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Transcription of > 50% of the mammalian coding genes follows circadian rhythm in an organ-specific manner. Recent findings highlighted the influence of time of the day in the progression of various neurological diseases and therapies. In the present study, we evaluated the effect of time of occurrence of traumatic brain injury (TBI) on behavioral and neuropathological outcomes in mice of both sexes. Following a controlled cortical impact injury induced between Zeitgeber time (ZT)1–4 or ZT13-16, behavioral deficits and brain damage were evaluated. There were no significant differences in post-TBI motor function between groups ZT1-4 and ZT13-16 in either male or female mice compared with the sex-matched naïve control. TBI-induced anxiety-like behavior was significantly higher in the female ZT13-16 cohort compared to the naïve cohort; but, no difference was observed between injured groups in both sexes. Similarly, spatial learning and memory were not significantly different between the ZT1-4 and ZT13-16 groups in both sexes. Post-TBI cortical lesion volume was also not significantly different between ZT1-4 and ZT-13–16 groups in both sexes. The present study observed no significant effects of occurrence time on TBI-induced brain damage or behavioral deficits in male and female mice. [ABSTRACT FROM AUTHOR]

Assessing sex as a biological variable is critical to determining the influence of environmental and lifestyle risks and protective factors mediating behavior and neuroplasticity across the lifespan. We investigated sex differences in affective behavior, memory, and hippocampal neurogenesis following short- or long-term exposure to exercise or chronic mild stress in young and aged mice. Male and female mice were assigned control, running, or chronic stress rearing conditions for 1 month (young) or for 15 months (aged), then underwent a behavioral test battery to assess activity, affective behavior, and memory. Stress exposure into late-adulthood increased hyperactivity in both sexes, and enhanced anxiety-like and depressive-like behavior in aged female, but not male, mice. One month of stress or running had no differential effects on behavior in young males and females. Running increased survival of BrdU-labelled hippocampal cells in both young and aged mice, and enhanced spatial memory in aged mice. These findings highlight the importance of considering sex when determining how aging is differently impacted by modifiable lifestyle factors across the lifespan. [ABSTRACT FROM AUTHOR]

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Chronic stress can adversely affect the female reproductive endocrine system, potentially leading to disorders and impairments in ovarian function. However, current research lacks comprehensive understanding regarding the biochemical characteristics and underlying mechanisms of ovarian damage induced by chronic stress. We established a stable chronic unpredictable stress (CUS)-induced diminished ovarian reserve (DOR) animal model. Our findings demonstrated that prolonged CUS treatment over eight weeks resulted in increased atresia follicles in female mice. This atresia was accompanied by decreased AMH and increased FSH levels. Furthermore, we observed elevated levels of corticosterone both in the peripheral blood and within the ovary. Additionally, we detected abnormalities in ATP metabolism within the ovarian tissue. CUS exposure led to oxidative stress in the ovaries, fostering a microenvironment characterized by oxidative damage to mouse ovarian granulosa cells (mGCs) and heightened levels of reactive oxygen species. Furthermore, CUS prompted mGCs to undergo apoptosis via the mitochondrial pathway. These findings indicate a direct association between the fundamental physiological alterations leading to DOR and the oxidative phosphorylation processes within mGCs. The diminished ATP production by mGCs, triggered by CUS, emerges as a pivotal indicator of CUS-induced DOR. Our study establishes an animal model to investigate the impact of chronic stress on ovarian reserve function and sheds light on potential mechanisms underlying this phenomenon. [ABSTRACT FROM AUTHOR]

[Display omitted] • The combination of mbTBI and post-injury alcohol drinking revealed behavioral and histological changes in male mice at various timepoints. • mbTBI led to a decrease in locomotion and short-term memory loss at 1-week post injury, which was alleviated by post-injury alcohol drinking. • mbTBI and subsequent alcohol drinking collectively increased explorative behavior at 1-week post injury. • mbTBI and alcohol drinking synergistically caused long-term memory loss and acrolein accumulation at 3-weeks post injury. Traumatic brain injury is a prevalent condition that affects millions worldwide with no clear understanding or effective therapeutic management available. Military soldiers have a high risk of exposure to blast-induced traumatic brain injury (bTBI). Furthermore, alcohol drinking is common in this population, and studies have shown that post-TBI alcohol exposure can result in memory loss. Hence, it is possible that alcohol could contribute to the overall pathological outcome of brain trauma. However, such a possibility has not been explored in detail. Here, we combined a mild bTBI (mbTBI) model with the drinking-in-the-dark (DID) paradigm to investigate the pathological synergy between mbTBI and alcohol consumption by examining brain oxidative stress levels and behavioral alterations in mice. The results revealed the anxiolytic and short-term memory improvement effects of post-trauma alcohol drinking examined at an early timepoint post mbTBI. However, extended alcohol drinking for up to three weeks post mbTBI impaired long-term memory and was accompanied by intensified oxidative stress in brain regions associated with memory and anxiety. These findings, as well as those from previous in vitro TBI/alcohol studies, suggest a pathological synergy of physical force and post-impact alcohol exposure. This knowledge could potentially aid in establishing guidelines for TBI victims to avoid further injury to their brains as well as to help maximize their recovery following TBI. [ABSTRACT FROM AUTHOR]

Aberrant light/dark (LD) cycles are prevalent in modern society due to electric light usage, leading to mood disorders from circadian disruption or misalignment. However, research on the physiological and behavioral effects of LD variations on brain neurotransmitters is limited. We investigated the effects of extreme LD cycles on body weight (BW), core body temperature (Tcore), locomotor activity (ACT), emotional behaviors, and monoamine levels (noradrenaline [NA], dopamine [DA], and serotonin [5-HT]) in male Wistar rats that were exposed to 1 month of either long light phase (20 L:4D), long dark phase (4 L:20D), or normal (12 L:12D) LD cycles. The 20 L:4D rats exhibited blunted rhythms, with decreased amplitude and advanced/delayed acrophase in Tcore and ACT, alongside increased BW. The 4 L:20D rats showed circadian misalignment, with increased/decreased amplitude in Tcore or ACT and delayed acrophase in Tcore and ACT, also gaining BW. In the 20 L:4D group, NA and 5-HT levels decreased in the suprachiasmatic nucleus and amygdala, respectively, while the 4 L:20D group had increased DA and 5-HT levels in the caudate putamen and dorsomedial hypothalamus, respectively. Open field and social interaction tests indicated anxiety-like behaviors in both test groups. Overall, each extreme LD cycle affected Tcore, ACT amplitude, acrophase, and monoamine levels differently, inducing anxiogenic responses. [ABSTRACT FROM AUTHOR]

