Emerging role of microglia in the developing dopaminergic system: Perturbation by early life stress

Early life stress correlates with a higher prevalence of neurological disorders, including autism, attention-deficit/hyperactivity disorder, schizophrenia, depression, and Parkinson's disease. These conditions, primarily involving abnormal development and damage of the dopaminergic system, pose significant public health challenges. Microglia, as the primary immune cells in the brain, are crucial in regulating neuronal circuit development and survival. From the embryonic stage to adulthood, microglia exhibit stage-specific gene expression profiles, transcriptome characteristics, and functional phenotypes, enhancing the susceptibility to early life stress. However, the role of microglia in mediating dopaminergic system disorders under early life stress conditions remains poorly understood. This review presents an up-to-date overview of preclinical studies elucidating the impact of early life stress on microglia, leading to dopaminergic system disorders, along with the underlying mechanisms and therapeutic potential for neurodegenerative and neurodevelopmental conditions. Impaired microglial activity damages dopaminergic neurons by diminishing neurotrophic support (e.g., insulin-like growth factor-1) and hinders dopaminergic axon growth through defective phagocytosis and synaptic pruning. Furthermore, blunted microglial immunoreactivity suppresses striatal dopaminergic circuit development and reduces neuronal transmission. Furthermore, inflammation and oxidative stress induced by activated microglia can directly damage dopaminergic neurons, inhibiting dopamine synthesis, reuptake, and receptor activity. Enhanced microglial phagocytosis inhibits dopamine axon extension. These long-lasting effects of microglial perturbations may be driven by early life stress-induced epigenetic reprogramming of microglia. Indirectly, early life stress may influence microglial function through various pathways, such as astrocytic activation, the hypothalamic-pituitary-adrenal axis, the gut-brain axis, and maternal immune signaling. Finally, various therapeutic strategies and molecular mechanisms for targeting microglia to restore the dopaminergic system were summarized and discussed. These strategies include classical antidepressants and antipsychotics, antibiotics and anti-inflammatory agents, and herbal-derived medicine. Further investigations combining pharmacological interventions and genetic strategies are essential to elucidate the causal role of microglial phenotypic and functional perturbations in the dopaminergic system disrupted by early life stress.

2'-FL and cross-feeding bifidobacteria reshaped the gut microbiota of infants with atopic dermatitis ex vivo and prevented dermatitis in mice post-microbiota transplantation through retinol metabolism activation

2'-Fucosyllactose (2'-FL), a predominant human milk oligosaccharide, plays a crucial role in the development of the infant gut microbiota and immune system. However, the microbiota of infants with atopic dermatitis (AD) often has difficulty utilizing 2'-FL. Here, we found that strains from human milk, Bifidobacterium bifidum FN120 and Bifidobacterium longum subsp. longum FN103, utilized 2'-FL for growth by cross-feeding. Through an ex vivo continuous fermentation system, we found that 2'-FL and cross-feeding bifidobacteria synergistically enhanced the production of short-chain fatty acids (SCFAs), particularly acetate and propionate, while reshaping the gut microbiota in infants with AD. The reshaped microbiota was then transplanted into oxazolone-induced mice. We observed that AD symptoms in mice were effectively prevented, with significant changes in the ileum microbiota and increased intestinal SCFA levels. RNA sequencing analysis of Peyer's patches in the small intestine revealed activation of the retinol metabolic pathway. Nontargeted metabolomics analysis revealed a significant increase in plasma retinoate levels, which correlated markedly with AD-related markers. Collectively, our study demonstrated that supplementation with cross-feeding bifidobacteria and 2'-FL reshaped the gut microbiota, activated retinol metabolic pathways, promoted immune tolerance, and thereby prevented AD. Our findings provide novel insights into the therapeutic potential of combining prebiotics and probiotics to modulate the gut - skin axis and support immune tolerance in early life, offering a promising strategy for infantile AD management and prevention.

Dissecting the shared molecular mechanisms underlying polycystic ovary syndrome and schizophrenia etiology: a translational integrative approach

Recent evidence suggests that individuals with polycystic ovary syndrome (PCOS) have an increased risk of developing mental health disorders and comorbidities linked to nervous system dysfunction. Interestingly, patients with schizophrenia (SCZ) often exhibit PCOS symptoms, indicating a possible connection between the two conditions. However, the underlying molecular links between these diseases remain poorly understood. We employed a comprehensive in-silico approach, utilizing publicly available datasets to investigate shared biomarkers candidates and key regulators involved in the development of PCOS and SCZ. We retrieved the datasets from the NCBI GEO database and differentially expressed genes (DEGs) were identified for each dataset. Common DEGs (cDEGs) were determined, and transcription factors (TFs) and miRNA targeting cDEGs were examined using the mirDIP portal and TRRUST database, respectively. We also assessed the TF-miRNA interactions by TransmiR database and constructed a regulatory network including TFs-microRNAs-cDEGs. Our analysis identified a total of 15 cDEGs that are regulated by 15 TFs and 8 mRNAs. Among our findings, we prioritized RELA as a potential TF regulator for both diseases, demonstrating synergistic interaction with four cDEGs (EGR1, CXCL8, IL1RN, IL1B) and seven microRNAs (hsa-miR-580, hsa-miR-5695, hsa-miR-936, hsa-miR-3675, hsa-miR-634, hsa-miR-603, hsa-miR-222) that target these genes. Our data highlights potential common biomarkers for PCOS and SCZ, presenting a novel regulatory network that elucidates the molecular mechanisms underlying both conditions. This emphasizes the importance of further research to explore new translational approaches, which may ultimately lead to improved diagnostic and therapeutic strategies for affected individuals.

Exploring the role of gut microbiota in antibiotic resistance and prevention

BACKGROUND/INTRODUCTION

Antimicrobial resistance (AMR) and the evolution of multiple drug-resistant (MDR) bacteria is of grave public health concern. To combat the pandemic of AMR, it is necessary to focus on novel alternatives for drug development. Within the host, the interaction of the pathogen with the microbiome plays a pivotal role in determining the outcome of pathogenesis. Therefore, microbiome-pathogen interaction is one of the potential targets to be explored for novel antimicrobials.

MAIN BODY

This review focuses on how the gut microbiome has evolved as a significant component of the resistome as a source of antibiotic resistance genes (ARGs). Antibiotics alter the composition of the native microbiota of the host by favouring resistant bacteria that can manifest as opportunistic infections. Furthermore, gut dysbiosis has also been linked to low-dosage antibiotic ingestion or subtherapeutic antibiotic treatment (STAT) from food and the environment.

DISCUSSION

Colonization by MDR bacteria is potentially acquired and maintained in the gut microbiota. Therefore, it is pivotal to understand microbial diversity and its role in adapting pathogens to AMR. Implementing several strategies to prevent or treat dysbiosis is necessary, including faecal microbiota transplantation, probiotics and prebiotics, phage therapy, drug delivery models, and antimicrobial stewardship regulation.

Long nighttime sleep duration and risk of renal tubular damage: evidence from rural China and a Mendelian randomization analysis

OBJECTIVE

Renal tubular damage, a pivotal pathological feature of chronic kidney disease (CKD), predicts disease progression. While extreme nighttime sleep duration is linked to glomerular injury by prior studies, its impact on tubular damage remains unclear. Given that 7-9 h of sleep per night is widely recommended for maintaining overall health, this study aimed to assess whether long nighttime sleep duration is associated with renal tubular damage using both observational and genetic evidence.

METHODS

We analyzed 2,683 adults in rural China to assess the link between nighttime sleep duration and renal tubular damage (measured by retinol-binding protein and β2-microglobulin). Mendelian randomization (MR) analysis was performed to assess the causal relationship between prolonged nighttime sleep duration and elevated kidney injury molecule-1 (KIM-1) levels.

RESULTS

Multivariate logistic regression indicated that sleeping more than 9 h per night was associated with a 1.38-fold increased risk of renal tubular damage (95% CI: 1.11-1.71) compared to 7-9 h of sleep, with particularly pronounced effects observed in elderly individuals and women. MR analysis further supported a causal relationship between genetically predicted long nighttime sleep duration and elevated KIM-1 levels (β: 0.994, 95% CI: 0.282-1.707), suggesting a genetic predisposition linking prolonged sleep duration with renal tubular damage.

CONCLUSIONS

Our findings provide observational and genetic evidence linking prolonged nighttime sleep to increased renal tubular damage risk. Given that 7-9 h of sleep per night is the widely accepted recommendation for maintaining overall health, our results emphasize the potential risks of excessive sleep duration exceeding 9 h.

The role of long-term hair steroids as diagnostic and intervention-related biomarkers in a multimorbid inpatient sample with posttraumatic stress disorder

Background: Steroid hormone dysregulations have frequently been implicated in posttraumatic stress disorder (PTSD) pathogenesis. However, the translation into naturalistic clinical settings as markers of symptomatology and treatment success remains complex. Particularly, there is little longitudinal data on steroid secretion over the course of interventions.Objective: This study examined the potential of long-term steroid hormone secretion assessed in hair as diagnostic and intervention-related biomarkers among medicated, multimorbid inpatients with PTSD.Method: As part of a secondary analysis of a randomised controlled trial, 54 female inpatients with a primary diagnosis of PTSD received standardised treatment and provided hair samples at pre-treatment, post-treatment, and 3-month follow-up. Cortisol, cortisone, and dehydroepiandrosterone (DHEA) were determined, alongside clinical assessments.Results: Cross-sectional results showed a negative association of pre-treatment DHEA with anxiety symptoms and a trend-level association with lifetime trauma exposure. While inpatients improved in PTSD symptomatology during treatment, neither pre-treatment steroids, nor treatment-induced steroid changes predicted PTSD symptoms at post-treatment or 3-month follow-up.Conclusion: The study highlights the challenges of establishing biomarkers in naturalistic clinical populations. While the association of attenuated DHEA with anxiety symptoms warrants further exploration, our data points towards the potential necessity of patient sub-sample selection to understand, and in the long run clinically target, the endocrine mechanisms in PTSD.

