Behavioral Tests Research Articles

Rutin Attenuates Distraction Spinal Cord Injury by Inhibiting Microglial Inflammation Through Downregulation of P38 MAPK/NF-κB/STAT3 Pathway.

Distraction spinal cord injury (DSCI) is a severe complication followingscoliosis correction surgery, for which there are currently no effective clinical treatments. This study aims to evaluate the inhibitory effects of rutin, a natural product, on inflammation inDSCI and to investigate the underlying mechanisms. In vitro, microglial cells were exposed directly to rutin to assess its ability to inhibit lipopolysaccharide (LPS)-induced inflammation. In rats with DSCI, the inhibitory effect of rutin on DSCI was evaluated using behavioral tests. mRNA sequencing was performed on spinal cord tissues to elucidate the mechanism of rutin's action. Rutin significantly suppressed the LPS-induced increase in inflammatory factors in microglial cells. In DSCI rats treated with rutin, scores in the Basso-Beattie-Bresnahan (BBB) were significantly improved. The mechanism of rutin's action was found to be related to its ability to reduce inflammatory infiltration in spinal cord tissue, protecting neurons from apoptosis and microstructural demyelination. Through assays of transcriptomic differentially expressed genes (DEGs), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and RT-qPCR validation of the top DEGs, MAPK13 (also known as P38 MAPK) was finally identified as the key target gene in promoting DSCI development. Further molecular docking analysis indicated an interaction between rutin and P38 MAPK, supporting the rutin's action and the underlying mechanism in anti-inflammation. In conclusion, rutin effectively inhibited the development of DSCI in rats. The mechanism of rutin's action was associated with its activity in blocking the P38 MAPK/NF-κB/STAT3 pathway in the microglial cells of spinal cord. Rutin could be developed as a potential anti-DSCI drug for clinical applications.

CD2AP deficiency aggravates Alzheimer’s disease phenotypes and pathology through p38 MAPK activation

BackgroundAlzheimer’s disease (AD) is the most common form of neurodegenerative disorder, which is characterized by a decline in cognitive abilities. Genome-wide association and clinicopathological studies have demonstrated that the CD2-associated protein (CD2AP) gene is one of the most important genetic risk factors for AD. However, the precise mechanisms by which CD2AP is linked to AD pathogenesis remain unclear.MethodsThe spatiotemporal expression pattern of CD2AP was determined. Then, we generated and characterized an APP/PS1 mouse model with neuron-specific Cd2ap deletion, using immunoblotting, immunofluorescence, enzyme-linked immunosorbent assay, electrophysiology and behavioral tests. Additionally, we established a stable CD2AP-knockdown SH-SY5Y cell line to further elucidate the specific molecular mechanisms by which CD2AP contributes to AD pathogenesis. Finally, the APP/PS1 mice with neuron-specific Cd2ap deletion were treated with an inhibitor targeting the pathway identified above to further validate our findings.ResultsCD2AP is widely expressed in various regions of the mouse brain, with predominant expression in neurons and vascular endothelial cells. In APP/PS1 mice, neuronal knockout of Cd2ap significantly aggravated tau pathology, synaptic impairments and cognitive deficits. Mechanistically, the knockout of Cd2ap activated p38 mitogen-activated protein kinase (MAPK) signaling, which contributed to increased tau phosphorylation, synaptic injury, neuronal apoptosis and cognitive impairment. Furthermore, the phenotypes of neuronal Cd2ap knockout were ameliorated by a p38 MAPK inhibitor.ConclusionOur study presents the first in vivo evidence that CD2AP deficiency exacerbates the phenotypes and pathology of AD through the p38 MAPK pathway, identifying CD2AP/p38 MAPK as promising therapeutic targets for AD.

