The association of perceived ethnic discrimination and institutional verbal violence with chronic stress in an immigrant sample: The role of protective factors - results from the VIOLIN study.

Immigrants are exposed to a variety of stressors, such as ethnic discrimination, and therefore experience a higher risk of developing adverse health outcomes. However, the role of potentially protective psychological factors is not well-studied. The present study addresses the question how discrimination and institutional verbal violence (IVV) are associated with chronic stress in an immigrant sample. In addition, this study highlights moderating effects of migration-specific variables (first or second migration generation and citizenship status). Participants (n = 232; 69.4 % female) completed an online-survey, which included demographics, questionnaires (Everyday Discrimination Scale, EDS; Perceived Stress Scale, PSS-4; Resilience Scale, RS-11; Self-Compassion Scale, SCS-SF) as well as a self-developed questionnaire on institutional verbal violence. Only participants living in Germany with migration background (self or one parent migrated to Germany) were included. Results showed that perceived discrimination and institutional verbal violence were highly associated with chronic stress. Further, self-compassion buffered the connection between discrimination and stress, whereas resilience was no protective factor. The inclusion of migration-specific variables showed that the second-generation sub-group experienced less discrimination-related stress and self-compassion was shown to be particularly protective within this sub-group. Citizenship status did not appear to be a moderator, but especially persons with temporary or permanent residence status, compared to German/EU-citizens, reported higher values of verbal violence and discrimination-related stress. These findings highlight the importance of considering not only psychological but also structural and societal protective and risk factors, as they may be differentially associated with immigrants' stress perceptions. Implications for future research and practical implementations are presented.

Effects of arketamine on depression-like behaviors and demyelination in mice exposed to chronic restrain stress: A role of transforming growth factor-ß1.

BACKGROUND: Chronic restrain stress (CRS) induces depression-like behaviors and demyelination in the brain; however, the relationship between these depression-like behaviors and demyelination remains unclear. Arketamine, the (R)-enantiomer of ketamine, has shown rapid antidepressant-like effects in CRS-exposed mice. METHODS: We examined whether arketamine can improve both depression-like behaviors and demyelination in the brains of CRS-exposed mice. Additionally, we investigated the role of transforming growth factor ß1 (TGF-ß1) in the beneficial effects of arketamine. RESULTS: A single dose of arketamine (10 mg/kg) improved both depression-like behavior and demyelination in the corpus callosum of CRS-exposed mice. Correlations were found between depression-like behaviors and demyelination in this region. Furthermore, pretreatment with RepSox, an inhibitor of TGF-ß1 receptor, significantly blocked the beneficial effects of arketamine on depression-like behaviors and demyelination in CRS-exposed mice. Finally, a single intranasal administration of TGF-ß1 ameliorated both depression-like behaviors and demyelination in CRS-exposed mice. LIMITATIONS: The precise mechanisms by which TGF-ß1 contributes to the effects of arketamine remain unclear. CONCLUSIONS: These data suggest that CRS-induced demyelination in the corpus callosum may contribute to depression-like behaviors, and that arketamine can mitigate these changes through a TGF-ß1-dependent mechanism.

A single intravenous reelin injection restores corticosterone-induced neurochemical and behavioral alterations in dams during the post-partum period.

Introduction: Treatment with the synaptic plasticity protein reelin has rapid antidepressant-like effects in adult corticosterone (CORT)-induced depressed rats, whether administered repeatedly or acutely. However, these effects remain unexplored in the context of post-partum depression (PPD). Methods: This study investigated the antidepressant-like effect of a single injection of reelin in a CORT-induced model of PPD. Long-Evans female dams received either daily subcutaneous CORT (40 mg/kg) or saline injections (controls) from the post-partum day (PD) 2 to 22, and on PD22 were treated with a single intravenous reelin (3 µg) or vehicle injection. Results: Reelin treatment fully normalized to control levels the CORT-induced increase in Forced Swim Test (FST) immobility and the decrease in reelin-positive cells in the subgranular zone of the intermediate hippocampus. It also increased the number of oxytocin-positive cells in the paraventricular nucleus (PVN), the number of reelin-positive cells in the dorsal and ventral hippocampus, and the dendritic complexity of newborn neurons in the intermediate hippocampus, causing a partial recovery compared to controls. None of these changes were associated with fluctuations in estrogen levels measured peripherally. Discussion: This study brings new insights into the putative antidepressant-like effect of peripherally administered reelin in an animal model of PPD. Future studies should be conducted to investigate these effects on a dose-response paradigm and to further elucidate the mechanisms underlying the antidepressant-like effects of reelin.

