Search

Objectives Evolutionary changes in hominin social complexity have been associated with increases in absolute brain size. The temporal lobes are nestled in the middle cranial fossae (MCF) of the skull, the dimensions of which allow estimation of temporal lobe volume (TLV) in extant and fossil taxa. Materials and Methods The main aim of this study is to determine where along the hominid phylogeny, major temporal lobe size transitions occurred. We used computed tomography (CT) scans of crania, 3D photogrammetry data, and laser surface scans of endocranial casts to measure seven MCF metrics in 11 extant anthropoid taxa using multiple regressions to estimate TLV in 5 extant hominids and 10 fossil hominins. Phylogenetic comparative methods mapped temporal lobe size, brain size, and temporal lobe proportions onto phylogenetic trees broadly for Hominidae and specifically for Hominini. Results Extant Homo sapiens were not an outlier in relative brain size, temporal lobe size, or proportions of the temporal lobes, but some proportions within the lobe were uniquely altered. The most notable changes in relative temporal lobe size and proportions saw a decrease in relative temporal lobe size and proportions in the genus Pan compared to other extant great apes and fossil hominins while there was a relative increase in the temporal lobe width and length in Australopithecus–Paranthropus clade compared to the genus Homo and other extant great apes including modern humans. Discussion We do not find support for the social brain, environmental or functional craniology hypotheses alone but think it prudent to consider the implications of cerebral reorganization between the temporal lobes and other regions of the brain within the context of these hypotheses and with future investigation is warranted. [ABSTRACT FROM AUTHOR]

There are well‐established relationships between aging and neurodegenerative changes, and between aging and hearing loss. The goal of this study was to determine how structural brain aging is influenced by hearing loss. Human Connectome Project Aging data were analyzed, including T1‐weighted Magnetic Resonance Imaging (MRI) and Words in noise (WIN) thresholds (n = 623). Freesurfer extracted gray and white matter volume, and cortical thickness, area, and curvature. Linear regression models targeted (1) interactions between age and WIN threshold and (2) correlations with WIN threshold adjusted for age, both corrected for false discovery rate (pFDR < 0.05). WIN threshold moderated age‐related increase in volume in bilateral inferior lateral ventricles, with a higher threshold associated with increased age‐related ventricle expansion. Age‐related differences in the occipital cortex also increased with higher WIN thresholds. When controlling for age, high WIN threshold was correlated with reduced cortical thickness in Heschl's gyrus, calcarine sulcus, and other sensory regions, and reduced temporal lobe white matter. Older volunteers with poorer hearing and cognitive scores had the lowest volume in left parahippocampal white matter. These results suggest that better hearing is associated with reduced age‐related differences in medial temporal lobe, while better hearing at any age is associated with greater cortical tissue in auditory and other sensory regions. Future longitudinal studies are needed to assess the causal nature of these relationships, but these results indicate interventions that preserve or protect hearing function may combat some neurodegenerative changes in aging. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antioxidant, clock, and neurotrophic factors oscillate in the temporal cortex (TC). • Age-related oxidative stress disrupts the circadian organization in the TC. • Arrhythmic Nrf2 expression becomes rhythmic in the TC of aged rats. • Daily average of Bdnf and Rc3 expression increases in the old TC. Disruption of circadian rhythms contributes to deficits in cognitive functions during aging. Up to date, the biochemical, molecular and chronobiological bases of such deterioration have not been completely elucidated. Here, we aim: 1) to investigate the endogenous nature of 24 h-rhythms of antioxidant defenses, oxidative stress, clocḱ's, and neurotrophic factors expression, in the rat temporal cortex (TC), and 2) to study the consequences of aging on the circadian organization of those factors. We observed a circadian organization of antioxidant enzymes activity, lipoperoxidation and the clock, BMAL1 and RORa, proteins, in the TC of young rats. Such temporal organization suggests the existence of a two-way communication among clock transcription factors and antioxidant defenses. This might generate the rhythmic and circadian expression of Bdnf and Rc3 genes involved in the TC-depending cognitive function. Noteworthy, such circadian organization disappears in the TC of aged rats. Aging also reduces glutathione peroxidase activity and expression, and it increases lipid peroxidation, throughout a 24 h-period. An increased oxidative stress makes the cellular redox environment change into an oxidative status which alters the endogenous clock activity and disrupts the circadian organization of, at least part, of the molecular basis of the synaptic plasticity in the TC. [ABSTRACT FROM AUTHOR]

Aged rhesus monkeys, like aged humans, show declines in cognitive function. We present cognitive test data from a large sample of male and female rhesus monkeys, 34 young (aged 3.5-13.6 years) and 71 aged (aged 19.9-32.5 years at the start of cognitive testing). Monkeys were tested on spatiotemporal working memory (delayed response), visual recognition memory (delayed nonmatching to sample), and stimulus-reward association learning (object discrimination), tasks with an extensive evidence base in nonhuman primate neuropsychology. On average, aged monkeys performed worse than young on all 3 tasks. Acquisition of delayed response and delayed nonmatching to sample was more variable in aged monkeys than in young. Performance scores on delayed nonmatching to sample and object discrimination were associated with each other, but neither was associated with performance on delayed response. Sex and chronological age were not reliable predictors of individual differences in cognitive outcome among the aged monkeys. These data establish population norms for multiple cognitive tests in young and aged rhesus monkeys in the largest sample reported to date. They also illustrate independence of cognitive aging in task domains dependent on the prefrontal cortex and medial temporal lobe.

Recent psychology and neuroscience studies have used tactile stimuli in patients, concluding after their experiments that touch is a sense tightly linked to emotions. In parallel, a new way of seeing films, 4D cinema, has added new stimuli to the traditional audiovisual via, including the tactile vibration. In this work, we have studied the brain activity of audience while viewing a scene filmed and directed by us and with an emotional content, under two different conditions: 1) image + sound, 2) image + sound + vibro-tactile stimulation. We have designed a glove where pulse trains are generated in coin motors at specific moments and recorded 35 viewers' electroencephalograms (EEGs) to evaluate the impact of the vibro-tactile stimulation during the film projection. Hotelling's T-squared results show higher brain intensity if the tactile stimulus is received during the viewing than if no tactile stimulus is injected. Condition 1 participants showed activation in left and right orbitofrontal areas, whereas Condition 2 they also showed activities in right superior frontal and right-medial frontal areas. We conclude that the addition of vibrotactile stimulus increases the brain activity in areas linked with attentional processes, while producing a higher intensity in those related to emotional processes. [ABSTRACT FROM AUTHOR]