Microglial CD2AP deficiency exerts protection in an Alzheimer’s disease model of amyloidosis

BackgroundThe CD2-associated protein (CD2AP) was initially identified in peripheral immune cells and regulates cytoskeleton and protein trafficking. Single nucleotide polymorphisms (SNPs) in the CD2AP gene have been associated with Alzheimer’s disease (AD). However, the functional role of CD2AP, especially its role in microglia during AD onset, remains elusive.MethodsCD2AP protein levels in cultured primary cells and in 5xFAD mice was studied. Microglial CD2AP-deficient mice were crossed with 5xFAD mice and the offspring were subjected to neuropathological assessment, behavioral tests, electrophysiology, RNA-seq, Golgi staining, and biochemistry analysis. Primary microglia were also isolated for assessing their uptake and morphology changes.ResultsWe find that CD2AP is abundantly expressed in microglia and its levels are elevated in the brain of AD patients and the 5xFAD model mice at pathological stages. We demonstrate that CD2AP haploinsufficiency in microglia significantly attenuates cognitive and synaptic deficits, weakens the response of microglia to Aβ and the formation of disease-associated microglia (DAM), and alleviates synapse loss in 5xFAD mice. We show that CD2AP-deficient microglia exhibit compromised uptake ability. In addition, we find that CD2AP expression is positively correlated with the expression of the complement C1q that is important for synapse phagocytosis and the formation of DAM in response to Aβ deposition. Moreover, we reveal that CD2AP interacts with colony stimulating factor 1 receptor (CSF1R) and regulates CSF1R cell surface levels, which may further affect C1q expression.ConclusionsOur results demonstrate that CD2AP regulates microgliosis and identify a protective function of microglial CD2AP deficiency against Aβ deposition, suggesting the importance of detailed investigation of AD-associated genes in different brain cells for thoroughly understanding their exact contribution to AD.

Quantification and time course of subjective psychotropic and somatic effects of tetrahydrocannabinol – a prospective, single-blind, placebo-controlled exploratory trial in healthy volunteers

BackgroundCannabis is increasingly used and debates about the legalisation of the recreational use of cannabis are ongoing. In this prospective, placebo-controlled study in healthy volunteers not regularly consuming cannabis, subjective psychotropic and somatic effects after a single dose of intravenous THC were assessed and quantified over 48 h.MethodsTwenty-five healthy volunteers received a single IV bolus of THC and 6 received normal saline. Psychotropic and somatic effects of THC were assessed by two questionnaires that were completed at up to 14 timepoints from shortly before drug administration to 48 h later.ResultsDemographic data did not differ between groups. Differences between THC and placebo for all assessed effects, except for euphoria, irritation and headache, were clearly discernible. Subdimensions related to positive mood were less and those related to negative mood were more pronounced in the THC group. Peak plasma concentrations were observed at 1 to 5 min after THC administration while peak effects occurred between 45 and 60 min. Differences between THC and placebo were pronounced and seen for up to 90 to 120 min for most effects, except for “sleepiness” and “deactivation”, where the effect of THC was discernible for up to 5 h. At 24 and 48 h, there were no statistically significant difference between THC and placebo group.ConclusionsTHC triggers a large range of psychotropic and somatic effects with peak effects at 45 to 60 min after IV administration of THC, much later than plasma peak levels. Most effects are short-lasting with a duration of up to 2 h, but some effects like sleepiness and deactivation can be longer-lasting and persist for 5 h or longer in cannabis-naïve or cannabis-abstinent individuals. Since effects of THC demonstrate a time course that differs from the time course of plasma concentrations it might be important to base the judgment of a possible impairment related to THC consumption on clinical or behavioral tests in addition to THC plasma levels.Trial registrationwww.isrctn.com; registration number ISRCTN53019164.

Novel automated method to assess group dynamics reveals deficits in behavioral contagion in rats with social deficits

Behavioral copying is a key process in group actions, but it is challenging for individuals with autism spectrum disorder (ASD). We investigated behavioral contagion, or instinctual replication of behaviors, in Krushinky-Molodkina (KM) rats (n = 16), a new potential rodent model for ASD, compared to control Wistar rats (n = 15). A randomly chosen healthy Wistar male (“demonstrator rat”) was introduced to the homecage of experimental rats (“observers”) 10–14 days before the experiments to become a member of the group. For the implementation of the behavioral contagion experiment, we used the IntelliCage system, where rats can live in a group of 5–6 rats and their water visits can be automatically scored. During the experiment, the demonstrator was taken out of IntelliCage for a pre-test water deprivation and then placed back for the behavioral contagion test. As a result, a drinking behavior of the water-deprived demonstrator rat prompted water-seeking and drinking behaviors in the whole group. Unlike the Wistar controls, KM observers showed fewer visits to the drinking bottles, particularly lacking inspection visits (i.e., visits without drinking). The control group, in contrast, exhibited a dynamic, cascade-like visiting of the water corners. The proportion of activated observers in KM rats was significantly lower, as compared to Wistar ones, and they did not mimic other observer rats. KM rats, therefore, displayed an attenuated pattern of behavioral contagion, highlighting social deficits in this strain. This study suggests that measuring group dynamics of behavioral contagion in an automated, non-invasive setup offers valuable insights into social behavior in rodents.