Prevalence of war-related posttraumatic stress disorder in adolescents: a systematic review and meta-analysis

Background: Posttraumatic stress disorder is common in civilians who are currently experiencing, or who have experienced, war. Most previous studies have focused on adult populations and, despite the recognised detrimental effect of war trauma on adolescent mental health, there remains a paucity of evidence on the prevalence of war-related PTSD in adolescents.Objective: This pre-registered (https://osf.io/dqg2z) systematic review and meta-analysis aims to understand the prevalence of PTSD, as well as both risk and protective factors for developing PTSD, in adolescents aged 10-24 years from across the world who are experiencing, or have experienced, war-related traumatic events, described in papers published in a 10 year period (2013-2023). We also examine how the choice of PTSD diagnostic assessment tool influences prevalence rates.Method: Medline (PubMed), PsycINFO (EBSCOhost), and PTSDpubs (ProQuest) were searched, which resulted in 21 papers eligible for inclusion. Data was searched, extracted and synthesised using the software tool Covidence.Results: The age range of adolescents in the included papers was 11-19 years. The average prevalence of PTSD was 29.4% (95% CI [18.7%, 43.0%]), although prevalence rates across studies were highly inconsistent (I2 = 99.4%). Prevalence rates were significantly higher in studies conducted longer after war exposure, and the PTSD diagnostic assessment tool used influenced prevalence.Conclusions: There is high prevalence of PTSD in adolescents during and after war. The prevalence of war-related PTSD increases with time in the post-war period, highlighting the need for access to psychological services following war. This study underscores the importance of defining age ranges and using validated and culturally sensitive assessment tools when interpreting prevalence rates of PTSD in adolescents.

Creatine in women's health: bridging the gap from menstruation through pregnancy to menopause

BACKGROUND

Creatine supplementation in women has gained attention for its potential benefits beyond muscle growth, including reproductive health, cognitive health and aging. Women exhibit distinct physiological differences from men, influenced by hormonal fluctuations during pre-menopause, pregnancy, and menopause, and these factors should be considered for their influence on creatine metabolism.

OBJECTIVE

This review aims to provide a historical evaluation of creatine supplementation in women, its potential applications across female-specific life stages, recent research highlights, and targets for future research. The review also considers the impact of hormonal changes on creatine metabolism and effectiveness as a dietary supplementation.

METHODS

This is a narrative overview of historical and recent research evaluating the effects of creatine in women.

RESULTS

Early studies demonstrated the benefits of creatine on exercise performance in women, though they often overlooked menstrual cycle variability. Recent research has begun to account for these hormonal fluctuations, enhancing the understanding of creatine's applications. Creatine supplementation has shown positive effects on muscle strength, exercise performance, and body composition, particularly when combined with resistance training. Additionally, creatine may improve mood and cognitive function, potentially alleviating symptoms of depression. Emerging evidence suggests creatine's benefits during pregnancy and post-menopause, though data on perimenopausal women remains limited.

CONCLUSION

Creatine supplementation presents a promising strategy for enhancing various aspects of women's health across the lifespan. Future research should focus on optimizing dosing strategies, understanding long-term health implications, and exploring creatine's effects during pregnancy and perimenopause.

Sex differences in the murine HPA axis after acute and repeated restraint stress

Chronic stress and stress-related mental illnesses such as major depressive disorder (MDD) constitute some of the leading causes of disability worldwide with a higher prevalence in women compared to men. However, preclinical research into stress and MDD is heavily biased toward using male animals only. Aberrant activity of the hypothalamic-pituitary-adrenal (HPA) axis has been linked to the development of MDD and several animal models of MDD have been established based on HPA axis dysregulation. In the present study, we compared stress biomarkers and behavior of male and female mice after acute and chronic restraint stress to investigate potential effects of sex differences in the stress response. Further, the validity of the interrupted repeated restraint stress (IRRS) model as an animal model for the HPA axis disturbances seen in MDD was assessed. After acute stress, female mice showed increased corticosterone secretion and changes in molecular markers suggesting increased HPA axis feedback sensitivity. Acute stress-induced signs of anxiety-like behavior were observed in male mice only suggesting that female mice may be more resilient to the anxiogenic effects of acute stress. Males and females responded similarly to IRRS with no sustained perturbations in HPA axis biomarkers. The IRRS model did not adequately translate to the changes reported in MDD with HPA axis overactivity and more severe perturbation models are likely needed. However, in alignment with previous studies, these data support that there are important sex differences in the HPA axis and that these may contribute to the etiology of stress-related psychiatric disorders.

Corticosterone rapidly modulates dorsomedial hypothalamus serotonin and behavior in an estrogen- and progesterone-dependent manner in adult female rats: potential role of organic cation transporter 3 (OCT3)

Previous studies have shown that corticosterone rapidly alters extracellular serotonin (5-hydroxytryptamine; 5-HT) concentrations in the dorsomedial hypothalamus (DMH) of adult male rats, suggesting a role for corticosterone actions in the DMH in regulation of physiological and behavioral responses. Whether or not corticosterone also rapidly alters extracellular serotonin concentrations in the DMH of female rats, and the dependence of this effect on ovarian hormones, is not known. To determine the effects of 17β-estradiol (E2), progesterone (P), and corticosterone on extracellular concentrations of serotonin in the DMH, corticosterone and/or P were delivered into the DMH of ovariectomized rats via reverse microdialysis in E2-primed rats. Combined, but not separate, delivery of corticosterone and P into the DMH rapidly and transiently increased extracellular 5-HT concentrations, a result that was dependent upon circulating E2. This effect of corticosterone on DMH 5-HT was replicated by local perfusion of the organic cation transporter 3 (OCT3) competitive inhibitor normetanephrine. Intra-DMH infusions of either corticosterone or normetanephrine also reversibly suppressed lordosis responses in E2 + P-primed females. These results suggest that ovarian hormones in combination with corticosterone modulate OCT3-mediated 5-HT clearance in the DMH, potentially representing an adaptive mechanism that allows sexually receptive females to respond rapidly to acute stressors.

Adverse childhood experiences and intimate partner violence in adulthood among transgender women: exploring the chain mediating role of self-esteem and LGBT minority stress

BACKGROUND

Transgender women experience a high incidence of intimate partner violence (IPV) in adulthood. The well-documented risk factors contributing to IPV include adverse childhood experiences (ACEs), low self-esteem, and the minority stress experienced by LGBT individuals. The object of the present study was to examine how ACEs influence IPV in adulthood, and to explore the chain mediating function of self-esteem and LGBT minority stress.

METHODS

In February 2022, we recruited 264 transgender women through snowball sampling in Shenyang, China. Participants completed a questionnaire assessing background characteristics, ACEs, IPV in adulthood, self-esteem and LGBT minority stress. Relationships among study variables were examined through variance and correlation analyses. A chain mediation model was tested using PROCESS.

RESULTS

There was a significant correlation among the four variables. ACEs positively predicted IPV in adulthood (r = 0.449, p < 0.001). The sequential mediation model demonstrated that self-esteem (the estimated effect = 0.0708, 95%CI: 0.0152-0.1327) and minority stress (the estimated effect = 0.0404, 95%CI: 0016-0.0847) had the potential to mediate the connection between ACEs and IPV respectively. Additionally, the combined mediating influence of self-esteem and minority stress (the estimated effect = 0.0298, 95%CI: 0.0105-0.0591) similarly exerted such an effect. In summary, the mediating effect accounts for 34.59% of the overall effect size.

CONCLUSION

Taken together, the findings underscore the high prevalence of IPV among Chinese transgender women, highlighting the need for additional attention from violence service providers and other healthcare professionals on ACEs, low self-esteem, and minority stress, as these factors may place this population at risk for IPV.

Long COVID and gut microbiome: insights into pathogenesis and therapeutics

Post-acute coronavirus disease 2019 syndrome (PACS), following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19), is typically characterized by long-term debilitating symptoms affecting multiple organs and systems. Unfortunately, there is currently a lack of effective treatment strategies. Altered gut microbiome has been proposed as one of the plausible mechanisms involved in the pathogenesis of PACS; extensive studies have emerged to bridge the gap between the persistent symptoms and the dysbiosis of gut microbiome. Recent clinical trials have indicated that gut microbiome modulation using probiotics, prebiotics, and fecal microbiota transplantation (FMT) led to improvements in multiple symptoms related to PACS, including fatigue, memory loss, difficulty in concentration, gastrointestinal upset, and disturbances in sleep and mood. In this review, we highlight the latest evidence on the key microbial alterations observed in PACS, as well as the use of microbiome-based therapeutics in managing PACS symptoms. These novel findings altogether shed light on the treatment of PACS and other chronic conditions.