• Mediterranean diet is associated with lower expression of proinflammatory pathways. • Mediterranean diet is associated with higher expression of neuroprotective pathways. • Mediterranean diets may confer protection against peripheral & central inflammation. • Mediterranean diet may help to preserve brain structure and socioemotional behavior. • Nonhuman primates are useful models for studying diet effects on the body & brain. Mediterranean diets may be neuroprotective and prevent cognitive decline relative to Western diets; however, the underlying biology is poorly understood. We assessed the effects of Western versus Mediterranean-like diets on RNAseq-generated transcriptional profiles in lateral temporal cortex and their relationships with longitudinal changes in neuroanatomy, circulating monocyte gene expression, and observations of social isolation and anxiety in 38 socially-housed, middle-aged female cynomolgus macaques (Macaca fascicularis). Diet resulted in differential expression of seven transcripts (FDR < 0.05). Cyclin dependent kinase 14 (CDK14), a proinflammatory regulator, was lower in the Mediterranean group. The remaining six transcripts [i.e., "lunatic fringe" (LFNG), mannose receptor C type 2 (MRC2), solute carrier family 3 member 2 (SLCA32), butyrophilin subfamily 2 member A1 (BTN2A1), katanin regulatory subunit B1 (KATNB1), and transmembrane protein 268 (TMEM268)] were higher in cortex of the Mediterranean group and generally associated with anti-inflammatory/neuroprotective pathways. KATNB1 encodes a subcomponent of katanin, important in maintaining microtubule homeostasis. BTN2A1 is involved in immunomodulation of γδ T-cells which have anti-neuroinflammatory and neuroprotective effects. CDK14 , LFNG , MRC2, and SLCA32 are associated with inflammatory pathways. The latter four differentially expressed cortex transcripts were associated with peripheral monocyte transcript levels, neuroanatomical changes determined by MRI, and with social isolation and anxiety. These results provide important insights into the potential mechanistic processes linking diet, peripheral and central inflammation, and behavior. Collectively, our results provide evidence that, relative to Western diets, Mediterranean diets confer protection against peripheral and central inflammation which is reflected in preserved brain structure and socioemotional behavior. Ultimately, such protective effects may confer resilience to the development of neuropathology and associated disease. [ABSTRACT FROM AUTHOR]

Noninvasive brain stimulation (NIBS) techniques, including transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS), are emerging as promising tools for enhancing cognitive functions by modulating brain activity and enhancing cognitive functions. Despite their potential, the specific and combined effects of tDCS and tRNS on brain functions, especially regarding functional connectivity, cortical inhibition, and memory performance, are not well-understood. This study aims to explore the distinct and combined impacts of tDCS and tRNS on these neural and cognitive parameters. Using a within-subject design, ten participants underwent four stimulation conditions: sham, tDCS, tRNS, and combined tDCS + tRNS. We assessed the impact on resting-state functional connectivity, cortical inhibition via Cortical Silent Period (CSP), and visuospatial memory performance using the Corsi Block-tapping Test (CBT). Our results indicate that while tDCS appears to induce brain lateralization, tRNS has more generalized and dispersive effects. Interestingly, the combined application of tDCS and tRNS did not amplify these effects but rather suggested a non-synergistic interaction, possibly due to divergent mechanistic pathways, as observed across fMRI, CSP, and CBT measures. These findings illuminate the complex interplay between tDCS and tRNS, highlighting their non-additive effects when used concurrently and underscoring the necessity for further research to optimize their application for cognitive enhancement. [ABSTRACT FROM AUTHOR]

This study aimed to delineate the association between menopausal-related symptoms and brain cortical hemodynamics in peri-postmenopause women. Cross-sectional data from a total of 358 Han-Chinese women who visited the Menopause Clinic in the Shanghai Sixth People's Hospital from August 2019 to August 2022. Menopausal-related symptoms were analyzed through Kupperman index (KMI) scale and PSQI scale, while cerebral blood flow was measured using a functional near-infrared spectroscopy (fNIRS). Multiple linear regression model was used to assess the risk factors for subregions of brain hemodynamic response. After adjusting for confounding factors, we identified that menopausal symptom (B = −1.575, 95 % CI (−2.661, −0.488), p = 0.005) and duration of menopause (B = −14.583, 95 % CI (−26.753, −4.192), p = 0.007) were independently associated with the lower brain hemodynamic response in the prefrontal lobe, while in the temporal lobe, overweight (BMI ≥ 24 kg/m2) was negatively associated with the lower brain cortical activity (B = −36.882, 95 % CI (−72.708, −1.056), p = 0.044) after adjusting for other confounding variables. Our findings proposed that menopausal symptom and overweight should be attached great importance to the postmenopausal women, which provides clinical evidence for the feasible early detection and effective prevention such as menopausal hormone therapy (MHT) of brain health in postmenopausal women. • Duration of menopause showed decreasing activation in the prefrontal and temporal region in a graded fashion. • Menopausal symptoms and menopause predicted the independent risk factors for lower hemodynamics response in prefrontal lobe. • Obesity (BMI ≥ 24kg/m2) was identified as the risk factor for lower hemodynamics response in the temporal cortex. [ABSTRACT FROM AUTHOR]

Objective is to investigate whether MDD patients exhibit specific real-time responses to IA stimulation in these brain regions. The findings from this study will provide clinical data and a possible theoretical basis for the assumption that stimulation of IA may treat MDD by modulating the relevant brain regions.Trial Registration: The study protocol has been registered in the clinicaltrials.gov with the code NCT05707299. [ABSTRACT FROM AUTHOR]

Aged rhesus monkeys, like aged humans, show declines in cognitive function. We present cognitive test data from a large sample of male and female rhesus monkeys, 34 young (aged 3.5–13.6 years) and 71 aged (aged 19.9–32.5 years at the start of cognitive testing). Monkeys were tested on spatiotemporal working memory (delayed response), visual recognition memory (delayed nonmatching to sample), and stimulus-reward association learning (object discrimination), tasks with an extensive evidence base in nonhuman primate neuropsychology. On average, aged monkeys performed worse than young on all 3 tasks. Acquisition of delayed response and delayed nonmatching to sample was more variable in aged monkeys than in young. Performance scores on delayed nonmatching to sample and object discrimination were associated with each other, but neither was associated with performance on delayed response. Sex and chronological age were not reliable predictors of individual differences in cognitive outcome among the aged monkeys. These data establish population norms for multiple cognitive tests in young and aged rhesus monkeys in the largest sample reported to date. They also illustrate independence of cognitive aging in task domains dependent on the prefrontal cortex and medial temporal lobe. [ABSTRACT FROM AUTHOR]

Abstract Characterization of inter-regional interactions in brain is essential for understanding the mechanism relevant to normal brain function and neurological disease. The recently developed flexible micro (μ)-electrocorticography (μECoG) device is one prominent method used to examine large-scale cortical activity across multiple regions. The sheet-shaped μECoG electrodes arrays can be placed on a relatively wide area of cortical surface beneath the skull by inserting the device into the space between skull and brain. Although rats and mice are useful tools for neuroscience, current μECoG recording methods in these animals are limited to the parietal region of cerebral cortex. Recording cortical activity from the temporal region of cortex in mice has proven difficult because of surgical barriers created by the skull and surrounding temporalis muscle anatomy. Here, we developed a sheet-shaped 64-channel μECoG device that allows access to the mouse temporal cortex, and we determined the factor determining the appropriate bending stiffness for the μECoG electrode array. We also established a surgical technique to implant the electrode arrays into the epidural space over a wide area of cerebral cortex covering from the barrel field to olfactory (piriform) cortex, which is the deepest region of the cerebral cortex. Using histology and computed tomography (CT) images, we confirmed that the tip of the μECoG device reached to the most ventral part of cerebral cortex without causing noticeable damage to the brain surface. Moreover, the device simultaneously recorded somatosensory and odor stimulus-evoked neural activity from dorsal and ventral parts of cerebral cortex in awake and anesthetized mice. These data indicate that our μECoG device and surgical techniques enable the recording of large-scale cortical activity from the parietal to temporal cortex in mice, including somatosensory and olfactory cortices. This system will provide more opportunities for the investigation of physiological functions from wider areas of the mouse cerebral cortex than those currently available with existing ECoG techniques.