Chronic Stress-induced Serotonin Impairs Intestinal Epithelial Cell Mitochondrial Biogenesis via the AMPK-PGC-1α Axis.

Chronic stress is closely associated with gastrointestinal disorders. However, the impact of stress-related neurotransmitters such as serotonin (5-hydroxytryptamine, 5-HT) on the intestines under chronic stress conditions remains poorly understood. This study aims to elucidate the mechanisms by which 5-HT affects mitochondrial biogenesis and intestinal barrier integrity during chronic stress. Employing a chronic restraint stress (CRS) mouse model, we observed elevated intestinal 5-HT levels, altered colonic mucosal structure, and disrupted tight junctions. The increase in 5-HT was associated with up-regulated serotonin synthesis enzymes and downregulated serotonin reuptake transporters, indicating an imbalance in serotonin homeostasis imbalance caused by chronic stress. Furthermore, serotonin exacerbated oxidative stress and impaired tight junction protein expression, highlighting its role in promoting intestinal barrier dysfunction. Experiments with cells in vitro demonstrated that 5-HT impairs mitochondrial biogenesis by inhibiting the AMPK-PGC-1α axis via 5-HT7 receptors and the cAMP-PKA pathway. Pharmacological inhibition of serotonin synthesis or 5-HT7 receptors alleviated the intestinal barrier damage caused by 5-HT and chronic stress, restoring mitochondrial biogenesis. These findings provide compelling evidence that serotonin exacerbates chronic stress-induced intestinal barrier disruption by inhibiting the AMPK-PGC-1α axis, paving the way for novel therapeutic interventions targeting the detrimental effects of serotonin on the intestine, particularly under chronic stress conditions.

Increased forebrain EAAT3 expression confers resilience to chronic stress.

Depression is a disabling and highly prevalent psychiatric illness. Multiple studies have linked glutamatergic dysfunction with the pathophysiology of depression, but the exact alterations in the glutamatergic system that contribute to depressive-like behaviors are not fully understood. Recent evidence suggests that a decreased level in neuronal glutamate transporter (EAAT3), known to control glutamate levels and limit the activation of glutamate receptors at synaptic sites, may contribute to the manifestation of a depressive phenotype. Here, we tested the possibility that increased EAAT3 expression at excitatory synapses could reduce the susceptibility of mice to develop depressive-like behaviors when challenged to a 5-week unpredictable chronic mild stress (UCMS) protocol. Mice overexpressing EAAT3 in the forebrain (EAAT3glo/CMKII) and control littermates (EAAT3glo) were assessed for depressive-like behaviors and long-term memory performance after being subjected to UCMS conditions. We found that, after UCMS, EAAT3glo/CMKII mice did not exhibit depressive-like behaviors or memory alterations observed in control mice. Moreover, we found that EAAT3glo/CMKII mice did not show alterations in phasic dopamine release in the nucleus accumbens neither in long-term synaptic plasticity in the CA1 region of the hippocampus after UCMS, as observed in control littermates. Altogether these results suggest that forebrain EAAT3 overexpression may be related to a resilient phenotype, both at behavioral and functional level, to the deleterious effect of chronic stress, highlighting the importance of neuronal EAAT3 in the pathophysiology of depressive-like behaviors.

