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Depression is a major global health burden, and current treatments are limited by delayed onset and incomplete efficacy, highlighting the need for novel, mechanism-based therapies. Chronic restraint stress (CRS) induces behavioral, hormonal, and synaptic changes relevant to depression, but the role of adiponectin signaling remains unclear. Here, we examined whether the adiponectin receptor agonist AdipoRon exerts antidepressant-like effects via brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling in mice subjected to 14 days of CRS. CRS produced anxiety- and depression-like behaviors, elevated plasma corticosterone, reduced circulating adiponectin, and selectively decreased hippocampal adiponectin and adiponectin receptor 2 (AdipoR2), accompanied by reduced PSD-95 and GluA1 in CA3 and the dentate gyrus (DG). AdipoRon treatment (20 mg/kg, days 8-14) prevented behavioral deficits, normalized corticosterone and adiponectin levels, and restored hippocampal AdipoR2, PSD-95, and GluA1 expression in CA3 and DG. AdipoRon also reversed CRS-induced decreases in hippocampal phosphorylated AMPK (p-AMPK), PPARα, BDNF, and phosphorylated TrkB (p-TrkB), with p-AMPK/AMPK and PPARα levels positively correlating with BDNF. Immunofluorescence confirmed BDNF recovery in CA3 and DG. Importantly, pretreatment with the TrkB antagonist ANA-12 abolished the behavioral, hormonal, and molecular effects of AdipoRon, indicating that its actions require BDNF-TrkB activation. These findings suggest that AdipoRon mitigates CRS-induced deficits via hippocampal AdipoR2-AMPK-PPARα-BDNF-TrkB signaling and highlight AdipoR2 as a promising target for depression therapy under chronic stress. Show less

Chronic stress is increasingly acknowledged as a pivotal precipitating factor in the pathogenesis of neuropsychiatric and neurodegenerative disorders, notably including depression and Alzheimer's disease (AD). Astrocytes, which constitute the predominant population of glial cells involved in the maintenance of synaptic homeostasis, the recycling of neurotransmitters, and the provision of metabolic support, display a pronounced susceptibility to sustained exposure to stress. The deleterious effects of astrocytic dysfunction instigate a series of neuroinflammatory and synaptic modifications that undermine both cognitive and emotional resilience. This review articulates the mechanistic interactions between stress-induced astrocyte dysfunction, neuroinflammatory signaling, and compromised neuroplasticity, underscoring the converging pathways that are implicated in both depression and AD. A thorough synthesis of the literature from 2020 to 2025 was conducted utilizing databases such as PubMed, Scopus, and Web of Science, with an emphasis on molecular, in vitro, in vivo, and translational studies that examine the modulation of astrocytic function under conditions of chronic stress and its pertinence to depression and AD. The chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis precipitates morphological alterations, diminished expression of glutamate transporters (GLT-1/EAAT2), disrupted brain-derived neurotrophic factor (BDNF) signaling, and an augmented release of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) from astrocytes. These biochemical alterations exacerbate excitotoxicity, disturb monoaminergic and glutamatergic neurotransmission, and hasten synaptic degeneration. In the context of depression, this phenomenon is manifested as impaired mood regulation and a decline in neurogenesis. In AD, it synergistically interacts with amyloid-beta and tau pathologies to facilitate progressive cognitive impairment. Both conditions exhibit a common feature of diminished neurosignaling plasticity, which limits the brain's capacity for adaptation and repair. Astrocyte dysfunction constitutes a central mechanistic nexus wherein chronic stress, neuroinflammation, and synaptic pathology intersect to promote the progression of depression and AD. The targeting of astrocytic health via the modulation of reactive astrocyte phenotypes, the restoration of glutamate homeostasis, and the enhancement of neurotrophic signaling emerges as a promising therapeutic avenue for alleviating stress-related neurodegeneration and mood disorders. Show less

