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Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimers disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We conducted kinetic analyses of γ-secretase activity in cell-free systems in the presence of Aβ, as well as cell-based and ex vivo assays in neuronal cell lines, neurons, and brain synaptosomes to assess the impact of Aβ on γ-secretases. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17-42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75, and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.

Brain microvessels possess the unique properties of a blood-brain barrier (BBB), tightly regulating the passage of molecules from the blood to the brain neuropil and vice versa. In models of brain injury, BBB dysfunction and the associated leakage of serum albumin to the neuropil have been shown to induce pathological plasticity, neuronal hyper-excitability, and seizures. The effect of neuronal activity on BBB function and whether it plays a role in plasticity in the healthy brain remain unclear. Here we show that neuronal activity induces modulation of microvascular permeability in the healthy brain and that it has a role in local network reorganization. Combining simultaneous electrophysiological recording and vascular imaging with transcriptomic analysis in rats, and functional and BBB-mapping MRI in human subjects, we show that prolonged stimulation of the limb induces a focal increase in BBB permeability in the corresponding somatosensory cortex that is associated with long-term synaptic plasticity. We further show that the increased microvascular permeability depends on neuronal activity and involves caveolae-mediated transcytosis and transforming growth factor β signaling. Our results reveal a role of BBB modulation in cortical plasticity in the healthy brain, highlighting the importance of neurovascular interactions for sensory experience and learning.

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.

Purpose: To review experimental peri-implantitis studies using rat models and summarize different peri-implantitis induction techniques and evaluate their effectiveness. Materials and Methods: Electronic searches were conducted by two independent examiners to address the following issues. Meta-analyses explored the marginal bone loss (MBL) of four types of peri-implantitis induction methods in rats. The detailed induction tactics--such as the implant design, implant size, surgical process, time cost, induction methods, and endpoint measurements--were summarized. Results: Of the 18 included studies, 38.9% of the studies placed implants at the maxillary first molar, and 44.4% placed them at the alveolar ridge region anterior to the maxillary first molar. As for the induction method, the numbers of published studies on ligature methods, bacterial inoculation, and bacterial lipopolysaccharide inoculation were equally high among all selected studies. The total implant survival rate at the end was 160 out of 213 implants (75.11%). Eight studies with high pooled heterogeneity (I2 = 98, P < .01) in the meta-analysis reported an overall MBL (µ-CT) of 0.47 mm (95% CI = 0.14 to 0.81). A subgroup analysis estimated an MBL of 0.31 mm (95% CI = 0.12 to 0.50) for bacterial inoculation and 0.66 mm (95% CI = 0.07 to 1.26) for the ligature method. Histopathologic analysis revealed that peri-implantitis in rats was similar to peri-implantitis lesions in humans. Conclusions: Implant placement at the maxillary first molar with bacterial inoculation and the silk ligature method to build peri-implantitis rat models is reliable to use for research on peri-implantitis. [ABSTRACT FROM AUTHOR]

This study aimed to assess the antioxidant capacity of lemon flavonoid extract Eriomin® (LE) and its impact on cholesterol metabolism in the context of healthy aging. We orally treated 24-month-old male Wistar rats with an LE (40 mg/kg) suspended in 0.3 mL of sunflower oil. At the same time, control groups received an equal volume of sunflower oil (CON) or remained untreated (ICON) daily for 4 weeks. We examined LEs effects on superoxide dismutase and catalase- and glutathione-related enzyme activities, the concentration of lipid peroxides and protein carbonyls, total oxidant status (TOS) and antioxidant status (TAS), and oxidative stress index (OSI) in the liver, jejunum, and ileum. We also measured total cholesterol, its biosynthetic precursors (lanosterol, lathosterol, desmosterol), its degradation products (bile acid precursors) in the serum, liver, jejunum, and ileum, and serum phytosterols (intestinal absorption markers). LE reduced TOS, TAS, and OSI (p < 0.05) compared with control values, indicating its consistent antioxidant action in all examined organs. LE lowered hepatic desmosterol (p < 0.05) while also reducing 7α- and 24-hydroxycholesterol levels in the liver and ileum (p < 0.01). Serum cholesterol, hepatic gene expression, and the immunostaining intensity of CYP7A1 were unchanged. In conclusion, LE exerted non-enzymatic antioxidant effects and reduced cholesterol degradation, reducing its biosynthesis products, thereby maintaining serum cholesterol levels.

The seventh iteration of the reference genome assembly for Rattus norvegicus-mRatBN7.2-corrects numerous misplaced segments and reduces base-level errors by approximately 9-fold and increases contiguity by 290-fold compared with its predecessor. Gene annotations are now more complete, improving the mapping precision of genomic, transcriptomic, and proteomics datasets. We jointly analyzed 163 short-read whole-genome sequencing datasets representing 120 laboratory rat strains and substrains using mRatBN7.2. We defined ∼20.0 million sequence variations, of which 18,700 are predicted to potentially impact the function of 6,677 genes. We also generated a new rat genetic map from 1,893 heterogeneous stock rats and annotated transcription start sites and alternative polyadenylation sites. The mRatBN7.2 assembly, along with the extensive analysis of genomic variations among rat strains, enhances our understanding of the rat genome, providing researchers with an expanded resource for studies involving rats.

Alcohol Use Disorder (AUD) is a chronic relapsing disorder affecting an estimated 283 million individuals worldwide, with substantial health and economic consequences. Peroxisome proliferator-activated receptors (PPARs), particularly PPAR-α and PPAR-γ, have shown promise in preclinical studies as potential therapeutic targets for AUD. In this human laboratory study, we aimed to translate preclinical findings on the PPAR-α agonist fenofibrate to a human population with current AUD. We hypothesized that, relative to placebo, fenofibrate at the highest FDA-approved dose of 145 mg/d would attenuate responsiveness to in vivo alcohol cues in the lab and reduce drinking under natural conditions. However, the results did not show significant differences in craving and alcohol consumption between the fenofibrate and placebo groups. Reverse translational studies in rodent models confirmed the lack of fenofibrate effect at human-equivalent doses. These findings suggest that inadequate translation of drug dose from rodents to humans may account for the lack of fenofibrate effects on alcohol craving and consumption in humans with AUD. The results highlight the need for new brain-penetrant PPAR-α agonists to adequately test the therapeutic potential of PPAR-α agonists for AUD, and the importance of reverse translational approaches and selection of human-equivalent doses in drug development.

Young blood plasma is known to confer beneficial effects on various organs in mice and rats. However, it was not known whether plasma from young adult pigs rejuvenates old rat tissues at the epigenetic level; whether it alters the epigenetic clock, which is a highly accurate molecular biomarker of aging. To address this question, we developed and validated six different epigenetic clocks for rat tissues that are based on DNA methylation values derived from n = 613 tissue samples. As indicated by their respective names, the rat pan-tissue clock can be applied to DNA methylation profiles from all rat tissues, while the rat brain, liver, and blood clocks apply to the corresponding tissue types. We also developed two epigenetic clocks that apply to both human and rat tissues by adding n = 1366 human tissue samples to the training data. We employed these six rat clocks to investigate the rejuvenation effects of a porcine plasma fraction treatment in different rat tissues. The treatment more than halved the epigenetic ages of blood, heart, and liver tissue. A less pronounced, but statistically significant, rejuvenation effect could be observed in the hypothalamus. The treatment was accompanied by progressive improvement in the function of these organs as ascertained through numerous biochemical/physiological biomarkers, behavioral responses encompassing cognitive functions. An immunoglobulin G (IgG) N-glycosylation pattern shift from pro- to anti-inflammatory also indicated reversal of glycan aging. Overall, this study demonstrates that a young porcine plasma-derived treatment markedly reverses aging in rats according to epigenetic clocks, IgG glycans, and other biomarkers of aging.

Consciousness is thought to be regulated by bidirectional information transfer between the cortex and thalamus, but the nature of this bidirectional communication - and its possible disruption in unconsciousness - remains poorly understood. Here, we present two main findings elucidating mechanisms of corticothalamic information transfer during conscious states. First, we identify a highly preserved spectral channel of cortical-thalamic communication that is present during conscious states, but which is diminished during the loss of consciousness and enhanced during psychedelic states. Specifically, we show that in humans, mice, and rats, information sent from either the cortex or thalamus via δ/θ/α waves (∼1-13 Hz) is consistently encoded by the other brain region by high γ waves (52-104 Hz); moreover, unconsciousness induced by propofol anesthesia or generalized spike-and-wave seizures diminishes this cross-frequency communication, whereas the psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) enhances this low-to-high frequency interregional communication. Second, we leverage numerical simulations and neural electrophysiology recordings from the thalamus and cortex of human patients, rats, and mice to show that these changes in cross-frequency cortical-thalamic information transfer may be mediated by excursions of low-frequency thalamocortical electrodynamics toward/away from edge-of-chaos criticality, or the phase transition from stability to chaos. Overall, our findings link thalamic-cortical communication to consciousness, and further offer a novel, mathematically well-defined framework to explain the disruption to thalamic-cortical information transfer during unconscious states.

