Beyond Birth Control: The Neuroscience of Hormonal Contraceptives.

Hormonal contraceptives (HCs) are one of the most highly prescribed classes of drugs in the world used for both contraceptive and noncontraceptive purposes. Despite their prevalent use, the impact of HCs on the brain remains inadequately explored. This review synthesizes recent findings on the neuroscience of HCs, with a focus on human structural neuroimaging as well as translational, nonhuman animal studies investigating the cellular, molecular, and behavioral effects of HCs. Additionally, we consider data linking HCs to mood disorders and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress response as a potential mediator. The review also addresses the unique sensitivity of the adolescent brain to HCs, noting significant changes in brain structure and function when HCs are used during this developmental period. Finally, we discuss potential effects of HCs in combination with smoking-derived nicotine on outcomes of ischemic brain damage. Methodological challenges, such as the variability in HC formulations and user-specific factors, are acknowledged, emphasizing the need for precise and individualized research approaches. Overall, this review underscores the necessity for continued interdisciplinary research to elucidate the neurobiological mechanisms of HCs, aiming to optimize their use and improve women's health.

Androgens Suppress Corticosteroid Binding Globulin in Male Mice, Affecting the Endocrine Stress Response.

Biological sex affects the activity of the hypothalamus-pituitary-adrenal (HPA) axis. However, how androgen deprivation affects this axis remains largely unknown. In this study, we investigated the effect of androgen status on different components of the HPA axis in male mice. Two weeks of androgen deprivation did not affect total plasma corticosterone levels but led to increased pituitary ACTH levels. Stress-induced total plasma corticosterone levels were increased, whereas the suppression of corticosterone after dexamethasone treatment under basal conditions was attenuated. Androgen-deprived mice displayed a 2-fold increase in plasma levels of corticosteroid binding globulin (CBG). A similar increase in CBG was observed in global androgen receptor knock-out animals, compared to wild-type littermates. Androgen deprivation was associated with a 6-fold increase in CBG mRNA in the liver and enhanced transcriptional activity at CBG regulatory regions, as evidenced by increased H3K27 acetylation. We propose that the induction of CBG as a consequence of androgen deprivation, together with the unaltered total corticosterone levels, results in lower free corticosterone levels in plasma. This is further supported by mRNA levels of androgen-independent GR target genes in the liver. The reduction in negative feedback on the HPA axis under basal condition would suffice to explain the enhanced stress reactivity after androgen deprivation. Overall, our data demonstrate that, in mice, tonic androgen receptor activation affects CBG levels in conjunction with effects on gene expression and HPA-axis reactivity.

Adolescent exposure to tris(1,3-dichloro-2-propyl) phosphate (TCPP) induces reproductive toxicity in zebrafish through hypothalamic-pituitary-gonadal axis disruption.

Tris(1,3-dichloro-2-propyl) phosphate (TCPP), a prevalent organophosphorus flame retardant in aquatic environments, has raised significant concerns regarding its ecological risks. This study aims to explore the impacts of TCPP on the reproductive functions of zebrafish and delineate its gender-related toxic mechanisms. By assessing the effects on zebrafish of 10 mg/L TCPP exposure from 30 to 120 days post-fertilization (dpf), we thoroughly evaluated the reproductive capability and endocrine system alterations. Our findings indicated that TCPP exposure disrupted gender differentiation in zebrafish and markedly impaired their reproductive capacity, resulting in decreased egg laying and offspring development quality. Histological analyses of gonadal tissues showed an abnormal increase in immature oocytes in females and a reduction in mature sperm count and spermatogonial structure integrity in males, collectively leading to compromised embryo quality. Additionally, molecular docking results indicated that TCPP showed a strong affinity for estrogen receptors, and TCPP-treated zebrafish exhibited imbalanced sex hormones and increased estrogen receptor expression. Alterations in genes associated with the hypothalamic-pituitary-gonadal (HPG) axis and activation of the steroidogenesis pathway suggested that TCPP targets the HPG axis to regulate sex hormone homeostasis. Tamoxifen (TAM), as a competitive inhibitor of estrogen, exhibited a biphasic effect, as evidenced by the counteraction of TCPP-induced effects in both male and female zebrafish after TAM addition. Overall, our study underscored the gender-dependent reproductive toxicity of TCPP exposure in zebrafish, characterized by diminished reproductive capacity and hormonal disturbances, likely due to interference in the HPG axis and steroidogenesis pathways. These findings emphasize the critical need to consider gender differences in chemical risk assessments for ecosystems and highlight the importance of understanding the mechanisms underlying the effects of chemical pollutants on the reproductive health of aquatic species.

Convergence of endothelial dysfunction, inflammation and glucocorticoid resistance in depression-related cardiovascular diseases.