Changes to the environmental landscapes from the Eocene to Holocene have influenced the evolution of Cercopithecoidea from arboreal origins in wet, forested regions in the Early Oligocene Fayum to semi-terrestrial lifestyles in drier Neogene landscapes and social systems of larger group living. These eco-behavioural transitions likely accompanied changes in behaviour, brain function, and associated skull morphology. The temporal lobe of the brain, an association cortex, is in close proximity to the middle cranial fossa (MCF) allowing prediction of temporal lobe volume (TLV) and investigation of cerebral reorganisation. We used micro-computed tomography (µCT) cranial scans (n = 135) generated into 3D virtual crania with seven MCF metrics predicting TLV from a multiple regression of 11 extant anthropoid taxa. We studied eight extinct taxa Proteopithecus sylviae and Catopithecus browni from the Late Eocene, Early Oligocene Apidium phiomense, Parapithecus grangeri and Aegyptopithecus zeuxis, Middle Miocene Victoriapithecus macinnesi, Pliocene Dinopithecus ingens, Pleistocene Papio angusticeps, and extant cercopithecines Cercocebus atys, Macaca mulatta and Papio anubis. PGLS regressions examined relative TLV to brain size between extinct and extant taxa. We tested differences in slopes and intercepts between extinct and extant cercopithecoids with statistically significant differences in slopes but not the intercepts, with stem-anthropoids having relative smaller TLV for brain size compared to extant cercopithecoids. Potential drivers for temporal lobe evolution include paleoenvironmental shifts from Eocene tropical rainforests to Plio-Pleistocene savannas. Socio-behavioural implications include change from arboreal to semi-terrestrial lifestyles, higher visual acuity, larger group sizes and greater cognitive complexity. [ABSTRACT FROM AUTHOR]

Visual processing in the brain has been understood as the ventral and dorsal pathways processing "what" and "where" information, respectively. Mocz et al. (Mocz V, Vaziri-Pashkam M, Chun M, Xu Y. J Cogn Neurosci 34: 2406-2435, 2022), however, report that the two pathways code object features in a parallel manner. These results support that information processing in the dorsal pathway is not strictly limited to "where" and that the two pathways work in parallel to process task-relevant information ("what we do with it"). [ABSTRACT FROM AUTHOR]

Background: Patients with schizophrenia show abnormal spontaneous oscillatory activity in scalp-level electroencephalographic (EEG) responses across multiple frequency bands. While oscillations play an essential role in the transmission of information across neural networks, few studies have assessed the frequency-specific dynamics across cortical source networks at rest. Identification of the neural sources and their dynamic interactions may improve our understanding of core pathophysiologic abnormalities associated with the neuropsychiatric disorders. Methods: A novel multivector autoregressive modeling approach for assessing effective connectivity among cortical sources was developed and applied to resting-state EEG recordings obtained from n = 139 schizophrenia patients and n = 126 healthy comparison subjects. Results: Two primary abnormalities in resting-state networks were detected in schizophrenia patients. The first network involved the middle frontal and fusiform gyri and a region near the calcarine sulcus. The second network involved the cingulate gyrus and the Rolandic operculum (a region that includes the auditory cortex). Conclusions: Schizophrenia patients show widespread patterns of hyper-connectivity across a distributed network of the frontal, temporal, and occipital brain regions. Results highlight a novel approach for characterizing alterations in connectivity in the neuropsychiatric patient populations. Further mechanistic characterization of network functioning is needed to clarify the pathophysiology of neuropsychiatric and neurological diseases.

Aim: The functions of the interlaminar astrocytes in layer I of the human cortex are currently unknown. Here, we aimed to explore whether there is any morphological remodelling of interlaminar astrocytes in layer I of the temporal cortex in epilepsy. Methods: Tissues were obtained from 17 epilepsy surgery patients and 17 post‐mortem age‐matched controls. In addition, 10 Alzheimer's disease (AD) patients and 10 age‐matched controls were used as the disease control group. Paraffin sections (6 μm) and frozen sections (35 or 150 μm) of inferior temporal gyrus tissue were used for immunohistochemistry. With the use of tissue transparency, 3D reconstruction and hierarchical clustering, we performed a quantitative morphological analysis of astrocytes. Results: Upper and lower zones were identified in layer I of the human cortex. Compared with the astrocytes in layers IV–V, layer I interlaminar astrocytes occupied a significantly smaller volume and exhibited shorter and fewer process intersections. Increased Chaslin's gliosis (consisting of types I and II subpial interlaminar astrocytes) and number of glial fibrillary acidic protein (GFAP)‐immunoreactive interlaminar astrocytes in layer I of the temporal cortex were confirmed in patients with epilepsy. There was no difference in the number of interlaminar astrocytes in layer I between AD and age‐matched control groups. Using tissue transparency and 3D reconstruction technology, the astrocyte domain in the human temporal cortex was classified into four clusters, among which the interlaminar astrocytes in cluster II were more abundant in epilepsy, showing specific topological structures in patients with epilepsy. Furthermore, there was a significant increase in the astrocyte domain of interlaminar cells in layer I of the temporal cortex in patients with epilepsy. Conclusion: The observed significant astrocytic structural remodelling in the temporal cortex of epilepsy patients showed that the astrocyte domain in layer I may play an important role in temporal lobe epilepsy. [ABSTRACT FROM AUTHOR]

Characterization of inter-regional interactions in brain is essential for understanding the mechanism relevant to normal brain function and neurological disease. The recently developed flexible micro (μ)-electrocorticography (μECoG) device is one prominent method used to examine large-scale cortical activity across multiple regions. The sheet-shaped μECoG electrodes arrays can be placed on a relatively wide area of cortical surface beneath the skull by inserting the device into the space between skull and brain. Although rats and mice are useful tools for neuroscience, current μECoG recording methods in these animals are limited to the parietal region of cerebral cortex. Recording cortical activity from the temporal region of cortex in mice has proven difficult because of surgical barriers created by the skull and surrounding temporalis muscle anatomy. Here, we developed a sheet-shaped 64-channel μECoG device that allows access to the mouse temporal cortex, and we determined the factor determining the appropriate bending stiffness for the μECoG electrode array. We also established a surgical technique to implant the electrode arrays into the epidural space over a wide area of cerebral cortex covering from the barrel field to olfactory (piriform) cortex, which is the deepest region of the cerebral cortex. Using histology and computed tomography (CT) images, we confirmed that the tip of the μECoG device reached to the most ventral part of cerebral cortex without causing noticeable damage to the brain surface. Moreover, the device simultaneously recorded somatosensory and odor stimulus-evoked neural activity from dorsal and ventral parts of cerebral cortex in awake and anesthetized mice. These data indicate that our μECoG device and surgical techniques enable the recording of large-scale cortical activity from the parietal to temporal cortex in mice, including somatosensory and olfactory cortices. This system will provide more opportunities for the investigation of physiological functions from wider areas of the mouse cerebral cortex than those currently available with existing ECoG techniques. [ABSTRACT FROM AUTHOR]

Objectives: Two decades ago, Rilling and Seligman, hereafter abbreviated to RAS Study, suggested modern humans had relatively larger temporal lobes for brain size compared to other anthropoids. Despite many subsequent studies drawing conclusions about the evolutionary implications for the emergence of unique cerebral specializations in Homo sapiens, no re‐assessment has occurred using updated methodologies. Methods: We reassessed the association between right temporal lobe volume (TLV) and right hemisphere volume (HV) in the anthropoid brain. In a sample compiled de novo by us, T1‐weighted in vivo Magnetic Resonance Imaging (MRI) scans of 11 extant anthropoid species were calculated by‐voxel from the MRI and the raw data from RAS Study directly compared to our sample. Phylogenetic Generalized Least‐Squares (PGLS) regression and trait‐mapping using Blomberg's K (kappa) tested the correlation between HV and TLV accounting for anthropoid phylogeny, while bootstrapped PGLS regressions tested difference in slopes and intercepts between monkey and ape subsamples. Results: PGLS regressions indicated statistically significant correlations (r2 < 0.99; p ≤ 0.0001) between TLV and HV with moderate influence from phylogeny (K ≤ 0.42). Bootstrapped PGLS regression did not show statistically significant differences in slopes between monkeys and apes but did for intercepts. In our sample, human TLV was not larger than expected for anthropoids. Discussion: Updated imaging, increased sample size and advanced statistical analyses did not find statistically significant results that modern humans possessed a disproportionately large temporal lobe volume compared to the general anthropoid trend. This has important implications for human and non‐human primate brain evolution. [ABSTRACT FROM AUTHOR]