Background: Chronic sleep deprivation (CSD) plays an important role in mood disorders. However, the changes in the gut microbiota and metabolites associated with CSD-induced anxiety/depression-like behavior in female mice have not been determined. Due to the influence of endogenous hormone levels, females are more susceptible than males to negative emotions caused by sleep deprivation. Here, we aim to investigate how CSD changes the gut microbiota and behavior and uncover the relationship between CSD and gut microbiota and its metabolites in female mice. Methods: We used a 48-day sleep deprivation (SD) model using the modified multiple platform method (MMPM) to induce anxiety/depression-like behavior in female C57BL/6J mice and verified our results using the open field test, elevated plus maze, novel object recognition test, forced swim test, and tail suspension test. We collected fecal samples of mice for 16S rDNA sequencing and untargeted metabolomic analysis and colons for histopathological observation. We used Spearmen analysis to find the correlations between differential bacterial taxa, fecal metabolites, and behaviors. Results: Our study demonstrates that CSD induced anxiety/depressive-like behaviors in female mice. The results of 16S rDNA sequencing suggested that the relative abundance of the harmful bacteria g_ Rothia, g_ Streptococcus, g_ Pantoea, and g_ Klebsiella were significantly increased, while the beneficial bacteria g_ Rikenella, g_ Eubacterium]-xylanophilum-group, and g_ Eisenbergiella were significantly decreased after SD. Glycerophospholipid metabolism and glutathione metabolism were identified as key pathways in the fecal metabolism related to oxidative stress and inflammatory states of the intestine. Histological observation showed hyperplasia of epithelial cells, a decrease in goblet cells, and glandular atrophy of the colon in SD mice. There were correlations between some of the differential bacterial taxa, fecal metabolites, and behaviors. Conclusion: In summary, we found that CSD induced anxiety/depression-like behavior, caused gut microbiota dysbiosis, altered fecal metabolism, and damaged the colon barrier in female mice. [ABSTRACT FROM AUTHOR]

To study the effects of Polygonatum kingianum polysaccharides (PKP) on lipid metabolism disorders and brain function impairments in obese mice, the obese mice were treated with PKP, prepared by enzyme-assisted extraction, for 12 weeks. Changes in body mass and blood lipids, as well as pathological changes in liver and adipose tissue were observed. Behavioral changes were detected to assess the autonomic activity and anxiety-like behavior of mice, and inflammation levels in liver, adipose tissue, serum, and brain as well as pathomorphological changes in brain were detected. The results showed that PKP (1 500 mg/kg) reduced body mass gain by 29.6% in obese mice, significantly alleviated dyslipidemia and pathological changes in liver and adipose tissue, and promoted the expression of peroxisome proliferator-activated receptors α (PPARα) in liver (46.0%) and the expression of uncoupling protein 1 in adipose tissue (59.0%). PKP significantly increased autonomic activity and suppressed anxiety-like behavior in obese mice. Furthermore, PKP reduced the expression of F4/80 in liver and adipose tissue by 55.0% and 67.2%, respectively, and the serum levels of pro-inflammatory cytokines in including interleukin 1β by 22.9%, interleukin 6 by 44.6%, and tumor necrosis factor α by 7.8%, but increased the serum level of anti-inflammatory cytokine interleukin 10 by 27.1%. Furthermore, PKP reduced the expression levels of ionized calcium binding adaptor molecule 1 in the hippocampus and cerebral cortex by 16.0% and 28.6%, respectively, and inhibited structural damages of the hippocampus and cerebral cortex. PKP mitigate obesity-induced lipid disorders and brain damages, indicating their potential as a functional food ingredient for obesity and suppressing obesity-induced brain damage.

Abstract Blast neurotrauma has been linked to impairments in higher-order cognitive functions, including memory, attention, and mood. Current literature is limited to a single overpressure exposure or repeated exposures at the same level of overpressure. In this study, a rodent model of primary blast neurotrauma was employed to determine the pressure at which acute and chronic neurological alterations occurred. Three pressure magnitudes (low, moderate and high) were used to evaluate injury thresholds. A biology shock tube (BST) was used to simulate shock waves with overpressures of 60 kPa, 90 kPa and 120 kPa respectively. Neurological behavior of the rats was assessed by the Multi-Conditioning System (MCS) at 1 d, 7 d, 28 d and 90 d after shock wave exposure. Serum dopamine (DA), 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF) and gamma-aminobutyric acid (GABA) were measured at the same time points. The proteomic analysis was conducted to identify potentially vulnerable cellular and molecule targets of serum in the immediate post-exposure period. Results revealed that: (1) Anxiety-like behavior increased significantly at 1 d post-exposure in the medium and high overpressure (90 kPa, 120 kPa) groups, returned to baseline at 7 days, and anxiety-like behavior in the high overpressure groups re-emerged at 28 d and 90 d. (2) High overpressure (120 kPa) impaired learning and memory in the immediate post-exposure period. (3) The serum DA levels decreased significantly at 1 d post-exposure in the medium and high overpressure groups; The 5-HT levels decreased significantly at 1 d and 90 d in the high overpressure groups; The BDNF levels decreased significantly at 90 d in the high overpressure groups. (4) Proteomic analysis identified 38, 306, and 57 differentially expressed proteins in serum following low, medium and high overpressure exposures, respectively. Two co-expressed proteins were validated. Functional analysis revealed significant enrichment of 1121, 2096, and 1121 Gene Ontology (GO) items and 33, 47, and 26 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, indicating extensive molecular responses to overpressure in the early phase. These findings suggest that exposure, even at moderate levels, can induce persistent neurobehavioral and molecular alterations, highlighting the need for further research into the long-term consequences of blast neurotrauma.

Postoperative pain is a type of pain that occurs in clinical patients after surgery. Among the factors influencing the transition from acute postoperative pain to chronic postoperative pain, chronic stress has received much attention in recent years. Here, we investigated the role of dopamine receptor D1/D2 expressing pyramidal neurons in the prelimbic cortex (PrL) in modulating chronic social defeat stress (CSDS)-induced anxiety-like behavior comorbidity with postoperative hyperalgesia in male mice. Our results showed that preoperative CSDS induced anxiety-like behavior and significantly prolonged postoperative pain caused by plantar incision, but did not affect plantar wound recovery and inflammation. Reduced activation of dopamine receptor D1 or D2 expressing neurons in the PrL is a remarkable feature of male mice after CSDS, and chronic inhibition of dopamine receptor D1 or D2 expressing neurons in the PrL induced anxiety-like behavior and persistent postoperative pain. Further studies found that activation of D1 expressing but not D2 expressing neurons in the PrL ameliorated CSDS-induced anxiety-like behavior and postoperative hyperalgesia. Our results suggest that dopamine receptor D1 expressing neurons in the PrL play a crucial role in CSDS-induced anxiety-like behavior comorbidity with postoperative hyperalgesia in male mice. [ABSTRACT FROM AUTHOR]