Animals, including humans, rely on contextual information to interpret ambiguous stimuli. Impaired context processing is a hallmark of several neuropsychiatric disorders, including schizophrenia, autism spectrum disorders, post-traumatic stress disorder, and addiction. While sex differences in the prevalence and manifestations of these disorders are well established, potential sex differences in context processing remain uncertain. Here, we examined sex differences in the contextual control over cue-evoked reward seeking and its neural correlates, in rats. Male and female rats were trained in a bidirectional occasion-setting preparation in which the validity of two auditory reward-predictive cues was informed by the presence, or absence, of a visual contextual feature (LIGHT: X+/DARK: X-/LIGHT: Y-/DARK: Y+). Females were significantly slower to acquire contextual control over cue-evoked reward seeking. However, once established, the contextual control over behavior was more robust in female rats; it showed less within-session variability (less influence of prior reward) and greater resistance to acute stress. This superior contextual control achieved by females was accompanied by an increased activation of the orbitofrontal cortex (OFC) compared to males. Critically, these behavioral and neural sex differences were specific to the contextual modulation process and not observed in simple, context-independent, reward prediction tasks. These results indicate a sex-biased trade-off between the speed of acquisition and the robustness of performance in the contextual modulation of cued reward seeking. The different distribution of sexes along the fast learning ↔ steady performance continuum might reflect different levels of engagement of the OFC, and might have implications for our understanding of sex differences in psychiatric disorders.

Neuroaxonal dystrophy (NAD) is a neurodegenerative disease characterized by spheroid (swollen axon) formation in the nervous system. In the present study, we focused on a newly established autosomal recessive mutant strain of F344-kk/kk rats with hind limb gait abnormalities and ataxia from a young age. Histopathologically, a number of axonal spheroids were observed throughout the central nervous system, including the spinal cord (mainly in the dorsal cord), brain stem, and cerebellum in F344-kk/kk rats. Transmission electron microscopic observation of the spinal cord revealed accumulation of electron-dense bodies, degenerated abnormal mitochondria, as well as membranous or tubular structures in the axonal spheroids. Based on these neuropathological findings, F344-kk/kk rats were diagnosed with NAD. By a positional cloning approach, we identified a missense mutation (V95E) in the Hspa8 (heat shock protein family A (Hsp70) member 8) gene located on chromosome 8 of the F344-kk/kk rat genome. Furthermore, we developed the Hspa8 knock-in (KI) rats with the V95E mutation using the CRISPR-Cas system. Homozygous Hspa8-KI rats exhibited ataxia and axonal spheroids similar to those of F344-kk/kk rats. The V95E mutant HSC70 protein exhibited the significant but modest decrease in the maximum hydrolysis rate of ATPase when stimulated by co-chaperons DnaJB4 and BAG1 in vitro, which suggests the functional deficit in the V95E HSC70. Together, our findings provide the first evidence that the genetic alteration of the Hspa8 gene caused NAD in mammals.

Alcohol Use Disorder (AUD) is a significant public health issue in the United States. It affects millions of individuals and their families and contributes to substantial societal and economic burdens. Despite the availability of some pharmacological treatments, there is still a pressing need to develop more effective therapeutic strategies to address the diverse range of symptoms and challenges associated with AUD. Catechol-O-methyltransferase (COMT) inhibition recently emerged as a promising new approach to treating AUD due to its potential to improve cognitive effects commonly associated with AUD. Tolcapone, an FDA-approved COMT inhibitor, has shown some promise for treating AUD; however, its ability to decrease drinking in ethanol-dependent rats has not been well-established. In this study, we evaluated the effects of tolcapone on operant, oral ethanol self-administration in non-dependent and dependent rats, and in rats that self-administered oral saccharin. To induce dependence, rats underwent the chronic intermittent exposure to vapor model, and their drinking levels were assessed during acute withdrawal from ethanol. Our results demonstrated that tolcapone attenuated responding for ethanol in dependent rats only, without affecting self-administration in non-dependent rats or rats self-administering saccharin. Moreover, we found that tolcapone was differentially effective in different estrous phases in female rats. These findings suggest that COMT inhibition, specifically using tolcapone, may be a valuable pharmacotherapy for treating AUD, particularly in individuals who are physically dependent on alcohol. Further research is needed to elucidate the precise mechanisms underlying the observed effects and to assess the potential of COMT inhibitors in a broader population of individuals with AUD.

The transverse dimensions of internasal and nasopremaxillary sutures in rats were assessed at different ages and following different dietary functional demands.Eighty‐four male Wistar rats were divided into two groups fed either a hard or a soft diet from 4 weeks of age, and sacrificed at 4 weeks (baseline: n = 12),16 weeks (n = 24), 26 weeks (n = 24), or 38 weeks (n = 24) of age. High‐resolution micro‐computed tomograms of the internasal and left nasopremaxillary sutures were obtained with 10 µm voxel size and 5 × 5 mm field of view. The endocranial and ectocranial suture widths, the mean suture width, and the suture height were measured. Linear regression analysis was used to estimate the effects of age and type of diet on suture dimensions. Internasal and nasopremaxillary suture dimensions were influenced by age, with a generally lower width and a larger height in the older animal. Regarding diet consistency, internasal suture widths were on average larger in the hard‐diet group (e.g., mean suture width 43 µm in the hard‐ versus 30 µm in the soft‐diet group at 26 weeks). In conclusion, the internasal and nasopremaxillary sutures tend to become narrower with age, while being influenced by masticatory functional demands. [ABSTRACT FROM AUTHOR]

BACKGROUND: Acupotomy is effective in the treatment of knee osteoarthritis, but its mechanism is not very clear. OBJECTIVE: To observe the effect of acupotomy on the apoptosis of knee chondrocytes in knee osteoarthritis rats based on osteoclast associated receptor (OSCAR)-tumor necrosis factor-associated apoptosis-inducing ligand (TRAIL)-osteoprotetin (OPG) pathway. METHODS: Twenty-seven Sprague-Dawley rats were randomly divided into normal group (n=9), model group (n=9) and acupotomy group (n=9). Rats in the normal group were routinely housed without any treatment. Animal models of knee osteoarthritis were established by knee injection of papain. Acupotomy intervention was performed 1 week after modeling, once a week for a total of three times. Relevant tests were performed at the end of the intervention. RESULTS AND CONCLUSION: The Lequesne MG behavioral scores of rats in the model group were elevated compared with the normal group (P < 0.01), while the Lequesne MG behavioral scores of rats in the acupotomy group were decreased compared with the model group (P < 0.01). Hematoxylin-eosin staining results showed that compared with the normal group, the cartilage surface of the rat’s knee joints in the model group was worn and uneven and the chondrocytes were swollen, ruptured, reduced in number, and arranged disorderly; while the cartilage surface of the rat’s knee joints in the acupotomy group was relatively smooth, and the chondrocytes were high in number and arranged in an orderly manner, with the structure basically clear. Immunohistochemical staining results showed that compared with the normal group, the positive expressions of OSCAR and TRAIL were increased in the model group (P < 0.01), while the positive expression of OPG was decreased (P < 0.01). Compared with the model group, the positive expressions of OSCAR and TRAIL in the acupotomy group were decreased (P < 0.01), while the positive expression of OPG was increased (P < 0.01). TUNEL staining results showed that compared with the normal group, the number of apoptotic cells in the model group were increased (P < 0.01); compared with the model group, the number of apoptotic cells in the acupotomy group decreased (P < 0.01). RT-qRCR and western blot results showed that compared with the normal group, the protein expressions of OSCAR, TRAIL and Bax in the model group were increased (P < 0.01), and the protein expressions of OPG and Bcl-2 were decreased (P < 0.01); compared with the model group, the protein expressions of OSCAR, TRAIL, and Bax in the acupotomy group were decreased (P < 0.01), and the protein expressions of OPG and Bcl-2 were increased (P < 0.01). To conclude, acupotomy can reduce cartilage injury of the knee joint in rats with knee osteoarthritis, which may be related to the blockage of mitochondrial pathway apoptotic signaling release by the OSCAR-TRAIL-OPG pathway. [ABSTRACT FROM AUTHOR]