Predictive coding (PC) has been suggested as one of the main mechanisms used by brains to interact with complex environments. PC theories posit top-down prediction signals, which are compared with actual outcomes, yielding in turn prediction error (PE) signals, which are used, bottom-up, to modify the ensuing predictions. However, disentangling prediction from PE signals has been challenging. Critically, while many studies found indirect evidence for PC in the form of PE signals, direct evidence for the prediction signal is mostly lacking. Here, we provide clear evidence, obtained from intracranial cortical recordings in human surgical patients, that the human lateral prefrontal cortex evinces prediction signals while anticipating an event. Patients listened to task-irrelevant sequences of repetitive tones including infrequent predictable or unpredictable pitch deviants. The broadband high-frequency amplitude (HFA) was decreased prior to the onset of expected relative to unexpected deviants in the frontal cortex only, and its amplitude was sensitive to the increasing likelihood of deviants following longer trains of standards in the unpredictable condition. Single-trial HFA predicted deviations and correlated with poststimulus response to deviations. These results provide direct evidence for frontal cortex prediction signals independent of PE signals.

Background: Driving cessation is a major negative life event that has been associated with a decline in health conditions including dementia. The increase in activity owing to the expansion of life space is a possible explanation for the positive relationship between driving and brain health. The present study examined the association between driving, life space, and structural brain volume in older individuals. Methods: High-resolution magnetic resonance imaging was employed to examine the brain volume in 1063 older adults. Participants were classified as non-drivers, those who drove

IntroductionComparative transcriptome analyses in Alzheimer's disease (AD) and other neurodegenerative proteinopathies can uncover both shared and distinct disease pathways.MethodsWe analyzed 940 brain transcriptomes including patients with AD, progressive supranuclear palsy (PSP; a primary tauopathy), and control subjects.ResultsWe identified transcriptional coexpression networks implicated in myelination, which were lower in PSP temporal cortex (TCX) compared with AD. Some of these associations were retained even after adjustments for brain cell population changes. These TCX myelination network structures were preserved in cerebellum but they were not differentially expressed in cerebellum between AD and PSP. Myelination networks were downregulated in both AD and PSP, when compared with control TCX samples.DiscussionDownregulation of myelination networks may underlie both PSP and AD pathophysiology, but may be more pronounced in PSP. These data also highlight conservation of transcriptional networks across brain regions and the influence of cell type changes on these networks.

Background: Mental disorders linked with dysfunction in the temporal cortex, such as anxiety and depression, can increase the morbidity and mortality of people living with HIV (PLWHA). Expressions of both nucleobindin 1 (NUCB1) and cannabinoid receptor 1 (CNR1) in the neurons have been found to alter in patients with depressive disorder, but whether it is involved in the development of depression in the context of HIV infection is unknown. Objectives To investigate the effects of NUCB1 on depressive disorder among PLWHA and preliminarily explore the underlying molecular mechanisms. Methods: Individuals who were newly HIV diagnosed were assessed on the Hospital Anxiety and Depression scale (HADS). Then SHIV-infected rhesus monkeys were used to investigate the possible involvement of the NUCB1 and the CNR1 protein in depression-like behavior. Results: The prevalence rate of depression among PLWHA was 27.33% (41/150). The mechanism results showing elevated NUCB1 levels in cerebrospinal fluid from HIV-infected patients suffering from depression were confirmed compared to those of HIV-infected patients. Moreover, the immunohistochemical analysis indicated the expression of NUCB1 in the temporal cortex neurons of SHIV-infected monkeys was higher than that of the healthy control. Conversely, CNR1 expression was down-regulated at protein levels. Conclusions: Depression symptoms are common among PLWHA and associate with NUCB1 expression increases, and NUCB1 may be a potential target for depression. [ABSTRACT FROM AUTHOR]

Catchy utterances, such as proverbs, verses, and nursery rhymes (i.e., "No pain, no gain" in English), contain strong-prosodic (SP) features and are child-friendly in repeating and memorizing; yet the way those prosodic features encoded by neural activity and their influence on speech development in children are still largely unknown. Using functional near-infrared spectroscopy (fNIRS), this study investigated the cortical responses to the perception of natural speech sentences with strong/weak-prosodic (SP/WP) features and evaluated the speech communication ability in 21 pre-lingually deaf children with cochlear implantation (CI) and 25 normal hearing (NH) children. A comprehensive evaluation of speech communication ability was conducted on all the participants to explore the potential correlations between neural activities and children's speech development. The SP information evoked right-lateralized cortical responses across a broad brain network in NH children and facilitated the early integration of linguistic information, highlighting children's neural sensitivity to natural SP sentences. In contrast, children with CI showed significantly weaker cortical activation and characteristic deficits in speech perception with SP features, suggesting hearing loss at the early age of life, causing significantly impaired sensitivity to prosodic features of sentences. Importantly, the level of neural sensitivity to SP sentences was significantly related to the speech behaviors of all children participants. These findings demonstrate the significance of speech prosodic features in children's speech development. [ABSTRACT FROM AUTHOR]

The neural processing of speech and music is still a matter of debate. A long tradition that assumes shared processing capacities for the two domains contrasts with views that assume domain-specific processing. We here contribute to this topic by investigating, in a functional magnetic imaging (fMRI) study, ecologically valid stimuli that are identical in wording and differ only in that one group is typically spoken (or silently read), whereas the other is sung: poems and their respective musical settings. We focus on the melodic properties of spoken poems and their sung musical counterparts by looking at proportions of significant autocorrelations (PSA) based on pitch values extracted from their recordings. Following earlier studies, we assumed a bias of poem-processing towards the left and a bias for song-processing on the right hemisphere. Furthermore, PSA values of poems and songs were expected to explain variance in left- vs. right-temporal brain areas, while continuous liking ratings obtained in the scanner should modulate activity in the reward network. Overall, poem processing compared to song processing relied on left temporal regions, including the superior temporal gyrus, whereas song processing compared to poem processing recruited more right temporal areas, including Heschl's gyrus and the superior temporal gyrus. PSA values co-varied with activation in bilateral temporal regions for poems, and in right-dominant fronto-temporal regions for songs. Continuous liking ratings were correlated with activity in the default mode network for both poems and songs. The pattern of results suggests that the neural processing of poems and their musical settings is based on their melodic properties, supported by bilateral temporal auditory areas and an additional right fronto-temporal network known to be implicated in the processing of melodies in songs. These findings take a middle ground in providing evidence for specific processing circuits for speech and music in the left and right hemisphere, but simultaneously for shared processing of melodic aspects of both poems and their musical settings in the right temporal cortex. Thus, we demonstrate the neurobiological plausibility of assuming the importance of melodic properties in spoken and sung aesthetic language alike, along with the involvement of the default mode network in the aesthetic appreciation of these properties.