Post-traumatic stress disorder (PTSD) is a multifactorial psychological disorder that affects different neurotransmitter systems, including the central CRH system. CRH acts via the CRHR1 and CRHR2 receptors, which exert opposite effects, i.e., anxiogenic or anxiolytic. The aim of this work was to investigate how intranasal administration of the CRHR2-specific agonist urocortin 2 (Ucn2) or urocortin 3 (Ucn3) affects manifestations of PTSD in a single prolonged stress (SPS) animal model of PTSD. Elevated plus maze (EPM) and open field (OF) tests were used to assess anxiety-like behavior. Changes in the gene expressions of CRH, CRHR1, CRHR2, glucocorticoid receptor (GR), and FKBP5 were measured in brain regions (BNST, amygdala, and PVN) responsible for modulating the stress response. The SPS animals spent less time in the OF central zone and were less mobile than the controls; however, the Ucn3 treatment reversed this effect. SPS decreased the GR and FKPB5 mRNA levels in the PVN. Ucn3 suppressed the effect of SPS on FKBP5 mRNA expression in the PVN and increased FKBP5 mRNA in the BNST and PVN compared to the stressed animals. We demonstrate that Ucn3 has the potential to ameliorate anxiety-like behavior in SPS animals and also to affect the neuroendocrine system in the BNST and PVN. In addition, we confirm the important role of CRHR2 signaling in mediating the stress response. [ABSTRACT FROM AUTHOR]

Background: Studies in experimental animals revealed that acute and chronic treatment with small‐molecule immunosuppressive drugs lead to neurobehavioral alterations in rodents. Methods: Against this background, this study investigated behavioral alterations in rats after repeated administration of FTY720, an immunosuppressive drug used for the treatment of multiple sclerosis, employing the open field, elevated plus maze, and dark/light tests. Results: Compared to controls, repeated FTY720 treatment affected behavior in rats, reflected by a reduction in distance traveled as well as increased time engaged in freezing in the open field and elevated plus maze. Furthermore, the time spent freezing in the elevated plus maze test positively correlated with FTY720 concentrations in the amygdala and insular cortex, two brain regions involved in regulation of emotionality. Since no changes in plasma corticosterone levels were observed, stress effects due to treatment, behavioral testing, or handling can be ruled out. Conclusion: The present findings indicate that treatment with FTY720 did not induce typical anxiety‐like behavioral patterns in otherwise healthy rats as seen following treatment with other immunosuppressive drugs. Nevertheless, it remains of great importance to evaluate behavioral effects in clinical practice to shed more light onto possible detrimental side effects emerging during treatment with small‐molecule immunosuppressive drugs. [ABSTRACT FROM AUTHOR]

Disturbances in the Hedgehog (Hh) signaling play an important role in dysmorphogenesis of bone tissue and central nervous system during prenatal alcohol exposure, which underlies development of fetal alcohol syndrome. The involvement of Hh proteins in the mechanisms of alcohol intake in adults remains obscure. We investigated the role of the Hh cascade in voluntary ethanol drinking and development of anxiety-like behavior (ALB) during early abstinence and assessed changes in the expression of Hh pathway components in different brain regions of male Wistar rats in a model of voluntary alcohol drinking using the intermittent access to 20% ethanol in a two-bottle choice procedure. Purmorphamine (Hh cascade activator and Smoothened receptor agonist) was administered intraperitoneally at a dose of 5 mg/kg body weight prior to 16-20 sessions of alcohol access. Purmorphamine had no effect on the ethanol preference; however, rats exposed to ethanol and receiving purmorphamine demonstrated changes in the ALB during the early abstinence period. Alcohol drinking affected the content of the Sonic hedgehog (Shh) and Patched mRNAs only in the amygdala. In rats exposed to ethanol and receiving purmorphamine, the level of Shh mRNA in the amygdala correlated negatively with the time spent in the open arms of the elevated plus maze. Therefore, we demonstrated for the first time that alterations in the Hh cascade induced by administration of purmorphamine did not affect alcohol preference in voluntary alcohol drinking. It was suggested that Hh cascade is involved in the development of anxiety after alcohol withdrawal through specific changes in the Hh cascade components in the amygdala. [ABSTRACT FROM AUTHOR]

Anxiety disorder is one of the most well-characterized behavioral disorders in individuals subjected to acute or chronic stress. However, few studies have demonstrated how different types of stressors can modulate the neurochemical alterations involved in the generation of anxiety. In this study, we hypothesize that subjects exposed to different aversive stimuli (mechanical, chemical, and spatial restriction) present varied intensities of anxiety-like responses associated with distinct patterns of gamma-aminobutyric acid (GABA) and glutamate release in the brain. Adult zebrafish, Danio rerio (n = 60), were randomly divided into four experimental groups; control, acute restraint stress (ARS), conspecific alarm substance (CAS), and chasing with net (CN). After the stress protocols, the animals were individually transferred to a novel tank diving test for behavioral analysis. Subsequently, their brains were collected and subjected to GABA and glutamate release assay for quantification by HPLC. Our behavioral results showed that all aversive stimuli were capable of inducing anxiety-like behavior. However, the impact of anxiogenic behavior was more prominent in the CN and CAS groups when compared to ARS. This phenomenon was evident in all analyzed behavioral parameters (time on top, freezing, mean speed, maximum speed, and erratic swimming). Our data also showed that all aversive stimuli significantly decreased GABA release compared to the control group. Only animals exposed to CN and CAS presented an increase in extracellular glutamate levels. Different acute stressors induced different levels of anxiety-like behavior in zebrafish as well as specific alterations in GABAergic and glutamatergic release in the brain. These results demonstrate the complexity of anxiety disorders, highlighting that both behavioral and neurochemical responses are highly context-dependent. [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]