Depression and anxiety during pregnancy are major public health concerns with lasting consequences for mother and child. Although the gut microbiome contributes to stress and mood regulation, its role in preconceptional stress and transgenerational outcomes remains unclear. Here, we examined behavioral, microbial, and thalamic transcriptional effects of preconceptional social isolation rearing (SIR) in female mice and tested whether maternal probiotic supplementation mitigates these alterations. SIR females displayed increased anxiety-like and social-avoidant behavior, reduced gut microbial diversity, depletion of Odoribacter, Tuzzerella, and Alloprevotella, and enrichment of Bacteroides and Lachnospiraceae. A multispecies probiotic (Lactobacillus rhamnosus HN001, L. acidophilus La-14, Bifidobacterium lactis HN019) reversed these behavioral and microbial changes. Adult offspring of SIR dams showed sex-dependent behavioral deficits and microbial alterations partly reflecting maternal patterns. Prenatal SIR was associated with reduced thalamic Bdnf expression in offspring and altered Grin2a/2b selectively in males. In contrast, prenatal probiotic exposure exerted broader transcriptional effects and restored Bdnf levels in SIR offspring. SIR-induced increases in Lachnospiraceae were transmitted to offspring, whereas reductions in Ruminococcaceae were normalized by maternal probiotic treatment. Predicted functional profiling indicated sex-dependent modulation of microbial pathways related to tryptophan and central carbon metabolism. These findings demonstrate enduring transgenerational effects of preconceptional stress on the gut-brain axis and support maternal probiotic supplementation as a potential strategy to mitigate stress-induced dysregulation. Show less

Cognitive flexibility is a core executive function vital for adaptation and adjustment to new information. The brain-derived neurotrophic factor (BDNF) single nucleotide polymorphism, val66met, has been suggested to modulate cognitive flexibility but it remains unclear how confounding variables such as stress and sex influence this relationship. Environmental enrichment (EE) may protect against stress-induced effects. The aim of this study was to test whether BDNF val66met alters reversal learning, a key component of cognitive flexibility, when tested under stressful water maze conditions. We used a Sprague Dawley val66met rat model where pregnant val/met dams were moved to either low or high EE environments. Dams and offspring stayed in these environments until weaning, after which the offspring was moved to standard, moderate enrichment housing. Adult male and female val/val, val/met and met/met offspring then underwent a water maze reversal learning protocol. All groups rapidly learned the new location of the platform. Mediation analysis showed the relationship between val66met and cognitive flexibility was mediated by differential use of spatial strategies. Sequential clustering analysis demonstrated that val66met interacted with sex to predict cognitive flexibility performance with lower flexibility in met/met males and val/met females compared to other genotypes. EE was not a strong promotor of cognitive flexibility. Water maze testing increased corticosterone levels, confirming the stressful nature of the test. This study demonstrates the importance of considering stress and sex when investigating the role of BDNF val66met in cognitive flexibility. Show less

Major Depressive Disorder (MDD) is a multifactorial psychiatric disease influenced by a combination of genetic and environmental factors. Among the genes linked to MDD, the Melanocortin 1 Receptor (MC1R), Catechol-O-Methyltransferase (COMT), Brain-Derived Neurotrophic Factor (BDNF), and the serotonin transporter (5-HTT) are of particular interest due to their critical roles in stress regulation and neural function. Despite their biological significance, the contribution of specific polymorphisms within these genes to MDD risk remains understudied. This retrospective observational case-control study included 87 Colombian patients diagnosed with MDD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The control group comprised Latino/admixed individuals without, sourced from the gnomAD v2.1.1 database. The complete coding region of the MC1R gene and three polymorphisms: 5-HTTLPR Insertion/Deletion 44 bp, BDNF-c.196G>A, and COMT-c.472G>A were genotyped using PCR and Sanger sequencing. The polymorphisms rs885479 and rs4680 were identified as protective factors against MDD, while the polymorphisms rs796296176, rs779504604, rs1805005 were associated with an increased risk of developing MDD (OR:22.87, OR:51.26, OR: 1.97, respectively). Several of the analyzed polymorphisms (rs796296176, rs779504604, rs1805005) increase the risk for MDD. Notably, we provide novel evidence of these polymorphisms in MC1R as a risk to MDD. Show less

