Development of the HPA axis: where and when do sex differences manifest?

A strike to the head: Parallels between the pediatric and adult human and the rodent in traumatic brain injury

Traumatic brain injury (TBI) is a condition that occurs commonly in children from infancy through adolescence and is a global health concern. Pediatric TBI presents with a bimodal age distribution, with very young children (0-4 years) and adolescents (15-19 years) more commonly injured. Because children's brains are still developing, there is increased vulnerability to the effects of head trauma, which results in entirely different patterns of injury than in adults. Pediatric TBI has a profound and lasting impact on a child's development and quality of life, resulting in long-lasting consequences to physical, cognitive, and emotional development. Chronic issues like learning disabilities, behavioral problems, and emotional disturbances can develop. Early intervention and ongoing support are critical for minimizing these long-term deficits. Many animal models of TBI exist, and each varies significantly, displaying different characteristics of clinical TBI. The neurodevelopment differs in the rodent from the human in timing and effect, so TBI outcomes in the juvenile rodent can thus vary from the human child. The current review compares findings from preclinical TBI work in juvenile and adult rodents to clinical TBI research in pediatric and adult humans. We focus on the four brain regions most affected by TBI: the prefrontal cortex, corpus callosum, hippocampus, and hypothalamus. Each has its unique developmental projections and thus is impacted by TBI differently. This review aims to compare the healthy neurodevelopment of these four brain regions in humans to the developmental processes in rodents.

Chronic variable stress leads to sex specific gut microbiome alterations in mice

Stress has been implicated in the incidence and severity of psychiatric and gastrointestinal disorders. The immune system is capable of modulating the activity and composition of the gut following stress and vice versa. In this study we sought to examine the sequential relationship between immune signaling and microbiome composition occurring in male and female mice over time using a variable stress paradigm. Tissue was collected prior to, during, and after the stress paradigm from the same mice. Cytokines from plasma and brain were quantified using a multiplexed cytokine assay. Fecal samples were collected at the same timepoints and 16S rRNA amplicon sequencing was performed to determine the relative abundance of microbiota residing in the guts of stressed and control mice. We found sex differences in the response of the gut microbiota to stress following 28 days of chronic variable stress but not 6 days of sub-chronic variable stress. Immune activation was quantified in the nucleus accumbens immediately following Sub-chronic variable when alterations of gut composition had not yet occurred. In both sexes, 28 days of stress induced significant changes in the proportion of Erysipelotrichaceae and Lactobacillaceae, but in opposite directions for male and female mice. Alterations to the gut microbiome in both sexes were associated with changes in cytokines related to eosinophilic immune activity. Our use of an animal stress model reveals the immune mechanisms that may underly changes in gut microbiome composition during and after stress. This study reveals potential drug targets and microbiota of interest for the intervention of stress related conditions.

Chemogenetic activation of CRF neurons as a model of chronic stress produces sex-specific physiological and behavioral effects

Trauma and chronic stress exposure are the strongest predictors of lifetime neuropsychiatric disease presentation. These disorders often have significant sex biases, with females having higher incidences of affective disorders such as major depression, anxiety, and PTSD. Understanding the mechanisms by which stress exposure heightens disease vulnerability is essential for developing novel interventions. Current rodent stress models consist of a battery of sensory, homeostatic, and psychological stressors that are ultimately integrated by corticotropin-releasing factor (CRF) neurons to trigger corticosteroid release. These stress paradigms, however, often differ between research groups in the type, timing, and duration of stressors utilized. These inconsistencies, along with the variability of individual animals' perception and response to each stressor, present challenges for reproducibility and translational relevance. Here, we hypothesized that a more direct approach using chemogenetic activation of CRF neurons would recapitulate the effects of traditional stress paradigms and provide a high-throughput method for examining stress-relevant phenotypes. Using a transgenic approach to express the Gq-coupled Designer Receptor Exclusively Activated by Designer Drugs (DREADD) receptor hM3Dq in CRF-neurons, we found that the DREADD ligand clozapine-N-oxide (CNO) produced an acute and robust activation of the hypothalamic-pituitary-adrenal (HPA) axis, as predicted. Interestingly, chronic treatment with this method of direct CRF activation uncovered a novel sex-specific dissociation of glucocorticoid levels with stress-related outcomes. Despite hM3Dq-expressing females producing greater corticosterone levels in response to CNO than males, hM3Dq-expressing males showed significant typical physiological stress sensitivity with reductions in body and thymus weights. hM3Dq-expressing females while resistant to the physiological effects of chronic CRF activation, showed significant increases in baseline and fear-conditioned freezing behaviors. These data establish a novel mouse model for interrogating stress-relevant phenotypes and highlight sex-specific stress circuitry distinct for physiological and limbic control that may underlie disease risk.

Differential c-Fos Response in Neurocircuits Activated by Repeated Predator Stress in Male and Female C57BL/6J Mice with Stress Sensitive or Resilient Alcohol Intake Phenotypes

Comorbidity of post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) worsens the prognosis for each of these individual disorders. The current study aimed to identify neurocircuits potentially involved in regulation of PTSD-AUD comorbidity by mapping expression of c-Fos in male and female C57BL/6J mice following repeated predator stress (PS), modeled by exposure to dirty rat bedding. In experiment 1, the levels of c-Fos in the paraventricular nucleus of the hypothalamus (PVH) and the nucleus accumbens shell were higher after the second PS vs the first PS, indicating a sensitized response to this stressor. Additional brain regions showed varied sex-dependent and independent regulation by the two consecutive PS exposures. In experiment 2, mice that increased voluntary alcohol consumption following four exposures to PS (Sensitive subgroup) showed higher c-Fos induction in the PVH, piriform cortex and ventromedial hypothalamus than mice that decreased consumption following these exposures (Resilient subgroup). In contrast to these brain regions, c-Fos was higher in the anterior olfactory nucleus of Resilient vs Sensitive mice. Taken together, these data demonstrate that repeated PS exposure and voluntary alcohol consumption increase neuronal activity across neurocircuits in which specific components depend on the vulnerability of individual mice to these stressors. Increased PVH activity observed across both experiments suggests this brain area as a potential mediator of PS-induced increases in alcohol consumption. Future investigations of specific neuronal populations within the PVH activated by PS, and manipulation of these specific neuronal populations, could improve our understanding of the mechanisms leading to PTSD-AUD comorbidity.

Cortisol in deciduous tooth tissues: A potential metric for assessing stress exposure in archaeological and living populations

OBJECTIVE

Cortisol is a glucocorticoid hormone produced by the hypothalamic-pituitary-adrenal axis that is regularly assessed in modern human and non-human populations in saliva, blood, and hair as a measure of stress exposure and stress reactivity. While recent research has detected cortisol concentrations in modern and archaeological permanent dental tissues, the present study assessed human primary (deciduous) teeth for cortisol concentrations.

MATERIALS AND METHODS

Fifty-one dentine and enamel samples from nine modern and 10 archaeological deciduous teeth were analyzed for cortisol concentrations via enzyme-linked immunosorbent assay (ELISA).

RESULTS

Detectable concentrations of cortisol were identified in 15 (of 32) dentine and 8 (of 19) enamel samples coming from modern and archaeological deciduous teeth.

CONCLUSIONS

This study is the first known analysis of cortisol from deciduous dental tissues, demonstrating the potential to identify measurable concentrations.

SIGNIFICANCE

The ability to analyze deciduous teeth is integral to developing dental cortisol methods with multiple potential future applications, including research on the biological embedding of stress in the skeleton. This study marks a key step in a larger research program to study stress in primary dentition from living and archaeological populations.

LIMITATIONS

Multiple samples generated cortisol values that were not detectable with ELISA. Minimum quantities of tissue may be required to generate detectable levels of cortisol.

SUGGESTIONS FOR FURTHER RESEARCH

Future research should include larger sample sizes and consideration of intrinsic biological and extrinsic preservation factors on dental cortisol. Further method validation and alternative methods for assessing dental cortisol are needed.

Sex Differences in the Neurobiology of Stress

This review highlights the existing knowledge and data that explain the physiologic impacts of stress, especially pertaining to neurobiology, and how these impacts differ by sex. Furthermore, this review explains the benefits of interventions aimed at preventing or mitigating the adverse effects of stress, because of both the significant toll of stress on the body and the disproportionate impact of these changes experienced by women.

Physical Activity and Chronic Stress in Early Life: Findings From the 2015 Pelotas (Brazil) Birth Cohort

BACKGROUND

The association of physical activity through early childhood on children's chronic stress still is unclear. Therefore, the aim of the present study is to test the association of physical activity through early childhood (1-4 y) with chronic stress, measured by hair cortisol at age 4.

METHODS

Longitudinal study including children from the 2015 Pelotas (Brazil) Birth Cohort. Cortisol at age 4 was measured using a hair sample, which provided cortisol concentration from the past months. Physical activity was measured using accelerometers at 1, 2, and 4 years. Linear regression models were used to assess the association between physical activity and chronic stress. Trajectory models were also applied to examine chronic stress in relation to physical activity patterns throughout early childhood.