D-Serine May Ameliorate Hippocampal Synaptic Plasticity Impairment Induced by Patients’ Anti-N-methyl-D-aspartate Receptor Antibodies in Mice

Objective: To establish a mouse model of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and assess the potential therapeutic benefits of D-serine supplementation in mitigating synaptic plasticity impairments induced by anti-NMDAR antibodies. Methods: Anti-NMDAR antibodies were purified from cerebrospinal fluid (CSF) samples of patients diagnosed with anti-NMDAR encephalitis and verified using a cell-based assay. CSF from patients with non-inflammatory neurological diseases served as the control. These antibodies were then injected intraventricularly into C57BL/6 mice. Forty-eight hours following the injection, mice were administered either D-serine (500 mg/kg) or sterile saline intraperitoneally for three consecutive days. Subsequent analyses included Western blotting, immunofluorescence, electrophysiological studies, and a series of behavioral tests to assess pathological changes caused by anti-NMDAR antibodies. Results: Mice injected with anti-NMDAR antibodies exhibited a significant reduction in hippocampal long-term potentiation compared to controls, which was notably ameliorated by D-serine treatment. Additionally, these mice displayed decreased levels of hippocampal membrane NMDAR1 protein and postsynaptic NMDAR1 density. However, D-serine administration did not significantly alter these conditions. Notably, no significant behavioral differences were observed between mice injected with anti-NMDAR antibodies and controls in open fields, elevated plus maze, novel object recognition, or Morris water maze tests. Conclusions: Our findings indicate that exogenous D-serine can improve hippocampal plasticity impairments caused by anti-NMDAR antibodies but does not reverse the decreased expression of NMDAR. Furthermore, a single intraventricular injection of patients’ antibodies was insufficient to induce anti-NMDAR encephalitis-related behaviors in mice.

Chemogenetic Inhibition of Prefrontal Cortex Ameliorates Autism-Like Social Deficits and Absence-Like Seizures in a Gene-Trap Ash1l Haploinsufficiency Mouse Model

Background: ASH1L (absent, small, or homeotic-like 1), a histone methyltransferase, has been identified as a high-risk gene for autism spectrum disorder (ASD). We previously showed that postnatal Ash1l severe deficiency in the prefrontal cortex (PFC) of male and female mice caused seizures. However, the synaptic mechanisms underlying autism-like social deficits and seizures need to be elucidated. Objective: The goal of this study is to characterize the behavioral deficits and reveal the synaptic mechanisms in an Ash1l haploinsufficiency mouse model using a targeted gene-trap knockout (gtKO) strategy. Method: A series of behavioral tests were used to examine behavioral deficits. Electrophysiological and chemogenetic approaches were used to examine and manipulate the excitability of pyramidal neurons in the PFC of Ash1l+/GT mice. Results: Ash1l+/GT mice displayed social deficits, increased self-grooming, and cognitive impairments. Epileptiform discharges were found on electroencephalograms (EEGs) of Ash1l+/GT mice, indicating absence-like seizures. Ash1l haploinsufficiency increased the susceptibility for convulsive seizures when Ash1l+/GT mice were challenged by pentylenetetrazole (PTZ, a competitive GABAA receptor antagonist). Whole-cell patch-clamp recordings showed that Ash1l haploinsufficiency increased the excitability of pyramidal neurons in the PFC by altering intrinsic neuronal properties, enhancing glutamatergic synaptic transmission, and diminishing GABAergic synaptic inhibition. Chemogenetic inhibition of pyramidal neurons in the PFC of Ash1l+/GT mice ameliorated autism-like social deficits and abolished absence-like seizures. Conclusions: We demonstrated that increased neural activity in the PFC contributed to the autism-like social deficits and absence-like seizures in Ash1l+/GT mice, which provides novel insights into the therapeutic strategies for patients with ASH1L-associated ASD and epilepsy.

