuroglia ,IHC, immunohistochemistry ,Research Paper ,Subcellular Fractions ,DNA, Complementary ,Neuroscience(all) ,Blotting, Western ,In situ hybridization ,Biology ,calcium signaling ,ER, endoplasmic reticulum ,Cellular and Molecular Neuroscience ,HEK, human embryonic kidney ,symbols.namesake ,PBS, phosphate buffered saline ,medicine ,Animals ,Brain Chemistry ,Membranes ,Dentate gyrus ,Endoplasmic reticulum ,Calcium-Binding Proteins ,GFAP, glial fibrillary acidic protein ,Golgi apparatus ,Molecular biology ,BCA, bicinchoninic acid ,Animals, Newborn ,nervous system ,SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis ,DAPI, 4',6-diamidino-2-phenylindole - Abstract
Calumenin is a Ca2+-binding protein that belongs to the CREC superfamily. It contains six EF-hand domains that exhibit a low affinity for Ca2+ as well as an endoplasmic reticulum retention signal. Calumenin exhibits a broad and relatively high expression in various brain regions during development as demonstrated by in situ hybridization. Signal intensity of calumenin is highest during the early development and then declines over time to reach a relatively low expression in adult animals. Immunohistochemistry indicates that at the P0 stage, calumenin expression is most abundant in migrating neurons in the zones around the lateral ventricle. In the brain of adult animals, it is expressed in various glial and neuronal cell types, including immature neurons in subgranular zone of hippocampal dentate gyrus. At the subcellular level, calumenin is identified in punctuate and diffuse distribution mostly in somatic regions where it co-localizes with endoplasmic reticulum (ER) and partially Golgi apparatus. Upon subcellular fractionation, calumenin is enriched in fractions containing membranes and is only weakly present in soluble fractions. This study points to a possible important role of calumenin in migration and differentiation of neurons, and/or in Ca2+ signaling between glial cells and neurons., Highlights ▶We analyze the expression of the Ca2+-binding protein calumenin in the rodent brain. ▶Calumenin exhibits higher expression in early developmental stages. ▶Calumenin is expressed by neurons, glia, and progenitor cells. ▶Calumenin co-localizes with the ER and the Golgi complex but not with synaptic sites. ▶Calumenin may play a role in migration, differentiation, and Ca2+ signaling of neurons.
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- 2012
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21. The coumarin scopoletin potentiates acetylcholine release from synaptosomes, amplifies hippocampal long-term potentiation and ameliorates anticholinergic- and age-impaired memory
- Author
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Ariane Hornick, Helmut Prast, Judith M. Rollinger, Hermann Stuppner, Andreas Lieb, and N.P. Vo
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Male ,Aging ,Cognitive, Behavioral, and Systems Neuroscience ,Long-Term Potentiation ,fEPSPs, field excitatory postsynaptic potentials ,DMSO, dimethyl sulfoxide ,Pharmacology ,Hippocampus ,CSF, cerebrospinal fluid ,Rats, Sprague-Dawley ,Mice ,AP-5, d,l-2-amino-5-phosphonopentanoic acid ,0302 clinical medicine ,LTP, long-term potentiation ,AChE, acetylcholinesterase ,Mecamylamine ,nicotinic acetylcholine receptor ,MEC, mecamylamine ,0303 health sciences ,MAO, monoamino oxidase ,Chemistry ,General Neuroscience ,AD, Alzheimer's dementia ,SCT, scopoletin ,Long-term potentiation ,DHE, dihydro-β-erythroidine ,3. Good health ,Nicotinic acetylcholine receptor ,Nicotinic agonist ,HFS, high-frequency stimulation ,Excitatory postsynaptic potential ,NMDA receptor ,T-maze ,Acetylcholine ,Research Paper ,medicine.drug ,Neuroscience(all) ,object recognition ,SCOP, scopolamine ,03 medical and health sciences ,hippocampus slice ,Memory ,medicine ,Animals ,030304 developmental biology ,Memory Disorders ,Scopoletin ,NMDA, N-methyl-D-aspartate ,ACh, acetylcholine ,Excitatory Postsynaptic Potentials ,nAChR, nicotinic acetylcholine receptor ,Rats ,Mice, Inbred C57BL ,ACh release ,nervous system ,Cholinergic ,030217 neurology & neurosurgery ,Synaptosomes - Abstract
In a previous study the simple, naturally derived coumarin scopoletin (SCT) was identified as an inhibitor of acetylcholinesterase (AChE), using a pharmacophore-based virtual screening approach. In this study the potential of SCT as procholinergic and cognition-enhancing therapeutic was investigated in a more detailed way, using different experimental approaches like measuring newly synthesized acetylcholine (ACh) in synaptosomes, long-term potentiation (LTP) experiments in hippocampal slices, and behavior studies. SCT enhanced the K+-stimulated release of ACh from rat frontal cortex synaptosomes, showing a bell-shaped dose effect curve (Emax: 4 μM). This effect was blocked by the nicotinic ACh receptor (nAChR) antagonists mecamylamine (MEC) and dihydro-β-erythroidine (DHE). The nAChR agonist (and AChE inhibitor) galantamine induced a similar increase in ACh release (Emax: 1 μM). SCT potentiated LTP in hippocampal slices of rat brain. The high-frequency stimulation (HFS)-induced, N-methyl-D-aspartate (NMDA) receptor dependent LTP of field excitatory postsynaptic potentials at CA3-CA1 synapses was greatly enhanced by pre-HFS application of SCT (4 μM for 4 min). This effect was mimicked by nicotine (2 μM) and abolished by MEC, suggesting an effect on nAChRs. SCT did not restore the total inhibition of LTP by NMDA receptor antagonist d, l-2-amino-5-phosphonopentanoic acid (AP-5). SCT (2 μg, i.c.v.) increased T-maze alternation and ameliorated novel object recognition of mice with scopolamine-induced cholinergic deficit. It also reduced age-associated deficits in object memory of 15–18-month-old mice (2 mg/kg sc). Our findings suggest that SCT possesses memory-improving properties, which are based on its direct nAChR agonistic activity. Therefore, SCT might be able to rescue impaired cholinergic functions by enhancing nAChR-mediated release of neurotransmitters and promoting neural plasticity in hippocampus., Highlights ▶The coumarin scopoletin has been described as AChE inhibitor. ▶Now we show it exerts promising procognitive properties via nAChRs. ▶It enhances release of ACh and potentiates hippocampal LTP. ▶It improves novel object recognition and T-maze alternation in scopolamine-amnestic mice and ameliorates object memory in age-impaired mice.
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- 2011
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22. Spike-timing relationship of neurochemically-identified dorsal raphe neurons during cortical slow oscillations
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Nicolas Mallet, Trevor Sharp, Jv V. Schweimer, Mark A. Ungless, and University of St Andrews. School of Psychology and Neuroscience
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Male ,Cognitive, Behavioral, and Systems Neuroscience ,Time Factors ,Dopamine ,5-HT ,Action Potentials ,PBS-X, PBS containing 0.2% Triton X-100 ,ANOVA, analyses of variance ,Rats, Sprague-Dawley ,PFC, prefrontal cortex ,Limbic system ,limbic system ,Basal ganglia ,Cerebral Cortex ,5-HT, 5-hydroxytryptamine ,General Neuroscience ,ECoG, electrocorticogram ,Electroencephalography ,COV-IS, coefficient of variation of the inter-spike-interval ,Immunohistochemistry ,medicine.anatomical_structure ,SWA, slow-wave activity ,basal ganglia ,dopamine ,RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry ,Research Paper ,Serotonergic Neurons ,TH, tyrosine hydroxylase ,Neuroscience(all) ,PBS, phosphate-buffered saline ,serotonergic ,Biology ,Serotonergic ,Bursting ,Dorsal raphe nucleus ,Neurochemical ,DRN, dorsal raphe nucleus ,medicine ,Animals ,Brain Waves ,Rats ,Electrophysiology ,nervous system ,RC0321 ,Raphe Nuclei ,Serotonin ,Neuroscience - Abstract
The firing activity of dorsal raphe neurons is related to arousal state. However, it is unclear how this firing activity is precisely related to cortical activity, in particular oscillations occurring during sleep rhythms. Here we conducted single-cell extracellular recordings and juxtacellular labelling while monitoring electrocorticogram (ECoG) activity in urethane anaesthetised rats, to relate activity in neurochemically identified groups of neurons to cortical slow-wave activity (SWA). We observed that electrophysiological heterogeneity in dorsal raphe neurons revealed different neurochemical groups of DRN neurons and was mirrored by significant differences in the phase and strength of coupling to the cortical slow oscillations. Spike firing relationship of clock-like neurons, identified as 5-HT (5-hydroxytryptamine) or serotonin neurons, was higher during the inactive component of the oscillations. In contrast, half of the identified bursting 5-HT neurons did not exhibit strong cortical entrainment; those that did fired most during the inactive component of the SWA. Two groups of putatively non-5-HT neurons (irregular slow-firing and fast-firing) exhibited significant coherence and fired most during the active component of the SWA. These findings indicate that within the DRN electrophysiologically and neurochemically discrete neuronal groups exhibit distinct relations to cortical activity., Highlights ▶DRN neurons exhibit heterogeneous firing in relation to cortical oscillations. ▶Clock-like 5-HT neurons fire most during inactive component of the oscillation. ▶Half of bursting 5-HT neurons did not exhibit coupling to the oscillation. ▶Non-5-HT neurons fired most during the active component of the oscillation.