Gut dysbiosis-induced vitamin B6 metabolic disorder contributes to chronic stress-related abnormal behaviors in a cortisol-independent manner

Chronic stress can result in various conditions, including psychological disorders, neurodegenerative diseases, and accelerated brain aging. Gut dysbiosis potentially contributes to stress-related brain disorders in individuals with chronic stress. However, the causal relationship and key factors between gut dysbiosis and brain disorders in chronic stress remain elusive, particularly under non-sterile conditions. Here, using a repeated restraint stress (RRS) rat model, we show that sequential transplantation of the cecal contents of different RRS stages to normal rats reproduced RRS-induced core phenotypes, including abnormal behaviors, increased peripheral blood corticosterone and inflammatory cytokines, and a unique gut microbial phenotype. This core phenotypic development was effectively inhibited with probiotic supplement. The RRS-induced unique gut microbial phenotypes at the genus level were positively or negatively associated with the levels of 20 plasma metabolites, including vitamin B6 metabolites 4-pyridoxic acid and 4-pyridoxate. Vitamin B6 supplement during RRS alleviated weight loss, abnormal behaviors, peripheral inflammation, and neuroinflammation, but did not affect the peripheral corticosterone levels in chronic stressed rats. Dampening inflammatory signaling via knocking out caspase 11 or caspase 1 inhibitor abolished RRS-induced abnormal behaviors and peripheral and neuroinflammation but did not decrease peripheral corticosterone in mice. These findings show that gut dysbiosis-induced vitamin B6 metabolism disorder is a new non-hypothalamic-pituitary-adrenal axis mechanism of chronic stress-related brain disorders. Both probiotics and vitamin B6 supplement have potential to be developed as therapeutic strategies for preventing and/or treating chronic stress-related illness.

Stevioside mitigates metabolic dysregulation in offspring induced by maternal high-fat diet: the role of gut microbiota-driven thermogenesis

Maternal obesity poses a significant threat to the metabolic profiles of offspring. Microorganisms acquired from the mother early in life critically affect the host's metabolic functions. Natural non-nutritive sweeteners, particularly stevioside (STV), play a crucial role in reducing obesity and affecting gut microbiota composition. Based on this, we hypothesized that maternal STV supplementation could improve the health of mothers and offspring by altering their gut microbiota. Our study found that maternal STV supplementation reduced obesity during pregnancy, decreased abnormal lipid accumulation in offspring mice caused by maternal obesity, and modified the gut microbiota of both dams and offspring, notably increasing the abundance of Lactobacillus apodemi (L. apodemi). Co-housing and fecal microbiota transplant experiments confirmed that gut microbiota mediated the effects of STV on metabolic disorders. Furthermore, treatment with L. apodemi alone replicated the beneficial effects of STV, which were associated with increased thermogenesis. In summary, maternal STV supplementation could alleviate lipid metabolic disorders in offspring by enhancing L. apodemi levels and promoting thermogenic activity, potentially involving changes in bile acid metabolism pathways.

Insights into depression prediction, likelihood, and associations in children and adolescents: evidence from a 12-years study

Purpose

The severity of depression among young Australians cannot be overstated, as it continues to have a profound impact on their mental health and general wellbeing. This study used machine learning (ML) algorithms to analyse longitudinal data, identifying key features to predict depression, assess future risk, and explore age-specific behaviours that contribute to its progression over time. The results emphasize the significance of early detection to prevent unfavourable consequences and shed light on the alterations in depressive symptoms during various stages of development.

Methods

Three widely regarded ML techniques-random forest (RF), support vector machine (SVM), and logistic regression (LR)-are being applied and compared with a longitudinal data analysis. Additionally, the Apriori algorithm is being utilized to explore potential relationships between health, behaviour, and activity issues with depression among different age groups (10-17).

Results

The analysis results indicate that the RF model is performing exceptionally well in diagnosing depression, with a 94% accuracy rate and weighted precision of 95% for non-depressed and 88% for depressed cases. In addition, the LR model shows promising results, achieving an 89% accuracy rate and 91% weighted precision. Moreover, insights from the Apriori algorithm underscore the significance of early detection by examining potential associations between health, behaviour, and activity problems and depression across diverse age groups.

Conclusion

Combining early screening programs with the RF model and the Apriori algorithm is crucial for understanding depression and developing effective prevention strategies. Emphasizing Apriori's factors and regularly updating strategies with new information will enhance depression management and prevention.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13755-025-00335-9.

Prognostic significance of Ki-67 in assessing the risk of progression, relapse or metastasis in pheochromocytomas and paragangliomas

INTRODUCTION

Since the Fourth edition of the WHO classification, PPGLs have been recognized for their metastatic potential, though no clear features can accurately predict this behavior. The prognostic value of Ki-67 in assessing the risk of progression, relapse, or metastasis in PPGLs remains debated.

METHODS

This cohort study included 501 patients diagnosed with PPGLs at the First Hospital of Jilin University between 2000 and 2022, with clinical data, treatment details, pathological indicators, and germline gene test results collected. Bulk sequencing was performed on formalin-fixed paraffin-embedded (FFPE) primary tumor samples from 87 patients. Progression-free survival (PFS) was analyzed using multivariable Cox regression.

RESULTS

Among the 119 enrolled patients with PPGLs, the average age was 45.7 ± 14.0 years, and the median follow-up time was 46 months. A significant finding was the high expression of CDK1, a gene known to be significantly associated with the metastatic risk of PPGLs, in samples with Ki-67 ≥ 3% (p < 0.0001). More importantly, patients with PPGLs and a Ki-67 level ≥ 3% had a 3.59-fold higher risk of progression, relapse or metastasis compared to those with Ki-67 < 3% (HR = 4.59, 95% CI: 1.06-11.95), after adjusting for all confounding factors. In the composite model, the addition of Ki-67 enhanced the predictive ability of the combined model of SDHB, primary site, tumor size, and invade neighboring tissue (AUC = 0.888, 95% CI: 0.808-0.967 vs. AUC = 0.874, 95% CI: 0.783-0.965).

CONCLUSION

A Ki-67 level ≥ 3% is associated with an increased risk of progression, relapse or metastasis in patients with PPGLs.

Unseen repercussions of war: psychological effects on Jordanians during the Israeli Palestinian war

BACKGROUND

People residing in war zones have direct exposure to trauma. In contrast, people living in nearby countries have indirect exposure to trauma and can develop negative psychological symptoms such as anxiety, depression or stress.

OBJECTIVE

This study aimed to study the mental ill effects of the war on people living in a neighbouring country to a war zone.

METHODS

A cross-sectional study of 568 community adults >18 years old who live in Jordan was conducted 1-2 months after the Israeli-Palestinian conflict erupted in October 2023. The online survey, spread through social media accounts, included the Depression Anxiety & Stress Scale - 21 (DASS-21) and questions about socio-demographic factors and measures to improve emotional status.

RESULTS

The mean age was 34.49 ± 12.75. 81.2%, 55.8% and 61.3% of the participants screened positive for depression, anxiety and stress, respectively, with 44.4%, 28.5%, and 32.9% of them having severe to extreme degrees of depression, anxiety and stress, respectively. Female gender, past anxiolytic treatment and daily time spent watching the news were positive predictors of depression, anxiety and stress. Knowing acquaintances in the war zone or living in a refugee camp were not predictors of psychological symptoms. Spirituality was the most commonly used coping strategy, yet talking to family and friends was the only coping strategy significantly associated with a better emotional state.

CONCLUSIONS

People living near conflicts often experience symptoms of depression, anxiety, and stress regardless of having acquaintances under direct conflict. High-risk groups include females, patients with past anxiolytic self-treatment, and those with long daily exposure to war-related media content. Emotional screening and support by trained healthcare workers to identify early signs of depression, anxiety and stress are warranted.

Repeated presentation of visual threats drives innate fear habituation and is modulated by threat history and acute stress exposure

To survive predation, animals must be able to detect and appropriately respond to predator threats in their environment. Such defensive behaviors are thought to utilize hard-wired neural circuits for threat detection, sensorimotor integration, and execution of ethologically-relevant behaviors. Despite being hard-wired, defensive behaviors (i.e. fear responses) are not fixed, but rather show remarkable flexibility, suggesting that extrinsic factors such as threat history, environmental contexts, and physiological state may alter innate defensive behavioral responses. The goal of the present study was to examine how extrinsic and intrinsic factors influence innate defensive behaviors in response to visual threats. In the absence of a protective shelter, our results indicate that mice showed robust freezing behavior following both looming (proximal) and sweeping (distal) threats, with increased behavioral vigor in response to looming stimuli, which represent a higher threat imminence. Repeated presentation of looming or sweeping stimuli at short inter-trial intervals resulted in robust habituation of freezing, which was accelerated at longer inter-trial intervals, regardless of contextual cues. Finally, prior stress history such as acute foot shock further disrupted innate freezing habituation, resulting in a delayed habituation phenotype, consistent with a heightened fear state. Together, our results indicate that extrinsic factors such as threat history, environmental familiarity, and stressors have robust and diverse effects on defensive behaviors, highlighting the behavioral flexibility in how mice respond to predator threats.