A promising therapeutic potential of Origanum vulgare extract in mitigating ethanol-induced working memory impairments and hippocampal oxidative stress in rats

ABSTRACT This study explored the therapeutic potential hydroalcoholic extract derived from Origanum vulgare leaf in mitigating ethanol-induced working memory impairments and hippocampal oxidative stress in rats. Eight groups, including controls, ethanol-exposed rats, and those treated with extract (100, 200, and 300 mg/kg) alone or combined with ethanol, were assessed using the radial arm maze (RAM) for behavioral tests. Ethanol increased working memory errors and time spent in error zones, effects notably reduced by the extract, especially at 300 mg/kg dose (P≤0.001). Biochemical tests showed ethanol suppressed catalase (CAT), superoxide dismutase (SOD), and acetylcholinesterase (AChE) activities within the hippocampus and cortex. while the extract elevated CAT and SOD activities and reduced AChE activity. These results suggest the extract’s neuroprotective properties, including oxidative stress reduction and neurotransmitter modulation, which mitigate ethanol-induced hippocampal damage. This highlights Origanum vulgare extract potential as a therapeutic adjunct for memory deficits and oxidative stress-related conditions.

Heritability and Genome-Wide Association Study of Dog Behavioral Phenotypes in a Commercial Breeding Cohort

Background: Canine behavior plays an important role in the success of the human–dog relationship and the dog’s overall welfare, making selection for behavior a vital part of any breeding program. While behaviors are complex traits determined by gene × environment interactions, genetic selection for desirable behavioral phenotypes remains possible. Methods: No genomic association studies of dog behavior to date have been reported on a commercial breeding (CB) cohort; therefore, we utilized dogs from these facilities (n = 615 dogs). Behavioral testing followed previously validated protocols, resulting in three phenotypes/variables [social fear (SF), non-social fear (NSF), and startle response (SR)]. Dogs were genotyped on the 710 K Affymetrix Axiom CanineHD SNP array. Results: Inbreeding coefficients indicated that dogs from CB facilities are statistically less inbred than dogs originating from other breeding sources. Heritability estimates for behavioral phenotypes ranged from 0.042 ± 0.045 to 0.354 ± 0.111. A genome-wide association analysis identified genetic loci associated with SF, NSF, and SR; genes near many of these loci have been previously associated with behavioral phenotypes in other populations of dogs. Finally, genetic risk scores demonstrated differences between dogs that were more or less fearful in response to test stimuli, suggesting that these behaviors could be subjected to genetic improvement. Conclusions: This study confirms several canine genetic behavioral loci identified in previous studies. It also demonstrates that inbreeding coefficients of dogs in CB facilities are typically lower than those in dogs originating from other breeding sources. SF and NSF were more heritable than SR. Risk allele and weighted risk scores suggest that fearful behaviors could be subjected to genetic improvement.

Life expectancy in ants explains variation in helpfulness regardless of phylogenetic relatedness

Abstract Rescue behavior aims to free a relative from danger. Ants are particularly known for such helpfulness and, perhaps not coincidentally, also show the highest level of social organization in the animal kingdom, i.e., eusociality. However, even among social species such as ants, there is a huge variation in rescue proneness and little is understood about the underlying causes of this variation. In this study, we explore the relationship between helpfulness in the form of rescue and life expectancy, focusing on 14 ant species with diverse phylogenetic backgrounds. We posit that species with longer worker life expectancies are more prone to engaging in rescue actions. To test this, we assessed worker lifespan in each species and conducted behavioral tests simulating entrapment scenarios involving a nestmate ensnared by an artificial obstacle. Observed behaviors involved contact with the nestmate, digging around it, pulling at its body parts, and biting the entrapping obstacle. Our findings reveal that species with longer worker life expectancies exhibit higher proneness to rescue endangered nestmates, irrespective of phylogenetic relatedness. Furthermore, we found no trace of a phylogenetic signal in the life expectancies or helpfulness of workers belonging to different species. The results underscore the significance of life expectancy as a key factor influencing the likelihood of rescue behavior in ants. This phenomenon warrants further investigation, given the varied physiologies, life histories, and ecologies observed among species. Nevertheless, the impact of life expectancy on behavioral patterns in social insects suggests that this parameter is likely significant across diverse taxa.

