HPA axis responsiveness to stress: implications for healthy aging

Neurocardiac Axis Physiology and Clinical Applications

The neurocardiac axis constitutes the neuronal circuits between the arteries, heart, brain, and immune organs (including thymus, spleen, lymph nodes, and mucosal associated lymphoid tissue) that together form the cardiovascular brain circuit. This network allows the individual to maintain homeostasis in a variety of environmental situations. However, in dysfunctional states, such as exposure to environments with chronic stressors and sympathetic activation, this axis can also contribute to the development of atherosclerotic vascular disease as well as other cardiovascular pathologies and it is increasingly being recognized as an integral part of the pathogenesis of cardiovascular disease. This review article focuses on 1) the normal functioning of the neurocardiac axis; 2) pathophysiology of the neurocardiac axis; 3) clinical implications of this axis in hypertension, atherosclerotic disease, and heart failure with an update on treatments under investigation; and 4) quantification methods in research and clinical practice to measure components of the axis and future research areas.

Severe PTSD is marked by reduced oxytocin and elevated vasopressin

Neuroendocrine analyses of posttraumatic stress disorder (PTSD) have generally focused on hypothalamic-pituitary-adrenal (HPA) axis alterations. In the present analyses, we examine two additional neuroendocrine factors that have been previously implicated in biological stress responses: oxytocin (OT) and arginine vasopressin (AVP). Here we examined basal neuropeptide status in military veterans clinically diagnosed with PTSD (n = 29) and in two non-traumatized comparison groups with previous stress exposure (n = 11 SWAT trainees and n = 21 ultramarathon runners). PTSD patients showed low levels of plasma OT and high levels of AVP. The ratio of AVP/OT robustly related to PTSD status, and emerged as a statistically plausible mediator of relationships between the number of personal traumatic experiences and subsequent PTSD symptom burden. Over the course of behavioral therapy for PTSD, measures of OT showed a significant but modest normalization. Plasma cortisol levels were not statistically different among the three groups. This study suggests that AVP/OT ratios may represent a neuroendocrine predictor of severe PTSD, as well as a potential treatment response biomarker.

Plasma Steroid Profiling Between Patients With and Without Diabetes Mellitus in Nonfunctioning Adrenal Incidentalomas

Context

Adrenal incidentalomas, including nonfunctioning adrenal incidentalomas (NFAI), are associated with a high prevalence of diabetes mellitus (DM). While NFAI is diagnosed by exclusion when no hormone excess exists, subtle cortisol secretion may exist and contribute to DM development. However, it alone cannot explain the increased risk, and whether other steroid metabolites are involved remains unclear.

Purpose

To investigate steroid metabolites associated with DM in patients with NFAI using plasma steroid profiles.

Methods

Using liquid chromatography-tandem mass spectrometry, 22 plasma steroid metabolites were measured in 68 patients with NFAI (31 men and 37 women). Data were adjusted for age before normalization.

Results

Discriminant analysis showed that plasma steroid profiles discriminated between patients with and without DM in men (n = 10 and = 21, respectively) but not women: 11β-hydroxytestosterone, an adrenal-derived 11-oxygenated androgen, contributed most to this discrimination and was higher in patients with DM than in those without DM (false discovery rate = .002). 11β-hydroxytestosterone was correlated positively with fasting plasma glucose (r = .507) and hemoglobin A1c (HbA1c) (r = .553) but negatively with homeostatic model assessment of β-cell function (HOMA2-B) (r = -.410). These correlations remained significant after adjusting for confounders, including serum cortisol after the 1-mg dexamethasone suppression test. Bayesian kernel machine regression analysis verified the association of 11β-hydroxytestosterone with HbA1c and HOMA2-B in men.

Main Conclusion

Plasma steroid profiles differed between those with and without DM in men with NFAI. 11β-hydroxytestosterone was associated with hyperglycemia and indicators related to pancreatic β-cell dysfunction, independently of cortisol.