Defining and distinguishing early life stress, trauma, adversity, toxic and chronic stress and allostatic load: a descriptive review.

AIMS: Various concepts are used to study the impact of stress on childhood development. These concepts are often used inconsistently or interchangeably. Our main objectives were to determine how selected stress concepts (chronic stress, toxic stress, allostatic load, early life stress, childhood adversity, childhood trauma and adverse childhood experiences; ACEs) are defined, operationalized and described, and to provide a theoretical context to aid the choice for a preferred concept in public health research. METHODS: For this descriptive review, we systematically searched for literature published before 4 August 2021, on PubMed, Embase and PsycInfo. Two independent reviewers included studies. Exclusion criteria were: no systematic review, not peer reviewed, not published in English, selected stress concepts were no predetermined variable or a substantial topic in the discussion, full text was unobtainable or study described non-human or non-childhood populations. Data extraction forms were used. Descriptives were gathered, publication fields were identified through Journal Citation Reports categories, and verbatim descriptions were ordered in text and Venn diagrams. RESULTS: Of 264 screened studies, 124 were included. ACEs, childhood adversity and childhood trauma were used most. ACEs were the main concept used most frequently (47.6%). A total of 11 of 14 public and environmental health journals used ACEs. All concepts refer to prolonged, repeated, interpersonal stress from 0 to 18 years, that can alter physiological systems. Four concepts were stressor oriented, two concepts focused on stress response and effect and one on the state of challenged homeostasis. CONCLUSIONS: ACEs seem most fitting for public health setting, due to their operationalizability, large set of core experiences and widespread use.

A novel probiotic formula, BLLL, ameliorates chronic stress-induced depression-like behaviors in mice by reducing neuroinflammation and increasing neurotrophic factors.

Introduction: Probiotics have been recognized for their various biological activities, including antioxidant and anti-inflammatory properties. This study investigates the therapeutic effect of a novel probiotic formula, BLLL, consisting of Bifidobacterium breve, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus helveticus, on chronic stress-induced depression-like behaviors in mice. Methods: The BLLL formula or phosphate-buffered saline (PBS) was given orally at a dose of 2, 4, or 8 × 1010 CFU/kg once daily for 10 days in mice treated with chronic unpredictable stress (CUS) treated or vehicle. Depression-like behaviors were assessed using the sucrose preference test (SPT), the forced swimming test (FST), and the tail suspension test (TST). The mRNA and/or protein expression of interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), IL-4, IL-10, and chitinase-3-like protein 3 (CHI3L1, also known as Ym-1), as well as the concentration of nitrite, malondialdehyde (MDA), glutathione (GSH), and brain-derived neurotrophic factor (BDNF) in the hippocampus and medial prefrontal cortex were examined. Results: The BLLL formula treatment at a dose of 8 × 1010 CFU/kg, but not at a dose of 2 or 4 × 1010 CFU/kg, improved CUS-induced depression-like behaviors in mice, as shown by the decrease in immobility time in the TST and FST and the increase in sucrose intake in the SPT. Further analysis revealed that BLLL treatment suppressed the CUS-induced increase in IL-1ß, IL-6, and TNF-α mRNA and protein levels, as well as the CUS-induced decrease in IL-4, IL-10, and Ym-1 mRNA and/or protein levels in the hippocampus and medial prefrontal cortex. In addition, treatment with the BLLL formula countered the CUS-induced increase in nitrite and MDA levels and the CUS-induced decrease in GSH content and BDNF concentration in the hippocampus and medial prefrontal cortex. Conclusion: These results demonstrate that the novel probiotic formula BLLL ameliorates chronic stress-induced depression-like behavior in mice by suppressing neuroinflammation and oxido-nitrosative stress in the brain.

Effects of a veterinary functional music-based enrichment program on the psychophysiological responses of farm pigs.