Anti-perilipin-1 autoantibodies in autoimmune Addison's disease and related endocrine disorders

Immune-mediated lipodystrophy syndromes are rare autoimmune disorders characterized by complete or partial destruction of adipocytes in the body. Recently, autoantibodies against perilipin-1 (PLIN1-autoAbs) have been linked to lipodystrophy. Since various perilipins are expressed in the adrenal cortex and ovaries, we asked whether PLIN1-autoAbs were present in patients with adrenal dysfunction and other autoimmune endocrinopathies. Using a sensitive radiobinding immune assay we analyzed anti-PLIN1-autoAbs in 521 patients with endocrinopathies including Sjögren's syndrome. We identified 22 (4.2%) PLIN1-autoAbs positive patients, of whom 15% had autoimmune polyendocrine syndrome type 1 (4/27), 4% autoimmune Addison's disease and/or autoimmune polyendocrine syndrome type 2 (11/274), 8% type 1 diabetes patients (4/53), and 2% Sjögren's syndrome patients (1/50). However, none of them had known lipodystrophy. In conclusion, PLIN1-autoAbs are found in subgroups of autoimmune endocrinopathies and indicate autoimmunity against adipose tissue, but their pathogenic role if any, remains to be defined. Investigating their role in disease progression and their potential as therapeutic targets could pave the way for novel interventions in autoimmune endocrine diseases.

The complex interaction between oestrogen receptor genes, oestradiol, and perinatal mood

INTRODUCTION

Genetic variations in oestrogen receptor (ER) genes are associated with inter-individual differences in the sensitivity of ER-α, ER-β and G protein-coupled oestrogen receptor (GPER). These sensitivity differences may modulate susceptibility to mood changes during phases of endogenous oestrogen fluctuations, thereby explaining individual vulnerability. This study examined the association between ER gene variations, oestradiol and perinatal mood disturbances.

METHODS

A total of 159 women were observed during the perinatal period, providing saliva samples for oestradiol assessment and completing self-report measures of depressive and anxiety symptoms at five time points. Polymorphisms in ER genes were determined from dried blood spots. The associations were analysed using linear mixed models.

RESULTS

The ER-α gene haplotypes were associated with perinatal mood disturbances. The CG haplotype was associated with perinatal depressive (p = 0.0162, F-test) and anxiety symptoms (p = 2.396e-05, F-test), whereas the TA haplotype was associated with perinatal anxiety symptoms (p = 0.004, F-test). The interaction between ER gene variations, oestradiol and perinatal mood disturbances was not significant.

CONCLUSIONS

ER-α gene variations are associated with an increased susceptibility to perinatal mood disturbances. Sensitivity differences in ER-α appear to play a more important role for emotional processes than those in ER-β and GPER, independently of oestradiol levels. This might be explained by ER-α's more dominant expression in the hypothalamus and amygdala.

Multilevel analysis of the central-peripheral-target organ pathway: contributing to recovery after peripheral nerve injury

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities. Research on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites, neglecting multilevel pathological analysis of the overall nervous system and target organs. This has led to restrictions on current therapeutic approaches. In this paper, we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective, covering the central nervous system, peripheral nervous system, and target organs. After peripheral nerve injury, the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves; changes such as neuronal apoptosis and axonal demyelination occur in the spinal cord. The nerve will undergo axonal regeneration, activation of Schwann cells, inflammatory response, and vascular system regeneration at the injury site. Corresponding damage to target organs can occur, including skeletal muscle atrophy and sensory receptor disruption. We then provide a brief review of the research advances in therapeutic approaches to peripheral nerve injury. The main current treatments are conducted passively and include physical factor rehabilitation, pharmacological treatments, cell-based therapies, and physical exercise. However, most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ pathway. Therefore, we should further explore multilevel treatment options that produce effective, long-lasting results, perhaps requiring a combination of passive (traditional) and active (novel) treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

Nanocarrier-mediated siRNA delivery: a new approach for the treatment of traumatic brain injury-related Alzheimer's disease

Traumatic brain injury and Alzheimer's disease share pathological similarities, including neuronal loss, amyloid-β deposition, tau hyperphosphorylation, blood-brain barrier dysfunction, neuroinflammation, and cognitive deficits. Furthermore, traumatic brain injury can exacerbate Alzheimer's disease-like pathologies, potentially leading to the development of Alzheimer's disease. Nanocarriers offer a potential solution by facilitating the delivery of small interfering RNAs across the blood-brain barrier for the targeted silencing of key pathological genes implicated in traumatic brain injury and Alzheimer's disease. Unlike traditional approaches to neuroregeneration, this is a molecular-targeted strategy, thus avoiding non-specific drug actions. This review focuses on the use of nanocarrier systems for the efficient and precise delivery of siRNAs, discussing the advantages, challenges, and future directions. In principle, siRNAs have the potential to target all genes and non-targetable proteins, holding significant promise for treating various diseases. Among the various therapeutic approaches currently available for neurological diseases, siRNA gene silencing can precisely "turn off" the expression of any gene at the genetic level, thus radically inhibiting disease progression; however, a significant challenge lies in delivering siRNAs across the blood-brain barrier. Nanoparticles have received increasing attention as an innovative drug delivery tool for the treatment of brain diseases. They are considered a potential therapeutic strategy with the advantages of being able to cross the blood-brain barrier, targeted drug delivery, enhanced drug stability, and multifunctional therapy. The use of nanoparticles to deliver specific modified siRNAs to the injured brain is gradually being recognized as a feasible and effective approach. Although this strategy is still in the preclinical exploration stage, it is expected to achieve clinical translation in the future, creating a new field of molecular targeted therapy and precision medicine for the treatment of Alzheimer's disease associated with traumatic brain injury.

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202509000-00023/figure1/v/2024-11-05T132919Z/r/image-tiff Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury, the fundamental regulatory and functional mechanisms remain insufficiently understood. As potent anti-inflammatory agents, the use of glucocorticoids in traumatic brain injury is still controversial, and their regulatory effects on microglial polarization are not yet known. In the present study, we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of action. In vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial polarization. Lipopolysaccharide, dexamethasone, RU486 (a glucocorticoid receptor antagonist), and ruxolitinib (a Janus kinase 1 antagonist) were administered. RNA-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of dexamethasone. The Morris water maze, quantitative reverse transcription-polymerase chain reaction, western blotting, immunofluorescence and confocal microscopy analysis, and TUNEL, Nissl, and Golgi staining were performed to investigate our hypothesis. High-throughput sequencing results showed that arginase 1, a marker of M2 microglia, was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at 3 days post-traumatic brain injury. Thus dexamethasone inhibited M1 and M2 microglia, with a more pronounced inhibitory effect on M2 microglia in vitro and in vivo . Glucocorticoid receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain injury. Additionally, glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death, and also decreased the density of dendritic spines. A possible downstream receptor signaling mechanism is the GR/JAK1/STAT3 pathway. Overactivation of glucocorticoid receptor by high-dose dexamethasone reduced the expression of M2 microglia, which plays an anti-inflammatory role. In contrast, inhibiting the activation of glucocorticoid receptor reduced the number of apoptotic glia and neurons and decreased the loss of dendritic spines after traumatic brain injury. Dexamethasone may exert its neurotoxic effects by inhibiting M2 microglia through the GR/JAK1/STAT3 signaling pathway.

Glucocorticoid receptor signaling in the brain and its involvement in cognitive function

The hypothalamic-pituitary-adrenal axis regulates the secretion of glucocorticoids in response to environmental challenges. In the brain, a nuclear receptor transcription factor, the glucocorticoid receptor, is an important component of the hypothalamic-pituitary-adrenal axis's negative feedback loop and plays a key role in regulating cognitive equilibrium and neuroplasticity. The glucocorticoid receptor influences cognitive processes, including glutamate neurotransmission, calcium signaling, and the activation of brain-derived neurotrophic factor-mediated pathways, through a combination of genomic and non-genomic mechanisms. Protein interactions within the central nervous system can alter the expression and activity of the glucocorticoid receptor, thereby affecting the hypothalamic-pituitary-adrenal axis and stress-related cognitive functions. An appropriate level of glucocorticoid receptor expression can improve cognitive function, while excessive glucocorticoid receptors or long-term exposure to glucocorticoids may lead to cognitive impairment. Patients with cognitive impairment-associated diseases, such as Alzheimer's disease, aging, depression, Parkinson's disease, Huntington's disease, stroke, and addiction, often present with dysregulation of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor expression. This review provides a comprehensive overview of the functions of the glucocorticoid receptor in the hypothalamic-pituitary-adrenal axis and cognitive activities. It emphasizes that appropriate glucocorticoid receptor signaling facilitates learning and memory, while its dysregulation can lead to cognitive impairment. This provides clues about how glucocorticoid receptor signaling can be targeted to overcome cognitive disability-related disorders.

Computer-aided precise hapten design strategy for the monospecific detection of altrenogest: Experimental validation and analysis of the molecular recognition mechanism

Altrenogest is one of the most commonly used steroid hormones; however, there are currently no relevant reports on monospecific molecular recognition elements and immunoassay methods for altrenogest. Herein, a computer-aided precise hapten design strategy was proposed for monospecific monoclonal antibodies (mAb) preparation. Based on this strategy, a monospecific and sensitive mAb-D7 was prepared for the first time. The mAb-D7 has the 50 % inhibitory concentration (IC50) of 0.12 ng/mL for altrenogest and does not cross-react with other common steroid hormones. Additionally, a single-chain variable fragment (scFv) for altrenogest was constructed for the first time, which exhibits an IC50 of 1.7 ng/mL for altrenogest. The molecular recognition mechanism studies showed the monospecific mAb-D7 to altrenogest originated from the amino acids PHE-94 and LEU-237, demonstrating the reliability of this strategy. Finally, two monospecific, rapid, and sensitive immunoassays were established for altrenogest in pork and pork liver for the first time.