Background: Prenatal and postnatal exposure to drugs such as cocaine is a public health problem that causes deficits in brain development and function in humans and animals. One of the main effects of prenatal and postnatal cocaine exposure is increased vulnerability to developing the substance use disorder at an early age. Furthermore, the negative emotional states associated with cocaine withdrawal increase the fragility of patients to relapse into drug abuse. In this sense, prenatal and postnatal cocaine exposure enhanced the cocaine‐ and nicotine‐induced locomotor activity and locomotor sensitization, and rats exposed prenatally to cocaine displayed an increase in anxiety‐ and depressive‐like behaviors in adulthood (PND 60–70). Objective: Therefore, the objective of this study was to determine the effect of prenatal and postnatal cocaine exposure on anxiety‐ and depressive‐like behaviors at different ages (30, 60, 90, and 120 days of age) in rats. Methods: The study was divided into two stages: prenatal and postnatal. In the prenatal stage, a group of pregnant female Wistar rats was administered daily from GD0 to GD21 cocaine (cocaine pre‐exposure group), and another group of pregnant female rats was administered daily saline (saline pre‐exposure group). In the postnatal stage, during lactation (PND0 to PND21), pregnant rats received administration of cocaine or saline, respectively. Of the litters resulting from the cocaine pre‐exposed and saline pre‐exposed pregnant female groups, only the male rats were used for the recording of the anxiety‐ and depressive‐like behaviors at different postnatal ages (30, 60, 90, and 120 days), representative of adolescence, adult, adulthood, and old age. Results: The study found that prenatal and postnatal cocaine exposure generated age‐dependent enhancement in anxiety‐ and depressive‐like behaviors, being greater in older adult (PND 120) rats than in adolescent (PND 30) or adults (PND 60–90) rats. Conclusions: This suggests that prenatal and postnatal cocaine exposure increases anxiety‐ and depressive‐like behaviors, which may increase the vulnerability of subjects to different types of drugs in young and adult age. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine the influence of sex and strain on striatal and nucleus accumbens dopamine neurochemistry and dopamine-related behavior due to a high-saturated-fat diet (HFD). Methods: Male and female C57B6/J (B6J) and Balb/cJ (Balb/c) mice were randomly assigned to a control-fat diet (CFD) containing 10% kcal fat/g or a mineral-matched HFD containing 60% kcal fat/g for 12 weeks. Results: Intraperitoneal glucose tolerance testing (IPGTT) and elevated plus maze experiments (EPM) confirmed that an HFD produced marked blunting of glucose clearance and increased anxiety-like behavior, respectively, in male and female B6J mice. Electrically evoked dopamine release in the striatum and reuptake in the nucleus accumbens (NAc), as measured by ex vivo fast scan cyclic voltammetry, was reduced for HFD-fed B6J females. Impairment in glucose metabolism explained HFD-induced changes in dopamine neurochemistry for B6J males and, to a lesser extent, Balb/c males. The relative expressions of protein markers associated with the activation of microglia, ionized calcium binding adaptor molecule (Iba1) and cluster of differentiation molecule 11b (CD11b) in the striatum were increased due to an HFD for B6J males but were unchanged or decreased amongst HFD-fed Balb/c mice. Conclusions: Our findings demonstrate that strain and sex influence the insulin- and microglia-dependent mechanisms of alterations to dopamine neurochemistry and associated behavior due to an HFD. [ABSTRACT FROM AUTHOR]

Background/Objectives: Limosilactobacillus (Lm.) reuteri is a widely utilized probiotic, recognized for its significant role in alleviating symptoms associated with gastrointestinal and psychiatric disorders. However, the effectiveness of Lm. reuteri is strain-specific, and its genetic diversity leads to significant differences in phenotypes among different strains. This study aims to identify potential probiotic strains by comparing the strain-specific characteristics of Lm. reuteri to better understand their efficacy and mechanisms in alleviating stress-induced anxiety-like behaviors and gastrointestinal symptoms. Methods: We cultivated 11 strains of Lm. reuteri from healthy human samples and conducted phenotypic and genomic characterizations. Two strains, WLR01 (=GOLDGUT-LR99) and WLR06, were screened as potential probiotics and were tested for their efficacy in alleviating anxiety-like behavior and intestinal symptoms in mouse models subjected to sleep deprivation (SD) and water avoidance stress (WAS). Results: The results showed that the selected strains effectively improved mouse behaviors, including cognitive impairment and inflammatory response, as well as improving anxiety and regulating gut microbiota composition. The improvements with WLR01 were associated with the regulation of the NLRP3 inflammasome pathway in the SD model mice and were associated with visceral hypersensitivity and intestinal integrity in the WAS model mice. Conclusions: In summary, this study identified the Lm. reuteri strain WLR01 as having the potential to alleviate anxiety-like behavior and intestinal symptoms through the analysis of Lm. reuteri genotypes and phenotypes, as well as validation in mouse models, thereby laying the foundation for future clinical applications. [ABSTRACT FROM AUTHOR]

Binge drinking causes a range of problems especially damage to the nervous system, and the specific neural mechanism of brain loss and behavioral abnormalities caused by which is still unclear. Extracellular regulated protein kinases (ERK) maintain neuronal survival, growth, and regulation of synaptic plasticity by phosphorylating specific transcription factors to regulate expression of brain-derived neurotrophic factor (BDNF). Dual-specific phosphatase 1 (DUSP1) and DUSP6 dephosphorylate tyrosine and serine/threonine residues in ERK1/2 to inactivate them. To investigate the molecular mechanism by which alcohol affects memory and emotion, a chronic intermittent alcohol exposure (CIAE) model was established. The results demonstrated that mice in the CIAE group developed short-term recognition memory impairment and anxiety-like behavior; meanwhile, the expression of DUSP1 and DUSP66 in the mPFC was increased, while the levels of p-ERK and BDNF were decreased. Micro-injection of DUSP1/6 inhibitor BCI into the medial prefrontal cortex (mPFC) restored the dendritic morphology by reversing the activity of ERK-BDNF and ultimately improved cognitive and emotional impairment caused by CIAE. These findings indicate that CIAE inhibits ERK-BDNF by increasing DUSP1/6 in the mPFC that may be associated with cognitive and emotional deficits. Consequently, DUSP1 and DUSP6 appear to be potential targets for the treatment of alcoholic brain disorders. [ABSTRACT FROM AUTHOR]

Accumulating evidence suggests an involvement of sphingolipids, vital components of cell membranes and regulators of cellular processes, in the pathophysiology of both Parkinson's disease and major depressive disorder, indicating a potential common pathway in these neuropsychiatric conditions. Based on this interaction of sphingolipids and synuclein proteins, we explored the gene expression patterns of α-, β-, and γ-synuclein in a knockout mouse model deficient for acid sphingomyelinase (ASM), an enzyme catalyzing the hydrolysis of sphingomyelin to ceramide, and studied associations with behavioral parameters. Normalized Snca, Sncb, and Sncg gene expression was determined by quantitative PCR in twelve brain regions of sex-mixed homozygous (ASM−/−, n = 7) and heterozygous (ASM+/−, n = 7) ASM-deficient mice, along with wild-type controls (ASM+/+, n = 5). The expression of all three synuclein genes was brain region-specific but independent of ASM genotype, with β-synuclein showing overall higher levels and the least variation. Moreover, we discovered correlations of gene expression levels between brain regions and depression- and anxiety-like behavior and locomotor activity, such as a positive association between Snca mRNA levels and locomotion. Our results suggest that the analysis of synuclein genes could be valuable in identifying biomarkers and comprehending the common pathological mechanisms underlying various neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