RESULTS

Children with valid physical activity and hair cortisol data were included in the analyses (N = 1475). Three groups of physical activity trajectories between 1 and 4 years were identified: low, medium, and high. No association between physical activity at 1, 2, and 4 years and chronic stress at age 4 was observed. However, children in the "high" physical activity trajectory presented low cortisol concentration; the magnitude of the regression coefficient was slightly larger in girls (β = -0.125; 95% confidence interval, -0.326 to 0.074) than boys (β = -0.051; 95% confidence interval, -0.196 to 0.09).

CONCLUSION

There was no clear association between physical activity and chronic stress in early childhood. Trajectories models suggest that higher activity throughout early childhood may positively impact chronic stress; however, more studies are needed to confirm that hypothesis.

The sex-dependent and enduring impact of pubertal stress on health and disease

Illness is often predicated long before the manifestation of its symptoms. Exposure to stressful experiences particularly during critical periods of development, such as puberty and adolescence, can induce various physical and mental illnesses. Puberty is a critical period of maturation for neuroendocrine systems, such as the hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-adrenal (HPA) axes. Exposure to adverse experiences during puberty can impede normal brain reorganizing and remodelling and result in enduring consequences on brain functioning and behaviour. Stress responsivity differs between the sexes during the pubertal period. This sex difference is partly due to differences in circulating sex hormones between males and females, impacting stress and immune responses differently. The effects of stress during puberty on physical and mental health remains under-examined. The purpose of this review is to summarize the most recent findings pertaining to age and sex differences in HPA axis, HPG axis, and immune system development, and describe how disruption in the functioning of these systems can propagate disease. Lastly, we delve into the notable neuroimmune contributions, sex differences, and the mediating role of the gut microbiome on stress and health outcomes. Understanding the enduring consequences of adverse experiences during puberty on physical and mental health will allow a greater proficiency in treating and preventing stress-related diseases early in development.

Lack of sex and estrous stage effects on compulsive behavior assessed using a schedule-induced polydipsia procedure in rats

Preclinical behavior models used for screening pharmacological treatments for mental disorders have generally used only male research subjects, and for studies that have included female subjects, few have utilized sex as a study variable. In fact, many mental disorders vary by prevalence and symptomatology between sexes, creating a need to evaluate established subject models for sex differences. Compulsive behavior is a feature shared across many mental disorders and effective treatments have been examined pre-clinically using the schedule-induced polydipsia procedure in rats. Drugs effective for reducing polydipsia include psychostimulants, such as d -amphetamine. Virtually no studies have examined sex differences using this procedure. For the present study, male and female rats were examined in the schedule-induced polydipsia paradigm. Rats were food-restricted and trained on a fixed-interval food reinforcement schedule and given free access to water during experimental sessions. Estrous stages were assessed during training and test sessions. The psychostimulant d -amphetamine was also tested once stable water consumption occurred. Excessive water intake developed over the course of training. Females required significantly more sessions to reach a stable level of drinking. Treatment with d -amphetamine (1.0 mg/kg, but not 0.25 or 0.5 mg/kg) significantly reduced drinking in both male and female rats. No sex differences were observed across other study variables including comparisons between diestrus and proestrus stages. Overall, these findings suggest that schedule-induced polydipsia procedures that employ similar methods can produce results generalizable across male and female subjects.

Effects of prenatal opioid exposure on synaptic adaptations and behaviors across development

In this review, we focus on prenatal opioid exposure (POE) given the significant concern for the mental health outcomes of children with parents affected by opioid use disorder (OUD) in the view of the current opioid crisis. We highlight some of the less explored interactions between developmental age and sex on synaptic plasticity and associated behavioral outcomes in preclinical POE research. We begin with an overview of the rich literature on hippocampal related behaviors and plasticity across POE exposure paradigms. We then discuss recent work on reward circuit dysregulation following POE. Additional risk factors such as early life stress (ELS) could further influence synaptic and behavioral outcomes of POE. Therefore, we include an overview on the use of preclinical ELS models where ELS exposure during key critical developmental periods confers considerable vulnerability to addiction and stress psychopathology. Here, we hope to highlight the similarity between POE and ELS on development and maintenance of opioid-induced plasticity and altered opioid-related behaviors where similar enduring plasticity in reward circuits may occur. We conclude the review with some of the limitations that should be considered in future investigations. This article is part of the Special Issue on 'Opioid-induced addiction'.

Early Life Stress-Induced Epigenetic Programming of Hippocampal NPY-Y2 Receptor Gene Expression Changes in Response to Adult Stress

Early Life Stress (ELS) can critically influence brain development and future stress responses and thus represents an important risk factor for mental health and disease. Neuropeptide Y (NPY) is discussed to be a key mediator of resilient vs. vulnerable adaptations and specifically, the NPY-Y2 receptor (Y2R) may be involved in the pathophysiology of depression due to its negative regulation of NPY-release. The present study addressed the hypotheses that ELS and adult stress (AS) affect the expression of hippocampal Y2R and that exposure to ELS induces an epigenetically mediated programming effect towards a consecutive stress exposure in adulthood. The specific aims were to investigate if (i) ELS or AS as single stressors induce changes in Y2 receptor gene expression in the hippocampus, (ii) the predicted Y2R changes are epigenetically mediated via promoter-specific DNA-methylation, (iii) the ELS-induced epigenetic changes exert a programming effect on Y2R gene expression changes in response to AS, and finally (iv) if the predicted alterations are sex-specific. Animals were assigned to the following experimental groups: (1) non-stressed controls (CON), (2) only ELS exposure (ELS), (3) only adult stress exposure (CON+AS), and (4) exposure to ELS followed by AS (ELS+AS). Using repeated maternal separation in mice as an ELS and swim stress as an AS we found that both stressors affected Y2R gene expression in the hippocampus of male mice but not in females. Specifically, upregulated expression was found in the CON+AS group. In addition, exposure to both stressors ELS+AS significantly reduced Y2R gene expression when compared to CON+AS. The changes in Y2R expression were paralleled by altered DNA-methylation patterns at the Y2R promoter, specifically, a decrease in mean DNA-methylation in the CON+AS males compared to the non-AS exposed groups and an increase in the ELS+AS males compared to the CON+AS males. Also, a strong negative correlation of mean DNA-methylation with Y2R expression was found. Detailed CpG-site-specific analysis of DNA-methylation revealed that ELS induced increased DNA-methylation only at specific CpG-sites within the Y2R promoter. It is tempting to speculate that these ELS-induced CpG-site-specific changes represent a “buffering” programming effect against elevations of Y2R expression induced by AS.

Sensitivity and Resilience to Predator Stress-Enhanced Ethanol Drinking Is Associated With Sex-Dependent Differences in Stress-Regulating Systems

Stress can increase ethanol drinking, and evidence confirms an association between post-traumatic stress disorder (PTSD) and the development of alcohol use disorder (AUD). Exposure to predator odor is considered a traumatic stressor, and predator stress (PS) has been used extensively as an animal model of PTSD. Our prior work determined that repeated exposure to intermittent PS significantly increased anxiety-related behavior, corticosterone levels, and neuronal activation in the hippocampus and prefrontal cortex in naïve male and female C57BL/6J mice. Intermittent PS exposure also increased subsequent ethanol drinking in a subgroup of animals, with heterogeneity of responses as seen with comorbid PTSD and AUD. The present studies built upon this prior work and began to characterize “sensitivity” and “resilience” to PS-enhanced drinking. Ethanol drinking was measured during baseline, intermittent PS exposure, and post-stress; mice were euthanized after 24-h abstinence. Calculation of median and interquartile ranges identified “sensitive” (>20% increase in drinking over baseline) and “resilient” (no change or decrease in drinking from baseline) subgroups. Intermittent PS significantly increased subsequent ethanol intake in 24% of male (↑60%) and in 20% of female (↑71%) C57BL/6J mice in the “sensitive” subgroup. Plasma corticosterone levels were increased significantly after PS in both sexes, but levels were lower in the “sensitive” vs. “resilient” subgroups. In representative mice from “sensitive” and “resilient” subgroups, prefrontal cortex and hippocampus were analyzed by Western Blotting for levels of corticotropin releasing factor (CRF) receptor 1, CRF receptor 2, CRF binding protein, and glucocorticoid receptor, vs. separate naïve age-matched mice. In prefrontal cortex, CRF receptor 1, CRF receptor 2, CRF binding protein, and glucocorticoid receptor levels were significantly higher in “sensitive” vs. naïve and “resilient” mice only in females. In hippocampus, CRF receptor 1, CRF receptor 2 and glucocorticoid receptor levels were significantly lower in “resilient” vs. naïve and “sensitive” mice across both sexes. These results indicate that sex strongly influences the effects of ethanol drinking and stress on proteins regulating stress and anxiety responses. They further suggest that targeting the CRF system and glucocorticoid receptors in AUD needs to consider the comorbidity of PTSD with AUD and sex of treated individuals.