A systematic review of resting-state functional-MRI studies in the diagnosis, comorbidity and treatment of postpartum depression

BACKGROUND

Postpartum depression (PPD) is a common and serious mental health problem that affects many new mothers and their families worldwide. In recent years, there has been an increasing number of studies using magnetic resonance techniques (MRI), particularly functional MRI (fMRI), to explore the neuroimaging biomarker of this disease.

METHODS

PubMed database was used to search for English literature focusing on resting-state fMRI and PPD published up to June 2024.

RESULTS

After screening, 17 studies were finally identified, among which all 17 studies reported abnormal regions or connectivity compared to health controls (HC), 4 studies reported results considering the differences between PPD and PPD with anxiety (PPD-A), and 2 studies reported biomarkers for the treatment of PPD. The existing studies indicate that PPD is characterized by functional impairments in multiple brain regions, especially the medial prefrontal cortex (MPFC), precentral gyrus and cerebellum. Abnormal functional connectivity has been widely reported in the dorsomedial prefrontal cortex (dmPFC), anterior cingulate cortex (ACC) and the orbitofrontal cortex (OFC). However, none of the four comorbidity studies identified overlapping discriminative biomarkers between PPD and PPD-A. Additionally, the two treatment-related studies consistently reported functional improvements in the amygdala after effective treatment.

CONCLUSION

The affected brain regions were highly overlapped with major depressive disorder (MDD), suggesting that PPD may be categorized as a potential subtype of MDD. Considering the negative effects of medication on PPD, future efforts should focus on developing non-pharmacological therapies, such as transcranial magnetic stimulation (TMS) and acupuncture, to support women with PPD in overcoming this unique and important phase.

The role of testosterone in modulating positive and negative empathy in social interactions

Empathy encompasses both negative (e.g., distress) and positive (e.g., shared joy) dimensions, yet the effects of testosterone on positive empathy and its modulation of intrinsic neural dynamics remain underexplored. This double-blind, placebo-controlled study examined how testosterone influences neural sensitivity to empathy within social inclusion and exclusion contexts, as well as its impact on resting-state EEG microstates-millisecond-scale transient patterns of brain activity. Healthy male participants received either testosterone or placebo before completing resting-state EEG recordings and an empathy task featuring social scenarios. While self-reported empathy ratings remained unchanged, testosterone amplified neurophysiological responses: it enhanced anterior N2 amplitude (250-310 ms), associated with negative empathy toward social exclusion, and increased posterior α-event-related desynchronization (8.28-10 Hz; 1226-1901 ms), linked to positive empathy during social inclusion. These findings suggest that testosterone enhances neural responsiveness to both threatening and affiliative social cues, reinforcing its role in adaptive social vigilance. Resting-state EEG microstate analysis further revealed that testosterone prolonged the temporal dominance of microstate E-a centro-parietal activity pattern associated with interoceptive awareness and emotional processing. Notably, these microstate E changes predicted increased emotional empathy across both positive and negative contexts. Together, our findings suggest that testosterone indirectly enhances empathy-related responsiveness by amplifying baseline interoceptive sensitivity to socially salient stimuli. These dual effects-enhanced intrinsic interoceptive processing and heightened neural reactivity to social cues-position testosterone as a key neuromodulator of context-adaptive social perception.

The impact of membrane receptors on modulating empathic pain

Humans can estimate each other's pain and provide adapted care to reduce it. Empathetic skills are crucial for caregivers involved in pain management; consequently, educational programs and theories have emphasized the positive role of empathy in reducing pain intensity. It is also widely assumed that if caregivers lack empathy, they will underestimate pain intensity in their patients, and this unempathetic attitude can negatively influence pain intensity perception. Empathy for pain is thought to activate the affective‒motivational components of the pain matrix, which includes the anterior insula, middle and anterior cingulate cortices and amygdala, as indicated by functional magnetic resonance imaging and other methodologies. Activity in this core neural network reflects the affective experience that activates our responses to pain and lays the neural foundation for our understanding of our own emotions and those of others. Additionally, a variety of factors can regulate the intensity of empathy for pain, such as oxytocin and vasopressin receptors. Therefore, we selectively review the molecular mechanisms by which membrane receptors modulate this pain modality.

Physical symptoms and inflammatory levels characterize post-COVID-19 depressive episodes compared to non-post-COVID-19 depression

Major depressive episodes (MDE) following COVID-19 have been described in approximately 30 % of cases. A clinical picture characterized by physical and cognitive symptoms with underlying immune-inflammatory changes has been reported. However, a comparison of post-COVID-19 MDE with non-post-COVID-19 depression is still lacking. This study aims to characterize 209 patients with MDE, post-COVID-19 vs. non-post-COVID-19, focusing on physical and cognitive symptomatology evaluated through Hamilton Depression (HDRS) and Anxiety Rating Scales (HARS), Digit Symbol Substitution Test (DSST), Perceived Deficits Questionnaire-Depression 5-items (PDQ-D5). Inflammatory levels were assessed with blood count-derived indexes. Post-COVID-19 group (46.9 % of patients) displayed higher rates of first-onset depressive episodes (p = 0.001), an older age at onset (p = 0.006), more physical and cognitive features according to subitems of HDRS (p = 0.001), HARS (p < 0.001), and PDQ-D5 scores (p = 0.019), as well as higher inflammatory indexes (p < 0.001). Logistic regression showed a significant association of post-COVID-19 MDE with physical symptomatology (p = 0.02) and Systemic Immune-Inflammatory Index (p = 0.04). Receiver Operating Characteristic (ROC) curves displayed a discriminative potential for this association (AUC = 0.921). These results highlight the specific clinical presentation of post-COVID-19 MDE, with prominent physical symptoms and increased inflammation levels, suggesting that a more careful characterization might inform personalized interventions and promote full functional recovery in these patients.

USP18 is a key regulator of immune function in mouse midbrain microglia

AIMS

Ubiquitin-specific peptidase 18 (USP18) is an important member of the deubiquitinating enzyme family, which has received much attention in recent years for its role in microglia regulation. The aim of this study was to investigate the role of USP18 in midbrain and its potential molecular mechanisms.

METHODS

In this study, we assessed behavioural phenotypes and pathological changes by adeno-associated virus (AAV)-mediated midbrain-specific USP18 high-expression mouse model. RNA sequencing and untargeted metabolomics were used for multi-omics analysis, and protein expression was detected by Western blot, and ELISA was used to detect neuroinflammatory factor levels.

RESULTS

Our analyses suggest that USP18 is a key regulator of immune activity in the midbrain. USP18 helps maintain the resting state of microglia and exerts neuroprotective effects by promoting TH protein expression. In the midbrain, interference with USP18 expression resulted in significant changes in neuroimmune responses, gene expression associated with inflammation, and metabolite levels. Notably, the TLR signalling pathway was significantly enriched. Loss of USP18 led to a significant increase in the expression of TLR2, Iba-1, and GFAP proteins and a significant decrease in TH levels, and this change was particularly pronounced in microglia. Importantly, the changes observed in USP18 silencing were also reflected in brain tissues of human neurodegenerative diseases.

SIGNIFICANCE

This study reveals the critical role of USP18 in midbrain and microglia, and suggests it can finely regulate neuroinflammatory and immune responses by modulating TLR2 protein levels. The findings provide new ideas for understanding mechanisms of neurodegenerative diseases and developing therapeutic strategies.

Hormonal and neuronal interactions shaping the brain metastatic microenvironment

Metastatic progression drives the majority of cancer-related fatalities, and involvement of the central nervous system (CNS) poses especially formidable challenges to patients and clinicians. Brain metastases (BrM), commonly originate from lung, breast and melanoma cancers, and carry disproportionately poor outcomes. Although therapeutic advances have extended survival for many extracranial tumors, BrM incidence continues to climb-underscoring critical knowledge gaps in understanding the unique biology of tumor colonization in the CNS. While definitive evidence remains limited, a growing focus on cancer neuroscience-especially regarding hormone dependent cancer cells in the brain-has begun to reveal that factors normally regulated by sex steroids and neurosteroids may similarly influence the specialized metastatic microenvironment in the CNS. Steroid hormones can permeate the blood-brain barrier (BBB) or be synthesized de novo by astrocytes and other CNS-resident cells, potentially influencing processes such as inflammation, synaptic plasticity, and immune surveillance. However, how these hormonal pathways are co-opted by disseminated cancer cells remains unclear. Here, we review the complex hormonal landscape of the adult brain and examine how neuroendocrine-immune interactions, often regulated by sex hormones, may support metastatic growth. We discuss the interplay between systemic hormones, local steroidogenesis, and tumor adaptation to identify novel therapeutic opportunities.

The role of puberty in experimental pain sensitivity in healthy adolescent girls

Introduction

Puberty is a critical developmental period during which changes in pain sensitivity are observed. Previous studies found that older and more mature adolescents have lower experimental pain sensitivity. However, it is unclear whether the differences in pain sensitivity are due to age or the pubertal maturation effect.

Objectives

This observational study examined the relationships between the pubertal maturation stage, age, and experimental pain sensitivity in healthy girls.