Major Depressive Disorder, or depression, has been extensively linked to dysregulated HPA axis function, chronic inflammation and cardiovascular diseases. While the former two have been studied in depth, the mechanistic connection between depression and cardiovascular disease is unclear. As major mediators of vascular homeostasis, vascular pathology and immune activity, endothelial cells represent an important player connecting the diseases. Exaggerated inflammation and glucocorticoid function are important topics to explore in the endothelial response to MDD. Glucocorticoid resistance in several cell types strongly promotes inflammatory signaling and results in worsened severity in many diseases. However, endothelial health and inflammation in chronic stress and depression are rarely considered from the perspective of glucocorticoid signaling and resistance. In this review, we aim to discuss (1) endothelial dysfunction in depression, (2) inflammation in depression, (3) general glucocorticoid resistance in depression and (4) endothelial glucocorticoid resistance in depression co-morbid inflammatory diseases. We will first describe vascular pathology, inflammation and glucocorticoid resistance separately in depression and then describe their potential interactions with one another in depression-relevant diseases. Lastly, we will hypothesize potential mechanisms by which glucocorticoid resistance in endothelial cells may contribute to vascular disease states in depressed people. Overall, endothelial-glucocorticoid signaling may play an important role in connecting depression and vascular pathology and warrants further study.

Diurnal cortisol patterns in chronic pain: Associations with work-family spillover, work, and home stress.

Chronic pain is a prevalent condition with significant impacts on individuals' lives, including heightened stress and impaired physiological functioning. Given that work and family are the two main social domains where stress manifests, this study aimed to investigate the interactions between chronic pain, work-family stressors, and diurnal cortisol patterns to understand how chronic pain affects daily life and physiological stress responses. We identified 1,413 adults with chronic pain and 1,413 matched controls within MIDUS II samples to examine work-family spillover, daily work and home stressors, and cortisol levels across multiple days. The chronic pain group reported more negative work to family spillover and experienced more instances of stressful home events, particularly avoided arguments. These results align with literature suggesting chronic pain exacerbates tensions in close relationships and increases stress. The chronic pain group also had higher cortisol levels cross late-day periods, indicative of hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This dysregulation is associated with poorer health outcomes, including increased inflammation and psychological distress. We did not find any differences in previously identified cortisol profiles, which are higher-level summaries of cortisol levels within each day. We discuss why such difference might not have appeared in this sample.

The curious case of the hypothalamic-pituitary-gonadal axis dysfunction in subordinate female naked mole-rats (Heterocephalus glaber): No apparent role of opioids and glucocorticoids.

The naked mole-rat (Heterocephalus glaber) is a unique model mammal in which to study socially induced inhibition of the hypothalamic-pituitary-gonadal (HPG) axis. Naked mole-rat groups exhibit a high degree of reproductive bias in which breeding is restricted to one female (the queen) and one male, with subordinate non-breeding colony members rarely, if ever, having the opportunity to reproduce due to a dysfunctional HPG axis. It is posited that aggression directed at subordinates by the queen suppresses reproduction in these subordinates, yet the underlying physiological mechanisms causing this dysfunction are unknown. This study aimed to investigate the possible factors contributing to the dysfunction of the HPG axis in subordinate female naked mole-rats with a specific focus on the role of ovarian feedback and stress-related factors such as circulating glucocorticoid and endogenous opioid peptides. The results showed that stress-related factors appear to not mediate the suppression of reproductive function in subordinate female naked mole rats. Indeed, in some cases, the activation of the stress axis may lead to reproductive activation instead of deactivation. At the same time, the role of ovarian sex steroid feedback in reproductive suppression is likely limited and not clearly delineated. This study highlights the need for detailed studies to elucidate the mechanism of reproductive suppression in this unique model mammalian species which may shed light on, and reveal novel mechanisms, in the social regulation of reproduction.

Dynamic interplay of cortisol and BDNF in males under acute and chronic psychosocial stress - A randomized controlled study.

The neurotrophic protein brain-derived neurotrophic factor (BDNF) plays a pivotal role in brain function and is affected by acute and chronic stress. We here investigate the patterns of BDNF and cortisol stress reactivity and recovery under the standardized stress protocol of the TSST and the effect of perceived chronic stress on the basal BDNF levels in healthy young men. Twenty-nine lean young men underwent the Trier Social Stress Test (TSST) and a resting condition. Serum BDNF and cortisol were measured before and repeatedly after both conditions. The perception of chronic stress was assessed by the Trier Inventory for Chronic Stress (TICS). After the TSST, there was a significant increase over time for BDNF and cortisol. Stronger increase in cortisol in response to stress was linked to an accelerated BDNF decline after stress. Basal resting levels of BDNF was significantly predicted by chronic stress perception. The increased BDNF level following psychosocial stress suggest a stress-induced neuroprotective mechanism. The presumed interplay between BDNF and the HPA-axis indicates an antagonistic relationship of cortisol on BDNF recovery post-stress. Chronically elevated high cortisol levels, as present in chronic stress, could thereby contribute to reduced neurogenesis, and an increased risk of neurodegenerative conditions in persons suffering from chronic stress.