Compound Nujia honey paste (Nujia), a classic formulation from Traditional Uyghur Medicine, has been historically used for depression treatment and is listed in the Catalog of Ancient Classical Famous Formulas issued by the National Administration of Traditional Chinese Medicine and the National Medical Products Administration. Clarifying its pharmacodynamic material basis is essential for understanding its efficacy, yet this remains incompletely characterized. This study aimed to systematically elucidate Nujia's antidepressant efficacy and mechanisms by combining chemical analysis, computational prediction, and experimental validation in a CUMS rat model, providing a comprehensive approach to understanding its action. This study employed LC/MS to analyze the chemical constituents and blood-absorbed compounds of Nujia. This was combined with network pharmacology and molecular docking to predict and verify its potential antidepressant targets and signaling pathways. Using behavioral tests, ELISA, histopathology, Western blot, and qRT-PCR in a CUMS rat model, the research thoroughly evaluated Nujia's therapeutic effects and mechanisms, fostering trust in the findings. In this study, LC/MS analysis identified 124 chemical constituents from Nujia, and further analysis determined 26 blood-absorbed compounds (including 10 prototype compounds). Network pharmacology analysis revealed that its potential antidepressant effects are closely associated with core targets such as AKT1 and TNF, a prediction subsequently verified by molecular docking results. In the CUMS-induced rat model of depression, intervention with Nujia significantly ameliorated depression-like behaviors in the animals and alleviated neuropathological damage in the hippocampus and prefrontal cortex. Mechanistic investigations revealed that Nujia upregulated the levels of monoamine neurotransmitters (5-HT, DA, NE) and neurotrophic factors (BDNF, NGF) in serum, while downregulating the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-18). Further molecular experiments confirmed that Nujia likely mitigates neuroinflammation by inhibiting the TNF-α/NF-κB signaling pathway, and inhibits neuronal apoptosis by activating the PI3K/AKT signaling pathway and its downstream anti-apoptotic proteins. Furthermore, Nujia significantly upregulated the expression of key synaptic plasticity proteins (SYP, GAP43, and PSD95) in hippocampal tissue, thereby enhancing synaptic structure and function. These findings underscore the complex, multi-target mechanisms underlying Nujia's antidepressant effects, encouraging further exploration of its therapeutic potential. This study systematically elucidates that Nujia achieves its antidepressant therapeutic effects by mediating multi-pathway synergistic actions, including but not limited to the TNF-α/NF-κB and PI3K/AKT signaling pathways, to ameliorate neuroinflammation, attenuate apoptosis, and enhance synaptic plasticity. Show less

Retigabine (RTG) shows notable neuroprotective efficacy in multiple brain injury models; however, its interplay with endoplasmic reticulum stress (ERS) is poorly understood. This study was designed to explore the therapeutic potential of RTG against CRS-induced depression-like behaviors and cognitive deficits in mice and to uncover the associated molecular mechanisms. A depression-like and cognitive impairment model was established in C57BL/6 male mice using chronic restraint stress (CRS). Six-week-old C57BL/6 male mice were randomly assigned to the following groups: control (Con), model (CRS), RTG (10 mg/kg), XE-991 (2 mg/kg) or tunicamycin (Tm, 2 mg/kg). Behavioral tests were conducted to assess depression-like behaviors and cognitive function. Hippocampal neuronal morphology was examined by H&E and immunofluorescence staining, while changes in endoplasmic reticulum stress (ERS)-related signaling pathways were analyzed by Western blot. Retigabine treatment reduced hippocampal neuronal damage and the expression of ERS-related factors (GRP78, CHOP) and the pro-apoptotic factor BAX in CRS-induced mice, while it increased the levels of BDNF. These effects were antagonized by XE-991 and the ERS agonist tunicamycin (Tm). Retigabine may alleviate CRS-induced depressive-like behaviors and cognitive impairment by inhibiting ERS-mediated apoptosis, suggesting its potential as a novel therapeutic strategy for depression. Show less

Yoga is increasingly incorporated into clinical practice for managing a wide range of mental and physical health conditions, especially those related to stress, and has shown beneficial effects on inflammatory processes and neuroendocrine regulation. Its influence on cytokines such as interleukin-6 and tumor necrosis factor-α, as well as its modulatory action on the hypothalamic pituitary adrenal axis, suggests a potential role in reducing systemic inflammation and improving stress resilience. Despite these promising indications, there is limited scientific evidence from India evaluating yoga's impact on biological markers of stress and inflammation. The present study was undertaken to assess the effects of a structured yoga program on selected biomarkers in 60 adult volunteers who underwent evaluations before and after 3 months of practice. The intervention consisted of a daily 1-h yoga session conducted 6 days a week and included postures, breathing practices, and relaxation techniques. Assessments focused on brain-derived neurotrophic factor, interleukin-6, tumor necrosis factor-α, high-sensitivity C-reactive protein, cortisol, and perceived stress levels. Findings indicated an increase in brain-derived neurotrophic factor and reductions in inflammatory markers, cortisol, and perceived stress. These outcomes suggest that regular yoga practice can positively influence neurotrophic activity, reduce inflammation, and lower stress, supporting its value as a complementary approach to improving overall health and well-being. Show less