Areas of Convergence and Divergence in Adolescent Social Isolation and Binge Drinking: A Review

Adolescence is a critical developmental period characterized by enhanced social interactions, ongoing development of the frontal cortex and maturation of synaptic connections throughout the brain. Adolescents spend more time interacting with peers than any other age group and display heightened reward sensitivity, impulsivity and diminished inhibitory self-control, which contribute to increased risky behaviors, including the initiation and progression of alcohol use. Compared to adults, adolescents are less susceptible to the negative effects of ethanol, but are more susceptible to the negative effects of stress, particularly social stress. Juvenile exposure to social isolation or binge ethanol disrupts synaptic connections, dendritic spine morphology, and myelin remodeling in the frontal cortex. These structural effects may underlie the behavioral and cognitive deficits seen later in life, including social and memory deficits, increased anxiety-like behavior and risk for alcohol use disorders (AUD). Although the alcohol and social stress fields are actively investigating the mechanisms through which these effects occur, significant gaps in our understanding exist, particularly in the intersection of the two fields. This review will highlight the areas of convergence and divergence in the fields of adolescent social stress and ethanol exposure. We will focus on how ethanol exposure or social isolation stress can impact the development of the frontal cortex and lead to lasting behavioral changes in adulthood. We call attention to the need for more mechanistic studies and the inclusion of the evaluation of sex differences in these molecular, structural, and behavioral responses.

Exercise to spot the differences: a framework for the effect of exercise on hippocampal pattern separation in humans

Exercise has a beneficial effect on mental health and cognitive functioning, but the exact underlying mechanisms remain largely unknown. In this review, we focus on the effect of exercise on hippocampal pattern separation, which is a key component of episodic memory. Research has associated exercise with improvements in pattern separation. We propose an integrated framework mechanistically explaining this relationship. The framework is divided into three pathways, describing the pro-neuroplastic, anti-inflammatory and hormonal effects of exercise. The pathways are heavily intertwined and may result in functional and structural changes in the hippocampus. These changes can ultimately affect pattern separation through direct and indirect connections. The proposed framework might guide future research on the effect of exercise on pattern separation in the hippocampus.

Carbamate pesticides exposure and delayed physical development at the age of seven: Evidence from the SMBCS study

BACKGROUND

Carbamate pesticides are widely used in agriculture and cause widespread human exposure. The health effect of carbamates on physical development remains unclear. The current study aimed to explore the carbamate's health effect on physical development.

METHODS

Prenatal, 3-year-old, 7-year-old urinary carbofuranphenol concentration was measured by gas chromatography tandem mass spectrometry and adjusted by creatinine. Anthropometric indices were measured by standard method and z-score standardized. Generalized linear models (GLM) were using to assess associations between exposure measurements and anthropometric indices. The generalized estimate equation (GEE) was applied to analyze the association between multiperiod exposure and anthropometric indices, and time-interaction terms were used to exam health effect consistency of exposure in each period. Gender-stratified analysis were conducted according to results of gender-interaction terms to identify gender-specific effects.

RESULTS

The gender-interaction term of prenatal exposure with height z-score was significant (β = -0.057; 95% CI: -0.113, -0.001; p = 0.045). The 3-year-old carbofuranphenol level showed negative associations with weight z-score (β = -0.019; 95% CI: -0.038, -0.000; p = 0.040), height z-score (β = -0.015; 95% CI: -0.028, -0.001; p = 0.026), chest circumference (β = -0.086; 95% CI: -0.171, -0.001; p = 0.046), and waist circumference (β = -0.128; 95% CI: -0.230, -0.026; p = 0.014). No statistically significant trend was found for prenatal and 7-year-old carbofuranphenol levels. In GEEs, carbofuranphenol level was negatively associated with weight z-score (β = -0.103; 95% CI: -0.195, -0.011; p = 0.027), height z-score (β = -0.087; 95% CI: -0.152, -0.022; p = 0.008), and chest circumference (β = -0.472; 95% CI: -0.918, -0.026; p = 0.037). Boy's height z-score was inversely associated with carbamate exposure (β = -0.140; 95% CI: -0.227, -0.053; p = 0.001).

CONCLUSIONS

Prenatal and postnatal carbamate exposure may affect physical developmental process.

Androgens and Their Role in Regulating Sex Differences in the Hypothalamic/Pituitary/Adrenal Axis Stress Response and Stress-Related Behaviors

Androgens play a pivotal role during development. These gonadal hormones and their receptors exert organizational actions that shape brain morphology in regions controlling the stress regulatory systems in a male-specific manner. Specifically, androgens drive sex differences in the hypothalamic/pituitary/adrenal (HPA) axis and corresponding hypothalamic neuropeptides. While studies have examined the role of estradiol and its receptors in sex differences in the HPA axis and associated behaviors, the role of androgens remains far less studied. Androgens are generally thought to modulate the HPA axis through the activation of androgen receptors (ARs). They can also impact the HPA axis through reduction to estrogenic metabolites that can bind estrogen receptors in the brain and periphery. Such regulation of the HPA axis stress response by androgens can often result in sex-biased risk factors for stress-related disorders, such as anxiety and depression. This review focuses on the biosynthesis pathways and molecular actions of androgens and their nuclear receptors. The impact of androgens on hypothalamic neuropeptide systems (corticotropin-releasing hormone, arginine vasopressin, oxytocin, dopamine, and serotonin) that control the stress response and stress-related disorders is discussed. Finally, this review discusses potential therapeutics involving androgens (androgen replacement therapies, selective AR modulator therapies) and ongoing clinical trials.

Gender Differences in Depressive and Anxiety Symptoms During the First Stage of the COVID-19 Pandemic: A Cross-Sectional Study in Latin America and the Caribbean

BACKGROUND

Previous studies have suggested that the pandemic impact on mental health could vary according to gender. We aimed to evaluate the gender influence in the prevalence of depressive and anxiety symptoms in Latin American and the Caribbean (LAC) countries in the first stage of the COVID-19 pandemic.

METHODS

We conducted a secondary analysis employing the Facebook-COVID-19 Symptom Survey developed by the University of Maryland. We categorized gender as men, women, and non-binary. The outcomes were the presence of anxiety or depressive symptoms, measured with two adapted questions extracted from the Kessler Psychological Distress Scale (K10). We used generalized linear models from the Poisson family, considering the survey's complex sampling. We calculated crude and adjusted prevalence ratios (PR) with their 95% confidence intervals (95% CI) and explored interactions with gender using the adjusted Wald test.

RESULTS

We included 1,338,320 adults from LAC countries; 48.0, 50.6, and 1.4% were men, women, and non-binary participants, respectively. The overall prevalence of anxiety or depressive symptoms was 44.8 and 46.6%, respectively. We found interactions between gender and the rest of the independent variables. In the non-binary group, the association between age and anxiety symptomatology was lost after an age of 55 years. Furthermore, whereas living in a town was associated with a lower prevalence of anxiety and depression symptomatology in men and women, this did not happen among non-binary individuals. Compliance with physical distancing was associated with a lower prevalence of anxiety and depression symptomatology among women (anxiety: PRa = 0.98; 95% CI = 0.97-0.99; p < 0.001, depression: PRa = 0.96; 95% CI = 0.95-0.97; p < 0.001) and only anxiety in non-binary participants (anxiety: PRa = 0.92; 95% CI = 0.88-0.98; p = 0.005). This was not evidenced among men participants (anxiety: PRa = 0.99; 95% CI = 0.96-1.01; p = 0.199, depression: PRa = 0.98; 95% CI = 0.96-1.00; p = 0.084). In addition, compliance with handwashing was associated with a higher prevalence of anxiety symptomatology among men (PRa = 1.06; 95% CI = 1.05-1.11; p < 0.001) and women participants (PRa = 1.03; 95% CI = 1.01-1.05; p = 0.016).

CONCLUSION

Approximately 4 out of 10 participants had anxiety or depressive symptoms. Women and non-binary gender people had more symptoms of anxiety or depression. The factors associated with these symptoms varied according to gender. It is essential to evaluate gender-related strategies to improve mental health during the COVID-19 pandemic.

Sex-specific plasticity in CRF regulation of inhibitory control in central amygdala CRF1 neurons after chronic voluntary alcohol drinking

Despite strong preclinical evidence for the ability of corticotropin releasing factor 1 (CRF1) antagonists to regulate alcohol consumption, clinical trials have not yet demonstrated therapeutic effects of these compounds in alcohol use disorder (AUD) patients. Several confounding factors may limit the translation of preclinical CRF1 research to patients, including reliance on experimenter-administered alcohol instead of voluntary consumption, a preponderance of evidence collected in male subjects only and an inability to assess the effects of alcohol on specific brain circuits. A population of particular interest is the CRF1-containing neurons of the central amygdala (CeA). CRF1 CeA neurons are sensitive to ethanol, but the effects of alcohol drinking on CRF signalling within this population are unknown. In the present study, we assessed the effects of voluntary alcohol drinking on inhibitory control of CRF1+ CeA neurons from male and female CRF1:GFP mice using ex vivo electrophysiology and determined the contributions of CRF1 signalling to inhibitory control and voluntary alcohol drinking. Chronic alcohol drinking produced neuroadaptations in CRF1+ neurons that increased the sensitivity of GABA_A receptor-mediated sIPSCs to the acute effects of alcohol, CRF and the CRF1 antagonist R121919, but these adaptations were more pronounced in male versus female mice. The CRF1 antagonist CP-154,526 reduced voluntary alcohol drinking in both sexes and abolished sex differences in alcohol drinking. The lack of alcohol-induced adaptation in the female CRF1 system may be related to the elevated alcohol intake exhibited by female mice and could contribute to the ineffectiveness of CRF1 antagonists in female AUD patients.