Anxiety is an adaptive response to potentially threatening conditions. Excessive and uncontrolled anxiety responses become nonadaptive and cause anxiety disorders. To better understand the anxiety-modulating effects of Mg sulfate, behavioral test batteries in the assessment of anxiety and learning and memory functions were performed simultaneously over a time period. This study also examines the effects of Mg sulfate compared to diazepam, an anxiolytic drug with amnestic effects on anxiety-like behavior, as well as possible oxidative-nitrosative stress and hippocampal changes in male rats exposed to predator odor. Young adult Sprague-Dawley male rats were used. The rats were assessed using a comprehensive neurobehavioral test battery consisting of novel object recognition, open field, and successive alleys tasks. Anxiety was induced by cat odor, and diazepam and Mg were used as study drugs. Of the frontal cortex and hippocampus, the state of total oxidant and antioxidant and NO levels and histological examination of hippocampal CA1, CA2, CA3, and DG regions were performed. Diazepam- and Mg-treated rats showed an improvement in anxiety-related behavior to predator odors. Furthermore, Mg treatment alleviated some of the increasing oxidative stress in the frontal cortex and hippocampus of rats, while diazepam treatment in particular enhanced hippocampal oxidant and antioxidant activity. In addition, brain NO increase induced by animal odor exposure or diazepam treatment was ameliorated by Mg administration. Overall, our work suggests that Mg had a partial anxiolytic effect on anxiety-like behaviors, although not as much as diazepam, and this effect varied depending on the dose. Mg treatment might counteract increased oxidative stress and elevated NO levels in the brain. [ABSTRACT FROM AUTHOR]

Repeated exposure to tobacco smoke causes neuroinflammation and neuroplasticity, which correlates with smoking withdrawal-induced anxiety. The purpose of this study was to investigate the anticipated involvement of antioxidant-rich nanoparticles (NPs) prepared by oxidation-triggered polymerization of green tea catechins in impacting these effects in a rat model of tobacco smoke exposure. Exposure to tobacco smoke was carried out for 2 h a day, 5 days a week, for a total of 36 days. Weekly behavioral tests were conducted prior to recommencing the exposure. Following a 20-day exposure period, rats were administered either distilled water or green tea (GT) NPs (20 mg/kg, orally) for an additional 16 days. Our findings revealed that tobacco smoke exposure induced anxiety-like behavior indicative of withdrawal, and this effect was alleviated by GT NPs. Tobacco smoke exposure caused a marked increase in the relative mRNA and protein expression of nuclear factor-kappa B (NF-κB) and reduced the relative mRNA and protein expression of brain-derived neurotrophic factor (BDNF) in the hippocampus (HIP) and hypothalamus (HYP) brain subregions. The intervention of GT NPs effectively inhibited these effects. Our findings demonstrate the potent protective role of GT NPs in reducing withdrawal-induced anxiety-like behavior, neuroinflammation, and neuroplasticity triggered by tobacco smoke exposure. [ABSTRACT FROM AUTHOR]

Many experts have extensively studied the potential of exercise as a treatment option for psychiatric conditions, including depression and autism spectrum disorder (ASD). Despite their core symptoms, these conditions exhibits comparable component traits, an anxiety. In this study, we explored the effect of exercise on behavioral abnormalities in psychiatric conditions, focusing on its intensity and emotional resilience. Shank3B knockout (KOSED) mice displaying self-injurious repetitive behavior and C57BL/6J mice, susceptible to stress as ASD and depression model, respectively, were subjected to moderate-intensity exercise (ME) for 2 weeks. ME mitigated the core symptoms (excessive grooming traits and behavioral despair) but did not exert a significant anxiolytic effect. Notably, exercise intensity has emerged as a critical determinant of its efficacy, as evidenced by a lower ventilation threshold and anxiolytic effect mediated by low-intensity exercise. The findings substantiate the notion that exercise is promising as a disease-modifying treatment, but intensity matters for emotional resilience. [ABSTRACT FROM AUTHOR]

Pregnancy is associated with neural and behavioral plasticity, systemic inflammation, and oxidative stress, yet the impact of inflammation and oxidative stress on maternal neural and behavioral plasticity during pregnancy is unclear. We hypothesized that healthy pregnancy transiently reduces learning and memory and these deficits are associated with pregnancy-induced elevations in inflammation and oxidative stress. Cognitive performance was tested with novel object recognition (recollective memory), Morris water maze (spatial memory), and open field (anxiety-like) behavior tasks in female Sprague-Dawley rats of varying reproductive states [nonpregnant (nulliparous), pregnant (near term), and 1–2 mo after pregnancy (primiparous); n = 7 or 8/group]. Plasma and CA1 proinflammatory cytokines were measured with a MILLIPLEX magnetic bead assay. Plasma oxidative stress was measured via advanced oxidation protein products (AOPP) assay. CA1 markers of oxidative stress, neuronal activity, and apoptosis were quantified via Western blot analysis. Our results demonstrate that CA1 oxidative stress-associated markers were elevated in pregnant compared with nulliparous rats (P ≤ 0.017) but there were equivalent levels in pregnant and primiparous rats. In contrast, reproductive state did not impact CA1 inflammatory cytokines, neuronal activity, or apoptosis. Likewise, there was no effect of reproductive state on recollective or spatial memory. Even so, spatial learning was impaired (P ≤ 0.007) whereas anxiety-like behavior (P ≤ 0.034) was reduced in primiparous rats. Overall, our data suggest that maternal hippocampal CA1 is protected from systemic inflammation but vulnerable to peripartum oxidative stress. Peripartum oxidative stress elevations, such as in pregnancy complications, may contribute to peripartum neural and behavioral plasticity. NEW & NOTEWORTHY: Healthy pregnancy is associated with elevated maternal systemic and brain oxidative stress. During postpregnancy, brain oxidative stress remains elevated whereas systemic oxidative stress is resolved. This sustained maternal brain oxidative stress is associated with learning impairments and decreased anxiety-like behavior during the postpregnancy period. [ABSTRACT FROM AUTHOR]