Intensification of swine production can predispose pigs to chronic stress, with adverse effects on the neuroendocrine and immune systems that can lead to health problems, poor welfare, and reduced production performance. Consequently, there is an interest in developing tools to prevent or eliminate chronic stress. Music is widely used as a therapeutic strategy for stress management in humans and may have similar benefits in non-human animals. This study evaluated the effects of a music-based auditory enrichment program in pigs from a multidimensional perspective by assessing psychophysiological responses. Two experimental groups of 20 pigs each were selected for the study: one enriched, exposed to a program of functional veterinary music designed for pigs, and a control group without auditory stimulation. Qualitative behavior assessment (QBA) and skin lesions indicative of agonistic behavior were used to evaluate the psychological determinants underlying the observed behaviors. Physiological assessment included hemograms, with the determination of the neutrophil:lymphocyte ratio and daily measurements of cortisol and salivary alpha-amylase levels. The results demonstrated a positive effect of a music-based auditory program on psychophysiological responses. Therefore, this strategy developed for environmental enrichment may be beneficial in reducing stress and contributing to the welfare and health of pigs under production conditions.

Substance Use Disorder and Suicidal Ideation in Rural Maryland.

Background: Rural areas in the United States have been disproportionately burdened with high rates of substance use, mental health challenges, chronic stress, and suicide behaviors. Factors such as a lack of mental health services, decreased accessibility to public health resources, and social isolation contribute to these disparities. The current study explores risk factors to suicidal ideation, using emergency room discharge data from Maryland. Methods: The current study used data from the Healthcare Cost and Utilization Project (HCUP) State Emergency Department Databases (SEDD) from the State of Maryland. Logistic regression was used to assess the association between ICD-10 coded opioid use disorder, alcohol use disorder, cannabis use disorder, major depressive disorder, and the outcome variable of suicidal ideation discharge. We controlled for income, race, age, and gender. Results: Lifetime major depressive disorder diagnosis (odds ration [OR] = 79.30; 95% confidence interval [CI] 51.91-121.15), alcohol use disorder (OR = 6.87; 95% CI 4.97-9.51), opioid use disorder (OR = 5.39; 95% CI 3.63-7.99), and cannabis use disorder (OR = 2.67; 95% CI 1.37-5.18) were all positively associated with suicidal ideation. Conclusions: The study highlights the strong link between prior substance use disorder, depression, and suicidal ideation visit to the emergency room, indicating the need for prevention and intervention, particularly among those in rural areas where the burden of suicidal ideation and chronic stress are high. As health disparities between rural and urban areas further widened during the COVID-19 pandemic, there is an urgent need to address these issues.

Neurobiological and psychological factors to depression.

Major Depressive Disorder (MDD) is a common condition with complex psychological and biological background. While its aetiology is still unclear, chronic stress stands amongst major risk factors to MDD pathogenesis. When researching on MDD, it is necessary to be familiar with the neurobiological effects of several prominent contributors to the chronic stress factor experienced across hypothalamic-pituitary-adrenal (HPA) axis, neurotransmission, immune system reflexivity, and genetic alterations. Bi-directional flow of MDD pathogenesis suggests that psychological factors produce biological effects. Here, a summary of how the MDD expresses its mechanisms of action across an overactive HPA axis, the negative impacts of reduced neurotransmitter functions, the inflammatory responses and their gene x environment interactions. This paper builds on these conceptual factors and their input towards the MDD symptomatology with a purpose of synthesising the current findings and create an integrated view of the MDD pathogenesis. Finally, relevant treatment implications will be summarised, along with recommendations to a multimodal clinical practice.

Daily crowding stress has limited, yet detectable effects on skin and head kidney gene expression in surgically tagged atlantic salmon (Salmo salar).