Neuroleptic malignant syndrome cases in a Moroccan intensive care unit: a retrospective analysis and literature review

Background: Neuroleptic malignant syndrome (NMS) is a rare but potentially life-threatening neuropsychiatric emergency. The aim of our study was to update our bedside procedures by investigating NMS cases managed in the intensive care unit (ICU).Methods: This retrospective study included all NMS patients admitted to our hospital between January 2012 and December 2019. The variables analyzed included demographics, diagnosis, therapeutics, and outcomes.Results: This study included 20 patients, with an average age of 36.6 years. The male to female ratio was 1:4. No patient had a history of NMS, and 60% of the patients had schizophrenia. First-generation neuroleptics (NLs) were the most commonly prescribed drugs (80%). The mean time between the introduction of NLs and onset of symptoms was 7.6 days. Rigidity was observed in 90% of the patients, hyperthermia and neuropsychic syndrome in 65%, and dysautonomia in 50%. The creatine phosphokinase level in all patients was four times the normal value. Mechanical ventilation was required in 20% of the patients and hemodialysis in one patient. None of the patients received specific therapy. The mean duration of ICU stay was 10 days. The mortality rate was 10%,, mainly associated with renal failure. The analysis of the predictors of mortality was limited by the size of our cohort.Conclusion: NMS is a rare condition requiring multidisciplinary implementation of contextualized and updated procedures. Early detection and supportive treatment could improve the prognosis in resource-limited settings, where specific treatments are not available. Predictive risk factors should be investigated in larger multicenter cohorts.

The dynamic changes of cellular immunity among frontline medical workers who supported Wuhan for fighting against the COVID-19

The outbreak of novel coronavirus disease 2019 (COVID-19) poses a great stress to frontline medical workers. Our previous study indicated that immune cells in the peripheral blood of frontline medical workers changed significantly. However, the dynamic changes of immune cells of frontline medical workers remain unclear. Here, we reported the dynamic changes of lymphocyte subsets in the peripheral blood of 51 frontline medical worker. The frontline medical workers struggling with COVID-19 from February 8 to March 31, 2020. Demographic and clinical data, including routine blood test data were extracted from the electronic health examination record and retrospectively analyzed. The lymphocyte (LYM) count and LYM ratio increased while the monocyte (MONO) ratio, neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR) and neutrophil (NEUT) ratio in the peripheral blood of frontline medical workers decreased 10 days after struggling with COVID-19. Interestingly, the differences of LYM count, LYM ratio, MONO ratio, NLR, NEUT ratio were more significantly in nurse than doctor. The differences of LYM ratio, NLR and NEUT ratio were more significantly in female than male. However, the changes of LYM count, LYM ratio, MONO ratio, NLR, MLR, NEUT ratio returned to the baseline 10 months after struggling with COVID-19. Together, these data indicated that immune cells in the peripheral blood changed significantly 10 days after struggling with COVID-19, but returned to normal after 10 months. Those maybe caused by psychological stress and we recommend to pay more attention to mental health and immune response of frontline medical workers.

Sex-specific effects of low-dose hydrocortisone on threat detection in HIV

One sex differences in the perception of emotion is that females, particularly those with high anxiety, often show heightened identification of fearful faces. To better understand the causal role of glucocorticoids in this sex difference, we examine these associations in people with HIV(PWH) where emotion perception is impaired and mental health disorders are frequent. In a double-blind, placebo-controlled, cross-over study, we used a single low-dose of hydrocortisone (10 mg; LDH) as a mechanistic probe of the effects of elevated glucocorticoids on negative emotion perception in 65 PWH (31 women). The primary outcome was accuracy in identifying emotional expressions on the Facial Emotion Perception Test (FEPT). Salivary cortisol, self-reported stress/anxiety, and childhood trauma were also assessed. LDH increased salivary cortisol levels versus placebo. The effect of LDH versus placebo on FEPT accuracy depended on the combined influence of facial expression and sex (P = 0.03). LDH influenced accuracy only for women (P = 0.03), specifically for fearful faces (Cohen's d = 0.44, P = 0.04). Women's enhanced threat detection varied with psychological burden (mood, anxiety, and post-traumatic stress symptoms), more pronounced among those with lower burden and trauma (P < 0.05). This result suggests a role of the HPA axis in sex differences for perception of fearful faces in women with HIV, potentially due to changes in glucocorticoid receptor availability/activity, or improved integration of signals from facial recognition and emotion processing regions. The blunting of this effect in men and in individuals with more severe trauma suggests that the mechanisms underlying threat detection differ by sex and trauma history and warrant further investigation.

Paeoniflorin: A neuroprotective monoterpenoid glycoside with promising anti-depressive properties

BACKGROUND

Depression, as a prevalent and debilitating psychiatric disease, severely decreases the life quality of individuals and brings heavy burdens to the whole society. Currently, some antidepressants are applied in the treatment of severe depressive symptoms, while there are still some undesirable drawbacks. Paeoniflorin is a monoterpenoid glycoside that was firstly extracted from Paeonia lactiflora Pall, a traditional Chinese herb that is widely used in the Chinese herbal formulas for treating depression.

PURPOSE

This review summarized the previous pre-clinical studies of paeoniflorin in treating depression and further discussed the potential anti-depressive mechanisms for that paeoniflorin to be further explored and utilized in the treatment of depression clinically.

METHODS

Some electronic databases, e.g., PubMed and China National Knowledge Infrastructure, were searched from inception until April 2021.

RESULTS

This review summarized the effective anti-depressive properties of paeoniflorin, which is related to its functions in the upregulation of the levels of monoaminergic neurotransmitters, inhibition of the hypothalamic-pituitary-adrenal axis hyperfunction, promotion of neuroprotection, promotion of hippocampus neurogenesis, and upregulation of brain-derived neurotrophic factor level, inhibition of inflammatory reaction, downregulation of nitric oxide level, etc. CONCLUSION: This review focused on the pre-clinical studies of paeoniflorin in depression and summarized the recent development of the anti-depressive mechanisms of paeoniflorin, which approves the role of paeoniflorin plays in anti-depression. However, more high-quality pre-clinical and clinical studies are expected to be conducted in the future.

Endocrine and Electrolyte Balances during Periovulatory Period in Cycling Mares

Simple Summary

This study provides new evidence on the physiological mechanisms involved in the electrolyte balance during periovulatory period in cycling mares. The interrelationships among adrenocorticotropic hormone (ACTH), cortisol (CORT), aldosterone (ALD) and electrolytes (sodium—Na⁺, potassium—K⁺ and chloride—Cl⁻) were evaluated. The simultaneous increase in ACTH, CORT and ALD toward the time of ovulation could suggest the involvement of the adrenocortical pituitary axis in the ovulatory mechanisms, contributing at the same time to the maintenance of electrolyte homeostasis.

Abstract

In cycling females, the periovulatory period is characterized by stimulation of the hypothalamic pituitary adrenal (HPA) axis. The aim of present study was to analyze the pattern and interrelationships among adrenocorticotropic hormone (ACTH), cortisol (CORT), aldosterone (ALD) and electrolytes (sodium—Na⁺, potassium—K⁺ and chloride—Cl⁻) during periovulatory period in cycling mares. Venous blood samples were obtained daily from a total of 23 Purebred Spanish broodmares, aged 7.09 ± 2.5 years, from day −5 to day +5 of estrous cycle, considering day 0, the day of ovulation. Plasma ACTH was measured by a fluorescent immunoassay kit, serum CORT and ALD by means of a competitive ELISA immunoassay, and plasma Na⁺, K⁺ and Cl⁻ were quantified by an analyzer with selective electrodes for the three ions. ACTH showed higher concentrations at day 0 compared to days −5 to −1 and +1 to +3 (p < 0.05). CORT showed higher concentrations at day 0 compared to days −5 to −2 and +1 to +5 (p < 0.05). ALD showed higher concentrations at day 0 compared to days −5 to −2 (p < 0.05) and +2 (p < 0.05). Na⁺ and Cl⁻ showed higher concentrations at day 0, compared to day −5 and +5. K⁺ showed lower concentrations at day 0 compared to day +1 (p < 0.05). The significant correlations obtained between ACTH and CORT (r = 0.20) and between ACTH and ALD (r = 0.32) suggest that although ACTH may have an effect both on CORT and ALD, there are other very important determinants that could be considered. Hence, it is possible to presume that the pituitary adrenocortical response and ALD may be involved in the ovulatory mechanisms without a direct relation with electrolyte pattern.