• Vagotomy mitigates Salmonella-induced systemic infection and anxiety-like behavior. • Vagotomy alleviates the Salmonella-induced gut inflammation and neuroinflammation. • Vagotomy enhanced GABA production and related microbes abundance in the infected mice. • Vagotomy relies on GABA production to alleviate gut inflammation. The vagus nerve, a pivotal link within the gut-brain axis, plays a critical role in maintaining homeostasis and mediating communication between the gastrointestinal tract and the brain. It has been reported that gastrointestinal infection by Salmonella typhimurium (S. typhimurium) triggers gut inflammation and manifests as anxiety-like behaviors, yet the mechanistic involvement of the vagus nerve remains to be elucidated. In this study, we demonstrated that unilateral cervical vagotomy markedly attenuated anxiety-like behaviors induced by S. typhimurium SL1344 infection in C57BL/6 mice, as evidenced by the open field test and marble burying experiment. Furthermore, vagotomy significantly diminished neuronal activation within the nucleus of the solitary tract and amygdala, alongside mitigating aberrant glial cell activation in the hippocampus and amygdala. Additionally, vagotomy notably decreases serum endotoxin levels, counters the increase in splenic Salmonella concentration, and modulates the expression of inflammatory cytokines—including IL-6, IL-1β, and TNF-α—in both the gastrointestinal tract and brain, with a concurrent reduction in IL-22 and CXCL1 expression. This intervention also fostered the enrichment of beneficial gut microbiota, including Alistipes and Lactobacillus species, and augmented the production of gamma-aminobutyric acid (GABA) in the gut. Administration of GABA replicated the vagotomy's beneficial effects on reducing gut inflammation and anxiety-like behavior in infected mice. However, blockade of GABA receptors with picrotoxin abrogated the vagotomy's protective effects against gut inflammation, without influencing its impact on anxiety-like behaviors. Collectively, these findings suggest that vagotomy exerts a protective effect against infection by promoting GABA synthesis in the colon and alleviating anxiety-like behavior. This study underscores the critical role of the vagus nerve in relaying signals of gut infection to the brain and posits that targeting the gut-brain axis may offer a novel and efficacious approach to preventing gastrointestinal infections and associated behavioral abnormalities. [ABSTRACT FROM AUTHOR]

Chronic treatment with clomipramine, a tricyclic antidepressant drug, reduces symptoms of obsessive-compulsive disorder (OCD) and can influence the activity of the hypothalamic-pituitary-adrenal axis. However, little is known regarding the effects of acute clomipramine on the immediate expression of stress responses. Serotonergic drugs can elicit surfacing, a behavioral profile potentially related to toxicity in fish, although surfacing has not yet been observed after clomipramine exposure. The present study investigated the impact of acute exposure to clomipramine on basal and stress-induced behaviors in the novel tank test and cortisol levels in mixed-sex, wild-type, adult zebrafish (Danio rerio). The findings show clomipramine-exposed groups (regardless of stress exposure) spent much more time in the top of the novel tank and had significantly less overall motor activity in the behavioral task compared to the fish not exposed to the drug. Then, the dose-dependent effects of acute clomipramine on activity in the surface of the novel tank (top third of the top half) were investigated further. Clomipramine dose-dependently increased surface-dwelling and elicited a dose-dependent hypoactivity in overall motor behavior. There were no statistically significant differences in whole-body cortisol levels in either experiment. Like other serotonin-acting drugs, clomipramine strongly elicited surface-dwelling and depressed motor behavior in adult zebrafish. Additional testing is needed to elucidate whether surfacing represents a toxic state and how serotonin regulates surfacing. [ABSTRACT FROM AUTHOR]

Anxiety disorder is one of the most well-characterized behavioral disorders in individuals subjected to acute or chronic stress. However, few studies have demonstrated how different types of stressors can modulate the neurochemical alterations involved in the generation of anxiety. In this study, we hypothesize that subjects exposed to different aversive stimuli (mechanical, chemical, and spatial restriction) present varied intensities of anxiety-like responses associated with distinct patterns of gamma-aminobutyric acid (GABA) and glutamate release in the brain. Adult zebrafish, Danio rerio (n = 60), were randomly divided into four experimental groups; control, acute restraint stress (ARS), conspecific alarm substance (CAS), and chasing with net (CN). After the stress protocols, the animals were individually transferred to a novel tank diving test for behavioral analysis. Subsequently, their brains were collected and subjected to GABA and glutamate release assay for quantification by HPLC. Our behavioral results showed that all aversive stimuli were capable of inducing anxiety-like behavior. However, the impact of anxiogenic behavior was more prominent in the CN and CAS groups when compared to ARS. This phenomenon was evident in all analyzed behavioral parameters (time on top, freezing, mean speed, maximum speed, and erratic swimming). Our data also showed that all aversive stimuli significantly decreased GABA release compared to the control group. Only animals exposed to CN and CAS presented an increase in extracellular glutamate levels. Different acute stressors induced different levels of anxiety-like behavior in zebrafish as well as specific alterations in GABAergic and glutamatergic release in the brain. These results demonstrate the complexity of anxiety disorders, highlighting that both behavioral and neurochemical responses are highly context-dependent.

Although sleep is tightly regulated by multiple neuronal circuits in the brain, nonneuronal cells such as glial cells have been increasingly recognized as crucial sleep regulators. Recent studies have shown that microglia may act to maintain wakefulness. Here, we investigated the possible involvement of microglia in the regulation of sleep quantity and quality under baseline and stress conditions through electroencephalography (EEG)/electromyography (EMG) recordings, and by employing pharmacological methods to eliminate microglial cells in the adult mouse brain. We found that severe microglial depletion induced by the colony-stimulating factor 1 receptor (CSF1R) antagonist PLX5622 (PLX) reversibly decreased the total wake time and the wake episode duration and increased the EEG slow-wave power during wakefulness under baseline conditions. To examine the role of microglia in sleep/wake regulation under mental stress, we used the acute social defeat stress (ASDS) paradigm, an ethological model for psychosocial stress. Sleep analysis under ASDS revealed that microglial depletion exacerbated the stress-induced decrease in the total wake time and increase in anxiety-like behaviors in the open field test. These results demonstrate that microglia actively modulate sleep quantity and architecture under both baseline and stress conditions. Our findings suggest that microglia may potentially provide resilience against acute psychosocial stress by regulating restorative sleep.