Abstract Background The human brain is the most complex organ in the body, and it is important to have a better understanding of how the protein composition in the brain regions contributes to the pathogenesis of associated neurological disorders. Methods In this study, a comparative analysis of the frontal and temporal cortex proteomes was conducted by isobaric tags of relative and absolute quantification (iTRAQ) labeling and two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS). Brain protein was taken from relatively normal tissue that could not be avoided of damage during emergent surgery of the TBI (traumatic brain injury) patients admitted in Beijing Tiantan Hospital from 2014 to 2017. Eight cases were included. Four frontal lobes and 4 temporal lobes proteome were analyzed and the proteins were quantitated. Gene Ontology (GO), Ingenuity Pathway Analysis (IPA), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to analyze the biological function of identified proteins, unchanged proteins, and differentially expressed proteins (DEPs). Results A total number of 2127 protein groups were identified in the frontal and temporal lobe proteomes. A total of 1709 proteins could be quantitated in both the frontal and temporal cortex. Among 90 DEPs, 14 proteins were screened highly expressed in the temporal cortex, including MAPT, SNCG, ATP5IF1, GAP43, HSPE1, STMN1, NDUFS6, LDHB, SNCB, NDUFA7, MRPS36, EPDR1, CISD1, and RALA. In addition, compared to proteins expressed in the frontal cortex, 14 proteins including EDC4, NIT2, VWF, ASTN1, TGM2, SSB, CLU, HBA1, STOM, CRP, LRG1, SAA2, S100A4, and VTN were a low expression in the temporal cortex. The biological process enrichment showed that unchanged proteins between the frontal and temporal cortex mainly take part in regulated exocytosis, axon guidance, and vesicle-mediated transport. The KEGG pathway analysis showed that unchanged proteins between the frontal and temporal cortex mainly take part in oxidative phosphorylation, carbon metabolism, Huntington’s disease, and Parkinson’s disease. Conclusions The majority of proteins are unchanged between the frontal and temporal cortex, and unchanged proteins are closely related to its function. Among DEPs, MATP (tau) is upregulated in the temporal cortex, closely related to Alzheimer’s disease (AD), and is one of the targets for the treatment of AD. CLU is downregulated in the temporal cortex which functions as an extracellular chaperone that prevents aggregation of non-native proteins. It was suggested that the temporal lobe may not be the “functional dumb area” of the traditional view, but could be involved in important neural metabolic circuits.

Large-scale analysis of single-cell gene expression has revealed transcriptomically defined cell subclasses present throughout the primate neocortex with gene expression profiles that differ depending upon neocortical region. Here, we test whether the interareal differences in gene expression translate to regional specializations in the physiology and morphology of infragranular glutamatergic neurons by performing Patch-seq experiments in brain slices from the temporal cortex (TCx) and motor cortex (MCx) of the macaque. We confirm that transcriptomically defined extratelencephalically projecting neurons of layer 5 (L5 ET neurons) include retrogradely labeled corticospinal neurons in the MCx and find multiple physiological properties and ion channel genes that distinguish L5 ET from non-ET neurons in both areas. Additionally, while infragranular ET and non-ET neurons retain distinct neuronal properties across multiple regions, there are regional morpho-electric and gene expression specializations in the L5 ET subclass, providing mechanistic insights into the specialized functional architecture of the primate neocortex. [Display omitted] • Transcriptomically defined L5 ET neurons project subcerebrally in macaques • Ion channel gene expression differentiates neuronal subclasses and neocortical areas • L5 ET versus non-ET neuron physiological differences are conserved across regions • Many cross-areal differences in L5 ET morpho-electric properties exist in macaques Using Patch-seq recordings of macaque infragranular pyramidal neurons, including retrogradely labeled corticospinal neurons, Dembrow et al. identify cell-type and areal differences in gene expression, morphology, and physiology. These data demonstrate that regional specializations in function and cytoarchitecture are accompanied by differences in the intrinsic properties of discrete cell types. [ABSTRACT FROM AUTHOR]

Response inhibition is a primary executive control function that allows the withholding of inappropriate responses, and requires appropriate perception of the external environment to achieve a behavioral goal. It remains unclear, however, how response inhibition is achieved when goal-relevant information involves perceptual uncertainty. Twenty-six human participants of both sexes performed a go/no-go task where visually presented random-dot motion stimuli involved perceptual uncertainties. The right inferior frontal cortex (rIFC) was involved in response inhibition, and the middle temporal (MT) region showed greater activity when dot motions involved less uncertainty. A neocortical temporal region in the superior temporal sulcus (STS) specifically showed greater activity during response inhibition in more perceptually certain trials. In this STS region, activity was greater when response inhibition was successful than when it failed. Directional effective connectivity analysis revealed that, in more coherent trials, the MT and STS regions showed enhanced connectivity to the rIFC, whereas in less coherent trials, the signal direction was reversed. These results suggest that a reversible fronto-temporal functional network guides response inhibition and perceptual decision-making under perceptual uncertainty, and in this network, perceptual information in the MT is converted to control information in the rIFC via STS, enabling achievement of response inhibition. [ABSTRACT FROM AUTHOR]

It is considered that brain ischemia can be causative connected to Alzheimer's disease. In the CA1 and CA3 regions of the hippocampus and temporal cortex, genes related to Alzheimer's disease, such as the amyloid protein precursor (APP), β-secretase (BACE1), presenilin 1 (PSEN1) and 2 (PSEN2), are deregulated by ischemia. The pattern of change in the CA1 area of the hippocampus covers all genes tested, and the changes occur at all post-ischemic times. In contrast, the pattern of gene changes in the CA3 subfield is much less intense, does not occur at all post-ischemic times, and is delayed in time post-ischemia relative to the CA1 field. Conversely, the pattern of gene alterations in the temporal cortex appears immediately after ischemia, and does not occur at all post-ischemic times and does not affect all genes. Evidence therefore suggests that various forms of dysregulation of the APP, BACE1 and PSEN1 and PSEN2 genes are associated with individual neuronal cell responses in the CA1 and CA3 areas of the hippocampus and temporal cortex with reversible cerebral ischemia. Scientific data indicate that an ischemic episode of the brain is a trigger of amyloidogenic processes. From the information provided, it appears that post-ischemic brain injury additionally activates neuronal death in the hippocampus and temporal cortex in an amyloid-dependent manner. [ABSTRACT FROM AUTHOR]