Immune response of frontline medical workers providing medical support for Wuhan COVID-19 patients, China

The outbreak of novel coronavirus disease 2019 (COVID-19) posed a great challenge and stress to frontline medical workers in China. Stress is closely related to immunity. However, the immune response of frontline medical workers providing medical support for COVID-19 patients is unclear. Here, we reported the immune response of 76 frontline medical workers and 152 controls from the Second Affiliated Hospital of Xi'an Jiaotong University. The frontline medical workers were involved in the care for Wuhan COVID-19 patients from February 8 to March 31, 2020 in Tongji Hospital of Huazhong University of Science and Technology. The controls were medical workers of our hospital who had not been in contact with COVID-19 patients during the same period. Demographic and clinical data, including routine blood test data were extracted from the electronic health examination record and retrospectively analyzed. The post-stress frontline medical workers had higher lymphocyte (LYM) count compared with controls or pre-stress. However, the post-stress frontline medical workers had lower monocyte (MONO) count, neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR) and neutrophil (NEUT) ratio than controls or pre-stress. Interestingly, we found the differences were more significantly in female subgroup and nurse subgroup. Together, these data indicated that changes of immune response were found in frontline medical workers providing medical support for Wuhan COVID-19 patients, especially in females and nurses. Those maybe caused by psychological stress and we recommend to pay more attention to mental health of frontline medical workers, and provide appropriate psychological interventions for them.

Sex-specific differences in HPA axis activity in VLBW preterm newborns

OBJECTIVE

Sex-specific differences in hypothalamic-pituitary-adrenal axis activity might explain why male preterm infants are at higher risk of neonatal mortality and morbidity than their female counterparts. We examined whether male and female preterm infants differed in cortisol production and metabolism at 10 days post-partum.

DESIGN AND METHODS

This prospective study included 36 preterm born infants (18 boys) with a very low birth weight (VLBW) (<1.500 g). At 10 days postnatal age, urine was collected over a 4- to 6-h period. Glucocorticoid metabolites were measured using gas chromatography-mass spectrometry. Main outcome measures were: (1) cortisol excretion rate, (2) sum of all glucocorticoid metabolites, as an index of corticosteroid excretion rate, and (3) ratio of 11-OH/11-OXO metabolites, as an estimate of 11B-hydroxysteroid dehydrogenase (11B-HSD) activity. Differences between sexes, including interaction with Score of Neonatal Acute Physiology Perinatal Extension-II (SNAPPE II), sepsis and bronchopulmonary dysplasia (BPD), were assessed.

RESULTS

No differences between sexes were found for cortisol excretion rate, corticosteroid excretion rate or 11B-HSD activity. Interaction was observed between: sex and SNAPPE II score on 11B-HSD activity (P = 0.04) and sex and BPD on cortisol excretion rate (P = 0.04).

CONCLUSION

This study did not provide evidence for sex-specific differences in adrenocortical function in preterm VLBW infants on a group level. However, in an interaction model, sex differences became manifest under stressful circumstances. These patterns might provide clues for the male disadvantage in neonatal mortality and morbidity following preterm birth. However, due to the small sample size, the data should be seen as hypothesis generating.

Desperately seeking stress: A pilot study of cortisol in archaeological tooth structures

OBJECTIVES

Cortisol is a glucocorticoid hormone produced through activation of the hypothalamic pituitary adrenal axis. It is known as the "stress hormone" for its primary role in the body's stress response and has been the focus of much modern clinical research. Within archaeology, only a few studies have analyzed cortisol in human remains and these have been restricted to hair (Webb et al., 2010; Webb, White, van Uum, & Longstaffe, 2015a; Webb, White, van Uum, & Longstaffe, 2015b). This study examines the utility of dentine and enamel, which survive well archaeologically, as possible reservoirs for detectable levels of cortisol.

MATERIALS AND METHODS

Then, 69 teeth from 65 individuals from five Roman and Post-Roman sites in France were tested via competitive enzyme-linked immunosorbent assay (ELISA) to assess and quantify the cortisol concentrations present within tooth dentine and enamel.

RESULTS

In both tooth dentine and enamel, detectable concentrations of cortisol were identified in multiple teeth. However, concentrations were low and not all teeth yielded results that were measurable through cortisol ELISA. Differences in cortisol values between dentine and enamel could suggest different uptake mechanisms or timing.

DISCUSSION

These results suggest that cortisol is incorporated within tooth structures and merits further investigation in both modern and archaeological contexts. Analysis of the results through liquid chromatographic-mass spectrometry would verify current results and might yield values that could be better integrated with published cortisol studies. Future studies of cortisol in tooth structures would greatly expand the research potential of cortisol in the past and could have implications for studies of human stress across deep time.

Sex differences in the association between childhood maltreatment and cardiovascular disease in the UK Biobank

OBJECTIVES

To assess and compare associations between childhood maltreatment and cardiovascular disease (CVD) in men and women in the UK. In secondary analyses, we also explored possible age differences and associations with early onset CVD (<50 years).

METHODS

We included 157 311 participants from the UK Biobank who had information on physical, sexual or emotional abuse, emotional or physical neglect. CVD outcomes were defined as any CVD, hypertensive disease, ischaemic heart disease (IHD) and cerebrovascular disease. These were extracted from self-report, blood pressure measurements, hospital register and death register. The associations between maltreatment and CVD were assessed using Poisson regression with robust variance to estimate risk ratios, stratified by sex and adjusted for socioeconomic and demographic factors.

RESULTS

All types of maltreatment were associated with increased risk of CVD and IHD in both sexes. Additionally, in women all types of maltreatment were associated with higher risk of hypertensive disease, and all, except emotional neglect, were associated with cerebrovascular disease. In men, all but sexual abuse, were associated with higher risk of hypertensive disease, and all, except physical and sexual abuse, were associated with cerebrovascular disease. Associations were generally stronger in women, and individuals who were younger at baseline had stronger associations of childhood maltreatment with any CVD and IHD, but age differences were less evident when only early onset CVD was considered.

CONCLUSIONS

Childhood maltreatment was consistently associated with CVD and stronger associations were generally observed in women and seemed to be stronger for early onset CVD.

Estradiol promotes and progesterone reduces anxiety-like behavior produced by nicotine withdrawal in female rats

This study assessed sex differences and the role of ovarian hormones in nicotine withdrawal. Study 1 compared physical signs, anxiety-like behavior, and corticosterone levels in male, intact female, and ovariectomized (OVX) female rats during nicotine withdrawal. Estradiol (E2) and progesterone levels were also assessed in intact females that were tested during different phases of the 4-day estrous cycle. Study 2 assessed the role of ovarian hormones in withdrawal by comparing the same measures in OVX rats that received vehicle, E2, or E2+progesterone prior to testing. Briefly, rats received a sham surgery or an ovariectomy procedure. Fifteen days later, rats were prepared with a pump that delivered nicotine for 14 days. On the test day, rats received saline or the nicotinic receptor antagonist, mecamylamine to precipitate withdrawal. Physical signs and anxiety-like behavior were assessed on the elevated plus maze (EPM) and light-dark transfer (LDT) tests. During withdrawal, intact females displayed greater anxiety-like behavior and increases in corticosterone levels as compared to male and OVX rats. Females tested in the estrus phase (when E2 is relatively low) displayed less anxiety-like behavior and had lower corticosterone levels versus all other phases. Anxiety-like behavior and corticosterone levels were positively correlated with E2 and negatively correlated with progesterone levels. Intact females displaying high E2/low progesterone showed greater anxiety-like behavior and corticosterone levels as compared to females displaying low E2/high progesterone. Lastly, OVX-E2 rats displayed greater anxiety-like behavior than OVX-E2+progesterone rats. These data suggest that E2 promotes and progesterone reduces anxiety-like behavior produced by nicotine withdrawal.

Roles for androgens in mediating the sex differences of neuroendocrine and behavioral stress responses

Estradiol and testosterone are powerful steroid hormones that impact brain function in numerous ways. During development, these hormones can act to program the adult brain in a male or female direction. During adulthood, gonadal steroid hormones can activate or inhibit brain regions to modulate adult functions. Sex differences in behavioral and neuroendocrine (i.e., hypothalamic pituitary adrenal (HPA) axis) responses to stress arise as a result of these organizational and activational actions. The sex differences that are present in the HPA and behavioral responses to stress are particularly important considering their role in maintaining homeostasis. Furthermore, dysregulation of these systems can underlie the sex biases in risk for complex, stress-related diseases that are found in humans. Although many studies have explored the role of estrogen and estrogen receptors in mediating sex differences in stress-related behaviors and HPA function, much less consideration has been given to the role of androgens. While circulating androgens can act by binding and activating androgen receptors, they can also act by metabolism to estrogenic molecules to impact estrogen signaling in the brain and periphery. This review focuses on androgens as an important hormone for modulating the HPA axis and behaviors throughout life and for setting up sex differences in key stress regulatory systems that could impact risk for disease in adulthood. In particular, impacts of androgens on neuropeptide systems known to play key roles in HPA and behavioral responses to stress (corticotropin-releasing factor, vasopressin, and oxytocin) are discussed. A greater knowledge of androgen action in the brain is key to understanding the neurobiology of stress in both sexes.