Insights into RNA-mediated pathology in new mouse models of Huntington's disease.

Huntington's disease (HD) is a neurodegenerative polyglutamine (polyQ) disease resulting from the expansion of CAG repeats located in the ORF of the huntingtin gene (HTT). The extent to which mutant mRNA-driven disruptions contribute to HD pathogenesis, particularly in comparison to the dominant mechanisms related to the gain-of-function effects of the mutant polyQ protein, is still debatable. To evaluate this contribution invivo, we generated two mouse models through a knock-in strategy at the Rosa26 locus. These models expressed distinct variants of human mutant HTT cDNA fragment: a translated variant (HD/100Q model, serving as a reference) and a nontranslated variant (HD/100CAG model). The cohorts of animals were subjected to a broad spectrum of molecular, behavioral, and cognitive analysis for 21 months. Behavioral testing revealed alterations in both models, with the HD/100Q model exhibiting late disease phenotype. The rotarod, static rod, and open-field tests showed some motor deficits in HD/100CAG and HD/100Q model mice during the light phase, while ActiMot indicated hyperkinesis during the dark phase. Both models also exhibited certain gene deregulations in the striatum that are related to disrupted pathways and phenotype alterations observed in HD. In conclusion, we provide invivo evidence for a minor contributory role of mutant RNA in HD pathogenesis. The separated effects resulting from the presence of mutant RNA in the HD/100CAG model led to less severe but, to some extent, similar types of impairments as in the HD/100Q model. Increased anxiety was one of the most substantial effects caused by mutant HTT RNA.

Behavioral Test Scores Could Be Linked to the Protein Expression Values of p62 and GLAST in the Brains of Mice with Neuropsychiatric Disorder-Related Behaviors

Neuropsychiatric disorders are a public health concern, in which diagnosis and prognosis may be based on clinical symptoms that might often diverge across individuals. Schizophrenia is a major neuropsychiatric disorder, which may affect millions worldwide. However, the biochemical alterations of this disorder have not been comprehensively distinguished. In addition, there is less confidence in finding specific biomarkers for neuropsychiatric disorders, including schizophrenia, but rather a specific characteristic behavioral pattern. In general, maternal immune activation is considered to be one of the important factors in the development of neuropsychiatric disorders. Here, a mouse model of neuropsychiatric disorders was created, in which poly I:C, sodium dextran sulfate (DSS), and κ-carrageenan (CGN) were utilized for maternal immune activation during the pregnancies of mother mice. Subsequently, we examined the link between biochemical changes in p62 and/or glutamate aspartate transporter (GLAST) in the brains of offspring mice and the alteration in their experimental behavior scores. Furthermore, a therapeutic study was conducted on these neuropsychiatric disorder model mice using butyric acid, piceid, and metformin. It was found that some molecules could effectively improve the behavioral scores of neuropsychiatric model mice. Importantly, significant correlations between certain behavioral scores and p62 protein expression, as well as between the scores and GLAST expression, were recognized. This is the first report of a significant correlation between pathological behaviors and biochemical alterations in neuropsychiatric disorder model animals. This concept could contribute to the development of innovative treatments to at least ameliorate the symptoms of several psychiatric disorders.

Obesity phenotype and gut microbiota alterations are not associated with anxiety-like behaviour in high-fat diet-fed mice.

Anxiety is a common co-morbidity with obesity and metabolic disease, and can lead to a significant impact on quality of life. The vast differences in the gut microbiota between obese and control individuals provide a potential avenue for therapeutic intervention. A high-fat diet (HFD) in rodent models have been shown to induce anxiety-like behaviour and has been tested through an array of distinct behavioural tests such as the elevated plus maze test, light-dark test and open field test. Despite differences in testing and assessment parameters, the behavioural outcomes have previously yielded similar results. Recent evidence suggests that HFD has an anxiolytic effect on mice, complicating the model. Here, we aimed to confirm whether HFD-fed mice are more susceptible to presenting anxiety-like behaviours. Our findings showed no significant differences in behaviour, plasma corticosterone and inflammation markers between HFD and control diet (CTD) mice, despite considerable differences in adiposity and faecal microbial communities. Additionally, daily oral gavage is one of the most common methods for testing bacterial probiotics in rodent models, but this handling could potentially also cause stress to the mice. Thus, we investigated if daily oral gavage could mask differences in HFD and CTD mice. We found no significant differences in weight, fat mass or anxiety-like behaviour in CTD-fed mice with or without daily oral gavage.