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- 2011
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23. Macroautophagy and the proteasome are differently involved in the degradation of alpha-synuclein wild type and mutated A30P in an in vitro inducible model (PC12/TetOn)
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Erika Peverelli, Serena Rodilossi, Diego Albani, Sara Batelli, and Gianluigi Forloni
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DOXY, doxycycline ,Proteasome Endopeptidase Complex ,Programmed cell death ,Cell Survival ,Neuroscience(all) ,alpha-synuclein ,Parkinson's disease ,animal diseases ,Blotting, Western ,Protein aggregation ,Biology ,PD, Parkinson's disease ,PC12 Cells ,protein aggregation ,LN, Lewy neurites ,chemistry.chemical_compound ,MG132 ,LB, Lewy bodies ,Autophagy ,medicine ,oxidative stress ,UPS, ubiquitin-proteasome system ,Animals ,Humans ,Point Mutation ,heterocyclic compounds ,Alpha-synuclein ,General Neuroscience ,Neurotoxicity ,Wild type ,Neurodegeneration, Neuroprotection, and Disease-Oriented Neuroscience ,Parkinson Disease ,medicine.disease ,Immunohistochemistry ,Molecular biology ,CMA, chaperone-mediated autophagy ,Rats ,nervous system diseases ,macroautophagy ,proteasome ,HS, horse serum ,nervous system ,Proteasome ,chemistry ,Toxicity ,health occupations ,FCS, fetal calf serum ,Research Paper ,LDH, lactate dehydrogenase release to lactate dehydrogenase - Abstract
Many data suggest that alpha synuclein (α-syn) aggregation is involved in Parkinson's disease (PD) neurotoxicity and is accelerated by the pathogenetic point mutation A30P. The triplication of α-syn gene has been linked to early-onset familial PD, suggesting that the cellular dosage of α-syn is an important modulator of its toxicity. To verify this point, we developed an inducible model of α-syn expression (both wild type [WT] and mutated A30P) in rat PC12/TetOn cells. At low expression level, both α-syn(WT) and (A30P) did not aggregate, were not toxic, and displayed a protective action against oxidative stress triggered by hydrogen peroxide (H2O2). By increasing α-syn expression, its antioxidant function was no longer detectable as for the A30P form, but again no aggregation and cell death were present both for the WT and the mutated protein. To clarify why α-syn did not accumulate at high expression level, we inhibited macroautophagy by 3-methyladenine (3-MA) and the proteasome by MG132. In presence of 3-MA, α-syn(WT) accumulated, A11 anti-oligomer antibody-positive aggregates were detectable, and cell toxicity was evident, while proteasome inhibition did not increase α-syn(WT) accumulation. Macroautophagy or proteasome inhibition slightly increased α-syn(A30P) toxicity, with no detectable aggregation. This model can provide useful details about α-syn function, aggregation, and degradation pathways., Graphical abstract Graphical abstract summarizing the main findings of the article. The red flow chart describes the system when α-syn expression was induced at low level, while the green part splits the different scenario for α-syn(WT) and α-syn(A30P) at high expression level. The slot blot shows the appearance of A11 immunoreactivity. 3-MA, 3-methyladenine; doxy, doxycycline. For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article. Highlights ▶We developed a model of alpha-synuclein (wild type or A30P) expression in PC12 cells. ▶At low alpha-synuclein expression, we found no aggregation but neuroprotection. ▶At high alpha-synuclein expression macroautophagy was activated without aggregation. ▶Macroautophagy inhibition lead to alpha-synuclein wild type aggregation and toxicity. ▶The A30P form was not toxic and its removal involved also the proteasome.
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- 2011
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24. Parvalbumin interneurons and calretinin fibers arising from the thalamic nucleus reuniens degenerate in the subiculum after kainic acid-induced seizures
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G. Sperk, Elke Kirchmair, Adrian Patrick Preidt, and Meinrad Drexel
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Male ,ROD, relative optical densities ,Hippocampus ,Epileptogenesis ,Nerve Fibers ,0302 clinical medicine ,TBS, tris-buffered saline ,Entorhinal Cortex ,PV, parvalbumin ,0303 health sciences ,Kainic Acid ,biology ,Chemistry ,musculoskeletal, neural, and ocular physiology ,General Neuroscience ,Subiculum ,Neurodegeneration, Neuroprotection, and Disease-oriented Neuroscience ,SE, status epilepticus ,NeuN, neuron specific nuclear protein ,temporal lobe epilepsy ,Parvalbumins ,medicine.anatomical_structure ,Calbindin 2 ,Thalamic Nuclei ,O-LM, oriens-lacunosum moleculare ,Nucleus reuniens ,KA, kainic acid ,Pyramidal cell ,Research Paper ,EC, entorhinal cortex ,Neuroscience(all) ,TLE, temporal lobe epilepsy ,Parasubiculum ,03 medical and health sciences ,S100 Calcium Binding Protein G ,Interneurons ,Seizures ,mental disorders ,medicine ,Animals ,RNA, Messenger ,ir, immunoreactive ,030304 developmental biology ,status epilepticus ,Entorhinal cortex ,Rats ,epilepsy models ,nervous system ,CR, calretinin ,biology.protein ,epileptogenesis ,Neuroscience ,030217 neurology & neurosurgery ,Parvalbumin - Abstract
The subiculum is the major output area of the hippocampus. It is closely interconnected with the entorhinal cortex and other parahippocampal areas. In animal models of temporal lobe epilepsy (TLE) and in TLE patients it exerts increased network excitability and may crucially contribute to the propagation of limbic seizures. Using immunohistochemistry and in situ-hybridization we now investigated neuropathological changes affecting parvalbumin and calretinin containing neurons in the subiculum and other parahippocampal areas after kainic acid-induced status epilepticus. We observed prominent losses in parvalbumin containing interneurons in the subiculum and entorhinal cortex, and in the principal cell layers of the pre- and parasubiculum. Degeneration of parvalbumin-positive neurons was associated with significant precipitation of parvalbumin-immunoreactive debris 24 h after kainic acid injection. In the subiculum the superficial portion of the pyramidal cell layer was more severely affected than its deep part. In the entorhinal cortex, the deep layers were more severely affected than the superficial ones. The decrease in number of parvalbumin-positive neurons in the subiculum and entorhinal cortex correlated with the number of spontaneous seizures subsequently experienced by the rats. The loss of parvalbumin neurons thus may contribute to the development of spontaneous seizures. On the other hand, surviving parvalbumin neurons revealed markedly increased expression of parvalbumin mRNA notably in the pyramidal cell layer of the subiculum and in all layers of the entorhinal cortex. This indicates increased activity of these neurons aiming to compensate for the partial loss of this functionally important neuron population. Furthermore, calretinin-positive fibers terminating in the molecular layer of the subiculum, in sector CA1 of the hippocampus proper and in the entorhinal cortex degenerated together with their presumed perikarya in the thalamic nucleus reuniens. In addition, a significant loss of calretinin containing interneurons was observed in the subiculum. Notably, the loss in parvalbumin positive neurons in the subiculum equaled that in human TLE. It may result in marked impairment of feed-forward inhibition of the temporo-ammonic pathway and may significantly contribute to epileptogenesis. Similarly, the loss of calretinin-positive fiber tracts originating from the nucleus reuniens thalami significantly contributes to the rearrangement of neuronal circuitries in the subiculum and entorhinal cortex during epileptogenesis., Graphical Abstract ••• Highlights ▶A subpopulation of PV neurons degenerates in subiculum and entorhinal cortex after KA seizures. ▶Surviving PV neurons exhibit increased PV mRNA expression. ▶The loss in PV neurons in subiculum and entorhinal cortex correlates to spontaneous seizures. ▶Degeneration of PV neurons in the subiculum may be related to seizure-induced loss of feed-forward inhibition. ▶CR-ir neurons in the N. reuniens thalami and their projections to the subiculum degenerate.
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- 2011
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25. A quantitative study of neuronal nitric oxide synthase expression in laminae I–III of the rat spinal dorsal horn
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Thomas C. P. Sardella, Masahiko Watanabe, Andrew J. Todd, and Erika Polgár
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Male ,VGLUT2, vesicular glutamate transporter 2 ,Glutamate decarboxylase ,nNOS, neuronal nitric oxide synthase ,Nitric Oxide Synthase Type I ,confocal microscopy ,NADPH, reduced nicotinamide adenine dinucleotide phosphate ,chemistry.chemical_compound ,GABA ,0302 clinical medicine ,Glycine receptor ,GFP, green fluorescent protein ,0303 health sciences ,Microscopy, Confocal ,General Neuroscience ,Cell biology ,Posterior Horn Cells ,medicine.anatomical_structure ,VGAT, vesicular GABA transporter ,Excitatory postsynaptic potential ,GABAergic ,Research Paper ,Neuroscience(all) ,Blotting, Western ,NPY, neuropeptide Y ,nNOS ,Biology ,Inhibitory postsynaptic potential ,Nitric oxide ,03 medical and health sciences ,Interneurons ,medicine ,Animals ,Rats, Wistar ,GAD67, 67 kDa molecular weight isoform of glutamic acid decarboxylase ,030304 developmental biology ,NO, nitric oxide ,NK1r, neurokinin 1 receptor ,PKCγ ,Pain Mechanisms and Sensory Neuroscience ,inhibitory interneurons ,PKCγ, protein kinase Cγ ,Spinal cord ,Rats ,chemistry ,nervous system ,cGMP, cyclic guanosine monophosphate ,sGC, soluble guanylate cyclase ,Neuroscience ,030217 neurology & neurosurgery ,Immunostaining - Abstract
Nitric oxide produced by neuronal nitric oxide synthase (nNOS) in the spinal cord is required for development of hyperalgesia in inflammatory and neuropathic pain states. nNOS is expressed by some dorsal horn neurons, and an early study that used a histochemical method to identify these cells suggested that they were mainly inhibitory interneurons. We have carried out a quantitative analysis of nNOS-immunoreactivity in laminae I–III of the rat dorsal horn, to determine the proportion of inhibitory and excitatory neurons and axonal boutons that express the protein. nNOS was present in ∼5% of neurons in laminae I and III, and 18% of those in lamina II. Although most cells with strong nNOS immunostaining were GABA-immunoreactive, two-thirds of the nNOS-positive cells in lamina II and half of those in lamina III were not GABAergic, and some of these expressed protein kinase Cγ (PKCγ). We estimate that nNOS is present in 17–19% of the inhibitory interneurons in laminae I–II, and 6% of those in lamina III. However, our results suggest that nNOS is also expressed at a relatively low level by a significant proportion (∼17%) of excitatory interneurons in lamina II. nNOS was seldom seen in boutons that contained vesicular glutamate transporter 2, which is expressed by excitatory interneurons, but was co-localised with the vesicular GABA transporter (VGAT, a marker for GABAergic and glycinergic axons). nNOS was detected in 13% of VGAT boutons in lamina I and in 7–8% of those in laminae II–III. However, it was only found in 2–4% of the VGAT boutons that were presynaptic to PKCγ-expressing interneurons in this region. These results indicate that nNOS is more widely expressed than previously thought, being present in both inhibitory and excitatory neurons. They provide further evidence that axons of neurochemically defined populations of inhibitory interneuron are selective in their post-synaptic targets., Highlights ▶nNOS is expressed by nearly 20% of neurons in lamina II and 5% of those in laminae I and III. ▶The majority of nNOS neurons in laminae II and III are not GABAergic. ▶Between 7 and 13% of GABAergic boutons in laminae I–III are nNOS-immunoreactive. ▶nNOS axons form few synapses with PKCγ+ excitatory interneurons.