How consciousness is lost in states such as sleep or anesthesia remains a mystery. To gain insight into this phenomenon, concurrent recordings of electrophysiology signals in the anterior cingulate cortex and whole‐brain functional magnetic resonance imaging (fMRI) are conducted in rats exposed to graded propofol, undergoing the transition from consciousness to unconsciousness. The results reveal that upon the loss of consciousness (LOC), there is a sharp increase in low‐frequency power of the electrophysiological signal. Additionally, fMRI signals exhibit a cascade of deactivation across a pathway including the hippocampus, thalamus, and medial prefrontal cortex (mPFC) surrounding the moment of LOC, followed by a broader increase in brain activity across the cortex during sustained unconsciousness. Furthermore, sliding window analysis demonstrates a temporary increase in synchrony of fMRI signals across the hippocampus‐thalamus‐mPFC pathway preceding LOC. These data suggest that LOC may be triggered by sequential activities in the hippocampus, thalamus, and mPFC, while wide‐spread activity increases in other cortical regions commonly observed during anesthesia‐induced unconsciousness may be a consequence, rather than a cause of LOC. Taken together, the study identifies a cascade of neural events unfolding as the brain transitions into unconsciousness, offering insight into the systems‐level neural mechanisms underpinning LOC. [ABSTRACT FROM AUTHOR]

Resveratrol, which is thought to have a preventive effect on the formation of different types of cancer, is abundant in grapes and other foods. Resveratrol has been shown to have anti‐cancer effects by in vitro andin vivo studies, however this is the first time its effect on atypical acinar cell foci (AACF), known as precursor forms of pancreatic carcinoma, has been experimentally investigated. Male Sprague Dawley rats, each consisting of 5 experimental groups (Cont, AzCont, AzRes10, AzRes15, and AzRes20), 10 of which were 14 days old, were used in the study. In the azaserine groups (AzCont, AzRes10, AzRes15, and AzRes20), it was investigated how the development of Atypical Cell Foci (AACF) resulting from intraperitoneal injection (i.p.) of azaserine (30 mg/kg bw) in 14‐day‐old rats was affected by dietary restoration. Male rats in the resveratrol group (AzRes10, AzRes15, and AzRes20) were fed diets containing 10%, 15%, or 20% mmol resveratrol for an 8‐month experimental period 1 week after the last azaserine injection. Pancreas preparations prepared from histological sections were examined for AACF burden and analyzed via a video image analyzer. One‐way analysis of variance (ANOVA) non‐parametric statistical analyses were performed to test whether there was a difference between the averages of the experimental and control groups. The AACF load in the azaserine group (AzCont) compared to the control group (Cont) was found to be statistically significant in all categories (p < 0.05). The calculated estimated mean AACF volume (mm3) values and the AACF ratio as a percentage of the calculated organ volume were statistically significantly lower in all resveratrol groups (AzRes10, AzRes15, and AzRes20) compared to the azaserine control group (AzCont). The calculated estimated mean AACF volume (mm3) values and the AACF ratio as a percentage of the calculated organ volume were statistically significantly lower in all resveratrol groups (AzRes10, AzRes15, and AzRes20) compared to the azaserine control group (AzCont) (p < 0.05). In addition, the calculated estimated mean AACF diameter (mm) in the AzRes10 and AzRes15 groups, in the AzRes15 group the calculated estimated mean AACF number in the whole organ and the calculated average AACF number per unit area were found to be statistically significant compared to the azaserine control group (AzCont) (p < 0.05). According to the results of our study, it has been shown that atypical acinar cell foci (AACF) formed in the exocrine pancreas of rats with azaserine can be reduced by a diet containing resveratrol. It was determined that the tumor burden decreased statistically significantly (p ≤ 0.05) in resveratrol‐treated rats. Accordingly, it is thought that the inhibitory effects of resveratrol may contribute to studies that reduce the occurrence of pancreatic cancer. [ABSTRACT FROM AUTHOR]

• Female rats show faster and more effective trauma extinction than males. • Shock reminder reactivates fear memory only in male rats. • Ultrasonic vocalizations mirror fear behavior profiles in both sexes. • Study underscores the need for female inclusion in preclinical PTSD research. Post-Traumatic Stress Disorder (PTSD) is a complex psychiatric condition arising from traumatic experiences, marked by abnormal fear memories. Despite women are twice as likely as men to develop PTSD, the biological mechanisms underlying this disparity remain inadequately explored, particularly in preclinical studies involving female subjects. Previous research shows that female rats exhibit active fear responses, while males display passive behaviors. Additionally, sex differences in ultrasonic vocalizations (USVs) during fear conditioning have been observed, indicating varying emotional responses. Here, we validated a traumatic stress model consisting of footshock exposure paired with social isolation − originally developed in male rats − on females for the first time, focusing on sex differences in fear memory expression, retention and extinction. Our findings reveal that only during trauma exposure, males predominantly exhibited passive responses, whereas females demonstrated more active responses, despite both sexes emitting similar numbers of alarm USVs. Females also showed lower levels of freezing and USV emissions throughout extinction sessions and displayed a higher extinction rate compared to males. Notably, only males displayed a conditioned fear response when triggered by a single mild stressor. These findings highlight sex differences in trauma responses and fear memory processes. The study emphasizes the importance of incorporating 22-kHz USV evaluations along with other behavioral metrics for a comprehensive understanding of fear memory. This research contributes to the existing literature on traumatic stress models as well as underscores the necessity of including female subjects in preclinical studies to better inform treatment and prevention strategies tailored to both sexes. [ABSTRACT FROM AUTHOR]

Pharmaceutical companies routinely screen compounds for hemodynamics related safety risk. In vitro secondary pharmacology is initially used to prioritize compounds while in vivo studies are later used to quantify and translate risk to humans. This strategy has shown limitations but could be improved via the incorporation of molecular findings in the animal-based toxicological risk assessment. The aim of this study is to develop a mathematical model for rat and dog species that can integrate secondary pharmacology modulation and therefore facilitate the overall pre-clinical safety translation assessment. Following an extensive literature review, we built two separate models recapitulating known regulation processes in dogs and rats. We describe the resulting models and show that they can reproduce a variety of interventions in both species. We also show that the models can incorporate the mechanisms of action of a pre-defined list of 50 pharmacological mechanisms whose modulation predict results consistent with known pharmacology. In conclusion, a mechanistic model of hemodynamics regulations in rat and dog species has been developed to support mechanism-based safety translation in drug discovery and development. [ABSTRACT FROM AUTHOR]

BACKGROUND: At present, bone marrow mesenchymal stem cells are the main seed cells used in cell therapy for the treatment of intervertebral disc degeneration. However, the use of bone marrow mesenchymal stem cells as seed cells for the regeneration of fibrous rings is at risk of heterotopic ossification and teratoma at the repair site. Therefore, it is of great economic and social significance to find a new kind of seed cells for tissue engineering of annulus fibrosus for the treatment of intervertebral disc degeneration. OBJECTIVE: To isolate and purify rat annulus fibrosus-derived stem cells by adherent method combined with fibronectin differential adhesion screening method, and to observe its purification effect and biological characteristics. METHODS: Annulus fibrosus tissue was obtained from a SD rat intervertebral disc. Primary annulus fibrosus-derived stem cells were obtained by the mechanical-enzymatic digestion method. Annulus fibronectin differential adhesion method was used to purify annulus fibrosus-derived stem cells. Morphological changes and proliferation of cells were observed through a microscope. The expression levels of stem cell markers were detected by immunofluorescence technique and qPCR. The screened cells were subjected to multi-lineage cell differentiation and characteristic gene detection. RESULTS AND CONCLUSION: (1) The purified cells grew well, and most of them were angular and star-shaped multi-process cells, which had good proliferation ability. (2) Cells were positive for cell membrane surface antigens CD73, CD90 and CD105, while negative for CD45 and CD34. (3) After specific induction, cells could successfully differentiate into osteoblasts, chondroblasts and lipoblasts. (4) Collagen-I, Runx-2 after osteogenic induction, Collagen II, Sox-9 after chondrogenic induction, and PPAR -γ and LPL after lipogenic induction were highly expressed in cells, and the difference was significant compared with that before induction (P < 0.05). (5) These findings confirm that the adherent method combined with fibronectin differential adhesion method is effective enough to screen, isolate and purify rat annulus fibrosus-derived stem cells, and has good cell biological properties, good proliferation ability and multiple differentiation potential. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to prepare cholesterol and stearic acid-based solid lipid nanoparticles of gabapentin (GAB-SLNs) for protection against streptozotocin (STZ)-induced retinal injury in rats. Methods: We prepared four preparations of GAB-SLNs using a hot high-shear homogenization ultrasonication process, and the best formulation was selected and tested for biological activity. The retinal injury was brought in male adult albino rats while gabapentin doses continued for 6 weeks. Six groups of rats were assigned as the vehicle, diabetic, diabetic + gabapentin (10–20 mg/kg), and diabetic + GAB-SLNs (10–20 mg/kg). GAB-SLN#2 was selected as the optimized formulation with high entrapment efficacy (EE%, 98.64% ± 1.97%), small particle size (185.65 ± 2.41 nm), high negative Zeta potential (−32.18 ± 0.98 mV), low polydispersity index (0.28 ± 0.02), and elevated drug release (99.27% ± 3.48%). The TEM image of GAB-SLN#2 revealed a smooth surface with a spherical shape. Results: GAB-SLNs provided greater protection against retinal injury than free gabapentin as indicated by the histopathology data which demonstrated more organization of retinal layers and less degeneration in ganglion cell layer in rats treated with GAB-SLN#2. Further, GAB-SLN#2 reduced the inflammatory proteins (IL-6/JAK2/STAT3) and vascular endothelial growth factor (VEGF). Conclusion: The preparation of GAB-SLNs enhanced the physical properties of gabapentin and improved its biological activity as a neuroprotectant. Further studies are warranted to validate this technique for the use of oral gabapentin in other neurological disorders. [ABSTRACT FROM AUTHOR]