Long -term multimodal exercise intervention for patients with frontotemporal lobar degeneration: Feasibility and preliminary outcomes

Introduction: After Alzheimer's disease, frontotemporal lobar degeneration (FTLD) is the second most common form of early-onset dementia. Despite the heavy burden of care for FTLD, pharmacological and non-pharmacological treatments with sufficient efficacy remain scarce. This study aimed to evaluate the feasibility of a multimodal exercise program for FTLD and to examine preliminary changes in the clinical outcomes of the program in FTLD. Methods: This single-arm preliminary study was conducted from July 2017 to July 2018 and recruited four male patients with FTLD aged 60–78 years. Patients exercised under the supervision of an exercise instructor once every 2 weeks for 48 weeks. The multimodal exercise program comprised cognitive training, moderate-intensity continuous training, strength training, balance training, and flexibility and relaxation training. Feasibility was measured using dropout and attendance rates. Cognitive, psychological, physical, and behavioral function tests were conducted before and after the intervention. Results: All patients completed the intervention (100%) and attended well (93.6%). Positive changes in scores in the Stroop Color Word Test (cognitive; 5 out of 6 items), Mood Check List-short form 2 (psychological), movement subscales of the Stereotypy Rating Inventory (behavioral), and timed up-and-go (TUG, physical) assessments demonstrated a medium-to-high effect size (open effect size: 0.52–0.97). While there were improvements in some domains, such as recovery self-efficacy and exercise efficacy, the MMSE-J scores showed an overall slight decline, especially in the SD case where a marked decrease was observed. Additionally, three physical function items showed no effect, except for a positive outcome in the TUG test. Functional near-infrared spectroscopy (fNIRS) revealed increased activation in the frontal lobe, indicated by elevated oxygenated hemoglobin levels before and after the exercise intervention. This pattern of activation suggests that the intervention may have stimulated neural activity in the frontal lobe, potentially enhancing cognitive and behavioral functions, including executive function and attention. Conclusion: The long-term multimodal exercise intervention may be feasible and positively change the cognitive, psychological, physical, and behavioral functions in older adults with FTLD. Although the intervention led to improvements in certain areas, there were also declines observed in various functions, which may not necessarily be due to the intervention itself but rather reflect the natural progression of the disease.

Cognitive and Neurobiological Correlates for Switching/Inhibition Moderate the Relations Between Word Reading and Reading Comprehension in Hebrew-Speaking Children: An fMRI Study.

The expanded Simple View of Reading model suggests language processing and word reading as contributors to reading comprehension and points at the participation of executive functions as supporting these abilities. Switching and inhibition are both executive functions (EF) contributing to reading, especially in languages with two writing systems-shallow and deep, such as Hebrew. Here, we aimed to determine the specific role of switching/inhibition both cognitively and neurobiologically in the Simple View of Reading model among 49 eight- to 12-year-old Hebrew-speaking children. Children underwent reading and cognitive behavioural testing as well as a five-min resting-state fMRI scan. Functional connectivity of the fronto-parietal network related to switching/inhibition was determined and included in a moderation model. Results suggest that both switching/inhibition abilities and functional connectivity within the fronto-parietal network moderate the relations between word reading and reading comprehension. This strengthens the contribution of switching/inhibition to facilitating reading comprehension and supports the need to include it as part of the expanded SVR model.