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- 2011
26. Which elements of the mammalian central nervous system are excited by low current stimulation with microelectrodes?
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Cornelia Wenger and Frank Rattay
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Central Nervous System ,microstimulation ,Neuroscience(all) ,Models, Neurological ,Action Potentials ,Cellular and Molecular Neuroscience ,pyramidal cells ,medicine ,Activating function ,Animals ,Humans ,Microstimulation ,Axon ,sodium channels ,Cerebral Cortex ,Mammals ,Neurons ,AIS, axon initial segment ,Dendritic spike ,activating function ,Chemistry ,General Neuroscience ,Depolarization ,Dendrites ,compartment model ,Axon initial segment ,Axons ,Electric Stimulation ,Microelectrode ,medicine.anatomical_structure ,Electrode ,cortex stimulation ,Biophysics ,Microelectrodes ,Neuroscience ,Research Paper - Abstract
Low current cortex stimulation produces a sparse and distributed set of activated cells often with distances of several hundred micrometers between cell bodies and the microelectrode. A modeling study based on recently measured densities of high threshold sodium channels Nav1.2 in dendrites and soma and low threshold sodium channels Nav1.6 in the axon shall identify spike initiation sites including a discussion on dendritic spikes. Varying excitability along the neural axis has been observed while studying different electrode positions and configurations. Although the axon initial segment (AIS) and nodes of Ranvier are most excitable, many thin axons and dendrites which are likely to be close to the electrode in the densely packed cortical regions are also proper candidates for spike initiation sites. Cathodic threshold ratio for thin axons and dendrites is about 1:3, whereas 0.2 μm diameter axons passing the electrode tip in 10 μm distance can be activated by 100 μs pulses with 2.6 μA. Direct cathodic excitation of dendrites requires a minimum electrode-fiber distance, which increases with dendrite diameter. Therefore thin dendrites can profit from the stronger electrical field close to the electrode but low current stimulation cannot activate large diameter dendrites, contrary to the inverse recruitment order known from peripheral nerve stimulation. When local depolarization fails to generate a dendritic spike, stimulation is possible via intracellular current flow that initiates an action potential, for example 200 μm distant in the low threshold AIS or in certain cases at the distal dendrite ending. Beside these exceptions, spike initiation site for cathodic low current stimulation appears rather close to the electrode.
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- 2010
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27. Functional expression of two system A glutamine transporter isoforms in rat auditory brainstem neurons
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Mona Bjørkmo, Daniela Billups, N.M. Uwechue, Antonin Blot, A.Z. Quazi, Brian Billups, and Farrukh A. Chaudhry
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Auditory Pathways ,Patch-Clamp Techniques ,Amino Acid Transport System A ,Glutamine ,SAT1 ,SAT2 ,Glutamine transport ,0302 clinical medicine ,MeAIB, N-(methylamino)isobutyric acid ,Protein Isoforms ,I/V, current–voltage ,Neurons ,0303 health sciences ,General Neuroscience ,EAAT, excitatory amino acid transporter ,MNTB, medial nucleus of the trapezoid body ,Glutamate receptor ,Immunohistochemistry ,medicine.anatomical_structure ,Biochemistry ,MK801, dizocilpine maleate ,SAT1, system A transporter 1 ,NBQX, 2,3-Dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide ,Research Paper ,Ipro, proline-induced current ,Signal Transduction ,Sodium Channel Blockers ,Proline ,Neuroscience(all) ,TCA, tricarboxylic acid ,Biology ,VGLUT, vesicular glutamate transporter ,03 medical and health sciences ,Organ Culture Techniques ,Igln, glutamine-induced current ,GST, glutathione-S-transferase ,medicine ,Animals ,Amino acid transporter ,TTX, tetrodotoxin ,Rats, Wistar ,SNAT1 ,030304 developmental biology ,SNAT2 ,APV, dl-2-amino-5-phosphonopentanoic acid ,dl-TBOA, dl-threo-b-benzyloxyaspartate ,Cell Membrane ,Transporter ,Membrane transport ,Rats ,Rhombencephalon ,SAT2, system A transporter 2 ,Cellular Neuroscience ,beta-Alanine ,Neuron ,BCH, 2-aminobicyclo-[2.2.1]-heptane-2-carboxylic acid ,Slc38a2 ,Slc38a1 ,030217 neurology & neurosurgery - Abstract
Glutamine plays multiple roles in the CNS, including metabolic functions and production of the neurotransmitters glutamate and GABA. It has been proposed to be taken up into neurons via a variety of membrane transport systems, including system A, which is a sodium-dependent electrogenic amino acid transporter system. In this study, we investigate glutamine transport by application of amino acids to individual principal neurons of the medial nucleus of the trapezoid body (MNTB) in acutely isolated rat brain slices. A glutamine transport current was studied in patch-clamped neurons, which had the electrical and pharmacological properties of system A: it was sodium-dependent, had a non-reversing current-voltage relationship, was activated by proline, occluded by N-(methylamino)isobutyric acid (MeAIB), and was unaffected by 2-aminobicyclo-[2.2.1]-heptane-2-carboxylic acid (BCH). Additionally, we examined the expression of different system A transporter isoforms using immunocytochemical staining with antibodies raised against system A transporter 1 and 2 (SAT1 and SAT2). Our results indicate that both isoforms are expressed in MNTB principal neurons, and demonstrate that functional system A transporters are present in the plasma membrane of neurons. Since system A transport is highly regulated by a number of cellular signaling mechanisms and glutamine then goes on to activate other pathways, the study of these transporters in situ gives an indication of the mechanisms of neuronal glutamine supply as well as points of regulation of neurotransmitter production, cellular signaling and metabolism in the native neuronal environment.
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- 2009
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28. Soma size distinguishes projection neurons from neurokinin 1 receptor-expressing interneurons in lamina I of the rat lumbar spinal dorsal horn
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K.S. Al Ghamdi, Andrew J. Todd, and Erika Polgár
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Male ,CTb, cholera toxin B subunit ,Interneuron ,Neuroscience(all) ,Population ,interneuron ,Biology ,Parabrachial area ,03 medical and health sciences ,0302 clinical medicine ,spinoparabrachial ,Interneurons ,Pain Mechanism ,lateral parabrachial area ,medicine ,Animals ,CVLM, caudal ventrolateral medulla ,Rats, Wistar ,education ,Posterior Horn Cell ,030304 developmental biology ,Neurons ,0303 health sciences ,education.field_of_study ,pyramidal cell ,NK1r, neurokinin 1 receptor ,PAG, periaqueductal grey matter ,General Neuroscience ,Pyramidal Cells ,Lumbosacral Region ,Anatomy ,Receptors, Neurokinin-1 ,Spinal cord ,Immunohistochemistry ,Rats ,Posterior Horn Cells ,caudal ventrolateral medulla ,medicine.anatomical_structure ,nervous system ,Medulla oblongata ,Soma ,LPb, lateral parabrachial area ,Pyramidal cell ,retrograde tracing ,030217 neurology & neurosurgery ,Research Paper - Abstract
Lamina I of the spinal dorsal horn contains neurons that project to various brain regions, and approximately 80% of these projection cells express the neurokinin 1 receptor (NK1r), the main receptor for substance P. Two populations of NK1r-immunoreactive neurons have been identified in lamina I: small weakly immunoreactive cells and large cells with strong immunolabelling [Cheunsuang O and Morris R (2000) Neuroscience 97:335-345]. The main aim of this study was to test the hypothesis that the large cells are projection neurons and that the small cells are interneurons. Projection neurons were identified by injection of tracers into the caudal ventrolateral medulla and lateral parabrachial area, and this was combined with immunostaining for NK1r. We found a bimodal size distribution for NK1r-immunoreactive neurons. The small cells (with somatic cross-sectional areas200 microm(2)) showed weak immunoreactivity, while immunostaining intensity was variable among the large cells. Virtually all (99%) of the immunoreactive cells with soma areas200 microm(2) were retrogradely labelled, while only 10% of retrogradely labelled cells were smaller than this. Soma sizes of retrogradely labelled neurons that lacked NK1r did not differ from those of NK1r-expressing projection neurons. It has been suggested that a population of small pyramidal projection neurons that lack NK1r may correspond to cells activated by innocuous cooling, and we therefore assessed the morphology of retrogradely labelled cells that were not NK1r-immunoreactive. Fifteen percent of these were pyramidal, but these did not differ in size from pyramidal NK1r-immunoreactive projection neurons. These results confirm that large NK1r-immunoreactive lamina I neurons are projection cells, and suggest that the small cells are interneurons. Since almost all of the NK1r-immunoreactive cells with soma size200 microm(2) were retrogradely labelled, cells of this type can be identified as projection cells in anatomical studies.