Obesity stands out as one of the most significant health problems in the modern world. The prevalence of high‐calorie diets (HCDs) globally exacerbates this condition. Throughout history, plants and plant‐derived food products have been utilized for medicinal purposes, demonstrating their efficacy in the treatment and prevention of various diseases. Gundelia tournefortii (GT), a plant of interest, is known to possess beneficial properties. Hence, this study aimed to investigate the immunotoxic and neurotoxic effects of two different doses of GT plant extract on the liver, brain, and heart tissues of obese rats. For this purpose, Wistar male rats were divided into four groups: “CG,” “HCDG,” “HCDGUN1,” and “HCDGUN2” At the conclusion of the study, adenosine deaminase (ADA) and myeloperoxidase (MPO) activities, as well as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) biomarkers, were evaluated in the liver, heart, and brain tissues. The study results revealed a statistically significant increase in ADA and MPO activities in the HCDG group compared to the CG group, alongside a significant decrease in the HCDGUN groups compared to the HCDG group. Regarding AChE and BChE activities, a statistically significant decrease was observed in the HCDG group compared to the CG group, whereas an increase was noted in the HCDGUN groups relative to the HCDG group, with the latter approaching values similar to those of the control group. In conclusion, the intake of GT plant extract exhibited positive effects on the immunotoxic and neurotoxic effects induced by HCD in rats with an experimental obesity model, as evidenced by tissue biomarker evaluations. [ABSTRACT FROM AUTHOR]

In the brains of adult rodents, the cells arising in the subventricular zone of the lateral ventricles maintain the ability to divide when migrating to the olfactory bulb along the rostral migratory stream (RMS). Dividing cells in the RMS are most frequently revealed through immunohistochemical detection of an exogenous marker of proliferation, 5-Bromo-2-deoxyuridine (BrdU), which incorporates into DNA during the S-phase of mitosis. The more recently recognized antigen Ki-67 (also known as Kiel-67 and MKI67), an endogenous protein expressed in nuclei at all stages of mitosis, is also used for proliferation detection. BrdU and Ki-67 are often used as alternative methods, but they have not previously been compared in the RMS. We analyzed the numbers and distribution of cells labeled either with BrdU or Ki-67 within the RMS of adult rats. The first group of animals received a single i.p. dose of BrdU. In the second group, dividing cells were visualized by Ki-67 immunohistochemistry. Some sections from brains of BrdU-treated rats were also immunostained for Ki-67. Labeled cells were counted in the three anatomical parts of the RMS (vertical arm, elbow and horizontal arm) using a method for unbiased estimation of cell density. The distribution of proliferating cells was similar for both markers. Most BrdU and Ki-67 positive cells were located in the vertical arm and in the elbow, but a caudo-rostral reduction in cell divisions was more evident with Ki-67 labeling. The number of Ki-67 positive cells significantly exceeded the number of BrdU positive cells in all parts of the RMS. Our results indicate that BrdU and Ki-67 are not interchangeable markers for evaluation of proliferative activity in the RMS. [ABSTRACT FROM AUTHOR]

Diffusion tensor imaging (DTI) has emerged as a promising neuroimaging tool for detecting blast-induced mild traumatic brain injury (bmTBI). However, lack of refined acute-phase monitoring and reliable imaging biomarkers hindered its clinical application in early diagnosis of bmTBI, leading to potential long-term disability of patients. In this study, we used DTI in a rat model of bmTBI generated by exposing to single lateral blast waves (151.16 and 349.75 kPa, lasting 47.48 ms) released in a confined bioshock tube, to investigate whole-brain DTI changes at 1, 3, and 7 days after injury. Combined assessment of immunohistochemical analysis, transmission electron microscopy, and behavioral readouts allowed for linking DTI changes to synchronous cellular damages and identifying stable imaging biomarkers. The corpus callosum (CC) and brainstem were identified as predominantly affected regions, in which reduced fractional anisotropy (FA) was detected as early as the first day after injury, with a maximum decline occurring at 3 days post-injury before returning to near normal levels by 7 days. Axial diffusivity (AD) values within the CC and brainstem also significantly reduced at 3 days post-injury. In contrast, the radial diffusivity (RD) in the CC showed acute elevation, peaking at 3 days after injury before normalizing by the 7-day time point. Damages to nerve fibers, including demyelination and axonal degeneration, progressed in lines with changes in DTI parameters, supporting a real-time macroscopic reflection of microscopic neuronal fiber injury by DTI. The most sensitive biomarker was identified as a decrease in FA, AD, and an increase in RD within the CC on the third day after injury, supporting the diagnostic utility of DTI in cases of bmTBI in the acute phase. [ABSTRACT FROM AUTHOR]

The current study explored a free‐operant analogue of discrete‐trial procedures to study the effects of amount and delay of reinforcement on choice and response rate. Rats responded on a multiple variable‐interval (VI) 45‐s, 45‐s schedule, with interspersed choice probe trials. Comparison of relative response rates and percentage of choice revealed some discrepancies between the free‐operant analogue and discrete‐trial procedures. Amount of reward controlled choice behavior when the ratios of delays were similar. When reward delays were more discrepant, delay length controlled choice behavior. Whereas the percentage of choice was larger for the larger magnitude reward, the relative rate of response for the larger magnitude was less than.50. In contrast, when the percentage of choice generally fell to below 50% (with large amount and large delay differences between alternatives), relative response rate indicated a preference for the larger amount alternative. This study shows the feasibility and utility of a free‐operant analogue of discrete‐choice studies that could be used to develop an analysis of preference. [ABSTRACT FROM AUTHOR]

The potential of silver-containing hydroxyapatite (Ag-HA) coatings to prevent orthopaedic implant-associated infection was explored previously; however, the resistance of Ag-HA coatings to late-onset orthopaedic infections is unknown. This study aimed to evaluate the long-term Ag+ elution and antibacterial properties of the Ag-HA coatings through in vitro and in vivo experiments. Ag-HA-coated disc specimens were immersed in fetal bovine serum (FBS) for six months. Ag concentration was measured over time using inductively coupled plasma-mass spectrometry to evaluate Ag release. The hydroxyapatite (HA)- or Ag-HA-coated disc specimens were immersed in FBS for 3 months to elute Ag+ for in vitro experiments. Methicillin-resistant Staphylococcus aureus (MRSA) suspensions were inoculated onto each disc; after 48 h, the number of colonies and the biofilm volume were measured. HA- or Ag-HA-coated disc specimens were inserted under the skin of Sprague-Dawley rats for three months for in vivo experiments. In in vivo experiment 1, specimens were inoculated with MRSA and the number of colonies was counted after 48 h. In in vivo experiment 2, the specimens were inoculated with bioluminescent S. aureus Xen36 cells, and bioluminescence was measured using an in vivo imaging system. The Ag-HA-coated disc specimens continued to elute Ag+ after six months. The biofilm volume in the Ag-HA group was lower than in the HA group. In in vitro and in vivo experiment 1, the bacterial counts in the Ag-HA group were lower than those in the HA group. In in vivo experiment 2, the bioluminescence in the Ag-HA group was lower than that in the HA group on days 1–7 after inoculation. The Ag-HA-coated discs continued to elute Ag+ for a long period and exhibited antibacterial activity and inhibition of biofilm formation against S. aureus. The Ag-HA coatings have the potential to reduce late-onset orthopaedic implant-associated infections. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to determine the single and combined antidiabetic activity and side effects of the retinoid X receptor agonist bexarotene and the thioredoxin-interacting protein inhibitor and peroxisome proliferator-activated receptor γ and AMP-activated protein kinase activator icariin. Methods The rats were grouped as healthy (control), diabetes, diabetes + bexarotene (20 mg/kg), diabetes + icariin (60 mg/kg), diabetes + bexarotene (10 mg/kg) + icariin (30 mg/kg) low-dose combination and diabetes + bexarotene (20 mg/kg) + icariin (60 mg/kg) high-dose combination groups. Key findings Icariin treatment led to a significant reduction in glucose levels compared with the diabetes control group, a remarkable outcome observed 45 days after the initial application. HbA1c levels of the icariin and low-dose combination treatment groups were significantly lower than in the diabetes group. Notably, icariin treatment also significantly elevated HOMA-β levels, which is indicative of improved β-cell function. Icariin significantly decreased glucose levels at 30 and 120 min in the oral glucose tolerance test. Moreover, it ameliorated hepatocyte degeneration, hepatic cord dissociation, congestion, mononuclear cell infiltration in the liver, and degeneration in the pancreas. Conclusions Icariin treatment exhibited robust antidiabetic effects with fewer side effects than other treatment options in this study. In future studies, long-term and varying doses of icariin will contribute to the development of novel antidiabetic drugs. [ABSTRACT FROM AUTHOR]