Stress exposure, whether acute or chronic, is now recognized to be a determinant of epileptogenic vulnerability. Psychological stress or trauma may not only precipitate seizures but also actively contribute to the development of epilepsy, a concept that in the clinical setting could be termed "psychoepileptogenesis". Recent evidence from both animal models and clinical studies supports the role of emotional stress in facilitating epileptogenesis, particularly within limbic structures such as the amygdala and hippocampus. In rodent models, chronic stress has been shown to lower seizure thresholds and promote epileptogenesis through mechanisms involving brain-derived neurotrophic factor (BDNF) and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Human studies reinforce these findings: individuals exposed to trauma or suffering from post-traumatic stress disorder (PTSD) exhibit an elevated risk of developing epilepsy, especially temporal lobe epilepsy (TLE), with structural and functional neuroimaging revealing changes in limbic and paralimbic circuits. These converging lines of evidence suggest that psychoepileptogenesis is a plausible, albeit complex, phenomenon. Further research is needed to identify biomarkers of vulnerability and evaluate whether early interventions targeting stress pathways might alter the course of epileptogenesis. Show less

Social context modulates stress physiology and resilience, yet preclinical rat paradigms vary widely in stressor type, timing of social exposure, contact modality, and endpoint definitions. We synthesized rat studies to quantify directional and, where feasible, standardized effect-size evidence for social buffering and to outline translational implications. PubMed, Scopus, and Web of Science were searched (2008-2025) for in vivo rat studies comparing conspecific (pair/group housing or conspecific presence) versus solitary conditions across validated stress and PTSD-like paradigms (e.g., fear conditioning/extinction, CUS/CMS, social defeat, predator threat). Data extraction and reporting followed PRISMA 2020 and SYRCLE guidance. Synthesis followed a two-tier approach: (i) all eligible contrasts were direction-coded as beneficial, neutral/mixed, or detrimental under conspecific conditions based strictly on reported statistical contrasts; and (ii) for domains with sufficient coded contrasts, the proportion of beneficial comparisons was estimated with exact binomial tests and 95% confidence intervals. Standardized mean-difference meta-analysis (Hedges' g; random-effects REML) was conducted only for predefined outcomes with adequate numerical reporting. Forty studies met inclusion criteria, yielding 89 extracted comparisons. Overall, 69/89 comparisons (≈78%) favored conspecific conditions. Domain-level directional syntheses supported predominance of beneficial outcomes for hormonal (0.72; 95% CI 0.50-1.00; p = 0.048) and neurotrophic/plasticity markers (0.89; 95% CI 0.57-1.00; p = 0.020), whereas inflammatory/oxidative outcomes were more variable (0.71; 95% CI 0.39-0.94; p = 0.227). For predefined behavioral endpoints with sufficient data, effect-size pooling showed a large reduction in conditioned fear (Hedges' g = -1.22 [-1.53; -0.91], p < 0.0001). Social buffering is robust at behavioral and neuroendocrine levels and often aligns with neurotrophic/plasticity markers, while peripheral immune/redox readouts are more context-dependent. Show less

Early-life stress is a critical determinant of vulnerability to later-life affective and cognitive dysfunction, yet the mechanisms through which adolescent adversity enhances adult stress susceptibility remain incompletely understood. Here, we employed a two-hit model combining adolescent social isolation stress (SIS) with adult chronic restraint stress (CRS) to examine how developmental stress interacts with adult stress exposure. SIS alone or CRS alone exerted minimal behavioral effects, whereas SIS followed by CRS markedly potentiated depression-like behaviors and impaired spatial and object recognition memory. Two-hit stress produced robust hippocampal neuroinflammatory responses, including increased astrocytic and microglial activation and elevated TNF-α, IL-1β, IL-6, and IL-17A levels. These inflammatory alterations were accompanied by pronounced suppression of the BDNF/TrkB/p-CREB signaling cascade, reduced synaptic protein expression, and diminished dendritic spine density and branching complexity in CA1 pyramidal neurons. Notably, light treatment (LT) administered during CRS exposure significantly reversed two-hit induced behavioral deficits, attenuated glial activation and cytokine upregulation, enhanced BDNF/TrkB and p-CREB signaling, and restored synaptic and structural plasticity. Together, these findings indicate that adolescent SIS primes the hippocampus for exaggerated neuroinflammatory and neuroplastic impairments following adult stress, thereby amplifying stress vulnerability. Furthermore, LT emerges as a safe non-pharmacological intervention capable of mitigating combined stress-induced emotional and cognitive dysfunction by targeting neuroinflammatory and neurotrophic pathways. Show less