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- 2009
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29. Therapeutic Potential of Natural Compounds in Subarachnoid Haemorrhage.
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Tan, Jiacong, Zhu, Huaxin, Zeng, Yanyang, Li, Jiawei, Zhao, Yeyu, and Li, Meihua
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- *
SUBARACHNOID hemorrhage , *CEREBRAL vasospasm , *CEREBRAL edema , *CEREBRAL ischemia , *CEREBROVASCULAR disease , *BLOOD-brain barrier , *OXIDATIVE stress - Abstract
• A systematic review of the pathophysiologic processes of SAH was conducted. • The role of natural compounds in the pathophysiologic process of SAH. • Signaling pathway mechanisms by which natural compounds act in SAH. • Natural compounds are categorized in detail. • Evaluate the prognostic potential of natural compounds to improve SAH. Subarachnoid hemorrhage (SAH) is a common and fatal cerebrovascular disease with high morbidity, mortality and very poor prognosis worldwide. SAH can induce a complex series of pathophysiological processes, and the main factors affecting its prognosis are early brain injury (EBI) and delayed cerebral ischemia (DCI). The pathophysiological features of EBI mainly include intense neuroinflammation, oxidative stress, neuronal cell death, mitochondrial dysfunction and brain edema, while DCI is characterized by delayed onset ischemic neurological deficits and cerebral vasospasm (CVS). Despite much exploration in people to improve the prognostic outcome of SAH, effective treatment strategies are still lacking. In recent years, numerous studies have shown that natural compounds of plant origin have unique neuro- and vascular protective effects in EBI and DCI after SAH and long-term neurological deficits, which mainly include inhibition of inflammatory response, reduction of oxidative stress, anti-apoptosis, and improvement of blood–brain barrier and cerebral vasospasm. The aim of this paper is to systematically explore the processes of neuroinflammation, oxidative stress, and apoptosis in SAH, and to summarize natural compounds as potential targets for improving the prognosis of SAH and their related mechanisms of action for future therapies. [ABSTRACT FROM AUTHOR]
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- 2024
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30. Utilizing Siamese 4D-AlzNet and Transfer Learning to Identify Stages of Alzheimer's Disease.
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Mehmood, Atif, Shahid, Farah, Khan, Rizwan, Ibrahim, Mostafa M., and Zheng, Zhonglong
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- *
ALZHEIMER'S disease , *CONVOLUTIONAL neural networks , *MILD cognitive impairment , *IDENTIFICATION , *MEMORY disorders , *DEEP learning - Abstract
• Introduced the Siamese 4D-Alznet, which combines five distinct blocks of CNNs. • We proposed three custom TL models incorporating frozen and replacing layers. • Our methods prove 95.07% binary classification performance in terms of accuracy. • All techniques performed best for NC, EMCI, LMCI, and AD classification. Alzheimer's disease (AD) is the general form of dementia, leading to a progressive neurological disorder characterized by memory loss due to brain cell damage. Artificial Intelligence (AI) assists in the early identification and prediction of AD patients, determining future risks and benefits for radiologists and doctors to save time and cost. Since deep learning (DL) approaches work well with massive datasets and have recently become helpful for AD detection, there remains an area for improvement in automating detection performance. Present approaches somehow addressed the challenges of limited annotated data samples for binary classification. This contrasts with prior state-of-the-art techniques, which were constrained by their incapacity to capture abstract-level information. In this paper, we proposed a Siamese 4D-AlzNet model comprised of four parallel convolutional neural network (CNN) streams (Five CNN layer blocks) and customized transfer learning models (Frozen VGG-19, Frozen VGG-16, and customized AlexNet). Siamese 4D-AlzNet was vertically and horizontally stored, and the spatial features were passed to the final layer for classification. For experiments, T1-weighted MRI images comprised of four distinct subject classes, normal control (NC), mild cognitive impairment (MCI), late mild cognitive impairment (LMCI), and AD, have been employed. Our proposed models achieved outstanding accuracy, with a remarkable 95.05% accuracy distinguishing between normal and AD subjects. The performance across remaining binary class pairs consistently exceeded 90%. We thoroughly compared our model with the latest methods using the same dataset as our reference. Our proposed model improved NC-AD and MCI-AD classification accuracy by 2% 7%. [ABSTRACT FROM AUTHOR]
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- 2024
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31. A Stay in Friedrich Bonhoeffer's Lab in Tubingen in the Mid-eighties.
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Godement, Pierre
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COMMUNITIES , *TECHNOLOGICAL innovations , *AXONS , *NEUROSCIENCES , *RETINA - Abstract
• Friedrich Bonhoeffer and his team discovered Roger Sperry's molecular labels. • He was pioneer in developing powerful in vitro assays for axon guidance. • He showed these labels were graded, membrane bound cues in retina and targets. • Throughout the 80′s-90′s, his lab was an epicenter of scientific innovation. • The fixed tissue DiI labeling method was discovered in his lab. The main focus of research for which Friedrich Bonhoeffer's work is known in the Neuroscience community was pioneer experiments on how axonal projections could organize into "maps", what mechanisms are involved in axon guidance and involve gradients of guiding molecules, and isolation of the first such molecules, e.g. RAGS (ephrin A5) and RGM (repulsive guidance molecule). Other papers have described in detail these contributions as well as Friedrich Bonhoeffer's personality. In the mid-eighties, I made a 2-year stay in his lab and initiated a line of research on development of binocular connections in Mammals, particularly the guidance of retinal fibers to one or the other side of the brain. In this paper I recall these circumstances as they pertain to Neuroscience as it stood at the time, and explain as best as I can how his lab was a conducive setting for the discoveries made there and how Friedrich Bonhoeffer acted for me as a scientist and a tutor. [ABSTRACT FROM AUTHOR]
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- 2023
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32. Subpopulations of neurokinin 1 receptor-expressing neurons in the rat lateral amygdala display a differential pattern of innervation from distinct glutamatergic afferents
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Francesco Ferraguti and Hari Kishore Sreepathi
- Subjects
Male ,Vesicular glutamate transporter 1 ,Vesicular Glutamate Transport Protein 2 ,BLA, basolateral complex of the amygdala ,GAD67, glutamate decarboxylase isoform of 67 kDa ,Rats, Sprague-Dawley ,parvalbumin ,TBS, tris-buffered saline ,PV, parvalbumin ,Neurons ,biology ,General Neuroscience ,LA, lateral nucleus of the amygdala ,NK1, neurokinin 1 ,Glutamate receptor ,HRP, horseradish peroxidase ,amygdala ,Receptors, Neurokinin-1 ,NGS, normal goat serum ,medicine.anatomical_structure ,Parvalbumins ,CBP, calcium binding protein ,RT, room temperature ,TBS-T, 0.1% v/v Triton X-100 in TBS ,CaMKIIα, calcium/calmodulin kinase IIα ,Research Paper ,Interneuron ,Neuroscience(all) ,Glutamic Acid ,glutamate ,interneuron ,VGluT, vesicular glutamate transporter ,CB, calbindin-D28K ,Amygdala ,NK1 receptor ,Glutamatergic ,Cellular and Molecular Neuroscience ,PBS, phosphate buffered saline ,medicine ,Animals ,Neurons, Afferent ,SP, substance P ,DAB, 3,3′-diaminobenzidine ,BP, band pass ,Rats ,BA, basal nucleus of the amygdala ,nervous system ,CR, calretinin ,Synapses ,Vesicular Glutamate Transport Protein 1 ,biology.protein ,Neuron ,Calcium-Calmodulin-Dependent Protein Kinase Type 2 ,Neuroscience ,Parvalbumin ,LI, like immunoreactivity - Abstract
Substance P by acting on its preferred receptor neurokinin 1 (NK1) in the amygdala appears to be critically involved in the modulation of fear and anxiety. The present study was undertaken to identify neurochemically specific subpopulations of neuron expressing NK1 receptors in the lateral amygdaloid nucleus (LA), a key site for regulating these behaviors. We also analyzed the sources of glutamatergic inputs to these neurons. Immunofluorescence analysis of the co-expression of NK1 with calcium binding proteins in LA revealed that ∼35% of NK1-containing neurons co-expressed parvalbumin (PV), whereas no co-localization was detected in the basal amygdaloid nucleus. We also show that neurons expressing NK1 receptors in LA did not contain detectable levels of calcium/calmodulin kinase IIα, thus suggesting that NK1 receptors are expressed by interneurons. By using a dual immunoperoxidase/immunogold-silver procedure at the ultrastructural level, we found that in LA ∼75% of glutamatergic synapses onto NK1-expressing neurons were labeled for the vesicular glutamate transporter 1 indicating that they most likely are of cortical, hippocampal, or intrinsic origin. The remaining ∼25% were immunoreactive for the vesicular glutamate transporter 2 (VGluT2), and may then originate from subcortical areas. On the other hand, we could not detect VGluT2-containing inputs onto NK1/PV immunopositive neurons. Our data add to previous localization studies by describing an unexpected variation between LA and basal nucleus of the amygdala (BA) in the neurochemical phenotype of NK1-expressing neurons and reveal the relative source of glutamatergic inputs that may activate these neurons, which in turn regulate fear and anxiety responses., Highlights ▶Subsets of LA neurons containing NK1 receptors co-express PV or CB, but not CR. ▶NK1- and CaMKIIα-like immunoreactivity do not co-localize in LA neurons. ▶In LA, ∼25% of glutamatergic inputs onto NK1-expressing neurons contain VGluT2. ▶NK1/PV labeled neurons do not seem to receive VGluT2-positive axon terminals.