Sex-Specific Effects of Early Life Stress on Brain Mitochondrial Function, Monoamine Levels and Neuroinflammation

Sex differences have been reported in the susceptibility to early life stress and its neurobiological correlates in humans and experimental animals. However, most of the current research with animal models of early stress has been performed mainly in males. In the present study, prolonged maternal separation (MS) paradigm was applied as an animal model to resemble the effects of adverse early experiences in male and female rats. Regional brain mitochondrial function, monoaminergic activity, and neuroinflammation were evaluated as adults. Mitochondrial energy metabolism was greatly decreased in MS females as compared with MS males in the prefrontal cortex, dorsal hippocampus, and the nucleus accumbens shell. In addition, MS males had lower serotonin levels and increased serotonin turnover in the prefrontal cortex and the hippocampus. However, MS females showed increased dopamine turnover in the prefrontal cortex and increased norepinephrine turnover in the striatum, but decreased dopamine turnover in the hippocampus. Sex differences were also found for pro-inflammatory cytokine levels, with increased levels of TNF-α and IL-6 in the prefrontal cortex and hippocampus of MS males, and increased IL-6 levels in the striatum of MS females. These results evidence the complex sex- and brain region-specific long-term consequences of early life stress.

Sex Differences in Work-Stress Memory Bias and Stress Hormones

Mental health problems related to chronic stress in workers appear to be sex-specific. Psychosocial factors related to work-life balance partly explain these sex differences. In addition, physiological markers of stress can provide critical information on the mechanisms explaining how chronic stress gets "under the skull" to increase vulnerability to mental health disorders in working men and women. Stress hormones access the brain and modulate attentional and memory process in favor of threatening information. In the present study, we tested whether male and female workers present a memory bias towards work-stress related information, and whether this bias is associated with concentrations of stress hormones in reactivity to a laboratory stressor (reactive levels) and samples taken in participants' workday (diurnal levels). In total, 201 participants (144 women) aged between 18 and 72 years underwent immediate and delayed recall tasks with a 24-word list, split as a function of valence (work-stress, positive, neutral). Participants were exposed to a psychosocial stressor in between recalls. Reactivity to stress was measured with saliva samples before and after the stressor. Diurnal cortisol was also measured with five saliva samples a day, during 2 workdays. Our exploratory results showed that men presented greater cortisol reactivity to stress than women, while women recalled more positive and neutral words than men. No sex difference was detected on the recall of work-stress words, before or after exposure to stress. These results do not support the hypothesis of a sex-specific cognitive bias as an explanatory factor for sex differences in stress-related mental health disorders in healthy male and female workers. However, it is possible that such a work-stress bias is present in individuals who have developed a mental-health disorder related to workplace stress or who have had one in the recent past. Consequently, future studies could use our stress memory bias task to assess this and other hypotheses in diverse working populations.

The effects of early life adversity on growth, maturation, and steroid hormones in male and female rats

Early life adversity is a risk factor for psychiatric disorders, yet the mechanisms by which adversity increases this risk are still being delineated. Here, we used a limited bedding and nesting (LBN) manipulation in rats that models a low resource environment to examine effects on growth, developmental milestones, and endocrine endpoints. In LBN, dams and pups, from pups' postnatal days 2-9, are exposed to an environment where dams lack proper materials to build a nest. This manipulation is compared to control housing conditions, where rat dams have access to ample nesting materials and enrichment throughout pups' development. We found that the LBN condition altered maternal care, increasing pup-directed behaviors while reducing self-care. This, perhaps compensatory, increase in nursing and attention to pups did not mitigate against changes in metabolism, as LBN reduced weight gain in both sexes and this effect persisted into adulthood. Although adult stress hormone levels in both sexes and vaginal opening and estrous cycle length in females were not disrupted, there was other evidence of endocrine dysregulation. Compared to controls, LBN rats of both sexes had shortened anogenital distances, indicating reduced androgen exposure. LBN males also had higher plasma estradiol levels in adulthood. This combination of results suggests that LBN causes a demasculinizing effect in males that could contribute to lasting changes in the brain and behavior. Importantly, alterations in metabolic and endocrine systems due to early life adversity could be one mechanism by which stress early in life increases risk for later disease.

Hair Cortisol Concentration in Healthy Children and Adolescents Is Related to Puberty, Age, Gender, and Body Mass Index

INTRODUCTION

Hair cortisol concentrations (HCC) have been found to be related to various common childhood diseases, like otitis media, conjunctivitis, respiratory viral infections, and asthma. However, the confounding effects of age, gender, body mass index (BMI), pubertal stage (Tanner stages), socioeconomic status (SES) as well as of some hair maintenance procedures on HCC are still not well examined.

METHODS

A population-based cohort of 434 children aged between 5 and 18 years was examined for HCC between January 2012 and February 2015 in the context of the Leipzig Research Centre for Civilization Diseases (LIFE) Child study. Thereby, anthropometric data, gender, BMI, SES and pubertal status were assessed. HCC was measured by liquid chromatography mass spectrometry.

RESULTS

In the total cohort, HCC levels ranged between 0.95 and 29.86 pg/mg. In prepuberty, boys showed significantly higher HCC than girls (6.54 vs. 3.73 pg/mg, p < 0.05). During puberty HCC values in both genders converged. Higher BMI was significantly associated with higher HCC in both genders. In girls, HCC did not differ depending on Tanner stages. In boys, HCC was significantly higher in Tanner stage 1 than in stages 2-5.

CONCLUSION

Measuring cortisol concentration in hair gives information about long-term release of cortisol. We have found that puberty, gender, and BMI had a profound effect on HCC. As a result, further research should take into account the potentially confounding role of puberty, gender and BMI and may use the results of our study as a reference at determining values of HCC in healthy children.

Sex differences in the interactive effects of early life stress and the endocannabinoid system

Sex differences in both the endocannabinoid system and stress responses have been established for decades. While there is ample evidence that the sexes respond differently to stress and that the endocannabinoid system is involved in this response, what is less clear is whether the endocannabinoid system mediates this response to stress differently in both sexes. Also, do the sexes respond similarly to exogenous cannabinoids (CBs) following stress? Can the administration of exogenous CBs normalize the effects of stress and if so, does this happen similarly in male and female subjects? This review will attempt to delineate the stress induced neurochemical alterations in the endocannabinoid system and the resulting behavioral changes across periods of development: prenatal, early neonatal or adolescent in males and females. Within this frame work, we will then examine the neurochemical and behavioral effects of exogenous CBs and illustrate that the response to CBs is determined by the stress history of the animal. The theoretical framework for this endeavor relates to the established effects of adverse childhood experiences (ACE) in increasing substance abuse, depression and anxiety and the possibility that individuals with high ACE scores may consume cannabinoids to "self-medicate". Overall, we see that while there are instances where exogenous cannabinoids "normalize" the adverse effects produced by early stress, this normalization does not occur in all animal models with any sort of consistency. The most compelling report where CB administration appears to normalize behaviors altered by early stress, shows minimal differences between the sexes (Alteba et al., 2016). This is in stark contrast to the majority of studies on early stress and the endocannabinoid system where both sexes are included and show quite divergent, in fact opposite, effects in males and females. Frequently there is a disconnect between neurochemical changes and behavioral changes and often, exogenous CBs have greater effects in stressed animals compared to non-stressed controls. This report as well as others reviewed here do support the concept that the effects of exogenous CBs are different in individuals experiencing early stress and that these differences are not equal in males and females. However, due to the wide variety of stressors used and the range of ages when the stress is applied, additional careful studies are warranted to fully understand the interactive effects of stress and the endocannabinoid system in males and females. In general, the findings do not support the statement that CB self-administration is an effective treatment for the adverse behavioral effects of early maltreatment in either males or females. Certainly this review should draw the attention of clinicians working with children, adolescents and adults exposed to early trauma and provide some perspective on the dysregulation of the endocannabinoid system in the response to trauma, the complex actions of exogenous CBs based on stress history and the unique effects of these factors in men and women.

Changes in Cortisol but Not in Brain-Derived Neurotrophic Factor Modulate the Association Between Sleep Disturbances and Major Depression

Sleep disturbance is a symptom consistently found in major depression and is associated with a longer course of illness, reduced response to treatment, increased risk of relapse and recurrence. Chronic insomnia has been associated with changes in cortisol and serum brain-derived neurotrophic factor (BDNF) levels, which in turn are also changed in major depression. Here, we evaluated the relationship between sleep quality, salivary cortisol awakening response (CAR), and serum BDNF levels in patients with sleep disturbance and treatment-resistant major depression (n = 18), and in a control group of healthy subjects with good (n = 21) and poor (n = 18) sleep quality. We observed that the patients had the lowest CAR and sleep duration of all three groups and a higher latency to sleep than the healthy volunteers with a good sleep profile. Besides, low CAR was correlated with more severe depressive symptoms and worse sleep quality. There was no difference in serum BDNF levels between groups with distinct sleep quality. Taken together, our results showed a relationship between changes in CAR and in sleep quality in patients with treatment-resistant depression, which were correlated with the severity of disease, suggesting that cortisol could be a physiological link between sleep disturbance and major depression.