Simple Summary: Fighting is the most common problem in group-housed male mice. Fighting leads to stress, wounds, and sometimes result in death, which is against animal welfare and contradicts the 3Rs principle. In this study, we aimed to evaluate behavior and stress levels in group-housed males and males pair-housed with ovariectomized female mice. Our study showed that whilst some group-housed males do fight, no male pair-housed with ovariectomized females does. In addition, pair-housed males had a better memory, and less anxiety-like behavior. Pair-housed male mice had a larger reduction in corticosterone levels during the study, indicating lower stress levels. These findings suggest that pair-housing male mice with ovariectomized females could refine the housing conditions for laboratory male mice. Aggressiveness, expressed by fighting, is a frequent problem in group-housed laboratory male mice and results in increased stress, injury, and death. One way to prevent fighting is by pairing the male mice with ovariectomized female mice to provide a compatible companion. However, the effect of these housing conditions remains unclear. Therefore, we aimed to evaluate behavior and stress levels in two different housing conditions, pair-housed with an ovariectomized female and group-housed with other males. Behavioral tests were performed to assess stress and anxiety-like behavior. Moreover, the corticosterone levels in plasma were measured by ELISA. Based on home cage behavior assessment, pair-housed male mice showed no signs of fighting, not even after isolation and regrouping. Our results also showed that the pair-housed males had a better memory and demonstrated less anxiety-like behavior. Subsequently, the pair-housed male mice had a larger reduction in corticosterone levels compared to group-housed males. Overall, pair-housing reduced anxiety-like behavior and stress levels in male mice compared to standard group-housing. [ABSTRACT FROM AUTHOR]

As wireless communication devices gain popularity, concerns about the potential risks of environmental exposure to complex frequency electromagnetic radiation (EMR) on mental health have become a public health issue. Historically, EMR research has predominantly focused on single-frequency electromagnetic waves, neglecting the study of multi-frequency electromagnetic waves, which more accurately represent everyday life. To address these concerns, our study compared the emotional effects of single-frequency and dual-frequency EMR while exploring potential molecular mechanisms and intervention targets. Our results revealed that single-frequency EMR at 2.65 or 0.8 GHz did not induce anxiety-like behavior in mice. However, exposure to dual-frequency EMR at 2.65/0.8 GHz significantly led to anxiety-like behavior in mice. Further analysis of mouse sera revealed substantial increases in corticosterone and corticotrophin releasing hormone levels following exposure to 2.65/0.8 GHz EMR. Transcriptome sequencing indicated a significant decrease in the expression of Cnr1, encoding cannabinoid receptor 1 Type (CB1R), in the cerebral. This finding was consistently verified through western blot analysis, revealing a substantial reduction in CB1R content. Additionally, a significant decrease in the endocannabinoid 2-arachidonoylglycerol was observed in the cerebral cortex. Remarkably, administering the cannabinoid receptor agonist Win55-212-2 significantly alleviated the anxiety-like behavior, and the cannabinoid receptor antagonist AM251 effectively counteracted the anti-anxiety effects of Win55-212-2. In summary, our research confirmed that dual-frequency EMR is more likely to induce anxiety-like behavior in mice than single-frequency EMR, with implications for the hypothalamic-pituitary-adrenal axis and the endocannabinoid system. Furthermore, our findings suggest that Win55-212-2 may represent a novel avenue for researching and developing anti-EMR drugs. [ABSTRACT FROM AUTHOR]

Fluorene-9-bisphenol (BHPF) is widely used in the manufacture of plastic products and potentially disrupts several physiological processes, but its biological effects on social behavior remain unknown. In this study, we investigated the effects of BHPF exposure on anxiety-like and social behavior in female mice and the potential mechanisms, thereby proposing a potential therapy strategy. We exposed female Balb/c mice to BHPF by oral gavage at different doses (0.5, 50 mg/kg bw/2-day) for 28 days, which were found BHPF (50 mg/kg) exposure affected motor activity in the open field test (OFT) and elevated cross maze (EPM), resulting in anxiety-like behaviors, as well as abnormal social behavioral deficits in the Social Interaction Test (SIT). Analysis of histopathological staining results showed that BHPF exposure caused damage to hippocampal neurons in the CA1/CA3/DG region and decreased Nissl pyramidal neurons in the CA1/CA3 regions of the hippocampus, as well as a decrease in parvalbumin neuron expression. In addition, BHPF exposure upregulated the expression of excitatory and inhibitory (E/I) vesicle transporter genes (Vglut1, Vglut2, VGAT, GAD67, Gabra) and axon growth gene (Dcc) in the mouse hippocampus. Interestingly, behavioral disturbances and E/I balance could be alleviated by exogenous melatonin (15 mg/kg bw/2-day) therapy. Our findings suggest that exogenous melatonin may be a potential therapy with protective potential for ameliorating or preventing BHPF-induced hippocampal neuronal damage and behavioral disturbances. This study provided new insight into the neurotoxicological effects on organisms exposed to endocrine-disrupting chemicals and aroused our vigilance in current environmental safety about chemical use. [ABSTRACT FROM AUTHOR]

As one of the most environmental concerns, inhaled particulate matter (PM 10) causes numerous health problems. However, the associations between anxiety behavior and toxicity caused by PM 10 have rarely been reported so far. To investigate the changes of behavior after PM 10 exposure and to identify the potential mechanisms of toxicity, PM 10 samples (with doses of 15 mg/kg and 30 mg/kg) were intratracheally instilled into rats to simulate inhalation of polluted air by the lungs. After instillation for eight weeks, anxiety-like behavior was evaluated, levels of oxidative stress and morphological changes of hippocampus were measured. The behavioral results indicated that PM 10 exposure induced obvious anxiety-like behavior in the open field and elevated plus maze tests. Both PM 10 concentrations tested could increase whole blood viscosity and trigger hippocampal neuronal damage and oxidative stress by increasing superoxide dismutase (SOD) activities and malondialdehyde levels, and decreasing the expressions of antioxidant-related proteins (e.g., nuclear factor erythroid 2-related factor 2 (Nrf2), SOD1 and heme oxygenase 1). Furthermore, through collecting and analyzing questionnaires, the data showed that the participants experienced obvious anxiety-related emotions and negative somatic responses under heavily polluted environments, especially PM 10 being the main pollutant. These results show that PM 10 exposure induces anxiety-like behavior, which may be related to suppressing the Nrf2/Keap1-SOD1 pathway. [Display omitted] • The participants experienced obvious anxiety emotions and negative somatic responses under heavily polluted environments. • Different concentrations of PM 10 exposure could induce severe anxiety-like behavior in rats. • PM 10 exposure aggravated hippocampal oxidative stress levels and increased whole blood viscosity. • There was a strong correlation between whole blood viscosity and oxidative stress. • The impaired Nrf2/Keap1-SOD1 pathway in hippocampus involved in anxiety-like behavior of PM 10 -exposed rats. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to investigate the relationship between ulcerative colitis (UC) and anxiety and explore its central mechanisms using colitis mice. Methods: Anxiety‐like behavior was assessed in mice induced by 3% dextran sodium sulfate (DSS) using the elevated plus maze and open‐field test. The spatial transcriptome of the hippocampus was analyzed to assess the distribution of excitatory and inhibitory synapses, and Toll‐like receptor 4 (TLR4) inhibitor TAK‐242 (10 mg/kg) and AAV virus interference were used to examine the role of peripheral inflammation and central molecules such as Glutamate Receptor Metabotropic 1 (GRM1) in mediating anxiety behavior in colitis mice. Results: DSS‐induced colitis increased anxiety‐like behaviors, which was reduced by TAK‐242. Spatial transcriptome analysis of the hippocampus showed an excitatory‐inhibitory imbalance mediated by glutamatergic synapses, and GRM1 in hippocampus was identified as a critical mediator of anxiety behavior in colitis mice via differential gene screening and AAV virus interference. Conclusion: Our work suggests that the hippocampus plays an important role in brain anxiety caused by peripheral inflammation, and over‐excitation of hippocampal glutamate synapses by GRM1 activation induces anxiety‐like behavior in colitis mice. These findings provide new insights into the central mechanisms underlying anxiety in UC and may contribute to the development of novel therapeutic strategies for UC‐associated anxiety. [ABSTRACT FROM AUTHOR]