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- 2011
33. Cyclic AMP modulates but does not mediate the inhibition of [3H]norepinephrine release by activation of alpha-2 adrenergic receptors in cultured rat ganglion cells
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Kafait U. Malik and Dean D. Schwartz
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medicine.medical_specialty ,Superior cervical ganglion ,Adrenergic receptor ,Chromatography, Paper ,Radioimmunoassay ,Stimulation ,In Vitro Techniques ,Biology ,Rats, Sprague-Dawley ,Adenylyl cyclase ,Norepinephrine (medication) ,Norepinephrine ,chemistry.chemical_compound ,Quinoxalines ,Internal medicine ,Cyclic AMP ,medicine ,Animals ,Cells, Cultured ,Ganglia, Sympathetic ,Forskolin ,General Neuroscience ,Colforsin ,Receptors, Adrenergic, alpha ,Thionucleotides ,Adenosine ,Electric Stimulation ,Rats ,Endocrinology ,Animals, Newborn ,chemistry ,Brimonidine Tartrate ,Alpha-2 adrenergic receptor ,Adrenergic alpha-Agonists ,medicine.drug - Abstract
The purpose of this study was to determine whether a decrease in cyclic AMP accumulation mediates the inhibition of norepinephrine release in response to alpha-2 adrenergic receptor activation in cultured rat superior cervical ganglion cells. Superior cervical ganglia from neonatal rats were dissociated and cultured on collagen-coated plastic strips. Neurotransmitter release was assessed by measuring the fractional overflow of tritium in superfused cells prelabeled with [ 3 H]norepinephrine. Intracellular cyclic AMP accumulation was measured using radioimmunoassay. Electrical field stimulation at 1 Hz, 30 pulses, 1 ms duration at 20 min intervals produced an increase in the fractional overflow of tritium that was composed predominantly of intact [ 3 H]norepinephrine. The alpha-2 adrenergic receptor agonist UK-14,304 dose-dependently attenuated the increase in fractional tritium overflow elicited by electrical field stimulation. The adenylyl cyclase activator, forskolin, increased cyclic AMP accumulation in superior cervical ganglion cells and UK-14,304 dose-dependently inhibited forskolin-stimulated cyclic AMP accumulation. UK-14,304 had no effect on basal cyclic AMP accumulation or cyclic AMP accumulation during electrical field stimulation. Forskolin (1–10 μM) or the non-hydrolysable cAMP analog, 8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate (1–100 μM), slightly increased basal and dose-dependently potentiated the increase in fractional tritium overflow in response to electrical stimulation. Despite enhancement by forskolin and 8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate of fractional tritium overflow caused by electrical field stimulation, UK-14304 (1–10 μM) reduced release to a similar degree as that observed in the absence of forskolin or 8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate. These data suggest that in cultured rat superior cervical ganglion cells, stimulation of alpha-2 adrenergic receptors decreases cyclic AMP accumulation when adenyl cyclase is activated. A decrease in cyclic AMP does not mediate the inhibition of [ 3 H]norepinephrine release in response to alpha-2 adrenergic receptor activation, although elevations in cyclic AMP can enhance electrically-stimulated release of [ 3 H]norepinephrine.
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- 1993
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34. Two populations of neurokinin 1 receptor-expressing projection neurons in lamina I of the rat spinal cord that differ in AMPA receptor subunit composition and density of excitatory synaptic input
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Erika Polgár, Andrew J. Todd, and K.S. Al Ghamdi
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CGRP, calcitonin gene-related peptide ,Synapse ,0302 clinical medicine ,LTP, long-term potentiation ,Pain Mechanism ,CGRP ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Neurons ,0303 health sciences ,General Neuroscience ,musculoskeletal, neural, and ocular physiology ,Glutamate receptor ,Long-term potentiation ,Receptors, Neurokinin-1 ,medicine.anatomical_structure ,Spinal Cord ,Excitatory postsynaptic potential ,LPb, lateral parabrachial area ,Glutamatergic synapse ,Research Paper ,Neuroscience(all) ,Calcitonin Gene-Related Peptide ,VGLUT2 ,Presynaptic Terminals ,Pain ,AMPA receptor ,glutamatergic synapse ,Biology ,VGLUT, vesicular glutamate transporter ,NK1 receptor ,pERK, phosphorylated extracellular signal-regulated kinases ,03 medical and health sciences ,Glutamatergic ,medicine ,Animals ,Receptors, AMPA ,Rats, Wistar ,030304 developmental biology ,Afferent Pathways ,NK1r, neurokinin 1 receptor ,dorsal horn ,AMPAr, AMPA, receptor ,TSA, tyramide signal amplification ,Rats ,Protein Subunits ,nervous system ,Synapses ,Vesicular Glutamate Transport Protein 2 ,Neuron ,Capsaicin ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Lamina I of the spinal cord contains many projection neurons that express the neurokinin 1 receptor (NK1r). It has been reported that these cells can undergo long-term potentiation (LTP), which may result from insertion of AMPA-type glutamate receptors (AMPArs) containing GluA1 or GluA4 subunits. We therefore investigated synaptic AMPAr expression on these cells with immunocytochemistry following antigen-retrieval. We also examined their density of glutamatergic input (by analysing AMPAr synaptic puncta and contacts from glutamatergic boutons), and phosphorylation of extracellular signal-regulated kinases (pERKs) following noxious stimulation. Our results indicate that there are two populations of NK1r-expressing projection neurons: large GluA4+/GluA1− cells with a high density of glutamatergic input and small GluA1+/GluA4− cells with a much lower input density. Results from pERK experiments suggested that the two groups may not differ in the types of noxious stimulus that activate them. Glutamatergic synapses on distal dendrites of the large cells were significantly longer than those on proximal dendrites, which presumably compensates for the greater attenuation of distally-generated excitatory postsynaptic currents (EPSCs). Both types of cell received contacts from peptidergic primary afferents, however, on the large cells these appeared to constitute over half of the glutamatergic synapses, and were often associated with elongated AMPAr puncta. This suggests that these afferents, which probably contain substance P, provide a powerful, secure synaptic input to large NK1r-expressing projection neurons. These results demonstrate the importance of GluA4-containing AMPArs in nociceptive transmission and raise the possibility that different forms of LTP in lamina I projection neurons may be related to differential expression of GluA1/GluA4.
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- 2010
35. A design and implementation of multi-character classification scheme based on motor imagery EEG signals.
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Pan, Hongguang, Zhang, Yibo, Li, Li, and Qin, Xuebin
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MOTOR imagery (Cognition) , *PEARSON correlation (Statistics) , *GROSS motor ability , *PRINCIPAL components analysis , *ENGLISH letters - Abstract
• We design a multi-classification scheme based on 29 electroencephalogram characters. • We use three methods for feature extraction and compare the results. • We use four classifiers for 29 classification and compare the results. • The final 29 classification accuracy using KNN and KPC is 96.2%. In the field of brain-to-text communication, it is difficult to finish highly dexterous behaviors of writing multi-character by motor-imagery-based brain–computer interface (MI-BCI), setting a barrier to restore communication in people who have lost the ability to move and speak. In this paper, we design and implement a multi-character classification scheme based on 29 characters of motor imagery (MI) electroencephalogram (EEG) signals, which contains 26 English letters and 3 punctuation marks. Firstly, we design a novel experimental paradigm to increase the variety of BCI inputs by asking subjects to imagine the movement of writing 29 characters instead of gross motor skills such as reaching or grasping. Secondly, because of the high dimension of EEG signals, we adopt power spectral density (PSD), principal components analysis (PCA), kernel principal components analysis (KPCA) respectively to decompose EEG signals and extract feature, and then test the results with pearson product-moment correlation coefficient (PCCs). Thirdly, we respectively employ k-nearest neighbor (kNN), support vector machine (SVM), extreme learning machine (ELM) and light gradient boosting machine (LightGBM) to classify 29 characters and compare the results. We have implemented a complete scheme, including paradigm design, signal acquisition, feature extraction and classification, which can effectively classify 29 characters. The experimental results show that the KPCA has the best feature extraction effect and the kNN has the highest classification accuracy, with the final classification accuracy reaching 96.2%, which is better than other studies. [ABSTRACT FROM AUTHOR]
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- 2024
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36. Vagal Nerve Stimulation: The Effect on the Brain Oscillatory Field Potential.
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Broncel, Adam, Bocian, Renata, and Konopacki, Jan
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VAGUS nerve stimulation , *BRAIN stimulation , *VAGUS nerve , *EPILEPTIFORM discharges , *LABORATORY animals , *ELECTROPHYSIOLOGY - Abstract
• VNS and rhythmic field activity. • Rhythmic brain oscillations and VNS. • VNS and brain EEG field potential. More than thirty years of medical treatment with the use of vagal nerve stimulation (VNS) has shown that this therapeutic procedure works in a number of homeostatic disturbances. Although the clinical usage of VNS has a long history, our knowledge about the central mechanisms underlying this treatment is still limited. In the present paper we review the effects of VNS on brain oscillations as a possible electrophysiological bio-marker of VNS efficacy. The review was prepared mainly on the basis of data delivered from clinical observations and the outcomes of electrophysiological experiments conducted on laboratory animals that are available in PubMed. We consciously did not focus on epileptiform activity understood as a pathologic oscillatory activity, which was widely discussed in the numerous previously published reviews. The main conclusion of the present paper is that further, well-designed experiments on laboratory animals are absolutely necessary to address the electrophysiological issues. These will fill a number of gaps in our present knowledge of the central mechanisms underlying VNS therapy. [ABSTRACT FROM AUTHOR]
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- 2022
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37. NEDD4 Like E3 Ubiquitin Protein Ligase Represses Astrocyte Activation and Aggravates Neuroinflammation in Mice with Depression via Paired Box 6 Ubiquitination.