Multifaceted physiological and therapeutical impact of curcumin on hormone-related endocrine dysfunctions: A comprehensive review

Over the past five decades, Curcumin (Cur), derived from turmeric (Curcuma longa), has gained considerable attention for its potential therapeutic applications. Synthesizing insights from clinical trials conducted over the last 25 years, this review delves into diseases where Cur has demonstrated promise, offering a nuanced understanding of its pharmacokinetics, safety, and effectiveness. Focusing on specific examples, the impact of Cur on various human diseases is explored. Endocrine glands and associated signaling pathways are highlighted, elucidating how Cur influences cellular signaling. The article underscores molecular mechanisms such as hormone level alteration, receptor interaction, cytokine and adipokine expression inhibition, antioxidant enzyme activity, and modulation of transcription factors. Cur showcases diverse protective mechanisms against inflammation and oxidative damage by suppressing antiapoptotic genes and impeding tumor promotion. This comprehensive overview emphasizes the potential of Cur as a natural agent for countering aging and degenerative diseases, calling for further dedicated research in this realm.

Emotion recognition and regulation in males: Role of sex and stress steroids

Understanding emotions in males is crucial given their higher susceptibility to substance use, interpersonal violence, and suicide compared to females. Steroid hormones are assumed to be critical biological factors that affect and modulate emotion-related behaviors, together with psychological and social factors. This review explores whether males' abilities to recognize emotions of others and regulate their own emotions are associated with testosterone, cortisol, and their interaction. Higher levels of testosterone were associated with improved recognition and heightened sensitivity to threatening faces. In contrast, higher cortisol levels positively impacted emotion regulation ability. Indirect evidence from neuroimaging research suggested a link between higher testosterone levels and difficulties in cognitive emotion regulation. However, this notion must be investigated in future studies using different emotion regulation strategies and considering social status. The present review contributes to the understanding of how testosterone and cortisol affect psychological well-being and emotional behavior in males.

Longitudinal Assessment of Hair Cortisol as a Predictor of Psychological Symptoms During COVID-19

BACKGROUND

There is a lack of evidence regarding enduring psychoneuroendocrine changes following an initial traumatic event, particular in the presence of an ongoing stressor. The coronavirus pandemic presents an opportunity to explore this matter. Consequently, the purpose of the present study was to investigate the impact of the ongoing pandemic (2021) on individuals, who experienced a first-time motor vehicle crash (MVC) at least 6 years earlier. To this end, we hypothesized that hair cortisol concentrations (HCC) following a first-time traumatic event positively predict symptoms of depression.

METHOD

We investigated N = 69 individuals (18 - 65 yrs.), who were victims of a MVC during 2010 - 2014. Hair strands were collected 10 days (t1) and 3 months after the MVC (t2), as well during the pandemic in 2021 (t3). To assess symptoms of depression, the participants filled out the Beck Depression Inventory at t1 - t3 and were additionally interviewed (Structured Clinical Interview for DSM-IV Axis I) at t1 and t2. Exclusion criteria conveyed a lifetime or acute mental disorder (incl. past trauma exposure).

RESULTS

Elevated pre-pandemic HCC following adversity (i.e., MVC) significantly predicted symptoms of depression in adults during the coronavirus pandemic (BDI: ß =.44, p =.010, R2 =.20), even after controlling for confounders. HCC significantly decreased over time, while in average psychological symptoms remained consistent.

CONCLUSION

Cortisol dysregulation in the past presents an enduring vulnerability to ongoing stress. In this regard, vulnerable groups may benefit from preventive measures. This finding validates the predictive power of HCC and extended past evidence in this regard, at the same time reinforcing the concept of the diathesis-stress model.

Factor structure and psychometric properties of the Perceived Stress Scale in Russian adolescents

This study involved a psychometric analysis of the 10-item Perceived Stress Scale (PSS-10). To investigate the Russian version of the PSS-10 for adolescents, 3530 adolescents aged 13-17 years were recruited. Confirmatory factor analysis revealed that the data corresponded to the expected two-factor configuration. Psychometric properties and factor structure were evaluated. As expected, the PSS-10 included two factors: perceived helplessness and perceived self-efficacy. Internal consistency demonstrated acceptable values (Cronbach's alpha was 0.82 for perceived helplessness, 0.77 for perceived self-efficacy, and 0.80 for the overall PSS score). Measurement invariance across sexes was assessed, and configural and metric invariance were confirmed. The developed diagnostic tool can be used both in the school system to alleviate the negative consequences of academic stress in adolescents and, in the future, in other areas, particularly in clinical practice.