Methods

Healthy adolescent girls (n = 52, mean age 12.0 ± 1.4 years) completed the Pubertal Developmental Scale (PDS) to assess their pubertal stage. In addition, they completed a comprehensive quantitative sensory testing session, including pain thresholds, pain ratings to noxious stimuli, and pain modulation tests. Separate regression models were performed to assess the effect of pubertal maturation and age on experimental pain sensitivity as well as differences in experimental pain sensitivity between girls in different subjective self-perceived pubertal timing relative to peers.

Results

No relationships were found between the PDS score and experimental pain sensitivity; however, age was significantly related to cold pain tolerance (P = 0.030). In addition, to differentiate between puberty and age, experimental pain sensitivity was compared in a subsample of girls of the same age but at different pubertal stages, and no differences in experimental pain sensitivity were observed. No differences were also found when comparing girls who mature early, same, or late relative to their peers.

Conclusion

Puberty and age may have no effect on experimental pain sensitivity in healthy girls.

Workplace stressors and mental health outcomes among personal support workers: A systematic review

BACKGROUND

Although there is a growing focus on the mental well-being of licensed clinicians, there remains a scarcity of comprehensive evidence concerning the mental well-being of personal support workers (broadly defined as direct care workers), a vital segment of the healthcare workforce, particularly for aging populations. This review aims to identify, summarize, and synthesize the literature on work-related stressors associated with mental health problems among personal support workers, while also examining the potential influence of gender or sex differences in this relationship.

METHODS

This systematic review searched the EMBASE, PsycINFO, PubMed/Medline, and Web of Science databases for relevant studies. Studies published between 1 January 2003 and 30 June 2024 were included in the review. A quality assessment of each study was conducted using the Joanna Briggs Institute Checklist for Analytical Cross-Sectional Studies and the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. Meta-analysis was not performed due to the heterogeneity of the studies' characteristics.

RESULTS

Fourteen (14) articles met the inclusion criteria. They assessed burnout, depression, and/or anxiety among personal support workers who were exposed to various work-related stressors including high workload, aggressive client behavior, insufficient resources (e.g., physical and staffing), role ambiguity, conflict, personal growth, job satisfaction, discrimination, lack of co-workers or supervisors support, emotional suppression, extended working hours, complicated grief, and organizational support or respect. Aggressive client behavior, role ambiguity, resource inadequacy, and high workload emerged as the most frequently reported stressors. Burnout was the most frequently observed outcome. These relationships persisted in many multivariable analyses, even after adjusting for potential confounders. Also, females who experienced work-related stressors were more likely than males to report burnout, depression, or anxiety.

LIMITATIONS

The considerable heterogeneity of various work-related stressors and measurements among selected studies prevented a meta-analysis.

CONCLUSIONS

Collectively, this review's results suggest a significant association between major work-related stressors and mental disorders among personal support workers, while also emphasizing notable gender/sex differences in this relationship. These findings not only guide future research into the mental well-being of personal support workers but also underscore the importance for healthcare institutions of implementing organizational interventions to mitigate stressors and cultivate a more supportive work environment.

The impact of stress on fear memory retention: A meta-analysis of rodent fear conditioning studies

Pavlovian fear conditioning is a widely used behavioural task for studying fear memory in rodents. During conditioning, rodents learn to associate a conditioned stimulus (e.g., context or tone; contextual or auditory fear conditioning, CFC or AFC, respectively) with an aversive one (e.g., footshock), resulting in a conditioned fear response. Fear memory retention is assessed thorough freezing behaviour, a species-specific defensive reaction, observed during exposure to the conditioned stimulus alone. Fear memory is influenced by sex and stress, with stress exposure prior to conditioning potentially inducing maladaptive fear responses. This meta-analysis examines how pre-conditioning stress exposure modulates memory retention in rodents. Across N = 94 studies included, we analyzed freezing behaviour based on several factors: type of paradigm (CFC vs AFC), species (rat vs mouse), sex (male vs female), stress type (physical vs pharmacological vs psychological vs combination of two or more stressors type), stress duration (acute or chronic), stress timing (prenatal vs early postnatal vs adolescence vs adulthood). The results indicate that stress significantly enhances contextual conditioned freezing behaviour. Stress-induced effects in CFC models vary across species but are not sex-specific. Additionally, these effects are influenced by stress-related factors. These findings highlight the importance of considering multiple variables when studying stress and fear memory processes, offering valuable insights for improving clinical approaches to fear memory-related diseases (e.g., post-traumatic stress disorder).

Vitamin D alleviates chronic stress-induced testicular steroidogenesis disruption in Wistar rats

Stress is associated with various health issues. Research has highlighted the relationship between chronic stress and male reproductive health. One of the primary mechanisms underlying stress-induced male reproductive dysfunction is impaired steroidogenesis. In the present study, we validated a chronic unpredictable stress (CUS) model and investigated testicular dysfunction in CUS rats. The CUS paradigm involved exposing rats to a variety of stressors daily for 8 weeks. Vitamin D (10 µg/kg/twice a week, p.o) was administered to CUS rats starting 2 weeks after the onset of stress exposure and continued until the end of study. The stress in rats was confirmed by the occurrence of anxiety and depressive-like behaviours through elevated plus-maze test & novelty-suppressed feeding test and rise in serum corticosterone levels. Testicular dysfunction in CUS rats was assessed via serum gonadotropins, testosterone, cytokines, oxidative stress, and testis-epididymis-sperm morphology. The reduction in steroidogenesis was confirmed via immunohistochemical analysis of 17β-hydroxysteroid dehydrogenase-3 (17β-HSD3), steroidogenic acute regulatory gene (StAR) and vitamin D receptor (VDR) expression. Further, we studied the role of vitamin D in alleviating stress-induced testicular damage and the potential mechanisms underlying steroidogenic alterations in CUS rats. Notably, vitamin D treatment prevented CUS-induced decline in testicular 17β-HSD3, StAR and VDR expression. Moreover, vitamin D ameliorated the CUS-induced reduction in serum testosterone levels. Histological assessment revealed that vitamin D prevented CUS-induced damage in sperm, testis and epididymis morphology. In conclusion, our findings suggest that CUS exposure induces testicular dysfunction, which can be prevented by vitamin D, potentially through the regulation of steroidogenic pathways.

Circadian attributes of neurological and psychiatric disorders as basis for their medication chronotherapy

This review focuses on (i) 24 h patterns in the symptom intensity of common neurologic and psychiatric disorders and (ii) medications prescribed for their management that have a recommended administration time or schedule, presumably to potentiate desired and minimize undesired effects and by definition qualify them as chronotherapies. Predictable-in-time patterning of symptoms is exhibited by many neurologic -- headaches, multiple sclerosis, neurogenic orthostatic hypotension, neuropathic pain, Parkinson's disease, epileptic seizure, attention deficit hyperactivity, Alzheimer's disease - and psychiatric - eating, depressive, obsessive-compulsive, post-traumatic stress, anxiety, and panic - disorders, due either to circadian rhythms of disease pathophysiology or inadequacies of medication-delivery systems. Circadian disruption and circadian misalignment of the sleep-wake and other 24 h rhythms plus late chronotype are characteristic of many of these disorders, suggesting involvement in the mechanisms or consequence of their pathology or as an adverse effect of therapy, especially when administered at an inappropriate biological time. The Prescribers' Digital Reference, a compendium of all prescription medications approved for marketing in the US, reveals 65 of them are utilized to manage neurologic and psychiatric disorders by a specified time-of-day or an asymmetrical interval or strength of dose schedule, presumably to optimize beneficial and minimize adverse effects, thereby qualifying them as chronotherapies. Overall, the contents of this review are intended to inform the development of future chronotherapies that incorporate state-of-the-art drug-delivery systems to improve management of neurologic and psychiatric disorders and associated circadian malalignment and disruption.

Tabersonine ameliorates depressive-like behavior by inhibiting NLRP3 inflammasome activation in a mouse model

Depression, a common mental disorder, is intimately linked to neuroinflammation. In the central nervous system, microglia, the principal cells involved in immunity, are crucial in neuroinflammation and closely associated with the pathogenesis of depression. Several studies have demonstrated that depressive-like behaviors could be ameliorated by improving brain inflammation. Notably, natural products occupy a critical position in the study of antidepressants. Herein, we explored the antidepressant effects of tabersonine (Tab), a natural inhibitor of NLRP3. Tab significantly improved depressive-like behaviors and anxiety in lipopolysaccharide (LPS)-treated mice. To further elucidate mechanisms underlying the antidepressant actions of Tab, BV2 microglial cells were exposed to LPS and ATP in vitro. Tab effectively inhibited NLRP3 inflammasome activation, subsequent Caspase-1 cleavage, and interleukin-1β secretion both in the hippocampi of mice in vivo and BV2 cells in vitro. Additionally, Tab strongly decreased the concentrations of the proinflammatory cytokines interleukin-1β, tumor necrosis factor, and interleukin-6 in BV2 cell culture supernatants and sera of mice. Further studies indicated that Tab improved LPS-induced neuronal loss, as indicated by a significant rise in the quantity of Nissl-positive cells within the hippocampal regions CA1, CA3, and dentate gyrus. Importantly, Tab counteracted the LPS-induced microglial activation in the hippocampus. Our results indicate that Tab significantly improves LPS-triggered depressive-like behaviors and reverses injuries to hippocampal microglia and neurons, implying its potential as a therapeutic agent for depression.