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Wang, Xin, Su, Mingming, Wang, Lesheng, Zhou, Yixuan, Li, Nan, and Yang, Bangkun
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UBIQUITINATION , *GLIAL fibrillary acidic protein , *LIGAND-gated ion channels , *ION channels , *NEUROINFLAMMATION , *COGNITIVE Abilities Test , *UBIQUITIN ligases , *MENTAL depression - Abstract
• NEDD4L is elevated in brain tissue of chronic mild unpredictable stress (CUMS) mice. • Inhibition of NEDD4 improves activated astrocytes and inflammation in CUMS mice. • NEDD4L binds to PAX6 (paired box 6) and promotes its ubiquitinated degradation. • PAX6 binds to P2X7R (purinergic ligand-gated ion channel 7 receptor) promoter. • Inhibition of PAX6 partially reverses the effect of NEDD4L on depression. Astrocytes are implicated in stress-induced neuroinflammatory responses in depression. This paper was to explore the molecular mechanism of the E3 ubiquitin ligase NEDD4L (NEDD4 like E3 ubiquitin protein ligase) in depressed mice by regulating astrocyte activation, and to find a new target for depression. A mouse model of depression was established by CUMS (chronic mild unpredictable stress) in 48 6-week male C57BL/6 mice and injected with sh-NEDD4L vector for testing behavioral and cognitive abilities, histopathological changes, and the number of GFAP-positive cells. The mRNA and protein levels of NEDD4L, PAX6 (paired box 6) and P2X7R (purinergic ligand-gated ion channel 7 receptor) were measured. Inflammation model was established by lipopolysaccharide treatment of mouse astrocyte line C8-D1A and infected with sh-NEDD4L. After CUMS induction, mice showed depression-like symptoms, increased inflammatory infiltration, decreased glial fibrillary acidic protein (GFAP)-positive cells in brain tissue, and increased NEDD4L protein levels. NEDD4L inhibition increased GFAP-positive cells, increased PAX6 protein levels and decreased P2X7R mRNA and protein levels, and decreased inflammatory factor secretion in brain tissue and in vitro cells. PAX6 knockdown or P2X7R overexpression partially reversed the effects of NEDD4L inhibition on astrocyte activation and neuroinflammation. To conclude, highly-expressed NEDD4L in depression-like mouse brain inhibits astrocyte activation and exacerbates neuroinflammation by ubiquitinating PAX6 and promoting P2X7R level. [ABSTRACT FROM AUTHOR]
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- 2023
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38. Characterization of Mitochondria Degeneration in Spinal Motor Neurons Triggered by Chronic Over-activation of α-Amino-3-Hydroxy-5-Methylisoxazole-4-Propionic Acid Receptors in the Rat Spinal Cord in Vivo.
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Ramirez-Jarquin, Uri Nimrod, Lopez-Huerta, Violeta Gisselle, and Tapia, Ricardo
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MOTOR neurons , *SPINAL cord , *ALZHEIMER'S disease , *MITOCHONDRIAL DNA , *MITOCHONDRIA - Abstract
• Mitochondria damage defines the cell death process in motoneuron degeneration. • Distal mitochondria are more susceptible to damage than perinuclear mitochondria. • The shift from apoptotic to necrotic process is controlled by mitochondria healthy population. Mitochondrial damage is a central mechanism involved in neurological disorders as Alzheimer's, and Parkinson's diseases and amyotrophic lateral sclerosis. Energy production is the most studied mitochondrial function; however, mitochondria are also involved in processes like calcium buffering homeostasis, and cell death control during apoptosis and necrosis. Using transmission electron microscopy, in this in vivo study in male rats, we describe ultrastructural mitochondrial alterations of spinal motor neurons along chronic AMPA-induced excitotoxicity, which has been described as one of the most relevant mechanisms in ALS disease. Mitochondrial alterations begin with a crest swelling, which progresses to a full mitochondrial swelling and crest disruption. Changes on the mitochondrial morphology from elongated to a circular shape also occur along the AMPA-excitotoxicity process. In addition, by combining the TUNEL assay and immunohistochemistry for mitochondrial enzymes, we show evidence of mitochondrial DNA damage. Evidence of mitochondrial alterations during an AMPA-excitotoxic event is relevant because resembles the mitochondrial alterations previously reported in ALS patients and in transgenic familial ALS models, suggesting that a chronic excitotoxic model can be related to sporadic ALS (as has been shown in recent papers), which represent more than the 90% of the ALS cases. Understanding the mechanisms involved in motor neuron degenerative process, such as the ultrastructural mitochondrial changes permits to design strategies for MN-degeneration treatments in ALS. [ABSTRACT FROM AUTHOR]
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- 2023
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39. Gut Microbiota, an Additional Hallmark of Human Aging and Neurodegeneration.
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Molinero, Natalia, Antón-Fernández, Alejandro, Hernández, Félix, Ávila, Jesús, Bartolomé, Begoña, and Moreno-Arribas, M. Victoria
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GUT microbiome , *NEURODEGENERATION , *BACTERIAL colonies , *AGING , *MICROORGANISM populations - Abstract
• Gut-brain axis is involve in aged-related neurological disorders like Alzheimer. • Oral and gut dysbiosis has been associated to biomarkers of cognitive decline. • Microbial-derived metabolites could modulate tau and β-amyloid deposition. • Gut microbiome could affect brain activity via epigenetic changes. • Oral and gut dysbiosis as additional hallmark of human aging and neurodegeneration. Gut microbiota represents a diverse and dynamic population of microorganisms harbouring the gastrointestinal tract, which influences host health and disease. Bacterial colonization of the gastrointestinal tract begins at birth and changes throughout life, with age being one of the conditioning factors for its vitality. Aging is also a primary risk factor for most neurodegenerative diseases. Among them, Alzheimeŕs disease (AD) is probably the one where its association with a state of dysbiosis of the gut microbiota has been most studied. In particular, intestinal microbial-derived metabolites have been associated with β-amyloid formation and brain amyloid deposition, tau phosphorylation, as well as neuroinflammation in AD patients. Moreover, it has been suggested that some oral bacteria increase the risk of developing AD. However, the causal connections among microbiome, amyloid-tau interaction, and neurodegeneration need to be addressed. This paper summarizes the emerging evidence in the literature regarding the link between the oral and gut microbiome and neurodegeneration with a focus on AD. Taxonomic features of bacteria as well as microbial functional alterations associated with AD biomarkers are the main points reviewed. Data from clinical studies as well as the link between microbiome and clinical determinants of AD are particularly emphasized. Further, relationships between gut microbiota and age-dependent epigenetic changes and other neurological disorders are also described. Together, all this evidence suggests that, in some sense, gut microbiota can be seen as an additional hallmark of human aging and neurodegeneration. [ABSTRACT FROM AUTHOR]
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- 2023
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40. Sleep consolidates the effector-independent representation of a motor skill
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Witt, K., Margraf, N., Bieber, C., Born, J., and Deuschl, G.
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- 2010
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41. Research Progress on Lipocalin-2 in Diabetic Encephalopathy.
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Zhang, Wenjie, Chen, Shihong, and Zhuang, Xianghua
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LIPOCALIN-2 , *TYPE 2 diabetes , *BRAIN diseases , *DISEASE risk factors , *DIABETES complications - Abstract
[Display omitted] • Type 2 Diabetes Mellitus increases the risk of dementia. • Lipocalin-2 levels may change with the progression of diabetes. • Lipocalin-2 is associated with the progression of diabetic encephalopathy. • Lipocalin-2 may be involved in inflammation and iron metabolism to affect cognition. Diabetic encephalopathy is a central nervous complication of diabetes mellitus which is characterized by cognitive impairment and structural and neurochemical abnormalities, which is easily neglected. Lipocalin-2 (LCN2) is a 25 kDa transporter in the lipocalin family that can transport small molecules, including fatty acids, iron, steroids, and lipopolysaccharides in the circulation. Recently, LCN2 has been found to be a significant regulator of insulin resistance and glucose homeostasis. Numerous studies have shown that LCN2 is connected to central nervous system abnormalities, including neuroinflammation and neurodegeneration, while the latest researches have found that LCN2 is closely related to the development of diabetic encephalopathy. Nevertheless, its precise role in the pathogenesis of diabetic encephalopathy remains to be determined. In this paper, we review recent evidence on the role of LCN2 in diabetic encephalopathy from multiple perspectives in order to decipher the impact of LCN2 in both the aetiology and treatment of diabetic encephalopathy. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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42. Intracranial Self-stimulation of the Medial Forebrain Bundle Ameliorates Memory Disturbances and Pathological Hallmarks in an Alzheimer's Disease Model by Intracerebral Administration of Amyloid-β in Rats.