Role of RNA m6A reader YTHDF2 in neurodegeneration of the aged mice

Objective: To investigate the role of RNA m6A reader YTHDF2 in neurodegeneration of the aged mice. Methods: Eighteen 18-month-old control C57BL/6 mice and 22 Ythdf2 conditional knockout (cKO) mice of the same age (that exhibited significant aging characteristics) were used. Five pairs of mice were used for morphological analysis. Thirteen control mice and 17 cKO mice were used for behavioral experiments. Immunofluorescence analysis was performed to detect the expression of YTHDF2 in the brains of 18-month-old C57BL/6 mice. After establishing the neural progenitor cell-specific knockout mice of Ythdf2, their phenotypes were analyzed through comparison of body weight, brain weight and H&E staining. Subsequently, immunohistochemistry and immunofluorescence analyses were used to detect the expression of various neural cell-specific markers in the aged control mice and Ythdf2 cKO mice. Finally, behavioral tests, including the open field test, new object recognition, and water maze, were used to assess the levels of anxiety, depression, learning and memory abilities. Results: Immunofluorescence staining showed that YTHDF2 was mainly expressed in the neurons. Compared with the age-matched control mice, there was no significant change in the body weight of the Ythdf2 cKO mice, but the brain weight decreased significantly (P<0.05). The immunostaining showed that Ythdf2 cKO mice had fewer neurons, fewer astrocytes with defective morphology, more microglia and activation of microglia (P<0.05). Behavioral tests showed that the aged Ythdf2 cKO mice exhibited impaired movement, learning and memory abilities (P<0.05). Conclusions: YTHDF2 is mainly expressed in the neurons of the aged brain. Conditional knockout of Ythdf2 causes quantitative and structural abnormalities in hippocampal neuronal cells, and impairs motor ability and learning and memory of the aged mice, suggesting that YTHDF2 plays an important role in neurodegeneration of the aged mice.

Assessment of neurotoxicity of rotenone and the possible protective effect of alpha lipoic acid in adult male albino rats

ABSTRACT Background Parkinson’s disease (PD) results from neurodegeneration of the dopaminergic neurons present in the substantia nigra (SN) of midbrain, manifested as locomotor deficits and behavioral changes. Rotenone pesticide affects the central nervous system and causes oxidative stress and apoptosis, pathological cause of PD. Alpha lipoic acid (ALA), a potent antioxidant, crosses the blood–brain barrier. Objective This study aimed to assess the antioxidant properties of ALA in neurodegenerative model of Parkinsonism induced by rotenone. Material and Methods Twenty-four adult male albino rats 9–11 weeks of age were divided into four equal groups: A (control water), B (control DMSO), C (model group) received rotenone 2.5 mg/kg bwt/kg IP, D (treated group) received both rotenone & ALA at a dose of 200 mg/kg PO for 28 days. At the end of the experiment, all animals were weighed, and behavioral tests to assess locomotor activities were performed, then blood was collected to measure oxidant and antioxidant markers (MDA, TAC, GSH, SOD). All animals were sacrificed, and the midbrains were excised. Sections were prepared for H&E histopathological and immunohistochemical studies for caspase-3 monoclonal antibodies. Results Rotenone administration caused significant signs of neurotoxicity like deterioration in behavioral patterns such as rearing, line crossings in open field test. MDA level was increased while TAC, GSH, and SOD were decreased. Macroscopic and stereomicroscopic findings showed a significant reduction in the dark color of neuromelanin pigment in SN. H&E sections showed absence of pigmented neurons in the SN with necrotic changes and Lewy bodies. The immunoreaction of caspase-3 was significantly expressed. Administration of ALA showed significant improvement in behavioral test and oxidative stress markers, immunoreaction with nearly normal pigmented neurocytes. Conclusion Rotenone is capable of inducing PD due to its oxidant and apoptotic capacities; ALA could reduce oxidative stress and apoptosis in PD.

Phytochemical Screening, Chromatographic Profiling and Anxiolytic Effect of Raphia australis Ethanol Extract in Adult Male Mice