To ensure welfare-friendly and effective internal tagging, the tagging process should not cause a long-term burden on individuals given that tagged fish serve as representatives for the entire population in telemetry applications. To some extent, stress is inevitable within regular aquaculture practices, and thus, the consequences of long-term stress should be described in terms of their effects on internal tagging. In fish, stressors activate the Hypothalamus-Pituitary-Interrenal (HPI) and Brain-Sympathetic-Chromaffin Cell (BSC) axes, leading to neuroimmunoendocrine communication and paracrine interactions among stress hormones. The interrelation between wound healing and stress is complex, owing to their shared components, pathways, and energy demands. This study assessed 14 genes (mmp9, mmp13, il-2, il-4, il-8a, il-10, il-12, il-17d, il-1b, tnfa, ifng, leg-3, igm, and crh) in the skin (1.5 cm from the wound) and head kidney over eight weeks. These genes, associated with cell signaling in immunity, wound healing, and stress, have previously been identified as influenced and regulated by these processes. Half of a group of Atlantic salmon (n = 90) with surgically implanted dummy smart-tags were exposed to daily crowding stress. The goal was to investigate how this gene panel responds to a wound alone and then to the combined effects of wounding and daily crowding stress. Our observations indicate that chronic stress impacts inflammation and impedes wound healing, as seen through the expression of matrix metalloproteinases genes in the skin but not in the head kidney. This difference is likely due to the ongoing internal wound repair, in contrast to the externally healed wound incision. Cytokine expression, when significant in the skin, was mainly downregulated in both treatments compared to control values, particularly in the study's first half. Conversely, the head kidney showed initial cytokine downregulation followed by upregulation. Across all weeks observed and combining both tissues, the significantly expressed gene differences were 12 % between the Wound and Stress+ groups, 28 % between Wound and Control, and 25 % between Stress+ and Control. Despite significant fluctuations in cytokines, sustained variations across multiple weeks are only evident in a few select genes. Furthermore, Stress+ individuals demonstrated the most cytokine correlations within the head kidney, which may suggest that chronic stress affects cytokine expression. This investigation unveils that the presence of stress and prolonged activation of the HPI axis in an eight weeklong study has limited yet detectable effects on the selected gene expression within immunity, wound healing, and stress, with notable tissue-specific differences.

Interplay Among Self-Regulation Processes Over Time for Adolescents in the Context of Chronic Stress.

Developmental changes in self-regulation are theorized to underlie adolescents' engagement in risky behaviors, physical health, mental health, and transition to adulthood. Two central processes involved in self-regulation, self-management (i.e., planning, concentration, and problem-solving) and disinhibition (e.g., distractibility and impulsivity) appear to develop asynchronously and may be differentially activated based on contextual factors. Using a sample identified based on exposure to chronic stressors, we investigated how changes in self-management and disinhibition affect each other over time and whether these changes occur differently for boys and girls. Youth aged 8-16 (N = 708) who attended a U.S. summer camp self-reported on components of disinhibition and self-management. Cross-lagged structural equation modeling revealed a reciprocal relationship between self-management and disinhibition, with anger coping and distractibility emerging as critical factors in shaping this relationship. Changes in concentration, planning, and problem-solving were components of self-management that drove subsequent changes in boys' disinhibition (for girls, however, planning did not). Autocorrelations for both broad processes remained strong from year to year, indicating a high degree of stability in rank order despite the myriad of physical, cognitive and socioemotional changes that occur during adolescence. We discuss implications of the reciprocal model with a focus on the relative pliability of components from each process and strategies for shaping them. Planning, concentration and distractibility are highlighted as potential targets for intervention.

Selection of references for quantitative real-time PCR analysis of microRNAs in Nile tilapia (Oreochromis niloticus) under osmotic stress.