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Puig-Parnau, Irene, Garcia-Brito, Soleil, Vila-Soles, Laia, Riberas, Andrea, Aldavert-Vera, Laura, Segura-Torres, Pilar, Kádár, Elisabet, and Huguet, Gemma
- Subjects
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IMPLICIT learning , *ALZHEIMER'S disease , *DEEP brain stimulation , *PROSENCEPHALON , *MEDICAL model , *EXPLICIT memory - Abstract
[Display omitted] • MFB-ICSS reverses spatial memory deficits in Aβ-injected rats. • MFB-ICSS reserves ptau levels in CA1 and enthorhinal cortex in Aβ rats. • DBN levels in temporal regions are restored in MFB-ICSS treated Aβ rats. • DBN levels and behavioral afectation correlations change after MFB-ICSS. No curative or fully effective treatments are currently available for Alzheimer's disease (AD), the most common form of dementia. Electrical stimulation of deep brain areas has been proposed as a novel neuromodulatory therapeutic approach. Previous research from our lab demonstrates that intracranial self-stimulation (ICSS) targeting medial forebrain bundle (MFB) facilitates explicit and implicit learning and memory in rats with age or lesion-related memory impairment. At a molecular level, MFB-ICSS modulates the expression of plasticity and neuroprotection-related genes in memory-related brain areas. On this basis, we suggest that MFB could be a promising stimulation target for AD treatment. In this study, we aimed to assess the effects of MFB-ICSS on both explicit memory as well as the levels of neuropathological markers ptau and drebrin (DBN) in memory-related areas, in an AD rat model obtained by Aβ icv-injection. A total of 36 male rats were trained in the Morris water maze on days 26–30 after Aβ injection and tested on day 33. Results demonstrate that this Aβ model displayed spatial memory impairment in the retention test, accompanied by changes in the levels of DBN and ptau in lateral entorhinal cortex and hippocampus, resembling pathological alterations in early AD. Administration of MFB-ICSS treatment consisting of 5 post-training sessions to AD rats managed to reverse the memory deficits as well as the alteration in ptau and DBN levels. Thus, this paper reports both cognitive and molecular effects of a post-training reinforcing deep brain stimulation procedure in a sporadic AD model for the first time. [ABSTRACT FROM AUTHOR]
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- 2023
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43. Differential Effect of Anesthesia on Visual Cortex Neurons with Diverse Population Coupling
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Lee, Heonsoo, Tanabe, Sean, Wang, Shiyong, and Hudetz, Anthony G.
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- 2021
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44. Images Reconstruction from Functional Magnetic Resonance Imaging Patterns Based on the Improved Deep Generative Multiview Model.
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Pan, Hongguang, Fu, Yunpeng, Li, Zhuoyi, Wen, Fan, Hu, Jianchen, and Wu, Bo
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FUNCTIONAL magnetic resonance imaging , *IMAGE reconstruction , *VISUAL perception , *DEEP learning , *LATENT variables - Abstract
• The improved encoder is proposed to get the latent variables from brain activity. • The improved decoder is proposed to reconstruct the image from the latent variables. • An optimizer is designed in the improved deep generative multiview model. • An optimizer is designed in the improved deep generative multiview model. • The image reconstruction performance of the proposed model is greatly improved. Reconstructing visual stimulus images from the brain activity signals is an important research task in the field of brain decoding. Many methods of reconstructing visual stimulus images mainly focus on how to use deep learning to classify the brain activities measured by functional magnetic resonance imaging or identify visual stimulus images. Accurate reconstruction of visual stimulus images by using deep learning still remains challenging. This paper proposes an improved deep generative multiview model to further promote the accuracy of reconstructing visual stimulus images. Firstly, an encoder based on residual-in-residual dense blocks is designed to fit the deep and multiview visual features of human natural state, and extract the features of visual stimulus images. Secondly, the structure of original decoder is extended to a deeper network in the deep generative multiview model, which makes the features obtained by each deconvolution layer more distinguishable. Finally, we configure the parameters of the optimizer and compare the performance of various optimizers under different parameter values, and then the one with the best performance is chosen and adopted to the whole model. The performance evaluations conducted on two publicly available datasets demonstrate that the improved model has more accurate reconstruction effectiveness than the original deep generative multiview model. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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45. Abnormal Properties of Cortical Functional Brain Network in Major Depressive Disorder: Graph Theory Analysis Based on Electroencephalography-Source Estimates.
- Author
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Teng, Chaolin, Wang, Mengwei, Wang, Wei, Ma, Jin, Jia, Min, Wu, Min, Luo, Yuanyuan, Wang, Yu, Zhang, Yiyang, and Xu, Jin
- Subjects
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MENTAL depression , *LARGE-scale brain networks , *GRAPH theory , *FUNCTIONAL connectivity , *TOPOLOGICAL property - Abstract
• The whole cortical functional brain networks were investigated in MDD patients based on EEG-sources. • MDD caused enhanced global functional connectivity in α band. • Increased global and local clustering coefficients were both found in MDD patients in α and β bands. Studies of scalp electroencephalography (EEG) had shown altered topological organization of functional brain networks in patients with major depressive disorder (MDD). However, most previous EEG-based network analyses were performed at sensor level, while the interpretation of obtained results was not straightforward due to volume conduction effect. To reduce the impact of this defect, the whole cortical functional brain networks of MDD patients were studied during resting state based on EEG-source estimates in this paper. First, scalp EEG signals were recorded from 19 patients with MDD and 20 normal controls under resting eyes-closed state, and cortical neural signals were estimated by using sLORETA method. Then, the correntropy coefficient of wavelet packet coefficients was performed to calculate functional connectivity (FC) matrices in four different frequency bands: δ, θ, α, β, respectively. Afterwards, topological properties of brain networks were analyzed by graph theory approaches. The results showed that the global FC strength of MDD patients was significantly higher than that of healthy subjects in α band. Also, it was found that MDD patients have abnormally increased clustering coefficient and local efficiency in both α and β bands compared to normal people. Furthermore, patients with MDD exhibited increased nodal clustering coefficients in the left lingual gryus and left precuneus in α band. In addition, β band global clustering coefficient was positively correlated with the scores of depression severity. Therefore, the findings indicated the cortical functional brain networks in MDD patients were disruptions, which suggested it would be one of potential causes of depression. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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46. A Novel End-to-end Network Based on a bidirectional GRU and a Self-Attention Mechanism for Denoising of Electroencephalography Signals.
- Author
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Wang, Wenlong, Li, Baojiang, and Wang, Haiyan
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SIGNAL denoising , *RECURRENT neural networks , *STANDARD deviations , *CONVOLUTIONAL neural networks , *BRAIN-computer interfaces - Abstract
[Display omitted] • Physiological signals from other body regions can interfere with EEG signals. • EMG and EOG artifacts are two of the most common artifacts in EEG signals. • GRU and self-attention are the state-of-art techniques for sequential data. • The model can reconstruct a clear EEG waveform with a decent SNR and RRMSE value. • The denoising algorithm can be applied to the preprocessing stage of the EEG signal. Electroencephalography (EEG) signals are nonlinear and non-stationary sequences that carry much information. However, physiological signals from other body regions may readily interfere with EEG signal capture, having a significant unfavorable influence on subsequent analysis. Therefore, signal denoising is a crucial step in EEG signal processing. This paper proposes a bidirectional gated recurrent unit (GRU) network based on a self-attention mechanism (BG-Attention) for extracting pure EEG signals from noise-contaminated EEG signals. The bidirectional GRU network can simultaneously capture past and future information while processing continuous time sequence. And by paying different levels of attention to the content of varying importance, the model can learn more significant feature of EEG signal sequences, highlighting the contribution of essential samples to denoising. The proposed model is evaluated on the EEGdenoiseNet data set. We compared the proposed model with a fully connected network (FCNN), the one-dimensional residual convolutional neural network (1D-ResCNN), and a recurrent neural network (RNN). The experimental results show that the proposed model can reconstruct a clear EEG waveform with a decent signal-to-noise ratio (SNR) and the relative root mean squared error (RRMSE) value. This study demonstrates the potential of BG-Attention in the pre-processing phase of EEG experiments, which has significant implications for medical technology and brain-computer interface (BCI) applications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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47. An Attempt to Conceptually Replicate the Dissociation between Syntax and Semantics during Sentence Comprehension.
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Siegelman, Matthew, Blank, Idan A., Mineroff, Zachary, and Fedorenko, Evelina
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SEMANTICS , *COMPREHENSION , *SYNTAX (Grammar) , *SENTENCES (Grammar) , *BROCA'S area - Abstract
Is sentence structure processed by the same neural and cognitive resources that are recruited for processing word meanings, or do structure and meaning rely on distinct resources? Linguistic theorizing and much behavioral evidence suggest tight integration between lexico-semantic and syntactic representations and processing. However, most current proposals of the neural architecture of language continue to postulate a distinction between the two. One of the earlier and most cited pieces of neuroimaging evidence in favor of this dissociation comes from a paper by Dapretto and Bookheimer (1999). Using a sentence-meaning judgment task, Dapretto & Bookheimer observed two distinct peaks within the left inferior frontal gyrus (LIFG): one was more active during a lexico-semantic manipulation, and the other during a syntactic manipulation. Although the paper is highly cited, no attempt has been made, to our knowledge, to replicate the original finding. We report an fMRI study that attempts to do so. Using a combination of whole-brain, group-level ROI, and participant-specific functional ROI approaches, we fail to replicate the original dissociation. In particular, whereas parts of LIFG respond reliably more strongly during lexico-semantic than syntactic processing, no part of LIFG (including in the region defined around the peak reported by Dapretto & Bookheimer) shows the opposite pattern. We speculate that the original result was a false positive, possibly driven by a small subset of participants or items that biased a fixed-effects analysis with low power. • Is sentence structure processed by the same brain regions that are recruited for processing word meanings? • We try to replicate distinct peaks in LIFG for semantic vs. syntactic processing reported by Dapretto and Bookheimer (1999). • Parts of LIFG respond reliably more strongly during semantic than syntactic processing. • No part of LIFG (including in the region defined around the peak reported by D&B) shows the opposite pattern. • The original D&B finding is likely a false positive driven by a subset of participants/items in a fixed-effects analysis. [ABSTRACT FROM AUTHOR]
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- 2019
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48. Effects of long-term moderate ethanol and cholesterol on cognition, cholinergic neurons, inflammation, and vascular impairment in rats
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Ehrlich, D., Pirchl, M., and Humpel, C.