Cannabinoids as therapeutics for PTSD

Post-traumatic stress disorder (PTSD) is a complex disorder that involves dysregulation of multiple neurobiological systems. The traumatic stressor plays a causal role in producing psychological dysfunction and the pattern of findings suggests that the hypothalamic-pituitary-adrenal (HPA) axis, which is instrumental for stress adaptation, is critically dysfunctional in PTSD. Given the lack of understanding of the basic mechanisms and underlying pathways that cause the disorder and its heterogeneity, PTSD poses challenges for treatment. Targeting the endocannabinoid (ECB) system to treat mental disorders, and PTSD in particular, has been the focus of research and interest in recent years. The ECB system modulates multiple functions, and drugs enhancing ECB signaling have shown promise as potential therapeutic agents in stress effects and other psychiatric and medical conditions. In this review, we focus on the interaction between the ECB-HPA systems in animal models for PTSD and in patients with PTSD. We summarize evidence supporting the use of cannabinoids in preventing and treating PTSD in preclinical and clinical studies. As the HPA system plays a key role in the mediation of the stress response and the pathophysiology of PTSD, we describe preclinical studies suggesting that enhancing ECB signaling is consistent with decreasing PTSD symptoms and dysfunction of the HPA axis. Overall, we suggest that a pharmacological treatment targeted at one system (e.g., HPA) may not be very effective because of the heterogeneity of the disorder. There are abnormalities across different neurotransmitter systems in the pathophysiology of PTSD and none of these systems function uniformly among all patients with PTSD. Hence, conceptually, enhancing ECB signaling may be a more effective avenue for pharmacological treatment.

Supplemental taurine during adolescence and early adulthood has sex-specific effects on cognition, behavior and neurotransmitter levels in C57BL/6J mice dependent on exposure window

The mammalian brain goes through final maturation during late adolescence and early adulthood with sex differences in timing. The key cellular processes, including changes in neurotransmitter receptor density and synaptic pruning, make this age uniquely vulnerable to neurotoxic insults. Teenagers and young adults are the major consumers of energy drinks, which contain high levels of taurine and caffeine. Taurine is one of the most abundant amino acids in the central nervous system, but the effects of supplemental taurine consumption during adolescence has not been well studied. We conducted an initial short-term exposure study with 0.12% taurine in drinking water and a long-term exposure dose-response study using 0.06 and 0.12% taurine in male and female C57BL/6J mice. We examined a broad range of cognitive functions and behaviors and measured neurotransmitter levels. We found no significant differences in anxiety, open field locomotor activity, or sensorimotor gating. However, we found impairments in novel object recognition and sex differences in Morris water maze. When taurine treatment stopped before behavioral experiments began, male mice had significant impairments in spatial learning and memory. In the dose-response study when taurine treatment continued throughout behavioral experiments, females had significant impairments. We also found sex differences in neurotransmitter levels with females having higher levels of glutamate, DOPAC and 5-HIAA. We conclude that both females and males are at risk from excess taurine consumption during final brain maturation.

Biological intersection of sex, age, and environment in the corticotropin releasing factor (CRF) system and alcohol

The neuropeptide corticotropin-releasing factor (CRF) is critical in neural circuit function and behavior, particularly in the context of stress, anxiety, and addiction. Despite a wealth of preclinical evidence for the efficacy of CRF receptor 1 antagonists in reducing behavioral pathology associated with alcohol exposure, several clinical trials have had disappointing outcomes, possibly due to an underappreciation of the role of biological variables. Although he National Institutes of Health (NIH) now mandate the inclusion of sex as a biological variable in all clinical and preclinical research, the current state of knowledge in this area is based almost entirely on evidence from male subjects. Additionally, the influence of biological variables other than sex has received even less attention in the context of neuropeptide signaling. Age (particularly adolescent development) and housing conditions have been shown to affect CRF signaling and voluntary alcohol intake, and the interaction between these biological variables is particularly relevant to the role of the CRF system in the vulnerability or resilience to the development of alcohol use disorder (AUD). Going forward, it will be important to include careful consideration of biological variables in experimental design, reporting, and interpretation. As new research uncovers conditions in which sex, age, and environment play major roles in physiological and/or pathological processes, our understanding of the complex interaction between relevant biological variables and critical signaling pathways like the CRF system in the cellular and behavioral consequences of alcohol exposure will continue to expand ultimately improving the ability of preclinical research to translate to the clinic. This article is part of the special issue on Neuropeptides.

Sex-specific association between the cortisol awakening response and obsessive-compulsive symptoms in healthy individuals

Background

Previous studies have shown associations between obsessive-compulsive disorder (OCD) and hypothalamic-pituitary-adrenal axis activity (HPA). We aimed to investigate the association between obsessive-compulsive (OC) symptoms and HPA axis functionality in a non-clinical sample and to explore whether there are sex differences in this relationship.

Methods

One hundred eighty-three healthy individuals without any psychiatric diagnosis (80 men, 103 women; mean age 41.3 ± 17.9 years) were recruited from the general population. The Obsessive-Compulsive Inventory Revised (OCI-R) was used to assess OC symptoms. State-trait anxiety, perceived stress, and stressful life events were also assessed. Saliva cortisol levels were determined at 6 time points (awakening, 30 and 60 min post-awakening, 10:00 a.m., 23:00 p.m. and 10:00 a.m. the following day of 0.25 mg dexamethasone intake [that occurred at 23:00 p.m.]). Three HPA axis measures were calculated: cortisol awakening response (CAR), cortisol diurnal slope, and cortisol suppression ratio after dexamethasone (DSTR). Multiple linear regression analyses were used to explore the association between OC symptoms and HPA axis measures while adjusting for covariates. Our main analyses were focused on OCI-R total score, but we also explored associations with specific OC symptom dimensions.

Results

No significant differences were observed between males and females in OC symptoms, anxiety measures, stress, or cortisol measures. In the multiple linear regression analyses between overall OC symptoms and HPA axis measures, a female sex by OC symptoms significant interaction (standardized beta = − 0.322; p = 0.023) for the CAR (but not cortisol diurnal slope nor DSTR) was found. Regarding specific symptom dimensions, two other sex interactions were found: a blunted CAR was associated with obsessing symptoms in women, whereas a more flattened diurnal cortisol slope was associated with ordering symptoms in men.

Conclusions

There are sex differences in the association between OC symptoms and HPA axis measures in healthy individuals.

Social instability in adolescence differentially alters dendritic morphology in the medial prefrontal cortex and its response to stress in adult male and female rats

Adolescence is an important period for HPA axis development and synapse maturation and reorganization in the prefrontal cortex (PFC). Thus, stress during adolescence could alter stress-sensitive brain regions such as the PFC and may alter the impact of future stressors on these brain regions. Given that women are more susceptible to many stress-linked psychological disorders in which dysfunction of PFC is implicated, and that this increased vulnerability emerges in adolescence, stress during this time could have sex-dependent effects. Therefore, we investigated the effects of adolescent social instability stress (SIS) on dendritic morphology of Golgi-stained pyramidal cells in the medial PFC of adult male and female rats. We then examined dendritic reorganization following chronic restraint stress (CRS) with and without a rest period in adult rats that had been stressed in adolescence. Adolescent SIS conferred long-term alterations in prelimbic of males and females, whereby females show reduced apical length and basilar thin spine density and males show reduced basilar length. CRS in adulthood failed to produce immediate dendritic remodeling in SIS rats. However, CRS followed by a rest period reduced apical dendritic length and increases mushroom spine density in adolescently stressed adult males. Conversely, CRS followed by rest produced apical outgrowth and decreased mushroom spine density in adolescently stressed adult females. These results suggest that stress during adolescence alters development of the PFC and modulates stress-induced dendritic changes in adulthood.

Oral Lorazepam is not Superior to Placebo for Lowering Stress in Children Before Digestive Endoscopy: A Double-Blind, Randomized, Controlled Trial

BACKGROUND

Digestive endoscopies must be performed within a safe and comfortable environment. We have previously shown that the quality of intravenous sedation is influenced by preoperative stress.

AIM

Our primary objective was to compare the effects of oral lorazepam and placebo on the salivary cortisol response of children undergoing a digestive endoscopy. Secondary objectives were the assessment of procedural pain and comfort as well as the occurrence of adverse events.

METHODS

Participants were randomized and received either lorazepam, placebo, or no premedication. Saliva was collected upon arrival at the hospital and 1 h following randomization. The sedation protocol included midazolam and fentanyl ± ketamine. Procedural pain was evaluated with the Nurse Assessed Patient Comfort Score (NAPCOMS). Patients completed a postoperative questionnaire. The primary outcome was defined as the proportion of children having a cortisol decrease ≥ 15 nmol/L.

RESULTS

101 participants (54 females) were included. The rate of children having a cortisol decrease ≥ 15 nmol/L was 27.3%, 35.3%, and 19.4% for lorazepam, placebo, and no premedication, respectively (p = 0.356). The median (IQR) NAPCOMS pain score was 3.0 (0-6) for lorazepam, 4.4 (0-6) for placebo, and 3.4 (3-4) for no premedication (p = 0.428). With lorazepam, 75.9% of children reported experiencing a comfortable procedure, compared with 41.9% taking placebo and 34.5% with no premedication (p = 0.013). Transient tachycardia was the most frequent intraoperative adverse event, particularly with lorazepam (62.5%, p = 0.029).

CONCLUSIONS

Oral lorazepam had no effect on patients' preoperative stress, as measured by salivary cortisol, but was associated with a higher rate of comfortable procedures.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, Identifier NCT03180632.