Cortisol awakening response in pregnant women with depressive disorders: a potential marker of recovery status from pregnancy to postpartum

Introduction

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been linked to peripartum depression, potentially contributing to symptom persistence. This study examines the relationship between the cortisol awakening response (CAR) during pregnancy and depressive symptom reduction postpartum.

Methods

Pregnant women with a current depressive episode were included in this study, part of a larger RCT on bright light therapy. At baseline (12-32 weeks of pregnancy), participants provided saliva samples at awakening, +30, and +60 min post-awakening. The CAR was assessed using three measures: area under the curve relative to ground (AUCg), area under the curve relative to increase (AUCi), and peak reactivity (difference between awakening and +30 min cortisol levels). Depressive symptoms were measured using the Hamilton Depression Rating Scale (HAM-D) at baseline and two months postpartum. Linear regression models assessed associations between CAR measures and depressive symptom change, adjusting for relevant covariates.

Results

The study included 55 pregnant women (mean age: 32.3 years, SD 4.8; mean gestational age: 19.7 weeks). Mean HAM-D scores decreased from 16.7 (SD 5.3) at baseline to 5.7 (SD 5.6) postpartum. Higher AUCi during pregnancy was associated with less symptom reduction postpartum (unadjusted β = 0.36, p = .02; adjusted β = 0.36, p = .02), as was peak cortisol reactivity (unadjusted β = 0.33, p = .03; adjusted β = 0.32, p = .03), while AUCg showed no significant association with symptom change (unadjusted p = .19; adjusted p = .28).

Conclusion

Higher AUCi and peak cortisol reactivity of the cortisol awakening response during pregnancy were linked to persistence of depressive symptoms postpartum, suggesting that heightened cortisol reactivity to awakening may indicate persistent stress vulnerability in peripartum depression. Total cortisol output (AUCg) was not predictive of recovery. These findings underscore the potential relevance of stress reactivity over basal cortisol levels in peripartum depression and highlight the need for further research in larger samples to elucidate the usefulness in clinical practice.

A novel sex-specific association between insulin resistance and depressive symptoms in older adults: The potential mediating role of Vascular Endothelial Growth Factor

BACKGROUND

Insulin resistance (IR) and depression are increasingly recognized as interconnected conditions in aging, potentially linked through chronic low-grade inflammation ("inflammaging"). The triglyceride-glucose (TyG) index has emerged as a validated surrogate marker of IR, yet its relationship with inflammatory biomarkers and depressive symptoms in older adults remains underexplored.

OBJECTIVE

This study investigated the association between the TyG index, depressive symptoms, and circulating inflammatory molecules in cognitively healthy older adults, with emphasis on sex-specific differences and the potential mediating role of vascular endothelial growth factor (VEGF).

METHODS

In this retrospective study, 118 non-diabetic older adults (mean age 74.1 years; 52.5 % men) with preserved cognition (MMSE ≥27) were assessed. Depressive symptoms were measured using the Geriatric Depression Scale (GDS), while cytokines and growth factors were quantified via multiplex immunoassay. The TyG index was calculated from fasting glucose and triglyceride levels. Multiple linear regression models controlled for age, sex, BMI, and medication use.

RESULTS

Depressive symptoms (GDS ≥5) were present in 31.35 % of participants. Those with depression had lower levels of anti-inflammatory cytokines and elevated levels of VEGF and MCP-1. TyG index correlated with both GDS scores (r = 0.239, p = 0.017) and VEGF (r = 0.271, p = 0.005), with significant associations observed only in women. VEGF emerged as a key mediator in the TyG-depression link in women (R2 = 0.425).

CONCLUSIONS

These findings suggest a sex-specific metabolic-inflammatory signature in late-life depression. VEGF may serve as a mechanistic link between IR and depressive symptoms in older women, supporting sex-tailored interventions.

Profiling clinical heterogeneity in Autism Spectrum Disorder at time of children's diagnosis: A cluster analysis from the ELENA cohort

BACKGROUND

Autism Spectrum Disorder (ASD) encompass a heterogeneous group of neurodevelopmental conditions characterized by deficits in social communication and repetitive behaviors. The rising prevalence of ASD highlights the urgent need for effective diagnostic and intervention strategies. However, the significant clinical, cognitive and etiological heterogeneity within ASD populations poses substantial challenges to these efforts.

AIMS

This study aimed to identify distinct ASD subtypes at time of diagnosis within the ELENA cohort by incorporating not only DSM-5 criteria but also measures of adaptive functioning and behavioral problems.

MATERIAL AND METHODS

Data from 458 children and adolescents with ASD were analyzed using hierarchical agglomerative clustering. Variables included autistic symptoms, intellectual quotient, adaptive behavior and behavioral problems. Clusters were identified based on these parameters, and post-hoc analyses were conducted to assess statistically significant differences in sex and age among the four clusters using Chi-square test and Student's t-tests.

RESULTS

Four distinct clusters were identified from the analysis: (1) High Autistic Symptom Severity with Lowest Behavioral Problems, (2) High Autistic Symptom Severity with High Behavioral Problems, (3) Low Autistic Symptom Severity with Highest Behavioral Problems and (4) Low Autistic Symptom Severity with low behavioral problems, while significant age differences were observed across clusters, no significant sex differences were found.

DISCUSSION

These clusters exhibited significant variability in adaptive functioning and behavioral problems, suggesting that DSM-5 criteria alone do not fully capture the complexity of ASD. The findings underscore the importance of incorporating measures of adaptive functioning and behavioral problems into ASD assessments and interventions. Future research should aim to validate these clusters in larger and more diverse populations and explore the integration of genetic and neuroimaging data to further refine the characterization of ASD subtypes. Additionally, longitudinal studies are needed to assess the stability and clinical relevance of these subtypes over time.

TRIAL REGISTRATION NUMBER

NCT02625116.

Epigollatecatechin gallate alleviates rheumatoid arthritis through PI3K-Akt pathway by inhibiting FLT1

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Ershiwuwei Luyue Pill (ELP), a Tibetan medicine prescription, is one of the most commonly used treatments for wind dampness and joint pain. However, its detailed mechanism of action remains unclear.

METHODS

Using network pharmacology approaches, the primary active compounds, potential targets, and related signaling pathways of ELP in the treatment of RA were evaluated. The binding action between the key active ingredient (-)-epigallocatechin-3-gallate (EGCG) and the key target fms related receptor tyrosine kinase 1 (FLT1) was verified through molecular docking. Lipopolysaccharide (LPS)-induced HLFS-RA cell injury model and collagen-induced arthritis mouse model (CIA model) were established. Cell viability, invasion and migration were tested by the CCK8 kit, Transwell assay, and scratch assay, respectively. The expression of inflammatory factors, PI3K/AKT pathway-related proteins, and FLT1 was assessed by RT-qPCR and western blot.

RESULTS

Network pharmacology revealed the strong binding activity between EGCG, a primary active component of ELP, and the key target FLT1 in the treatment of RA. In vitro and in vivo experimental data showed that EGCG treatment markedly reduced the expression of FLT1 and suppressed the expression of PI3K pathway-related proteins. FLT1 knockdown or EGCG treatment could inhibit cell viability, invasion and migration, as well as the expression of inflammatory factors, but accelerate cell apoptosis. In vivo experiments also confirmed that EGCG might regulate the PI3K pathway through FLT1.

CONCLUSION

EGCG, a key component of ELP, has significant therapeutic effects on RA by suppressing the PI3K/AKT signaling pathway and downregulating FLT1 gene expression, thereby exhibiting anti-inflammatory effects.

L-type calcium channel blockade attenuates cue-induced cocaine-seeking in female rats

Periods of cocaine abstinence are associated with a high risk of relapse, often triggered by exposure to drug-associated cues. Previous research has implicated L-type calcium channels (LTCCs) in drug-seeking behaviors, yet their role in cue-induced relapse, particularly in females, remains underexplored. This study investigated the effects of LTCC inhibition on cue-induced cocaine-seeking behavior during abstinence in female Sprague-Dawley rats. Following a 10-day cocaine self-administration and a 14-day forced abstinence period, the rats were tested for cue-induced cocaine-seeking after receiving systemic administration of isradipine, a non-selective LTCC inhibitor (0.0 mg/kg, 0.1 mg/kg, 0.4 mg/kg, or 1.2 mg/kg, i.p.). Isradipine significantly reduced cue-induced cocaine-seeking in a dose-dependent manner without affecting cocaine-taking or natural reward-taking or seeking behaviors. Notably, these findings in females were comparable to our prior results observed in males, demonstrating that LTCC inhibition selectively attenuates the impact of cocaine-associated cues across sexes. These results highlight the translational potential of LTCCs as a therapeutic agent to reduce relapse risk in cocaine-dependent individuals. This study underscores the importance of considering sex-specific mechanisms in addiction treatment and calls for further research into LTCCs as a target for relapse prevention.