Multiple lines of evidence suggest that a deficiency of Fragile X Mental Retardation Protein (FMRP) mediates dysfunction of the metabotropic glutamate receptor subtype 5 (mGluR5) in the pathogenesis of fragile X syndrome (FXS), the most commonly known single-gene cause of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Nevertheless, animal and human studies regarding the link between FMRP and mGluR5 expression provide inconsistent or conflicting findings about the nature of those relationships. Since multiple clinical trials of glutamatergic agents in humans with FXS did not demonstrate the amelioration of the behavioral phenotype observed in animal models of FXS, we sought measure if mGluR5 expression is increased in men with FXS to form the basis for improved clinical trials. Unexpectedly marked reductions in mGluR5 expression were observed in cortical and subcortical regions in men with FXS. Reduced mGluR5 expression throughout the living brains of men with FXS provides a clue to examine FMRP and mGluR5 expression in FXS. In order to develop the findings of our previous study and to strengthen the objective tools for future clinical trials of glutamatergic agents in FXS, we sought to assess the possible value of measuring both FMRP levels and mGluR5 expression in men with FXS. We aimed to show the value of measurement of FMRP levels and mGluR5 expression for the diagnosis and treatment of individuals with FXS and related conditions. We administered 3-[18F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([18F]FPEB), a specific mGluR5 radioligand for quantitative measurements of the density and the distribution of mGluR5s, to six men with the full mutation (FM) of FXS and to one man with allele size mosaicism for FXS (FXS-M). Utilizing the seven cortical and subcortical regions affected in neurodegenerative disorders as indicator variables, adjusted linear regression of mGluR5 expression and FMRP showed that mGluR5 expression was significantly reduced in the occipital cortex and the thalamus relative to baseline (anterior cingulate cortex) if FMRP levels are held constant (F(7,47) = 6.84, p < 0.001).These findings indicate the usefulness of cerebral mGluR5 expression measured by PET with [18F]FPEB and FMRP values in men with FXS and related conditions for assessments in community facilities within a hundred-mile radius of a production center with a cyclotron. These initial results of this pilot study advance our previous study regarding the measurement of mGluR5 expression by combining both FMRP levels and mGluR5 expression as tools for meaningful clinical trials of glutamatergic agents for men with FXS. We confirm the feasibility of this protocol as a valuable tool to measure FMRP levels and mGluR5 expression in clinical trials of individuals with FXS and related conditions and to provide the foundations to apply precision medicine to tailor treatment plans to the specific needs of individuals with FXS and related conditions. [ABSTRACT FROM AUTHOR]

The energy-dense western diet significantly increases the risk of obesity, type 2 diabetes, cardiovascular episodes, stroke, and cancer. Recently more attention has been paid to the contribution of an unhealthy lifestyle on the development of central nervous system disorders. Exposure to long-lasting stress is one of the key lifestyle modifications associated with the increased prevalence of obesity and metabolic diseases. The main goal of the present study was to verify the hypothesis that exposure to chronic stress modifies alterations in the brain proteome induced by the western diet. Female adult rats were fed with the prepared chow reproducing the human western diet and/or subjected to chronic stress induced by social instability for 6 weeks. A control group of lean rats were fed with a standard diet. Being fed with the western diet resulted in an obese phenotype and induced changes in the serum metabolic parameters. The combination of the western diet and chronic stress exposure induced more profound changes in the rat cerebrocortical proteome profile than each of these factors individually. The down-regulation of proteins involved in neurotransmitter secretion (Rph3a, Snap25, Syn1) as well as in learning and memory processes (Map1a, Snap25, Tnr) were identified, while increased expression was detected for 14-3-3 protein gamma (Ywhag) engaged in the modulation of the insulin-signaling cascade in the brain. An analysis of the rat brain proteome reveals important changes that indicate that a combination of the western diet and stress exposure may lead to impairments of neuronal function and signaling. [ABSTRACT FROM AUTHOR]

Background: Deficits in cognitive functioning, including attention, memory, and executive functions, along with impairments in language production, are present in patients with bipolar disorder (BD) patients during mood phases, but also during euthymia.Verbal fluency tasks (VFTs), being able to evaluate integrity of a wide range of cognitive domains and represent, can be used to screen for these disturbances. Neuroimaging studies, including Near-InfraRed Spectroscopy (NIRS), have repeatedly showed widespread alterations in the prefrontal and temporal cortex during the performance of VFTs in BD patients. This review aims to summarize the results of NIRS studies that evaluated hemodynamic responses associated with the VFTs in prefrontal and temporal regions in BD patients.Methods: We performed a scoping review of studies evaluating VFT-induced activation in prefrontal and temporal regions in BD patients, and the relationship between NIRS data and various clinical variables.Results: 15 studies met the inclusion criteria. In BD patients, compared to healthy controls, NIRS studies showed hypoactivation of the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and anterior temporal regions. Moreover, clinical variables, such as depressive and social adaptation scores, were negatively correlated with hemodynamic responses in prefrontal and temporal regions, while a positive correlation were reported for measures of manic symptoms and impulsivity.Limitations: The heterogeneity of the studies in terms of methodology, study design and clinical characteristics of the samples limited the comparability of the findings.Conclusions: Given its non-invasiveness, good time-resolution and no need of posturalconstraint, NIRS technique could represent a useful tool for the evaluation of prefrontal and temporal haemodynamic correlates of cognitive performances in BD patients. [ABSTRACT FROM AUTHOR]

The creatine-phosphocreatine cycle serves as a crucial temporary energy buffering system in the brain, regulated by brain creatine kinase (CKB), in maintaining Adenosine triphosphate (ATP) levels. Alzheimer's disease (AD) has been linked to increased CKB oxidation and loss of its regulatory function, although specific pathological processes and affected cell types remain unclear. In our study, cerebral cortex samples from individuals with AD, dementia with Lewy bodies (DLB), and age-matched controls were analyzed using antibody-based methods to quantify CKB levels and assess alterations associated with disease processes. Two independently validated antibodies exclusively labeled astrocytes in the human cerebral cortex. Combining immunofluorescence (IF) and mass spectrometry (MS), we explored CKB availability in AD and DLB cases. IF and Western blot analysis demonstrated a loss of CKB immunoreactivity correlated with increased plaque load, severity of tau pathology, and Lewy body pathology. However, transcriptomics data and targeted MS demonstrated unaltered total CKB levels, suggesting posttranslational modifications (PTMs) affecting antibody binding. This aligns with altered efficiency at proteolytic cleavage sites indicated in the targeted MS experiment. These findings highlight that the proper function of astrocytes, understudied in the brain compared with neurons, is highly affected by PTMs. Reduction in ATP levels within astrocytes can disrupt ATP-dependent processes, such as the glutamate-glutamine cycle. As CKB and the creatine-phosphocreatine cycle are important in securing constant ATP availability, PTMs in CKB, and astrocyte dysfunction may disturb homeostasis, driving excitotoxicity in the AD brain. CKB and its activity could be promising biomarkers for monitoring early-stage energy deficits in AD., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Functional and structural studies investigating macroscopic connectivity in the human cerebral cortex suggest that high-order associative regions exhibit greater connectivity compared to primary ones. However, the synaptic organization of these brain regions remains unexplored. In the present work, we conducted volume electron microscopy to investigate the synaptic organization of the human brain obtained at autopsy. Specifically, we examined layer III of Brodmann areas 17, 3b, and 4, as representative areas of primary visual, somatosensorial, and motor cortex. Additionally, we conducted comparative analyses with our previous datasets of layer III from temporopolar and anterior cingulate associative cortical regions (Brodmann areas 24, 38, and 21). 9,690 synaptic junctions were 3D reconstructed, showing that certain synaptic characteristics are specific to particular regions. The number of synapses per volume, the proportion of the postsynaptic targets, and the synaptic size may distinguish one region from another, regardless of whether they are associative or primary cortex. By contrast, other synaptic characteristics were common to all analyzed regions, such as the proportion of excitatory and inhibitory synapses, their shapes, their spatial distribution, and a higher proportion of synapses located on dendritic spines. The present results provide further insights into the synaptic organization of the human cerebral cortex., (© The Author(s) 2024. Published by Oxford University Press.)