For decades, major depressive disorder was attributed to a deficit in monoamine neurotransmitters. Clinical latency of tricyclic and selective serotonin reuptake inhibitors, high nonresponse rates, and inconsistent genetic findings challenged this view and redirected research toward downstream biology. Preclinical work revealed that chronic stress triggers dendritic and spine loss in the hippocampus and prefrontal cortex, whereas all effective treatments-including slow-acting monoaminergic drugs, rapid-acting ketamine, electroconvulsive therapy, and aerobic exercise-restore synapse number and function through brain-derived neurotrophic factor, TrkB, and mTOR signaling. Human connectomic studies then reframed depression as a disorder of mistimed large-scale networks; targeted neuromodulation of nodes intrinsically anticorrelated with the subgenual cingulate provides proof of concept. Parallel findings in immunology and gut-brain science show that psychosocial stress, peripheral cytokines, and metabolic cues converge on the same plasticity pathways, dissolving the historical boundary between "reactive" and "endogenous" depression. Ketamine crystallizes this multiscale model: within minutes, it induces dendritic-spine formation, normalizes default-mode and limbic connectivity, and relieves symptoms within hours. We synthesize these lines of evidence into a framework of precision synaptic psychiatry, in which pharmacological, neuromodulatory, and lifestyle interventions are selected according to biomarkers that index glutamatergic tone, inflammatory load, or network dynamics. Future therapeutics will be judged less by the neurotransmitters they influence and more by their capacity to restore flexible, resilient brain circuitry. Show less

Throughout time, there has always been a trend connecting stress and tangible damage to one's physical well-being. However, there's a lack of research that elucidates the physical and molecular traits of this stress on organ integrity. Chronic stress disrupts homeostasis, causing oxidative stress, mitochondrial dysfunction, inflammatory markers, and histological damage. In this study, a repeated forced-swim stress was used to induce stress in the C57BL/6 mice model, and its effects on the brain and liver were analyzed at behavioral, biochemical, histological, and genetic marker levels. Behavioral analysis showed reduced mobility duration in experimental mice. This was further supplemented by histopathological data, which revealed mild brain deterioration and moderate liver damage. Biochemical analysis revealed upregulated levels of aminotransferase and alkaline phosphatase (ALP) and decreased levels of mean corpuscular hemoglobin, pointing toward the existence of liver dysfunctionality due to stress. Moreover, we reported the gene expression analysis of stress biomarkers (Bdnf, Fkbp5, Npy, Comt, Ppm1f, Adra2b, and Slc6a4), with a particular focus on Fkbp5, which is associated with depression and cognitive impairment. Similarly, we also studied the expressions of Crp, Cyp2e1, and Irs-2 to gauge liver damage. Results revealed significantly upregulated expression of Npy, Fkbp5, and Ppm1f in stressed mice. Our study identifies that chronic stress shows physical and molecular realizations. Additionally, this offers further incentive to look closely at Fkbp5, Npy, and Ppm1f under similar conditions and highlights their possible roles as markers of stress-induced damage. Show less

Adolescence is a critical developmental window during which exposure to stress and alcohol can induce long-lasting neurobiological alterations. Binge-like alcohol consumption is particularly disruptive to corticostriatal circuits, but the extent to which prior stress history modulates these effects remains poorly understood. Here, we investigated how acute versus repeated restraint stress before intermittent alcohol exposure during adolescence shapes transcriptional changes in the dorsal striatum of male rats. Animals were exposed either to a single (acute) or five-day (repeated) restraint stress at postnatal day (PND) 32-36, followed by four weeks of intermittent intragastric ethanol (3 g/kg) or saline administration. At adult age, striatal mRNA expression of dopaminergic (Drd1, Drd2, Th), glutamatergic (Gls, Gls2, Gria2, Grin2a, Grin2b), endocannabinoid (Cnr1, Cnr2, Napepld, Faah, Dagla, Daglb, Mgll), neurotrophic (Bdnf, Ntrk2), and glial (Gfap, Aif1) genes was quantified. Alcohol exposure upregulated genes associated with glutamate synthesis and receptor signaling, endocannabinoid metabolism, and astrocytic activation. Acute stress amplified alcohol-induced expression of Gls, Gls2, Gria2, Napepld, Faah, Daglb, Ntrk2, and Gfap, while repeated stress blunted these effects and selectively enhanced Drd1, Drd2, Grin2a, and Bdnf expression. Microglial activation (Aif1) was increased by alcohol independently of stress. These results suggest that acute stress sensitizes glutamatergic and endocannabinoid pathways to alcohol, whereas repeated stress engages adaptive mechanisms consistent with the stress inoculation hypothesis. Overall, stress history critically determines the neurobiological outcomes of adolescent alcohol exposure, with implications for resilience and vulnerability to alcohol-induced psychopathology. Show less