Aim: This study seeks to evaluate the anxiolytic effect of the ethanol extract of the pulp of Raphia australis when tested in adult male mice, and to identify some of the anxiolytic secondary metabolites present in the plant’s pulp extract. Methodology: Phytochemical screening was carried out to determine the various classes of secondary metabolites present in the ethanol extract of R. australis. Both column chromatography and Liquid chromatography-mass spectrometer (LC-MS) were utilized to identify the bioactive compounds present in the ethanol extract of the pulp of Raphia australis. The extract was further subjected to Novelty Induced behaviour and anxiolytic tests using 4 groups of mice for each experiment comprising 5 mice in each group (n=5). Group one was administered normal saline (0.09% w/v NaCl. p.o) while 2 and 3 were administered 500 mgKg-1 and 1000 mgKg-1 (p.o) of ethanol extract of Raphia australis respectively. Group four was administered 2 mgKg-1, (p.o.) of diazepam (control). Results: The phytochemical screening result was positive for all the classes of secondary metabolites tested for. The LC-MS results revealed the presence of proanthocyanidin (m/z 577.1354), catechin (m/z 289.0704), epicatechin (m/z 289.0700), protocatechuic acid (m/z 153.0200), umbelliferon (m/z 353.0868) and quinic acid (m/z 191.0571). When mice were injected with Raphia australis extract at the doses of 500 mg Kg-1 and 1000 mgKg-1, statistically significant results were obtained for grooming (p&gt;0.01), head dipping (p&gt;0.01) and anxiolytic (p&gt;0.05) tests. Conclusion: Raphia australis contains bioactive compounds which could be utilized for relief of stress and anxiety.

Effects of tDCS on glutamatergic pathways in epilepsy: neuroprotective and therapeutic potential.

Epilepsy is a chronic neurological disease characterized by recurrent seizures caused by abnormal electrical activity in the brain. The aim of our study was to investigate the effect of tDCS on oxidative stress, Ca2+, glutamate, GABA, AMPAR1, and NMDAR1 levels in kindling-induced epilepsy model. Behavioral tests evaluated motor and cognitive functions, while assessing oxidative stress, Ca2+, glutamate, GABA, AMPAR1, and NMDAR1 levels in hippocampal tissue. tDCS stimulation therapy demonstrates a neuroprotective effect on motor and cognitive function postepilepsy. Our study reveals an increase in TOC, Ca2+, glutamate, GABA, AMPAR1, and NMDAR1 levels and a decline in total antioxidant capacity (TAC) following PTZ-induced seizures. However, tDCS treatment led to a significant decrease of Ca2+, total oxidant capacity (TOC), glutamate, GABA, AMPAR1, and NMDAR1 levels in the epilepsy cohorts, while simultaneously causing a spike in TAC levels. The study's results showed that tDCS treatment could have a therapeutic effect on oxidative stress, Ca2+, TOC, glutamate, GABA, AMPAR1, NMDAR1, and TAC in both acute and chronic kindling epilepsy models.

Hif-1α ablation reduces the efficiency of NeuroD1 gene-based therapy and aggravates the brain damage following ischemic stroke

ABSTRACT Introduction Hypoxia-inducible factor 1α [HIF1α] regulates gene expression, allowing the organism to respond to low oxygen levels. Meanwhile, astrocytes participate in inflammatory processes and are associated with neurotoxic chemicals that can increase stroke volume, contributing considerably to the devastating effects of a stroke. Objective To evaluate whether Hif-1α ablation from the central nervous system is implicated in motor dysfunction and ischemic brain damage following stroke. Furthermore, to explore if Hif-1α ablation affects the therapeutic impact of NeuroD1 gene-based therapy. Methods Endothelin-1 [ET-1] was injected to induce ischemic stroke in mice. Both wild-type and Hypoxia-inducible factor 1α conditional knockout [Hif-1α CKO] mice were used. The effect of Hif-1α ablation was assessed by the neuron numbers, astrocyte activity, vascular endothelial growth factor [VEGF] expression, and behavioral tests. Moreover, western blot, ELISA, and RNA sequencing were used. Then, we used pAAV2/9-GfaABC1D-NeuroD1-P2A-EGFP-WPRE injection to examine the impact of NeuroD1 in Hif-1α CKO mice following ischemic stroke. Results We found that following stroke, motor dysfunction significantly increased in Hif-1α CKO mice. Furthermore, elevation of apoptosis and activation in both microglia and astrocytes were observed, consequently up-regulating neuroinflammation. Meanwhile, Hif-1α ablation significantly decreased the efficiency of NeuroD1 gene-based therapy. Conclusion Our findings demonstrate that Hif-1α ablation from the nervous system is implicated in ischemic stroke pathogenesis mainly by increasing neuron cell death and inducing astrocytes as well as decreasing the efficiency of NeuroD1. These data support the idea that manipulating HIF-1α is a viable therapeutic for ischemic stroke.