Genome-wide association studies typically evaluate the autosomes and sometimes the X Chromosome, but seldom consider the Y or mitochondrial (MT) Chromosomes. We genotyped the Y and MT Chromosomes in heterogeneous stock (HS) rats (Rattus norvegicus), an outbred population created from 8 inbred strains. We identified 8 distinct Y and 4 distinct MT Chromosomes among the 8 founders. However, only 2 types of each nonrecombinant chromosome were observed in our modern HS rat population (generations 81–97). Despite the relatively large sample size, there were virtually no significant associations for behavioral, physiological, metabolome, or microbiome traits after correcting for multiple comparisons. However, both Y and MT Chromosomes were strongly associated with the expression of a few genes located on those chromosomes, which provided a positive control. Our results suggest that within modern HS rats there are no Y and MT Chromosomes differences that strongly influence behavioral or physiological traits. These results do not address other ancestral Y and MT Chromosomes that do not appear in modern HS rats, nor do they address effects that may exist in other rat populations, or in other species. [ABSTRACT FROM AUTHOR]

This experimental study was performed to evaluate the alterations in the expression of a few subunits composing glutamate AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and NMDA (N-methyl-D-aspartate) receptors in the hippocampal cells of Wistar rats in response to long-term fluoride (F-) exposure. The animals were given water with background 0.4 (control), 5, 20, and 50 ppm F- (as NaF) for 12 months. The cognitive capacities of rats were examined by novel object recognition (NOR), Y-maze test, and Morris water maze tests. RT-qPCR and Western blotting techniques were used to evaluate the expression of different AMPA and NMDA subunits at transcriptional and translational levels, respectively. Long-term F- poisoning disturbed the formation of hippocampus-dependent working spatial and long-term non-spatial memory. The expression of Gria1, Gria2, and Gria3 genes encoding different subunits of AMPA receptors were comparable in hippocampi of control and F--exposed animals, although the levels of both Grin2a and Grin2b mRNA increased. Long-term F- intake enhanced the ratio of phospho-GluA1/total-GluA1 proteins in subcellular fraction enriched with cytosolic proteins, while decreased content of GluA2 but elevated level of GluA3 were observed in subcellular fraction enriched with membrane proteins. Such changes were accompanied by increased phosphorylation of GluN2A and GluN2B subunits, higher ratios of GluN2A/GluN1 and GluN2B/GluN1 proteins in the cytosol, and GluN2A/GluN2B ratio in membranes. These changes indicate the predominance of Ca2+-permeable AMPARs in membranes and a shift between different NMDARs subunits in hippocampal cells of F--exposed rats, which is typical for neurodegeneration and can at least partially underly the observed disturbances in cognitive capacities of animals. [ABSTRACT FROM AUTHOR]

Background: After the Coronavirus Disease pandemic, depression became more present, including in adolescents. Escitalopram, a selective serotonin reuptake inhibitor, was approved in 2009 for treatment of the major depressive disorder, both in children and adolescents. The undesirable effects of antidepressants on sexual dysfunction are usually underestimated. Aims: To investigate the effects of chronic mild stress, induced from peripuberty up to adulthood, on male sexual behavior parameters, with or without the escitalopram treatment, using rats as experimental model in a translational study. Materials and methods: Forty‐four peripubertal male rats were distributed into four groups: Sham control, escitalopram, stress, and stress + escitalopram. The chronic mild stress consisted of nine different stressors randomly applied one per day, for 8 weeks (from 41 to 97 days postpartum). Escitalopram therapy by gavage (10 mg/kg) started at 70 days postpartum and lasted for 4 weeks. The male sexual behavior parameters were evaluated at 114 days postpartum. After that, euthanasia was performed for blood and testis collection. Histopathology of the testes and plasmatic testosterone level were carried out. Results: There was a reduction in sexual activity and motivation in rats exposed to the stress protocol, which were treated or not with escitalopram, as well as an increase in the total number of mounts in animals exposed to the stress and treated with escitalopram. The testosterone levels were lower in animals exposed to the stress, which were or not treated with escitalopram (stress and stress + escitalopram). The frequency of histologically normal seminiferous tubule sections was lower in animals that were exposed to the stress and/or received escitalopram (escitalopram, stress, and stress + escitalopram). Conclusion: Chronic mild stress induced from peripuberty, associated or not to escitalopram treatment, altered the testosterone levels and testicular histoarchitecture and seems to be related to the reduction in male sexual motivation. [ABSTRACT FROM AUTHOR]

• Oral acute and subchronic toxicities of Ziziphus jujuba were evaluated in rats. • No major signs of toxicity were observed in the liver and kidney. • Repeated oral administration is safe at up to 1000 mg kg-1 bw over a 28-day period. • Ziziphus jujuba bark is relatively safe at lower dose. Ziziphus jujuba is a medicinal botanical with various pharmacological properties against cardiovascular diseases, respiratory system diseases, gastrointestinal problems, dysentery, and diarrhea. Despite its exhaustive use for medicinal aims, no study has yet been directed to evaluate this plant's potentially toxic profile. The present work focused on the acute and subchronic toxicity of Z. jujuba bark extract. The acute oral toxicity was performed using the OECD guideline 425; Z. jujuba bark extract was administered to female rats at a single dose of 5000 mg kg-1 body weight. The subchronic acute oral toxicity was carried out according to OECD guidelines 407; Z. jujuba bark extract was administered to male and female rats at doses of 250, 500, and 1000 mg kg-1 bw; after 28 days of Z. jujuba bark extract daily administration, the animals were sacrificed. Hematological parameters, serum and urinary biochemical parameters, and histological sections of the liver and kidneys were assessed. Administration of the single-oral dose of Z. jujuba bark methanolic extract did not cause any death in rats, and the LD 50 was found to be greater than 5000 mg kg-1 bw. The repeated administration of Z. jujuba bark methanolic extract at 250, 500, and 1000 mg kg-1 bw did not induce any significant perturbation of the white blood cells, lymphocytes, red blood cells, hemoglobin, hematocrit, and platelets in rats as compared to the controls. For the lipid parameters, namely triglycerides and cholesterol, no significant difference was recorded between the profiles of the treated and untreated groups of animals. Likewise, we registered non-significant changes in renal parameters such as creatinine, urea, and proteins; this was confirmed by the histological sections, which showed a normal kidney structure. Besides, we did not observe any significant modification in the values of liver parameters, ALT and AST. This finding was further confirmed by the histological examination of the liver, which revealed the organ's normal structure. Finally, for single-oral administration, Z. jujuba bark extract is almost non-toxic. For repeated oral administration, Z. jujuba bark extract is safe at doses up to 1000 mg kg-1 bw over a 28-day period. [ABSTRACT FROM AUTHOR]

ABSTRACT Honey has a rich history of treating gastrointestinal diseases due to its diverse bioactive compounds. This study evaluated the protective effects of select Iranian honeys against cold water immersion stress (CWIS)‐induced ulcers in rats. Forty male Wistar rats (250–280 g) were randomly assigned to eight groups (n = 5): control, CWIS, and groups treated with strong (eucalyptus, Annaab, and Jangale) and weak honeys (Chand Giah, Sumaq, Gaz) + CWIS. Honey selection was based on antioxidant capacity, phenolic content, and protein concentration. Rats received 20% honey in water (1 mL/kg) orally twice daily for 14 days; controls received water. After a 24‐h fast, rats underwent 3‐h CWIS to induce ulcers. Serum samples were analyzed for malondialdehyde (MDA), total antioxidant capacity (TAC), thiol groups, tumor necrosis factor alpha (TNF‐α), and interleukin 6 (IL‐6) levels. Stomachs were assessed for ulcer severity (gastric ulcer index), gastric juice volume, and histopathological changes. Honey types were categorized as strong (eucalyptus, Annaab, and Jangale) or weak (Chand Giah, Sumaq, and Gaz) based on total phenolic content, antioxidant effects (FRAP and DPPH), and protein levels. Ulcer group showed significant increases in MDA (64%) and TNF‐α and IL‐6 levels (98.5% and 111.6%), and decreases in ferric reducing antioxidant power and 2,2‐diphenyl‐1 picrylhydrazyl (FRAP, DPPH, and thiol levels [26%, 14.39%, and 26%]) compared to controls. Strong honey groups exhibited 50% lower gastric ulcer index compared to weak honey groups. This study showed that strong honeys, due to their higher phenolic, total protein, and antioxidant content, offer greater protection against gastric damage and oxidative stress compared to weaker honeys. These results highlight the importance of bioactive compounds in honey's therapeutic properties. Therefore, high‐quality honeys with higher phenolic content can be considered as therapeutic supplements for gastrointestinal disorders, especially those caused by oxidative stress and inflammation. [ABSTRACT FROM AUTHOR]