Aims: Negative emotions induced by chronic pain are a serious clinical problem. Electroacupuncture (EA) is a clinically proven safe and effective method to manage pain‐related negative emotions. However, the circuit mechanisms underlying the effect of EA treatment on negative emotions remain unclear. Methods: Plantar injection of complete Freund's adjuvant (CFA) was performed to establish a rat model of chronic inflammatory pain‐induced anxiety‐like behaviors. Adeno‐associated virus (AAV) tracing was used to identify excitatory synaptic transmission from the rostral anterior cingulate cortex (rACC) to the dorsal raphe nucleus (DRN). Employing chemogenetic approaches, we examined the role of the rACC‐DRN circuit in chronic pain‐induced anxiety‐like behaviors and investigated whether EA could reverse chronic pain‐induced dysfunctions of the rACC‐DRN circuit and anxiety‐like behaviors. Results: We found that chemogenetic activation of the rACC‐DRN circuit alleviated CFA‐induced anxiety‐like behaviors, while chemogenetic inhibition of the rACC‐DRN circuit resulted in short‐term CFA‐induced anxiety‐like behaviors. Further research revealed that the development of CFA‐induced anxiety‐like behaviors was attributed to the dysfunction of rACC CaMKII neurons projecting to DRN serotonergic neurons (rACCCaMKII‐DRN5‐HT neurons) but not rACC CaMKII neurons projecting to DRN GABAergic neurons (rACCCaMKII‐DRNGABA neurons). This is supported by the findings that chemogenetic activation of the rACCCaMKII‐DRN5‐HT circuit alleviates anxiety‐like behaviors in rats with chronic pain, whereas neither chemogenetic inhibition nor chemogenetic activation of the rACCCaMKII‐DRNGABA circuit altered CFA chronic pain‐evoked anxiety‐like behaviors in rats. More importantly, we found that EA could reverse chronic pain‐induced changes in the activity of rACC CaMKII neurons and DRN 5‐HTergic neurons and that chemogenetic inhibition of the rACCCaMKII‐DRN5‐HT circuit blocked the therapeutic effects of EA on chronic pain‐induced anxiety‐like behaviors. Conclusions: Our data suggest that the reversal of rACCCaMKII‐DRN5‐HT circuit dysfunction may be a mechanism underlying the therapeutic effect of EA on chronic pain‐induced anxiety‐like behaviors. [ABSTRACT FROM AUTHOR]

Probiotic supplementation has been identified as a potential target to reduce inflammatory mediators associated with obesity. Therefore, this study assessed the effect of probiotic Lacticaseibacillus rhamnosus LB1.5 on anxiety-like behavior, gene expression in the prefrontal cortex, and neuroinflammation in the cerebral cortex and hippocampus of male mice fed a high-fat diet. Mice aged 21 days were divided into four groups: control (CONT), control plus probiotic (CONT + PROB), high-fat diet (HFD), and high-fat diet plus probiotic (HFD + PROB), and fed for 13 weeks. The probiotic Lact. rhamnosus 1.5 (3.1 × 108 CFU/mL, derived from raw buffalo milk) was administered by gavage three times a week. Probiotic supplementation provided an anxiolytic effect in CONT and HFD. The IL-6 showed lower levels after probiotic supplementation in the HFD. Regarding immunoreactivity for GFAP in the cerebral cortex, we demonstrated that animals HFD-fed had a reduction in cells number compared to CONT. In the hippocampus, we found an interaction between diet and supplementation, as well as an effect of probiotic supplementation. A higher number of Th positive cells was observed in the cerebral cortex in mice fed HFD. Lact. rhamnosus LB1.5 supplementation decreased serum IL-6 levels in HFD-fed mice and promoted a reduction in anxiety-like behavior. [ABSTRACT FROM AUTHOR]

Structural plasticity is critical for the functional diversity of neurons in the brain. Experimental autoimmune encephalomyelitis (EAE) is the most commonly used model for multiple sclerosis (MS), successfully mimicking its key pathological features (inflammation, demyelination, axonal loss, and gliosis) and clinical symptoms (motor and non-motor dysfunctions). Recent studies have demonstrated the importance of synaptic plasticity in EAE pathogenesis. In the present study, we investigated the features of behavioral alteration and hippocampal structural plasticity in EAE-affected mice in the early phase (11 days post-immunization, DPI) and chronic phase (28 DPI). EAE-affected mice exhibited hippocampus-related behavioral dysfunction in the open field test during both early and chronic phases. Dendritic complexity was largely affected in the cornu ammonis 1 (CA1) and CA3 apical and dentate gyrus (DG) subregions of the hippocampus during the chronic phase, while this effect was only noted in the CA1 apical subregion in the early phase. Moreover, dendritic spine density was reduced in the hippocampal CA1 and CA3 apical/basal and DG subregions in the early phase of EAE, but only reduced in the DG subregion during the chronic phase. Furthermore, mRNA levels of proinflammatory cytokines (Il1β, Tnfα, and Ifnγ) and glial cell markers (Gfap and Cd68) were significantly increased, whereas the expression of activity-regulated cytoskeletonassociated protein (ARC) was reduced during the chronic phase. Similarly, exposure to the aforementioned cytokines in primary cultures of hippocampal neurons reduced dendritic complexity and ARC expression. Primary cultures of hippocampal neurons also showed significantly reduced extracellular signal-regulated kinase (ERK) phosphorylation upon treatment with proinflammatory cytokines. Collectively, these results suggest that autoimmune neuroinflammation alters structural plasticity in the hippocampus, possibly through the ERK-ARC pathway, indicating that this alteration may be associated with hippocampal dysfunctions in EAE. [ABSTRACT FROM AUTHOR]