Menopause triggers microglia-associated neuroinflammation in Parkinson's disease

Microglia, the immune cells of brain, can drive neurodegenerative diseases like Parkinson's disease (PD). The resting microglia can polarize into two extremes, either proinflammatory M1 or anti-inflammatory M2 phenotype under a specific microenvironment. Different transcriptional factors and the release of various cytokines characterize these states. The released proinflammatory markers from M1 microglia lead to neuroinflammation that ultimately causes irreversible loss of dopaminergic neurons in PD patients, on the contrary, the M2 microglia possess neuroprotective activity. PD is caused by aggregation and misfolding of α-synuclein in the affected dopaminergic neurons. The misfolded α-synuclein is cytotoxic and can propagate like a prion from one cell to the other, acting like a template, that can initiate the conversion of normal proteins into abnormal conformation. The extracellular α-synuclein can interact and polarize the microglia into the M1 phenotype resulting in inflammation, thereby driving the progression of PD. The progression of neuroinflammation-mediated neurodegeneration in PD is seen higher in menopausal women; likely due to the low circulating estrogen levels. Estrogen hormones possess neuroprotective activity, and one of the ways is that they can polarize the microglia into M2 phenotypes and reduce α-synuclein-mediated microglial activation. A detailed understanding of the signaling mechanisms underlying microglial polarization between M1 and M2 phenotypes is crucial for identifying druggable targets to reduce PD symptoms, including in menopausal women.

Cell-based surface plasmon resonance approach for monitoring the inhibitory effect of Evasin-3 on Interleukin-8

Surface plasmon resonance (SPR) is a widely utilized technique for measuring the kinetics of molecular interactions. However, in dynamic living systems, the kinetics of target-ligand interactions may differ. Additionally, most cellular assays rely on end-point measurements, lacking the ability to monitor cellular interactions in real-time. In this study, a real-time cell-based SPR method was developed to investigate the inhibitory effect of small protein evasin-3 on the interaction between G protein-coupled receptors (GPCRs) and chemokine interleukin-8 (CXCL8). The interaction between CXCL8 and evasin-3 was first measured via a traditional SPR kinetic study. Their interaction was then confirmed and characterized using mass spectrometry, providing detailed insights into the complex formation of these two proteins. Endothelial EA.hy926 cells were immobilized on the SPR gold sensor, and real-time SPR response signals were monitored during stimulation with CXCL8, evasin-3 and their mixture. The results demonstrated the inhibitory effect of evasin-3 on the interaction between CXCL8 and GPCRs on EA.hy926 cells. This cell-based SPR method provides a valuable, physiologically relevant approach for studying inhibitory effects in living cells, presenting an effective alternative for analyzing complex molecular interactions.

Nitric oxide and experimental autoimmune encephalomyelitis review

Immunisation with neuroantigen in complete Freund's adjuvant (CFA) results in a range from severe experimental autoimmune encephalomyelitis (EAE) to no EAE in various strains and sexes of rodents. When CFA was substituted for carbonyl iron, all were EAE-susceptible. One of the differences between the two adjuvants was the strong induction of inducible nitric oxide synthase in EAE-resistant strains by CFA. The questions discussed in this review are: 1/ Could exaggerated production of nitric oxide protect against development of autoimmunity? 2/ Could non-susceptible strains be rendered susceptible to EAE by interfering with NO levels during the inductive phase? 3/ Could susceptible strains be rendered resistant to EAE by interfering with NO levels during the inductive phase? The answer to the three questions is "yes" and one of the reasons is the NO-induced actin polarization in the encephalitogenic T cells leading to their reduced trans-endothelial migration.

The impact of different types of extreme temperature events on mental disorders: A case-crossover study in Anhui Province, China

BACKGROUND

Extreme temperatures are expected to be more frequent, intense, and complex in the context of climate change. However, epidemiologic evidence about associations between extreme temperature and mental disorders is limited.

METHODS

We conducted a case-crossover study in Anhui Province, China, focusing on outpatients diagnosed with mental and behavioral disorders (ICD-10 codes: F00-F99), further classified into schizophrenia (F20-F21), depression (F32-F33), and anxiety (F40-F41). Defining the day of each outpatient visit to the Anhui Mental Health Center as the case day, a total of 762,895 case days and 3,362,574 control days were included in the study, covering the period from 2019 to 2021. Each subject was geocoded based on their home address and matched with environmental exposures, including meteorological data and air pollutant data sourced from the CN05.1 and the TAP dataset, respectively. Extreme temperature events were categorized into heat and cold extremes, further divided into daytime, nighttime, and compound extremes.

RESULTS

Among the outpatient visits for mental disorders included in this study, the proportions were schizophrenia (28.9 %), depression (23.9 %), and anxiety (18.5 %). Exposure to extreme heat and cold was associated with increased risks of outpatient visits for mental disorders, with odds ratios (ORs) of 2.23 (95 %CI: 2.16-2.30) and 1.95 (95 %CI: 1.89-2.01), respectively. Compound heat extremes posed the highest risk of mental disorders (OR = 1.17, 95 %CI: 1.13-1.22), followed by nighttime (OR = 1.11, 95 %CI: 1.08-1.14) and daytime heat (OR = 1.05, 95 %CI: 1.04-1.07). Notably, the risk of mental disorders significantly elevated with the increased intensity and duration of extreme heat events. Besides, extreme heat was strongly associated with higher risks of depression, schizophrenia and anxiety, while extreme cold was notably linked to schizophrenia.

CONCLUSION

These findings indicate a significant correlation between extreme temperature exposure and elevated mental disorder risks, emphasizing the urgent need to address increased mental health risks posed by extreme temperatures in the changing climate.

The interplay between gut microbiome, epigenetics, and substance use disorders: from molecular to clinical perspectives

Substance use disorders (SUDs) involve a complex series of central and peripheral pathologies, leading to impairments in cognitive, behavioral, and physiological processes. Emerging evidence indicates a more significant role for the microbiome-gut-brain axis (MGBA) in SUDs than previously recognized. The MGBA is interconnected with various body systems by producing numerous metabolites, most importantly short-chain fatty acids (SCFAs), cytokines, and neurotransmitters. These mediators influence the human body's epigenome and transcriptome. While numerous epigenetic alterations in different brain regions have been reported in SUD models, the intricate relationship between SUDs and the MGBA suggests that the gut microbiome may partially contribute to the underlying mechanisms of SUDs. Promising results have been observed with gut microbiome-directed interventions in patients with SUDs, including prebiotics, probiotics, antibiotics, and fecal microbiota transplantation. Nonetheless, the long-term epigenetic effects of these interventions remain unexplored. Moreover, various confounding factors and study limitations have hindered the identification of molecular mechanisms and clinical applications of gut microbiome interventions in SUDs. In the present review, we will (i) provide a comprehensive discussion on how the gut microbiome influences SUDs, with an emphasis on epigenetic alterations; (ii) discuss the current evidence on the bidirectional relationship of gut microbiome and SUDs, highlighting potential targets for intervention; and (iii) review recent advances in gut microbiome-directed therapies, along with their limitations and future directions.

Determination of 25-Hydroxyvitamin D3 in Rat Brain by Derivatization-Assisted LC/ESI-MS/MS

Recent studies have suggested that vitamin D deficiency may have relations with various neuropsychiatric diseases as well as bone diseases. However, the concentrations of vitamin D metabolites in the brain and the relationship between their brain and serum concentrations remain poorly understood. To answer these questions, we developed and validated an LC/ESI-MS/MS method for quantifying 25-hydroxyvitamin D3 [25(OH)D3], an established marker for assessing vitamin D sufficiency/deficiency, in the rat brain and compared the brain concentrations with the serum concentrations. To enhance the assay sensitivity and specificity, the 25(OH)D3 was derivatized with 4-[4-(1-pipelidinyl)phenyl]-1,2,4-triazoline-3,5-dione (PIPTAD) after purification of the brain sample by a two-step solid-phase extraction. A good linearity was obtained within the range of 20-1000 pg/g tissue, and the intra-assay and interassay precision and accuracy were acceptable. In normal rats (n = 6), the brain 25(OH)D3 concentrations ranged from 128 to 175 pg/g tissue, which were extremely low (approximately 1/100) compared to the serum concentrations. The bile duct ligation caused the decreased serum 25(OH)D3 level, which produced the subsequent decreased brain 25(OH)D3 level (44-79 pg/g, n = 6). These results strongly suggested that the serum 25(OH)D3 concentration has a significant effect on its brain level.

Expression pattern of sex steroid hormone receptors in the adult male rabbit brain

Progesterone (P4), estradiol (E2), and testosterone (T) are crucial for reproduction and are pivotal in several vertebrate central nervous system (CNS) functions. These hormones act by binding to their corresponding receptors, including those intracellularly located, such as progesterone receptor (PR), estrogen receptor (ER), and androgen receptor, which in this manuscript we named testosterone receptor (TR). The expression pattern of these receptors in the rabbit male brain is unknown. We studied PR, ER, and TR expression at mRNA and protein levels in several intact adult male brain regions by RT-qPCR and Western blot. We found the highest PR mRNA levels in the prefrontal cortex (PC) and the preoptic area (POA). PR protein content (110 kDa) was similar in all the analyzed brain regions. Maximum ERα mRNA levels were found in the mesencephalon (MSC) compared with the scarce levels presented in POA and cerebellum (CER). The two leading ERα bands (54 and 66 kDa) showed comparable content among analyzed brain regions, except in the olfactory bulb (OB). Considerable TR mRNA levels were found in the analyzed brain areas except in CER. TR protein (110 kDa) content was also high in MSC. The CER showed the lowest PR, ERα, and TR mRNA levels, but the corresponding protein contents were similar to those of different areas. These data reflect regional variability in the expression of sex steroid hormone receptors in the adult male rabbit brain. They constitute the basis for defining the distribution pattern of these receptors in the rabbit brain; in addition, they would allow comparisons to be made with reports of the expression of these receptors in female rabbit brains and the search for understanding their role in rabbits.