Objective(s): Gestational diabetes mellitus (GDM), one of the most common metabolic disorders in pregnancy, impacts maternal and fetal health. This study was designed to assess the effects of mild GDM on the histology, ultrastructure, and morphometry of fetal liver tissue. Materials and Methods: In this experimental study, twenty pregnant rats were randomly allocated into control and streptozotocin (STZ)-induced diabetic groups. Mild hyperglycemia was induced by intraperitoneal injection of STZ (40 mg/kg/bw) on the 5th day of gestation. At day 19 of gestation, fetal livers were separated and subjected to histological, transmission electron microscopic, and quantitative morphometric examinations. Results: In the GDM group, PAS staining was positive, revealing scattered eosinophilic inclusions in some hepatocytes. Masson trichrome staining was also positive and showed some fibrous tissue as fine fibers in the portal spaces that extended to the central vein. Reticulin staining in the GDM group was focally positive in the areas of fibrosis and the portal spaces. Ultrastructural examination showed pyknotic nuclei, karyolysis, degranulation and vesiculation of the rough endoplasmic reticulum, and degeneration of mitochondria in the GDM group. The morphometric examination demonstrated that the mean area of hepatocytes was significantly lower in the GDM group than in the control group (P<0.05). Moreover, the mean diameter of the central vein and the density of megakaryocytes were significantly higher in the GDM group than in the control group (P<0.05). Conclusion: Uncontrolled mild GDM induced the histological, ultrastructural and morphometric alterations in the fetal liver. [ABSTRACT FROM AUTHOR]

The regulatory role of estrogen receptor beta (ERβ) and the JNK signaling pathway in the effect of high-dose boron on rat splenic lymphocytes has been examined by measuring proliferation, apoptosis, and immune function. The results showed that, compared with the control group, the addition of high-dose boron (40 mmol/L) reduced the proportion of CD3+, CD4+, and CD8+ T lymphocytes, the concentrations of IgG, IL-2, IFN-γ, and IL-4, the proliferation rate of splenic lymphocytes, and the expression levels of PCNA and Bcl-2 mRNA (P < 0.01 or P < 0.05), and increased the apoptosis rate of splenic lymphocytes, caspase-3, and BAX mRNA expression levels (P < 0.01 or P < 0.05). After specific blocking of ERβ, the addition of high-dose boron could not reduce the proportion of CD8+ T lymphocytes, the concentrations of IgG and cytokines IL-2, IFN-γ, and IL-4, the lymphocyte proliferation rate, or PCNA mRNA expression levels, nor could it increase BAX mRNA expression levels. After specific blocking of JNK, the addition of high-dose boron could not increase BAX mRNA expression levels. However, after specific blocking of ERβ and JNK, the addition of high-dose boron could neither reduce the proportion of CD4+ and CD8+ T lymphocytes, the concentrations of IgG and IL-2 (P > 0.05), nor increase caspase-3 and BAX mRNA expression levels (P < 0.01). The results suggest that the ERβ-mediated JNK signaling pathway participates in regulating the effects of high-dose boron on the expression of genes related to the proliferation and apoptosis of rat splenic lymphocytes. [ABSTRACT FROM AUTHOR]

This study aimed to determine the protective role of l‐ascorbic acid in a pregnant rat model of cadmium‐induced toxicity. Cadmium is a toxic heavy metal that can seriously harm placenta and fetus tissue in pregnant women. Forty‐two healthy female Wistar albino rats (250–300 g weight and 14–16 weeks) were randomly distributed into six equal groups (n = 7): control, cadmium 1 mg (CD1), cadmium 5 mg (CD5), ascorbic acid (AA), CD1+AA, CD5+AA. Cadmium was administered to pregnant rats by oral gavage every other day, and/or AA (200 mg) was administered every day. At the end of pregnancy (Day 21), blood, placenta, and fetuses were collected from rats. The results indicated that cadmium‐induced oxidative stress by increasing the level of MDA and by decreasing the levels of GSH, SOD, and CAT activity in the serum of maternal. However, AA administration significantly decreased MDA levels and increased GSH levels, SOD, and CAT activity (p < 0.05). Cadmium (5 mg/kg) exposure significantly increased creatinine levels compared to AA and CD1+AA groups (p < 0.05). In addition, AA (200 mg/kg) significantly attenuated cadmium‐induced histopathological alteration in the placental and fetal tissues. In conclusion, AA may prevent cadmium toxicity in maternal and fetal tissues, as it regulates oxidative imbalance in pregnant rat tissues and alleviates histopathological changes. [ABSTRACT FROM AUTHOR]

Past studies in animal models have extensively investigated the impact of early life experiences on behavioral development, yet relatively few have specifically examined the implications of peripubertal experiences on the evolution of competitive behavior across distinct stages of adulthood. In the current research, we probed potential differences in competitive behavior during emerging adulthood (3 months old) and middle adulthood (12 months old) in 81 Sprague‐Dawley male rats exposed to three different peripubertal (postnatal Days 37–60) environments: an enriched environment (EE), a chronic unpredictable mild stress (CUMS) condition, and a control condition. Anxiety‐like behavior served as a positive control in our study. Results revealed significant variations in competitive behavior among the groups during emerging adulthood. The EE group displayed the least anxiety and outperformed their peers in food‐reward‐oriented competition, whereas the CUMS group excelled in status‐driven, agonistic competition. However, these behavioral differentiations gradually attenuated by middle adulthood, at which point the control group began to show an advantage. Our findings suggest that although peripubertal experiences significantly shape competitive behavior in the emerging adulthood stage, this effect diminishes over time and is nearly non‐detectable during mid‐adulthood, underscoring the fluidity of behavioral development and demonstrating that the effects of peripubertal experiences can be modulated by subsequent life experiences. [ABSTRACT FROM AUTHOR]

Oxidative stress and inflammation caused by cisplatin, which is frequently used in the treatment of many cancers, damage healthy tissues as well as cancer cells. In this study, we aimed to investigate the effect of epigallocatechin-3-gallate (EGCG) and infliximab (INF) administration on pancreatic endocrine cells in rats treated with systemic cisplatin (CDDP). The rats were randomly divided into 6 groups: group 1 (control group), group 2 (EGCG group), group 3 (CDDP group), group 4 (EGCG + CDDP group), group 5 (CDDP + INF group), and group 6 (EGCG + CDDP + INF group). The study's findings demonstrated that EGCG and INF effectively reduced the cellular damage induced by CDDP in histopathologic investigations of the pancreas. EGCG and INF, whether used individually or in combination, demonstrated a significant reduction in malondialdehyde (MDA) levels and an increase in glutathione (GSH) levels in the rat pancreas compared to the CDDP group. Immunohistochemically, the enhanced presence of insulin and glucagon positivity in the EGCG and INF groups, along with the absence of TUNEL immunopositivity, indicate that both treatments reduced CDDP-induced apoptosis. Furthermore, the observed lack of immunopositivity in TNF-α and 8-OHdG in the groups treated with EGCG and INF, compared to those treated with CDDP, indicates that these substances can inhibit inflammation. EGCG and INF, whether provided alone or together, can potentially reduce the damage caused to pancreatic islet cells by cisplatin. This effect is achieved through their anti-inflammatory and antioxidant properties during the early stages of the condition. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal with significant environmental health hazards. It enters the body through various routes with tissue accumulation. The relatively longer half-life with slow body clearance significantly results in hepatotoxicity during its liver detoxification. Therefore, researchers are exploring the potential use of herbal-derived phytocomponents to mitigate their toxicity. Here, we investigated, for the first time, the possible ameliorative effect of the phytochemical Morin (3,5,7,29,49-pentahydroxyflavone) against acute Cd-induced hepatotoxicity while resolving its underlying cellular mechanisms in a rat animal model. The study involved 50 adult male Sprague–Dawley rats weighing 200–250 g. The animals were divided into five equal groups: control, Cd, Morin100 + Cd, Morin200 + Cd, and Morin200. The 2nd, 3rd, and 4th groups were intraperitoneally treated with Cd (6.5 mg/kg), while the 3rd, 4th, and 5th groups were orally treated with Morin (100 and 200 mg/kg) for 5 consecutive days. On the 6th day, hepatic function (serum ALT, AST, ALP, LDH enzyme activities, and total bilirubin level) testing, transcriptome analysis, and immunohistochemistry were performed to elucidate the ameliorative effect of Morin on hepatotoxicity. In addition to restoring liver function and tissue injury, Morin alleviated Cd-induced hepatic oxidative/endoplasmic reticulum stress in a dose-dependent manner, as revealed by upregulating the expression of antioxidants (SOD, GSH, Gpx, CAT, and Nrf2) and decreasing the expression of ER stress markers. The expression of the proinflammatory mediators (TNF-α, IL-1-β, and IL-6) was also downregulated while improving the anti-inflammatory (IL-10 and IL-4) expression levels. Morin further slowed the apoptotic cascades by deregulating the expression of pro-apoptotic Bax and Caspase 12 markers concomitant with an increase in anti-apoptotic Blc2 mRNA expression. Furthermore, Morin restored Cd-induced tissue damage and markedly suppressed the cytoplasmic expression of JNK and p-PERK immunostained proteins. This study demonstrated the dose-dependent antioxidant hepatoprotective effect of Morin against acute hepatic Cd intoxication. This effect is likely linked with the modulation of upstream p-GRP78/PERK/ATF6 pro-apoptotic oxidative/ER stress and the downstream JNK/BAX/caspase 12 apoptotic signaling pathways. [ABSTRACT FROM AUTHOR]