MicroRNAs play crucial regulatory roles in various aspects of development and physiology, including environmental adaptation and stress responses in teleosts. RT-qPCR is the most commonly used method for studying microRNA expression, with the accuracy and reliability of results depending on the use of an appropriate reference gene for normalization. This study aimed to evaluate seven miRNAs (U6, Let-7a, miR-23a, miR-25-3, miR-103, miR-99-5, and miR-455) expression stability in different tissues of Nile tilapia subjected to osmotic stress. Fish were divided into two groups: a control and an experimental group, raised in 0 and 12 ppt salinity water respectively. After 21 days, brain, gills, liver, and posterior intestine were collected for analysis. Different mathematical algorithms (geNorm, NormFinder, BestKeeper, and the comparative ΔCt method) were employed to identify the most suitable reference miRNAs. The results indicate that the miR-455/miR-23a combination is a robust reference for normalizing miRNA expression levels in studies of osmotic stress responses in Nile tilapia. The stability of miRNA expression can vary depending on specific stress conditions and biological processes, underscoring the necessity of selecting appropriate normalizing miRNAs for each experimental context. This study identifies reliable reference genes for future RT-qPCR analyses of miRNA expression, thereby enhancing our understanding of molecular responses in fish to environmental challenges. These insights are fundamental to the development of new technologies for the improved management and sustainability of aquaculture practices.

Baicalin reduces chronic stress-induced breast cancer metastasis via directly targeting ß2-adrenergic receptor.

Recent studies have shown that stress can substantially facilitate breast cancer metastasis, which can be reduced by nonselective ß1/ß2-adrenergic receptor (ß1/ß2-AR) blocker. However, several side effects were identified. Thus, it is extremely warranted to explore more effective and better-tolerated ß2-AR blocker. Currently, we demonstrated that baicalin (BA), a major bioactive component of Scutellaria baicalensis Georgi, could significantly attenuate stress hormones especially epinephrine (Epi)-induced breast cancer cell migration and invasion in vitro. Mechanistically, we identified that ß2-AR was a direct target of BA via the drug affinity responsive target stability (DARTS) combined with mass spectrum assay, and BA photoaffinity probe with pull-down assay, which was further confirmed by a couple of biophysical and biochemical assays. Furthermore, we demonstrated that BA could directly bind to the Phe-193 and Phe-289 of ß2-AR, subsequently inhibit cyclic adenosine monophosphate-protein kinase A-focal adhesion kinase (cAMP-PKA-FAK) pathway, and thus impede epithelial-mesenchymal transition (EMT), thereby hindering the metastatic progression of the chronic stress coupled with syngeneic and xenograft in vivo orthotopic and tail vein mouse model. These findings firstly identify BA as a potential ß2-AR inhibitor in the treatment of stress-induced breast cancer metastasis.

Dimethyl Fumarate Prevents the Development of Chronic Social Stress-Induced Hypertension in Borderline Hypertensive Rats.

This study investigated the effects of chronic crowding-induced social stress and dimethyl fumarate (DMF) on borderline hypertensive rats, focusing on the transcription nuclear factor (erythroid-derived 2)-like 2 (NRF2) gene Nfe2l2, on the expression of selected NFR2-mediated gene expressions in the heart, and on vascular function. Rats were exposed to chronic crowding, DMF treatment (30 mg/kg/day, p.o.), or a combination of both for six weeks. Blood pressure (BP) was measured non-invasively, gene expressions were analysed using RT-qPCR, and vascular function was assessed by measuring noradrenaline (NA)-induced vasoconstriction and endothelium-dependent and -independent relaxations in the femoral arteries using a wire myograph. Chronic stress increased BP, Nfe2l2 expression, and NA-induced vasoconstriction, though it did not affect relaxation responses nor the left heart ventricle-to-body weight (LHV/BW) ratio. DMF elevated Nfe2l2 expression (as the main effect) in the heart but did not alter BP and vascular functions vs. control when administered alone. Interestingly, DMF increased the LHV/BW ratio, supposedly due to reductive stress induced by continuous NRF2 activation. When combined with stress, DMF treatment prevented stress-induced hypertension and mitigated NA-induced vasoconstriction without altering relaxation functions. In addition, the combination of stress and DMF increased Tnf and Nos2 expression and the expressions of several genes involved in iron metabolism. In conclusion, these findings suggest that DMF can prevent chronic stress-induced hypertension by reducing vascular contractility. Moreover, DMF itself may produce reductive stress in the heart and induce inflammation when combined with stress. This indicates a need for the careful consideration of long-term DMF treatment considering its impact on the heart.