• Human and macaque temporal cortex share two principles of organisation. • Amongst other metrics, human's temporal cortex processing capacity is significantly larger than that of other primates; connectivity of the temporal lobe shows elaboration in particular primate lineages. • Human temporal cortex also shows a distinct organization centred around expanded arcuate fascicle projections. • Many human abilities, including semantic processing, can be interpreted as elaborations and recycling of skills present in their common ancestor with other primates. Temporal cortex is a primate specialization that shows considerable variation in size, morphology, and connectivity across species. Human temporal cortex is involved in many behaviors that are considered especially well developed in humans, including semantic processing, language, and theory of mind. Here, we ask whether the involvement of temporal cortex in these behaviors can be explained in the context of the 'general' primate organization of the temporal lobe or whether the human temporal lobe contains unique specializations indicative of a 'step change' in the lineage leading to modern humans. We propose that many human behaviors can be explained as elaborations of temporal cortex functions observed in other primates. However, changes in temporal lobe white matter suggest increased integration of information within temporal cortex and between posterior temporal cortex and other association areas, which likely enable behaviors not possible in other species. [ABSTRACT FROM AUTHOR]

Whilst functional neuroimaging has been used to investigate cortical processing of degraded speech in adults, much less is known about how these signals are processed in children. An enhanced understanding of cortical correlates of poor speech perception in children would be highly valuable to oral communication applications, including hearing devices. We utilised vocoded speech stimuli to investigate brain responses to degraded speech in 29 normally hearing children aged 6-12 years. Intelligibility of the speech stimuli was altered in two ways by (i) reducing the number of spectral channels and (ii) reducing the amplitude modulation depth of the signal. A total of five different noise-vocoded conditions (with zero, partial or high intelligibility) were presented in an event-related format whilst participants underwent functional near-infrared spectroscopy (fNIRS) neuroimaging. Participants completed a word recognition task during imaging, as well as a separate behavioural speech perception assessment. fNIRS recordings revealed statistically significant sensitivity to stimulus intelligibility across several brain regions. More intelligible stimuli elicited stronger responses in temporal regions, predominantly within the left hemisphere, while right inferior parietal regions showed an opposite, negative relationship. Although there was some evidence that partially intelligible stimuli elicited the strongest responses in the left inferior frontal cortex, a region previous studies have suggested is associated with effortful listening in adults, this effect did not reach statistical significance. These results further our understanding of cortical mechanisms underlying successful speech perception in children. Furthermore, fNIRS holds promise as a clinical technique to help assess speech intelligibility in paediatric populations. [ABSTRACT FROM AUTHOR]

Increased brain size is a characteristic of the Homo erectus hypodigm compared to early fossil hominins with changes in cerebral reorganization of evolutionary importance for the genus Homo. The close spatial proximity of the temporal lobes of the brain to the cranial base, specifically, the middle cranial fossa (MCF), provides inference of temporal lobe evolution. To date, differences in MCF proportions and relative scaling in the H. erectus hypodigm compared to extant Homo sapiens is unknown. A total sample (n = 51) of cranial Computed Tomography scans (CT) from extant H. sapiens and fossil specimens attributed to African Homo ergaster and Javanese H. erectus were generated into three-dimensional (3D) virtual models with three linear metrics digitally measured on the MCF and two metrics to approximate cranial size. Reduced Major Axis (RMA) log-log regressions and resampling with permutations determined if relative MCF scaling in the fossil sample was greater than observed among extant H. sapiens. An increase or decrease in MCF proportions in the fossil sample compared to extant H. sapiens was used to determine potential changes in temporal lobe size. There were no differences in the allometric trend of relative MCF scaling with no statistically significant differences suggesting that the fossil sample were beyond the range observed for extant H. sapiens , but the effects of the small fossil sample size could not be excluded. However, relative MCF proportions showed extant H. sapiens had a larger MCF to relative to cranial size, while specimens attributed to Javanese H. erectus which had a relatively longer and wider MCF compared to African H. ergaster. These findings indicate that despite sampling limitations, the fossil sample did not show differences in allometric scaling compared to extant H. sapiens, but these specimens attributed to Javanese H. erectus and African H. ergaster share the same total cranial size but had different MCF proportions relative to cranial size. The paleoneurological implications are that these specimens attributed to Javanese H. erectus had longer and wider temporal lobes relative to total brain size compared to African H. ergaster suggesting different patterns of cerebrocranial organization within the Homo erectus hypodigm. [ABSTRACT FROM AUTHOR]

Auditory repetition suppression and omission activation are opposite neural phenomena and manifestations of principles of predictive processing. Repetition suppression describes the temporal decrease in neural activity when a stimulus is constant or repeated in an expected temporal fashion; omission activity is the transient increase in neural activity when a stimulus is temporarily and unexpectedly absent. The temporal, repetitive nature of musical rhythms is ideal for investigating these phenomena. During an fMRI session, 10 healthy participants underwent scanning while listening to musical rhythms with two levels of metric complexity, and with beat omissions with different positional complexity. Participants first listened to 16-s-long presentations of continuous rhythms, before listening to a longer continuous presentation with beat omissions quasi-randomly introduced. We found deactivation in bilateral superior temporal gyri during the repeated presentation of the normal, unaltered rhythmic stimulus, with more suppression of activity in the left hemisphere. Omission activation of bilateral middle temporal gyri was right lateralized. Persistent activity was found in areas including the supplementary motor area, caudate nucleus, anterior insula, frontal areas, and middle and posterior cingulate cortex, not overlapping with either listening, suppression, or omission activation. This suggests that the areas are perhaps specialized for working memory maintenance. We found no effect of metric complexity for either the normal presentation or omissions, but we found evidence for a small effect of omission position—at an uncorrected threshold—where omissions in the more metrical salient position, i.e., the first position in the bar, showed higher activation in anterior cingulate/medial superior frontal gyrus, compared to omissions in the less salient position, in line with the role of the anterior cingulate cortex for saliency detection. The results are consistent with findings in our previous studies on Parkinson’s disease, but are put into a bigger theoretical frameset.

Auditory repetition suppression and omission activation are opposite neural phenomena and manifestations of principles of predictive processing. Repetition suppression describes the temporal decrease in neural activity when a stimulus is constant or repeated in an expected temporal fashion; omission activity is the transient increase in neural activity when a stimulus is temporarily and unexpectedly absent. The temporal, repetitive nature of musical rhythms is ideal for investigating these phenomena. During an fMRI session, 10 healthy participants underwent scanning while listening to musical rhythms with two levels of metric complexity, and with beat omissions with different positional complexity. Participants first listened to 16-s-long presentations of continuous rhythms, before listening to a longer continuous presentation with beat omissions quasi-randomly introduced. We found deactivation in bilateral superior temporal gyri during the repeated presentation of the normal, unaltered rhythmic stimulus, with more suppression of activity in the left hemisphere. Omission activation of bilateral middle temporal gyri was right lateralized. Persistent activity was found in areas including the supplementary motor area, caudate nucleus, anterior insula, frontal areas, and middle and posterior cingulate cortex, not overlapping with either listening, suppression, or omission activation. This suggests that the areas are perhaps specialized for working memory maintenance. We found no effect of metric complexity for either the normal presentation or omissions, but we found evidence for a small effect of omission position —at an uncorrected threshold—where omissions in the more metrical salient position, i.e., the first position in the bar, showed higher activation in anterior cingulate/medial superior frontal gyrus, compared to omissions in the less salient position, in line with the role of the anterior cingulate cortex for saliency detection. The results are consistent with findings in our previous studies on Parkinson's disease, but are put into a bigger theoretical frameset. [ABSTRACT FROM AUTHOR]

Although a crucial role of the fusiform gyrus (FG) in face processing has been demonstrated with a variety of methods, converging evidence suggests that face processing involves an interactive and overlapping processing cascade in distributed brain areas. Here we examine the spatio-temporal stages and their functional tuning to face inversion, presence and configuration of inner features, and face contour in healthy subjects during passive viewing. Anatomically-constrained magnetoencephalography (aMEG) combines high-density whole-head MEG recordings and distributed source modeling with high-resolution structural MRI. Each person's reconstructed cortical surface served to constrain noise-normalized minimum norm inverse source estimates. The earliest activity was estimated to the occipital cortex at ~100 ms after stimulus onset and was sensitive to an initial coarse level visual analysis. Activity in the right-lateralized ventral temporal area (inclusive of the FG) peaked at ~160 ms and was largest to inverted faces. Images containing facial features in the veridical and rearranged configuration irrespective of the facial outline elicited intermediate level activity. The M160 stage may provide structural representations necessary for downstream distributed areas to process identity and emotional expression. However, inverted faces additionally engaged the left ventral temporal area at ~180 ms and were uniquely subserved by bilateral processing. This observation is consistent with the dual route model and spared processing of inverted faces in prosopagnosia. The subsequent deflection, peaking at ~240 ms in the anterior temporal areas bilaterally, was largest to normal, upright faces. It may reflect initial engagement of the distributed network subserving individuation and familiarity. These results support dynamic models suggesting that processing of unfamiliar faces in the absence of a cognitive task is subserved by a distributed and interactive neural circuit.