The mammalian cerebral cortex is composed of a rich diversity of cell types. Sensory cortical cells are organized into networks that rely on their functional diversity to ultimately carry out a variety of sophisticated cognitive functions for perception, learning, and memory. The auditory cortex (AC) has been most extensively studied for its experience-dependent effects, including for perceptual learning and associative memory. Here, we used single-nucleus RNA sequencing (snRNA-seq) in the AC of the adult rat to investigate the breadth of transcriptionally diverse cell types that likely support the role of AC in experience-dependent functions. A variety of unique excitatory and inhibitory neuron subtypes were identified that harbor unique transcriptional profiles of genes with putative relevance for the adaptive neuroplasticity of cortical microcircuits. In addition, we report for the first time a diversity of astrocytes in AC that may represent functionally unique subtypes, including those that could integrate experience-dependent adult neuroplasticity at cortical synapses. Together, these results pave the way for building models of how cortical neurons work in concert with astrocytes to fulfill dynamic and experience-dependent cognitive functions. [ABSTRACT FROM AUTHOR]

Background: The autonomic nervous system (ANS) is affected by several factors, including major nutrients. However, their effects on the ANS remains unclear. Most studies had several limitations. They focused on humans, therefore they had difficulties excluding factors other than the nutrients. Their observation periods were too short (<4 hours) to align with typical absorption times of carbohydrates versus fats. They assessed the effects compared with the pre-prandial state rather than comparisons between different nutrient types. Objective: We aimed to investigate the effects of carbohydrates and fats on the ANS. Method: We employed a rat model to exclude the effects of external stimuli, used sufficient observation period, and compared the ANS parameters among animals fed 3 different diets. The rats were divided into carbohydrate-rich-diet (carb group) and fat-rich-diet (fat group) groups. We investigated the effects of carbohydrates and fats on the ANS by measuring heart rate variability parameters in rats. Electrodes and electrocardiography (ECG) transmitters were implanted in 14 Wistar rats maintained on a standard diet for 2 days followed by the experimental diets for 2 days. ECG readings were continuously recorded for 4 days. The R waves, function of the R-R interval, and time were calculated. A fast Fourier transform was used to obtain the power spectrum of the fluctuation (low frequency [LF: 0.2-0.75 Hz]; high frequency [HF: 0.75-3.0 Hz]; LF/HF ratio). Result: Compared with the standard-diet group, the carb group showed significantly increased HF activity, while the fat group showed a significantly increased LF/HF ratio. Conclusion: The results reveal a link between macronutrients and ANS activity. [ABSTRACT FROM AUTHOR]

The Raphe Pallidus (RPa) is a brainstem nucleus containing sympathetic premotor neurons that control thermogenesis and modulate cardiovascular function. It receives inputs from various hypothalamic areas, including the Lateral Hypothalamus (LH), a heterogeneous region intricately involved in several autonomic and behavioral functions. A key subpopulation of neurons in the LH expresses orexin/hypocretin, a neuropeptide which is crucially involved in the regulation of the wake-sleep states and feeding behavior. The RPa receives orexinergic projections from the LH and orexinergic signalling in the RPa has been shown to enhance thermogenesis in the anaesthetized rat, but only in the presence of an already existing thermogenic drive, without significantly affecting cardiovascular function. The present work was aimed at exploring the effects on thermoregulation and autonomic function and the possible role in the modulation of the wake-sleep states and feeding behavior of orexin injection in the RPa in the free-behaving rat. In order to assess the influence of an already present thermogenic drive on orexinergic signalling in the RPa, animals were studied at three different ambient temperatures (Ta, 10°C, 24°C, and 32°C). We found that orexin injection into the RPa variably affected the wake-sleep states, autonomic functions, motor activity, and feeding behavior, at the different Tas. In particular, in the first post-injection hour, we observed an increase in wakefulness, which was large at Ta 24°C and Ta 10°C and rather mild at Ta 32°C. Deep brain temperature was increased by orexin injection at Ta 10°C, but not at either Ta 24°C or Ta 32°C. Moreover, an increase in mean arterial blood pressure occurred at Ta 24°C, which was probably masked by the high baseline levels at Ta 10°C and was completely absent at Ta 32°C. Finally, an enhancement in feeding behavior was observed at Ta 24°C and 10°C only. In accordance with what observed in anaesthetized rats, orexinergic signalling in the RPa seems to be ineffective in the absence of any thermogenic drive. Moreover, the effects observed on the wake-sleep states and feeding behavior introduce the RPa as a novel player in the central neural network promoting wakefulness and feeding. [ABSTRACT FROM AUTHOR]

Purpose: Cumulating evidence supports the close association between periodontal diseases, neuroinflammation and neurodegenerative pathologies, except for peri-implantitis (PI). Thus, this study explored the association between experimental PI and neuropathological changes in the rat brain. Materials and methods: After bilateral first molars extraction, experimental PI was induced at titanium implants placed in the maxillae by lipopolysaccharide injections and ligature placement. Following 28-weeks of disease progression, the maxillae and brains were retrieved from 6 rats. Healthy brains from 3 rats were used as control. Brains were analyzed by immunohistochemistry to detect signs of neuroinflammation (interleukin (IL)-6 and tumor necrosis factor (TNF)-α)), microglial activation (IBA-1) and astrogliosis (GFAP). To explore signs of neurodegeneration, hematoxylin/eosin and Nissl stainings were used. Also, four different antibodies against amyloid beta (Aβ 1–42) were tested. Results: Chronic PI lesions showed peri-implant bone resorption accompanied by large inflammatory infiltrates. IL-6+ and TNF-α+ cells were found within the CA1 and Dentate Gyrus regions of the hippocampus of the PI-affected group, while almost no immune-positivity was detected in the control (p < 0.05). Detection of activated GFAP+ microglia and IBA-1+ astrocytes surface were significantly higher at the CA areas, and cerebral cortex of the PI-affected group, in comparison with control (p < 0.05). Shrunk neurons with pyknotic nuclei were inconsistently found among the PI-affected group, and these were almost not detected in control. No positive Aβ reactivity was detected in any of the samples. Conclusion: Chronic experimental PI lesions led to an increased detection of IL-6 and TNF-α, GFAP+ microgliosis and IBA-1+ astrocytosis, and in some cases, neurodegeneration, in the rat brain. [ABSTRACT FROM AUTHOR]

The aim of the present study was to establish a simple and reliable ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method and apply it for the determination of pharmacokinetics of moxidectin-loaded microspheres (MOX-MS) in rats. Plasma samples were processed using a simplified liquid–liquid extraction method and were separated using an Agilent Zorbax Eclipse Plus C18 column (50 mm × 2.1 mm, 1.8 μm) with a mobile phase consisting of a 10 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) at a flow rate of 0.4 mL/min for 5 min. Avermectin B1a was used as an internal standard (IS). The sample was injected at a volume of 10 μL with a column temperature of 35 °C and detected in a positive ion mode. A good linear response across the concentration range of 1.00–200 ng/mL (r2 > 0.99) and a lower limit of quantification (LLOQ) of 1.00 ng/mL were achieved. The extraction recovery of moxidectin exceeded 94.1%, the matrix effect was between 91.2% and 96.2%, the accuracy ranged from 100.1 to 103.6%, and the relative standard deviation (RSD) did not exceed 15% for the intra- and inter-day accuracy and precision. The pharmacokinetic results showed that MOX-MS significantly decreased Cmax, prolonged T1/2, and improved bioavailability. The developed method significantly reduced the assay volume, shortened detection time, simplified sample processing methods and saved assay costs, which may contribute to the development of the new antiparasitic drug. [ABSTRACT FROM AUTHOR]