Fetal programming of adrenal PNMT and hypertension by glucocorticoids in WKY rats is dose and sex-dependent

Biochemical changes in utero may alter normal fetal development, resulting in disease later in life, a phenomenon known as fetal programming. Recent epidemiological studies link fetal programming to negative health outcomes, such as low birth weight and hypertension in adulthood. Here, we used a WKY rat model and studied the molecular changes triggered by prenatal glucocorticoid (GC) exposure on the development of hypertension, and on the regulation of phenylethanolamine N-methyl transferase (PNMT), the enzyme responsible for biosynthesis of epinephrine, and a candidate gene linked to hypertension. Clinically, high doses of the synthetic GC dexamethasone (DEX) are used to treat infant respiratory distress syndrome. Elevated maternal GCs have been correlated with fetal programming of hypertension. The aim of this study was to determine if lower doses of DEX would not lead to detrimental fetal programming effects such as hypertension. Our data suggests that prenatal stress programs for increased expression of PNMT and altered regulation of PNMT in males and females. Importantly, we identified that DEX mediated programming was more apparent in the male rats, and the lower dose 10μg/kg/day of DEX did not lead to changes in blood pressure (BP) in female rats suggesting that this dose is below the threshold for programming of hypertension. Furthermore, sex-specific differences were observed in regards to programming mechanisms that may account for hypertension in males.

Leucine-Rich Repeat Kinase 2 Is Associated With Activation of the Paraventricular Nucleus of the Hypothalamus and Stress-Related Gastrointestinal Dysmotility

Leucine-rich repeat kinase 2 (LRRK2) is a molecule associated with familial and sporadic Parkinson's disease. It regulates many central neuronal functions, such as cell proliferation, apoptosis, autophagy, and axonal extension. Recently, it has been revealed that LRRK2 is related to anxiety/depression-like behavior, implying an association between LRRK2 and stress. In the present study, we investigated for the first time the stress pathway and its relationship to gastrointestinal motility in LRRK2-knockout (KO) mice. The mice were subjected to acute restraint stress, and analyzed for activation of the paraventricular nucleus of the hypothalamus (PVN) using an immunohistochemical approach. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) was assessed by Western blotting. The KO mice showed a lower number of c-Fos-positive cells and disruption of the ERK signaling pathway in the PVN in the presence of restraint stress. Stress responses in terms of both upper and lower gastrointestinal motility were alleviated in the mice, accompanied by lower c-Fos immunoreactivity in enteric excitatory neurons. Our present findings suggest that LRRK2 is a newly recognized molecule regulating the stress pathway in the PVN, playing a role in stress-related gastrointestinal dysmotility.

Neuroendocrine Networks and Functionality

Women undergo developmental and cyclic changes in hormonal exposures that affect brain function and mental health. Some women are more vulnerable to the effects of these hormonal exposures, for reasons that remain to be determined. Evidence to date indicates that anxiety and mood disorders are the most sensitive to hormonal fluctuations in women but there is also growing evidence for a protective effect of female reproductive hormones on schizophrenia. The hormonal exposures of the menstrual cycle, pregnancy, the postpartum period, lactation, and menopause are quite different and may be associated with at least partially distinct symptom profiles.

Sex differences in the hypothalamic-pituitary-adrenal axis: An obstacle to antidepressant drug development?

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has long been implicated in the pathophysiology of depression, and HPA axis-based compounds have served as potential new therapeutic targets, but with no success. This review details sex differences from animal and human studies in the function of HPA axis elements (glucocorticoids, corticotropin releasing factor, and vasopressin) and related compounds tested as candidate antidepressants. We propose that sex differences contribute to the failure of novel HPA axis-based drugs in clinical trials. Compounds studied preclinically in males were tested in clinical trials that recruited more, if not exclusively, women, and did not control, but rather adjusted, for potential sex differences. Indeed, clinical trials of antidepressants are usually not stratified by sex or other important factors, although preclinical and epidemiological data support such stratification. In conclusion, we suggest that clinical testing of HPA axis-related compounds creates an opportunity for targeted, personalized antidepressant treatments based on sex. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Modulation of Serum Brain-Derived Neurotrophic Factor by a Single Dose of Ayahuasca: Observation From a Randomized Controlled Trial

Serotonergic psychedelics are emerging as potential antidepressant therapeutic tools, as suggested in a recent randomized controlled trial with ayahuasca for treatment-resistant depression. Preclinical and clinical studies have suggested that serum brain-derived neurotrophic factor (BDNF) levels increase after treatment with serotoninergic antidepressants, but the exact role of BDNF as a biomarker for diagnostic and treatment of major depression is still poorly understood. Here we investigated serum BDNF levels in healthy controls (N = 45) and patients with treatment-resistant depression (N = 28) before (baseline) and 48 h after (D2) a single dose of ayahuasca or placebo. In our sample, baseline serum BDNF levels did not predict major depression and the clinical characteristics of the patients did not predict their BDNF levels. However, at baseline, serum cortisol was a predictor of serum BDNF levels, where lower levels of serum BDNF were detected in a subgroup of subjects with hypocortisolemia. Moreover, at baseline we found a negative correlation between BDNF and serum cortisol in volunteers with eucortisolemia. After treatment (D2) we observed higher BDNF levels in both patients and controls that ingested ayahuasca (N = 35) when compared to placebo (N = 34). Furthermore, at D2 just patients treated with ayahuasca (N = 14), and not with placebo (N = 14), presented a significant negative correlation between serum BDNF levels and depressive symptoms. This is the first double-blind randomized placebo-controlled clinical trial that explored the modulation of BDNF in response to a psychedelic in patients with depression. The results suggest a potential link between the observed antidepressant effects of ayahuasca and changes in serum BDNF, which contributes to the emerging view of using psychedelics as an antidepressant. This trial is registered at http://clinicaltrials.gov (NCT02914769).

Developmental influences on stress response systems: Implications for psychopathology vulnerability in adolescence

The adolescent transition is marked by increases in stress exposure and significant maturation of neural and hormonal stress processing systems. Variability in the development of these systems during adolescence may influence the risk for stress-related psychopathology. This paper aims to review the developmental maturation of the HPA axis and related stress regulation systems, and demonstrate how interference in this adaptive developmental process may increase the risk for negative outcomes. We argue that the developmental maturation of the HPA axis aims to improve the regulatory capacity of the axis in order to more adaptively respond to these increases in stress reactivity. Additionally, we review evidence that sex differences in the development of the HPA and related axes may contribute to sex differences in the risk for stress-related psychopathology. Finally, we discuss how contextual factors, such as early trauma and obesity may alter the development of HPA axis during the adolescence transition and how alterations of normative development increase the risk for stress-related disorders.

Sex differences in the hypothalamic-pituitary-adrenal axis' response to stress: an important role for gonadal hormones

The hypothalamic-pituitary-adrenal (HPA) axis, a neuroendocrine network that controls hormonal responses to internal and external challenges in an organism's environment, exhibits strikingly sex-biased activity. In adult female rodents, acute HPA function following a stressor is markedly greater than it is in males, and this difference has largely been attributed to modulation by the gonadal hormones testosterone and estradiol. These gonadal hormones are produced by the hypothalamic-pituitary-gonadal (HPG) axis and have been shown to determine sex differences in adult HPA function after acute stress via their activational and organizational effects. Although these actions of gonadal hormones are well supported, the possibility that sex chromosomes similarly influence HPA activity is unexplored. Moreover, questions remain regarding sex differences in the activity of the HPA axis following chronic stress and the underlying contributions of gonadal hormones and sex chromosomes. The present review examines what is currently known about sex differences in the neuroendocrine response to stress, as well as outstanding questions regarding this sex bias. Although it primarily focuses on the rodent literature, a brief discussion of sex differences in the human HPA axis is also included.

Structure of human cortisol-producing cytochrome P450 11B1 bound to the breast cancer drug fadrozole provides insights for drug design

Human cytochrome P450 11B1 (CYP11B1) is responsible for the final step generating the steroid hormone cortisol, which controls stress and immune responses and glucose homeostasis. CYP11B1 is a promising drug target to manage Cushing's disease, a disorder arising from excessive cortisol production. However, the design of selective inhibitors has been hampered because structural information for CYP11B1 is unavailable and the enzyme has high amino acid sequence identity (93%) to a closely related enzyme, the aldosterone-producing CYP11B2. Here we report the X-ray crystal structure of human CYP11B1 (at 2.1 Å resolution) in complex with fadrozole, a racemic compound normally used to treat breast cancer by inhibiting estrogen-producing CYP19A1. Comparison of fadrozole-bound CYP11B1 with fadrozole-bound CYP11B2 revealed that despite conservation of the active-site residues, the overall structures and active sites had structural rearrangements consistent with distinct protein functions and inhibition. Whereas fadrozole binds to both CYP11B enzymes by coordinating the heme iron, CYP11B2 binds to the R enantiomer of fadrozole, and CYP11B1 binds to the S enantiomer, each with distinct orientations and interactions. These results provide insights into the cross-reactivity of drugs across multiple steroidogenic cytochrome P450 enzymes, provide a structural basis for understanding human steroidogenesis, and pave the way for the design of more selective inhibitors of each human CYP11B enzyme.