The mediation role of allostatic load/chronic stress on the relationship between cancer survivorship and cardiovascular disease mortality.

Background: Cancer survivors face an elevated risk of cardiovascular disease (CVD) and cardiovascular disease mortality (CVDm) compared to the general population. Allostatic load (AL), a composite score reflecting cardiovascular, metabolic, and immune markers, assesses the cumulative impact of chronic stress and life events. Increased AL in cancer patients is linked to up to a 30 % higher CVD risk. We hypothesized that cancer diagnosis and therapy contribute to increased AL, mediating the association between cancer survivorship and CVDm. Methods: This retrospective cohort study analyzed National Health and Nutrition Examination Survey (NHANES) data linked with the National Death Index (NDI) from 1988 to 2019. Cancer survivorship (yes vs. no), AL, and CVDm were the exposure, mediator, and outcome variables, respectively. Mediation analyses adapted to survival outcomes were performed. Results: Among 14,416 participants, cancer survivors <65 years-old exhibited a 41 % higher associated CVDm risk. High AL mediated 5.4 %, 8.9 %, and 3.6 % of the effect for all adults, 18-64 years, and ≥65 years, respectively. Black patients <65 years-old had an 84 % higher associated CVDm risk, with AL mediating 9.2 %, 5.8 %, and 12.6 % for all adults, 18-64 years, and ≥65 years, respectively. White patients showed a 20 % higher associated CVDm risk, with AL mediating 4.4 %, 2.8 %, and 5.7 % for all adults, 18-64 years, and ≥65 years, respectively. Conclusions: Increased CVDm risk among cancer survivors, particularly in Black individuals, is associated with higher AL mediation. These disparities may stem from social determinants of health.

Chronic Stress Alters Synaptic Inhibition/Excitation Balance of Pyramidal Neurons But Not PV Interneurons in the Infralimbic and Prelimbic Cortices of C57BL/6J Mice.

The medial prefrontal cortex (mPFC) plays a pivotal role in regulating working memory, executive function, and self-regulatory behaviors. Dysfunction in the mPFC circuits is a characteristic feature of several neuropsychiatric disorders including schizophrenia, depression, and post-traumatic stress disorder. Chronic stress (CS) is widely recognized as a major triggering factor for the onset of these disorders. Although evidence suggests synaptic dysfunction in mPFC circuits following CS exposure, it remains unclear how different neuronal populations in the infralimbic (IL) and prelimbic (PL) cortices are affected in terms of synaptic inhibition/excitation balance (I/E ratio). Here, using neuroproteomic analysis and whole-cell patch-clamp recordings in pyramidal neurons (PNs) and parvalbumin (PV) interneurons within the PL and IL cortices, we examined the synaptic changes after 21 d of chronic unpredictable stress, in male mice. Our results reveal distinct impacts of CS on PL and IL PNs, resulting in an increased I/E ratio in both subregions but through different mechanisms: CS increases inhibitory synaptic drive in the PL while decreasing excitatory synaptic drive in the IL. Notably, the I/E ratio and excitatory and inhibitory synaptic drive of PV interneurons remained unaffected in both PL and IL circuits following CS exposure. These findings offer novel mechanistic insights into the influence of CS on mPFC circuits and support the hypothesis of stress-induced mPFC hypofunction.

Comprehensive Review of Chronic Stress Pathways and the Efficacy of Behavioral Stress Reduction Programs (BSRPs) in Managing Diseases.