Associations between adolescent perceived loneliness and hair cortisol concentration.

INTRODUCTION: Adolescents experience high levels of loneliness, which is linked to poor health in adulthood. Loneliness may contribute to poor health through chronic dysregulation of the hypothalamic-pituitary-adrenal axis. In this analysis, we examined the associations between survey- and ecological momentary assessment (EMA)-based measures of loneliness and hair cortisol concentrations (HCC) in a sample of 1102 adolescents and assessed sex differences in this relationship. METHODS: Data came from wave 1 of the Adolescent Health and Development in Context study. We conducted a series of multivariable linear regression models to examine the associations between loneliness and HCC. Models were adjusted for adolescent and caregiver demographics, adolescent clinical factors, adolescent hair care practices, and adolescent lifetime mental health diagnosis and current psychotropic medication use. An interaction term between sex and loneliness was added to assess for effect moderation. RESULTS: In our sample, the mean HCC was 1.35 pg/mg (SD=1.1). The mean for the unstandardized survey loneliness measure was 1.79 (SD=0.79) for the total analytic sample. The unstandardized mean for the EMA loneliness measure was - 0.02 (SD=2.1) for the total analytic sample. In model one testing the bivariate linear relationship between loneliness and HCC, higher loneliness via survey and EMA measures was associated with lower HCC (Survey: b= - 0.10, SE=0.03, p=.004; EMA: b= - 0.09, SE=0.03, p=.005). In model two, higher loneliness remained significantly associated with lower HCC (Survey: b= - 0.07, SE=0.03, p=.023; EMA: b= - 0.07, SE=0.03, p=.037), after controlling for the following covariates: sociodemographic factors, pubertal development and BMI, corticosteroid use, hair care practices, season of collection and assayed hair length. In model 3, youth lifetime mental health diagnosis and current psychotropic medication use were added into the regression model, and higher loneliness remained significantly associated with lower HCC (Survey: b= - 0.07, SE=0.03, p=.029; EMA: b= - 0.07, SE=0.03, p=.039). There was no effect modification by sex (Survey: b=0.04, SE=0.06, p=.552; EMA: b= - 0.01, SE=0.06, p=.843). CONCLUSIONS: In our analysis, both survey- and EMA-reported loneliness measures were associated with lower HCC. No evidence of an interaction between sex and loneliness was observed. Future research is needed to validate these findings and investigate longitudinal relationships among adolescent loneliness, stress physiology, and downstream health sequelae.

The brain-skin axis in vitiligo.

Vitiligo is an acquired autoimmune skin disease characterized by patchy depigmentation of the skin, often accompanied by white hair. The aetiology of vitiligo is complex and difficult to cure, and its disfiguring appearance significantly impacts patients' mental and physical health. Psychological stress is a major factor in inducing and exacerbating vitiligo, as well as affecting its treatment efficacy, though the specific mechanisms remain unclear. Increasing research on the brain-skin axis in skin immunity suggests that psychological stress can influence local skin immunity through this axis, which may play a crucial role in the pathogenesis of vitiligo. This review focuses on the role of brain-skin axis in the pathogenesis of vitiligo, and explores the possible mechanism of brain-skin axis mediating the pathogenesis of vitiligo from the aspects of sympathetic nervous system, hypothalamic-pituitary-adrenal (HPA) axis and hormones and neuropeptides, aiming to provide the necessary theoretical basis for psychological intervention in the prevention and treatment of vitiligo.

Oral Supplementation of L-Carnosine Attenuates Acute-Stress-Induced Corticosterone Release and Mitigates Anxiety in CD157 Knockout Mice.

Corticosterone, an end product of the hypothalamic-pituitary-adrenal (HPA) axis, is a crucial stress hormone. A dysregulated HPA axis and corticosterone release play pivotal roles in the onset and persistence of symptoms of stress-related psychiatric disorders, such as anxiety. The intake of nutrients, probiotics, and prebiotic supplements decreases blood corticosterone levels. The dipeptide L-carnosine is composed of beta-alanine and L-histidine and is commercially available as a nutritional supplement for recovery from fatigue. L-carnosine is involved in stress-induced corticosterone responses and anxiety behaviors in rodents. Here, we assessed the effect of L-carnosine in CD157 knockout (KO) mice, a murine model of autism spectrum disorder (ASD). The uptake of L-carnosine suppressed the increase in plasma corticosterone levels in response to acute stress and attenuated anxiety-like behaviors in CD157 KO mice. These results suggest that L-carnosine supplementation may relieve anxiety by suppressing excessive stress responses in individuals with ASD.