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Male ,Neuroscience(all) ,IL-1β, interleukin 1-β ,NGF, nerve growth factor ,WRME, working-reference memory error ,Hypercholesterolemia ,IgG, immunoglobulin G ,PBS, phosphate-buffered saline ,nbM, basal nucleus of Meynert ,tPA, tissue-plasminogen activator ,Time ,Aβ, beta-amyloid ,Rats, Sprague-Dawley ,Alcohol-Induced Disorders, Nervous System ,APP, amyloid precursor protein ,ChAT, choline-acetyltransferase ,mental disorders ,Animals ,BBB, blood–brain barrier ,ANOVA, analysis of variance ,MIP-2, macrophage inflammatory protein-2 ,ACh, acetylcholine ,RME, reference memory error ,WME, working memory errors ,Dementia, Vascular ,TNF-α, tumor necrosis factor-alpha ,RET, retention ,Neurodegeneration, Neuroprotection, and Disease-Oriented Neuroscience ,ELISA, enzyme-linked immunosorbent assay ,T-PBS, triton/PBS ,cognitive decline ,Cholinergic Neurons ,Rats ,Disease Models, Animal ,HPLC, high-performance liquid chromatography ,AD, Alzheimer's disease ,ethanol ,Inflammation Mediators ,blood–brain barrier leakage ,EtOH, ethanol ,cholinergic dysfunction ,Research Paper - Abstract
There is strong evidence that vascular risk factors play a role in the development of Alzheimer's disease (AD) or vascular dementia (vaD). Ethanol (EtOH) and cholesterol are such vascular risk factors, and we recently showed that hypercholesterolemia causes pathologies similar to AD [Ullrich et al. (2010) Mol Cell Neurosci 45, 408–417]. The aim of this study was to investigate the effects of long-term (12 months) EtOH treatment (20% v/v in drinking water) alone or long-term 5% cholesterol diet alone or a combination (mix) in adult Sprague–Dawley rats. Long-term EtOH treatment (plasma EtOH levels 58±23 mg/dl) caused significant impairment of spatial memory, reduced the number of choline acetyltransferase- and p75 neurotrophin receptor-positive nucleus basalis of Meynert neurons, decreased cortical acetylcholine, elevated cortical monocyte chemoattractant protein-1 and tissue-type plasminogen activator, enhanced microglia, and markedly induced anti-rat immunoglobulin G-positive blood–brain barrier leakage. The effect of long-term hypercholesterolemia was similar. Combined long-term treatment of rats with 20% EtOH and 5% cholesterol (mix) did not potentiate treatment with EtOH alone, but instead counteracted some of the EtOH-associated effects. In conclusion, our data show that vascular risk factors EtOH and cholesterol play a role in cognitive impairment and possibly vaD., Highlights ▶Long-term chronic ethanol causes cognitive impairment in rats in vivo. ▶Chronic ethanol causes cholinergic neurodegeneration. ▶Chronic ethanol induces cortical rat IgG-influx and MCP-1 upregulation. ▶Chronic mild hypercholesterolemia causes similar impairments. ▶Hypercholesterolemia partly counteracts some of the ethanol-induced effects.
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49. Capsaicin-sensitive primary sensory neurons in the mouse express N-Acyl phosphatidylethanolamine phospholipase D
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B. Nagy, Cleoper C. Paule, A. Photiou, Laki Buluwela, István Nagy, C. Fedonidis, John Wahba, and Daqing Ma
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Male ,Mice ,chemistry.chemical_compound ,PCR, polymerase chain reaction ,0302 clinical medicine ,Dorsal root ganglion ,Ganglia, Spinal ,anandamide, N-arachidonoyl ethanolamine ,Neurotoxin ,anandamide ,pain ,FAAH, fatty acid amide hydrolase ,Cells, Cultured ,0303 health sciences ,General Neuroscience ,TRPV1, transient receptor potential vanilloid type 1 ,Anandamide ,Cell biology ,medicine.anatomical_structure ,Biochemistry ,transient receptor vanilloid type 1 ,GAPDH, glyceraldehyde-3-phosphate dehydrogenase ,RT, reverse transcriptase ,lipids (amino acids, peptides, and proteins) ,NAPE-PLD, N-acyl phosphotidylethanolamine phospholipase D ,Research Paper ,dorsal root ganglion ,Sensory Receptor Cells ,Neuroscience(all) ,Central nervous system ,TRPV1 ,Down-Regulation ,TRPV Cation Channels ,Biology ,03 medical and health sciences ,Phospholipase D ,medicine ,Animals ,030304 developmental biology ,nociceptive ,Spinal cord ,Sensory neuron ,DRG, dorsal root ganglia ,chemistry ,Capsaicin ,CB1, cannabinoid 1 ,CB2, cannabinoid 2 ,Sensory System ,030217 neurology & neurosurgery - Abstract
Our previous finding, that the capsaicin- and KCl-induced Ca(2+)-dependent production of the intra- and intercellular signaling molecule N-arachidonoyl ethanolamine (anandamide) in cultured primary sensory neurons could be abolished and reduced by approximately 2/3 by capsaicin-induced degeneration of capsaicin-sensitive neurons, respectively suggests that a major sub-population of capsaicin-sensitive cells together with a group of non-capsaicin-sensitive cells should express enzymes involved in Ca(2+)-dependent anandamide synthesis. N-acyl phosphotidylethanolamine phospholipase D (NAPE-PLD) is known to be involved in Ca(2+)-dependent anandamide production. Hence, here, we used reverse transcriptase and quantitative real time polymerase chain reaction to study NAPE-PLD expression in dorsal root ganglia and to clarify the sub-population of cells expressing this enzyme. Cultures prepared from mouse dorsal root ganglia were grown either in the absence or presence of the neurotoxin, capsaicin (10 muM) overnight. We report, that NAPE-PLD is expressed both in dorsal root ganglia and cultures prepared from dorsal root ganglia and grown in the absence of capsaicin. Furthermore, we also report that capsaicin application downregulates the expression of NAPE-PLD as well as the capsaicin receptor, transient receptor potential vanilloid type 1 ion channel, by about 70% in the cultures prepared from dorsal root ganglia. These findings indicate that a major sub-population of capsaicin-sensitive primary sensory neurons expresses NAPE-PLD, and suggest that NAPE-PLD is expressed predominantly by capsaicin-sensitive neurons in dorsal root ganglia. These data also suggest that NAPE-PLD might be a target to control the activity and excitability of a major sub-population of nociceptive primary sensory neurons.
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50. Altered GABA transmission in a mouse model of increased trait anxiety
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A. Bukovac, Nicolas Singewald, Yvan Peterschmitt, Simone B. Sartori, Ramon O. Tasan, G. Sperk, and Rainer Landgraf
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Male ,Cognitive, Behavioral, and Systems Neuroscience ,Glutamate decarboxylase ,Anxiety ,Synaptic Transmission ,GAD67, glutamic acid decarboxylase of 67 kilo Dalton ,Mice ,chemistry.chemical_compound ,MEA, medial amygdala ,Neurotransmitter ,gamma-Aminobutyric Acid ,CEA, central amygdala ,ROD, relative optical density ,GABAA receptor ,General Neuroscience ,amygdala ,medicine.anatomical_structure ,BLA, basolateral amygdala ,HAB, high anxiety-related behavior ,Proto-Oncogene Proteins c-fos ,Research Paper ,medicine.drug ,FOSB ,medicine.medical_specialty ,Neuroscience(all) ,GABAB receptor ,Biology ,Amygdala ,Statistics, Nonparametric ,gamma-Aminobutyric acid ,GAD65, glutamic acid decarboxylase of 65 kilo Dalton ,FosB ,Internal medicine ,medicine ,Animals ,NAB, normal anxiety-related behavior ,RNA, Messenger ,Maze Learning ,Analysis of Variance ,HAB ,high anxiety-related behavior ,Receptors, GABA-A ,EPM, elevated plus maze ,Disease Models, Animal ,Protein Subunits ,LAB, low anxiety-related behavior ,Endocrinology ,Gene Expression Regulation ,chemistry ,nervous system ,glutamate decarboxylase ,Basolateral amygdala - Abstract
Anxiety disorders are the most prevalent central nervous system diseases imposing a high social burden to our society. Emotional processing is particularly controlled by GABA-ergic transmission in the amygdala. Using in situ hybridization and immunohistochemistry we now investigated changes in the expression of GABA synthesizing enzymes (GAD65 and GAD67), GABAA (α1–5, β1–3, γ1–2) and GABAB receptor subunits (GBBR1, GBBR2) in amygdaloid nuclei of high anxiety-related behavior (HAB) mice in comparison to mice selected for normal anxiety-related behavior (NAB). Levels of GAD65 and GAD67 mRNAs and protein, as well as those of GABA were increased in the amygdala of HAB mice. Relative to NAB controls, mRNA expression of the GABAA receptor subunits β1, β2 and γ2 was specifically increased in the basolateral amygdala of HAB mice while transcription of α5 and γ1 subunits was reduced in the central and medial amygdala. On the protein level, increases in β2 and γ2 subunit immunoreactivities were evident in the basolateral amygdala of HAB mice. No change in GABAB receptor expression was observed. These findings point towards an imbalanced GABA-ergic neurotransmission in the amygdala of HAB mice. On the other hand, FosB, a marker for neuronal activity, was increased in principal neurons of the basolateral amygdala in HAB mice, reflecting activation of excitatory neurons, possibly as a consequence of reduced GABA-ergic tonic inhibition through α5 and γ1 containing receptors. Ultimately these mechanisms may lead to the compensatory activation of GABA transmission, as indicated by the increased expression of GAD65/67 in HAB mice., Graphical Abstract Highlights ▶Mice with increased trait anxiety revealed: ▶Increased activity of principal neurons of the basolateral amygdala. ▶A compensatory increase of glutamate decarboxylase expression. ▶Differential alterations of GABAA receptor subunit expression in the amygdala.
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