The connection between chronic psychological stress and the onset of various diseases, including diabetes, HIV, cancer, and cardiovascular conditions, is well documented. This review synthesizes current research on the neurological, immune, hormonal, and genetic pathways through which stress influences disease progression, affecting multiple body systems: nervous, immune, cardiovascular, respiratory, reproductive, musculoskeletal, and integumentary. Central to this review is an evaluation of 16 Behavioral Stress Reduction Programs (BSRPs) across over 200 studies, assessing their effectiveness in mitigating stress-related health outcomes. While our findings suggest that BSRPs have the potential to enhance the effectiveness of medical therapies and reverse disease progression, the variability in study designs, sample sizes, and methodologies raises questions about the generalizability and robustness of these results. Future research should focus on long-term, large-scale studies with rigorous methodologies to validate the effectiveness of BSRPs.

Dynamic quantitative monitoring of cerebrospinal fluid monoamine neurotransmitter markers during the modeling process of chronic stress-induced depression in monkeys (Macaca mulatta).

BACKGROUND: Depression is known as the "mental cold" and is also considered a major cause of disability worldwide. It is estimated that over 300 million people worldwide suffer from severe depression, equivalent to 4.4% of the world's population. The monoamine hypothesis of depression predicts the underlying pathophysiological mechanisms of depression, but in-depth research has failed to find convincing evidence. METHOD: In this study, we will dynamically and strictly quantitatively monitor the concentration changes of monoamine transmitters in the cerebrospinal fluid (CSF) of macaques, based on our previous work. In the experiment, timed and quantitative collection of CSF samples from macaques was performed and the concentration of monoamine transmitters was determined. RESULT: The results showed that after 2 months of chronic stress, the concentrations of high vanillin acid (HVA) and 3,4-dihydroxy-phenylacetic acid were significantly higher in the maternal separation (MS) group, whereas there was no significant difference in dopamine and 5-hydroxyindoleacetic acid. CONCLUSION: This study is the first to observe the long-term dynamic relationship between early adversity, chronic stress, adolescent depression, and CSF monoamine concentrations. The research suggests that MS and chronic stress play an undeniable role in the pathogenesis of depression and that concentrations of HVA and dihydroxyphenylacetic acid are likely to serve as early markers of depressive-like symptoms in macaques.

The effects of chronic stress on rat heart function following regional ischemia: a sex-dependent investigation.

Chronic psychosocial stress is a recognized, yet understudied risk factor for heart disease, with potential sex-specific effects. We investigated whether chronic stress triggers sex-dependent cardiac dysfunction in isolated Wistar rat hearts subjected to ischemia-reperfusion injury. The experimental cohort underwent 1 hour of daily restraint stress for four weeks versus matched controls, followed by euthanasia (sodium pentobarbitone) and heart excision for ex vivo perfusion. Blood analysis revealed sex-specific alterations in stress hormones and inflammatory markers. Compared to controls, chronic restraint stress (CRS) males displayed decreased plasma brain-derived neurotrophic factor (BDNF) levels (p<0.05), while CRS females exhibited elevated plasma adrenocorticotropic hormone (ACTH) (p<0.01) and reduced corticosterone (p<0.001) alongside lower serum estradiol (p<0.001) and estradiol/ progesterone ratio (p<0.01). Of note, CRS females showed increased serum cardiac troponin T (p<0.05) and tumor necrosis factor-alpha (TNF-a) (p<0.01) with suppressed interleukin (IL)-1a, IL-1ß, IL-6, and IL-10 levels (p<0.05) when compared to controls. Ex vivo Langendorff perfusions revealed that CRS female hearts displayed impaired post-ischemic functional recovery for baseline stroke volume (p<0.01), work performance (p<0.05), aortic output (p<0.05), coronary flow (p<0.01), and overall cardiac output (p<0.01) when compared to matched controls and CRS males (p<0.05). Our findings reveal intriguing sex-specific responses at both the systemic and functional levels in stressed hearts. Here, the dysregulation of stress hormones, pro-inflammatory state, and potential underlying cardiomyopathy in females following the stress protocol renders them more prone to damage following myocardial ischemia. This study emphasizes the importance of incorporating sex as a biological variable in cardiac research focusing on stress-related cardiomyopathy.