Background: Mental disorders linked with dysfunction in the temporal cortex, such as anxiety and depression, can increase the morbidity and mortality of people living with HIV (PLWHA). Expressions of both nucleobindin 1 (NUCB1) and cannabinoid receptor 1 (CNR1) in the neurons have been found to alter in patients with depressive disorder, but whether it is involved in the development of depression in the context of HIV infection is unknown. Objectives To investigate the effects of NUCB1 on depressive disorder among PLWHA and preliminarily explore the underlying molecular mechanisms. Methods: Individuals who were newly HIV diagnosed were assessed on the Hospital Anxiety and Depression scale (HADS). Then SHIV-infected rhesus monkeys were used to investigate the possible involvement of the NUCB1 and the CNR1 protein in depression-like behavior. Results: The prevalence rate of depression among PLWHA was 27.33% (41/150). The mechanism results showing elevated NUCB1 levels in cerebrospinal fluid from HIV-infected patients suffering from depression were confirmed compared to those of HIV-infected patients. Moreover, the immunohistochemical analysis indicated the expression of NUCB1 in the temporal cortex neurons of SHIV-infected monkeys was higher than that of the healthy control. Conversely, CNR1 expression was down-regulated at protein levels. Conclusions: Depression symptoms are common among PLWHA and associate with NUCB1 expression increases, and NUCB1 may be a potential target for depression.

From the early days of life infants distinguish between social and non-social physical entities and have different expectations for the way these two entities should move and interact. At the same time, we know very little about the cortical systems that support this early emerging ability. The goal of the current research was to assess the extent to which infant’s processing of social and non-social physical entities is mediated by distinct information processing systems in the temporal cortex. Using a cross-sectional design, infants aged 6–9 months (Experiment 1) and 11–18 months (Experiment 2) were presented with two types of events: social interaction and mechanical interaction. In the social interaction event (patterned after Hamlin et al., 2007), an entity with googly eyes, hair tufts, and an implied goal of moving up the hill was either helped up, or pushed down, a hill through the actions of another social entity. In the mechanical interaction event, the googly eyes and hair tufts were replaced with vertical black dots and a hook and clasp, and the objects moved up or down the hill via mechanical interactions. FNIRS was used to measure activation from temporal cortex while infants viewed the test events. In both age groups, viewing social and mechanical interaction events elicited different patterns of activation in the right temporal cortex, although responses were more specialized in the older age group. Activation was not obtained in these areas when the objects moved in synchrony without interacting, suggesting that the causal nature of the interaction events may be responsible, in part, to the results obtained. This is one of the few fNIRS studies that has investigated age-related patterns of cortical activation and the first to provide insight into the functional development of networks specialized for processing of social and non-social physical entities engaged in interaction events.

From the early days of life infants distinguish between social and non-social physical entities and have different expectations for the way these two entities should move and interact. At the same time, we know very little about the cortical systems that support this early emerging ability. The goal of the current research was to assess the extent to which infant's processing of social and non-social physical entities is mediated by distinct information processing systems in the temporal cortex. Using a cross-sectional design, infants aged 6–9 months (Experiment 1) and 11–18 months (Experiment 2) were presented with two types of events: social interaction and mechanical interaction. In the social interaction event (patterned after Hamlin et al., 2007), an entity with googly eyes, hair tufts, and an implied goal of moving up the hill was either helped up, or pushed down, a hill through the actions of another social entity. In the mechanical interaction event, the googly eyes and hair tufts were replaced with vertical black dots and a hook and clasp, and the objects moved up or down the hill via mechanical interactions. FNIRS was used to measure activation from temporal cortex while infants viewed the test events. In both age groups, viewing social and mechanical interaction events elicited different patterns of activation in the right temporal cortex, although responses were more specialized in the older age group. Activation was not obtained in these areas when the objects moved in synchrony without interacting, suggesting that the causal nature of the interaction events may be responsible, in part, to the results obtained. This is one of the few fNIRS studies that has investigated age-related patterns of cortical activation and the first to provide insight into the functional development of networks specialized for processing of social and non-social physical entities engaged in interaction events. [ABSTRACT FROM AUTHOR]

Human object recognition is dependent on occipito-temporal cortex (OTC), but a complete understanding of the complex functional architecture of this area must account for how it is connected to the wider brain. Converging functional magnetic resonance imaging evidence shows that univariate responses to different categories of information (e.g., faces, bodies, and nonhuman objects) are strongly related to, and potentially shaped by, functional and structural connectivity to the wider brain. However, to date, there have been no systematic attempts to determine how distal connectivity and complex local high-level responses in occipito-temporal cortex (i.e., multivoxel response patterns) are related. Here, we show that distal functional connectivity is related to, and can reliably index, high-level representations for several visual categories (i.e., tools, faces, and places) within occipito-temporal cortex; that is, voxel sets that are strongly connected to distal brain areas show higher pattern discriminability than less well-connected sets do. We further show that in several cases, pattern discriminability is higher in sets of well-connected voxels than sets defined by local activation (e.g., strong amplitude responses to faces in fusiform face area). Together, these findings demonstrate the important relationship between the complex functional organization of occipito-temporal cortex and wider brain connectivity. [ABSTRACT FROM AUTHOR]

Noninvasive brain stimulation (NIBS) techniques, including transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS), are emerging as promising tools for enhancing cognitive functions by modulating brain activity and enhancing cognitive functions. Despite their potential, the specific and combined effects of tDCS and tRNS on brain functions, especially regarding functional connectivity, cortical inhibition, and memory performance, are not well-understood. This study aims to explore the distinct and combined impacts of tDCS and tRNS on these neural and cognitive parameters. Using a within-subject design, ten participants underwent four stimulation conditions: sham, tDCS, tRNS, and combined tDCS + tRNS. We assessed the impact on resting-state functional connectivity, cortical inhibition via Cortical Silent Period (CSP), and visuospatial memory performance using the Corsi Block-tapping Test (CBT). Our results indicate that while tDCS appears to induce brain lateralization, tRNS has more generalized and dispersive effects. Interestingly, the combined application of tDCS and tRNS did not amplify these effects but rather suggested a non-synergistic interaction, possibly due to divergent mechanistic pathways, as observed across fMRI, CSP, and CBT measures. These findings illuminate the complex interplay between tDCS and tRNS, highlighting their non-additive effects when used concurrently and underscoring the necessity for further research to optimize their application for cognitive enhancement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wu, Huang, Lee, Chang, Wang and Lin.)