The study of the pathogenesis of febrile seizures and their consequences frequently necessitates gene expression analysis. The primary methodology employed for such analysis is reverse transcription with quantitative polymerase chain reaction (RT-qPCR). To ensure the accuracy of data obtained by RT-qPCR, it is crucial to utilize stably expressed reference genes. The objective of this study was to identify the most suitable reference genes for use in the analysis of mRNA production in various brain regions of rats following prolonged neonatal febrile seizures. The expression stability of eight housekeeping genes was evaluated using the online tool RefFinder in the dorsal and ventral hippocampal regions and in the temporal and medial prefrontal cortex of the brain. The Ppia gene exhibited the greatest stability of expression. Conversely, the genes with the least stable expression levels were Actb and Ywhaz; thus, it is not recommended to use them for normalization in a febrile seizure model. Additionally, the majority of housekeeping genes demonstrate age-related, region-specific fluctuations. Therefore, it is crucial to employ the appropriate housekeeping genes for each brain structure under investigation when examining the expression dynamics of genes of interest in a febrile seizure model. [ABSTRACT FROM AUTHOR]

Head direction (HD) neurons, signalling facing direction, generate a signal that is primarily anchored to the outside world by visual inputs. We investigated the route for visual landmark information into the HD system in rats. There are two candidates: an evolutionarily older, larger subcortical retino‐tectal pathway and a more recently evolved, smaller cortical retino‐geniculo‐striate pathway. We disrupted the cortical pathway by lesioning the dorsal lateral geniculate thalamic nuclei bilaterally, and recorded HD cells in the postsubicular cortex as rats foraged in a visual‐cue‐controlled enclosure. In lesioned rats we found the expected number of postsubicular HD cells. Although directional tuning curves were broader across a trial, this was attributable to the increased instability of otherwise normal‐width tuning curves. Tuning curves were also poorly responsive to polarizing visual landmarks and did not distinguish cues based on their visual pattern. Thus, the retino‐geniculo‐striate pathway is not crucial for the generation of an underlying, tightly tuned directional signal but does provide the main route for vision‐based anchoring of the signal to the outside world, even when visual cues are high in contrast and low in detail. Key points: Head direction (HD) cells indicate the facing direction of the head, using visual landmarks to distinguish directions.In rats, we investigated whether this visual information is routed through the thalamus to the visual cortex or arrives via the superior colliculus, which is a phylogenetically older and (in rodents) larger pathway.We lesioned the thalamic dorsal lateral geniculate nucleus (dLGN) in rats and recorded the responsiveness of cortical HD cells to visual cues.We found that cortical HD cells had normal tuning curves, but these were slightly more unstable during a trial. Most notably, HD cells in dLGN‐lesioned animals showed little ability to distinguish highly distinct cues and none to distinguish more similar cues.These results suggest that directional processing of visual landmarks in mammals requires the geniculo‐cortical pathway, which raises questions about when and how visual directional landmark processing appeared during evolution. [ABSTRACT FROM AUTHOR]

The cryopreservation of rat embryos is useful for efficiently archiving rat resources in bioresource repositories. The cryopreserved fertilized oocytes can be quickly reanimated to rats with homozygous mutations using embryo transfer. In addition, cryopreserved rat fertilized oocytes are easier to transport than live animals. Before cryopreservation, fertilized oocytes are obtained by mating or in vitro fertilization. However, it is not clear which fertilized oocytes are most suited to cryopreservation. In this study, we performed a systematic comparison of the fertilizing ability, cryotolerance, and developmental ability of cryopreserved fertilized oocytes at the pronuclear stage produced either by mating (in vivo) or in vitro fertilization (in vitro) in SD and F344 rats. In vivo-fertilized oocytes had higher cryotolerance and developmental ability than in vitro-fertilized oocytes in SD and F344 rats. Furthermore, the fertilization ability, cryotolerance, and developmental ability of vitrified-warmed fertilized oocytes differed between SD and F344 rats. In conclusion, our study suggests that in vivo-fertilized rat oocytes were more suitable for cryopreservation. Our protocol provides an optimized system for the management of rat colonies using fertilized oocytes cryopreservation and contributes to the 3Rs principle by reducing the number of animals used for research. [ABSTRACT FROM AUTHOR]

This study evaluates silver-doped carbon dots (AgCDs) as a novel agent for chemical castration using a rat model. Six groups of rats (five males and ten females each, except for the surgical group which had only males) were utilized to compare the effects of different concentrations of AgCDs. The groups included control, sham, and three experimental groups injected with 1.25, 50, and 200 µg/mL AgCDs, respectively, along with a surgical castration group. Testosterone levels, sperm parameters, fertility index, oxidative damage, histopathological parameters, and gene expression of P53, Bax, Bcl-2, caspase-3, AKT, and PI3K were analyzed. Results demonstrated that the high-dose AgCDs group significantly reduced testosterone levels, sperm concentration, and motility, resulting in a decreased fertility index. MDA and NO significantly increased, while CAT, SOD, GPx, and TAC significantly reduced in the chemically castrated groups. Histological and genes expression analysis also revealed apoptosis and testicular damage in the AgCDs groups, indicated by significant increases in P53, Bax, and Caspase-3 levels, and significant reductions in AKT, PI3K, and Bcl-2. Based on these findings, AgCDs could be considered a potent and efficient agent for chemical castration, offering a less invasive, cost-effective solution with potential applications for population control. [ABSTRACT FROM AUTHOR]

Objective Methods Results Significance This study was undertaken to test whether the postinjury plasma concentration of phosphorylated neurofilament heavy chain (pNF‐H), a marker of axonal injury, is a prognostic biomarker for the development of posttraumatic epilepsy.Tail vein plasma was sampled 48 h after traumatic brain injury (TBI) from 143 rats (10 naïve, 21 controls, 112 with lateral fluid percussion injury) to quantify pNF‐H by enzyme‐linked immunosorbent assay. During the 6th postinjury month, rats underwent 30 days of continuous video‐electroencephalographic monitoring to detect unprovoked seizures and evaluate epilepsy severity. Somatomotor (composite neuroscore) and spatial memory (Morris water maze) testing and quantitative T2 magnetic resonance imaging were performed to assess comorbidities and lesion severity.Of the 112 TBI rats, 25% (28/112) developed epilepsy (TBI+) and 75% (84/112) did not (TBI−). Plasma pNF‐H concentrations were higher in TBI+ rats than in TBI− rats (p < .05). Receiver operating characteristic curve analysis indicated that plasma pNF‐H concentration distinguished TBI+ rats from TBI− rats (area under the curve [AUC] = .647, p < .05). Differentiation was stronger when comparing TBI+ rats exhibiting severe epilepsy (≥3 seizures/month) with all other TBI rats (AUC = .732, p < .01). Plasma pNF‐H concentration on day 2 (D2) distinguished TBI+ rats with seizure clusters from other TBI rats (AUC = .732, p < .05). Higher plasma pNF‐H concentration on D2 after TBI correlated with lower neuroscores on D2 (p < .001), D6 (p < .001), and D14 (p < .01). Higher pNF‐H concentration on D2 correlated with greater T2 signal abnormality volume on D2 (p < .001) and D7 (p < .01) and larger cortical lesion area on D182 (p < .01). Plasma pNF‐H concentration on D2 did not correlate with Morris water maze performance on D37–D39.Plasma pNF‐H is a promising clinically translatable prognostic biomarker for the development of posttraumatic epilepsy with frequent seizures or seizure clusters. [ABSTRACT FROM AUTHOR]

Aluminum chloride (Al) is associated with Alzheimer's disease (AD) and reproductive disorders. But the relationship between gonadotropin-releasing hormone (GnRH) and c-Fos levels, the end product of MAP-kinase signaling, in AD is unknown, so we aimed to investigate this relationship. We exposed rats to Al dissolved in drinking water (10 and 50 mg/kg) for two and four weeks. The control group received only drinking water. At the end, the blood sample was collected under deep anesthesia and the brain was dissected on ice, and the testicular tissue was fixed in formalin. Amyloid beta (βA) plaques in brain regions and the number of CA1 neurons were evaluated by Congo red staining and cresyl violet staining. Activation of neuronal nitric oxide synthase (nNOS) was studied using NADPH-diaphorase. The levels of c-Fos and testosterone receptors in the target area were examined immunohistochemically. Brain GnRH levels were determined by blotting, and serum levels of gonadotropins and steroids were measured by enzyme-linked immunosorbent assay (ELISA). All data were analyzed using analysis of variance (ANOVA) at α = 0.05 level. The accumulation of βA plaque was observed along with a decrease in the number of CA1 pyramidal neurons and a significant decrease in the levels of c-Fos and GnRH in the brains of rats receiving Al, which was aligned with a significant decrease in serum levels of testosterone and LH. This study, for the first time, showed a link between dementia and a concomitant decrease in brain GnRH and c-Fos levels. [ABSTRACT FROM AUTHOR]