Anxiety and Alzheimer's disease pathogenesis: focus on 5-HT and CRF systems in 3xTg-AD and TgF344-AD animal models

Dementia remains one of the leading causes of morbidity and mortality in older adults. Alzheimer's disease (AD) is the most common type of dementia, affecting over 55 million people worldwide. AD is characterized by distinct neurobiological changes, including amyloid-beta protein deposits and tau neurofibrillary tangles, which cause cognitive decline and subsequent behavioral changes, such as distress, insomnia, depression, and anxiety. Recent literature suggests a strong connection between stress systems and AD progression. This presents a promising direction for future AD research. In this review, two systems involved in regulating stress and AD pathogenesis will be highlighted: serotonin (5-HT) and corticotropin releasing factor (CRF). Throughout the review, we summarize critical findings in the field while discussing common limitations with two animal models (3xTg-AD and TgF344-AD), novel pharmacotherapies, and potential early-intervention treatment options. We conclude by highlighting promising future pharmacotherapies and translational animal models of AD and anxiety.

Changes in hormones, Leukocyte Telomere Length (LTL), and p16INK4a expression in SM-exposed individuals in favor of the cellular senescence

Sulfur mustard (SM) is a chemical warfare agent with well-known severe toxic effects and may cause long-term debilitating injuries. We aimed to evaluate aging and longevity in Iranian SM-exposed survivors using some endocrine and molecular biomarkers for the first time. Dehydroepiandrosterone (DHEA), prolactin (PRL), cortisol, testosterone, and luteinizing hormone (LH) were measured in 289 male SM-veterans and 66 age-matched males using the ELISA method. Leukocyte Telomere Length (LTL) measurement and p16INK4a expression were measured in the peripheral blood leukocytes of 55 males who were exposed to SM. We found a significantly lower serum DHEAS level and higher serum PRL level in SM-exposed groups (without any related to the severity of lung injuries) compared to healthy controls, but no significant difference in serum levels of cortisol, testosterone, and LH. The molar ratio of DHEAS/cortisol was significantly higher in controls compared to the SM-exposed individuals especially those with severe lung damage. Some biological parameters of allostatic load score such as DHEAS and DHEAS/cortisol ratio significantly decreased long-term after the SM exposure. Additionally, we found that LTL was shorter in SM-exposed veterans rather than unexposed controls while p16INK4a gene expression significantly increased in these groups. It seems that DHEAS, DHEAS/cortisol ratio, LTL, and p16INK4a gene expression have changed significantly in favor of cellular senescence in SM-exposed patients. Therefore, it seems that SM exposure increases biological age compared to chronological age in SM-exposed survivors.

Attachment across the lifespan: Examining the intersection of pair bonding neurobiology and healthy aging

Increasing evidence suggests that intact social bonds are protective against age-related morbidity, while bond disruption and social isolation increase the risk for multiple age-related diseases. Social attachments, the enduring, selective bonds formed between individuals, are thus essential to human health. Socially monogamous species like the prairie vole (M. ochrogaster) form long-term pair bonds, allowing us to investigate the mechanisms underlying attachment and the poorly understood connection between social bonds and health. In this review, we explore several potential areas of focus emerging from data in humans and other species associating attachment and healthy aging, and evidence from prairie voles that may clarify this link. We examine gaps in our understanding of social cognition and pair bond behavior. Finally, we discuss physiologic pathways related to pair bonding that promote resilience to the processes of aging and age-related disease. Advances in the development of molecular genetic tools in monogamous species will allow us to bridge the mechanistic gaps presented and identify conserved research and therapeutic targets relevant to human health and aging.

Sex differences in pituitary corticotroph excitability

Stress-related illness represents a major burden on health and society. Sex differences in stress-related disorders are well documented, with women having twice the lifetime rate of depression compared to men and most anxiety disorders. Anterior pituitary corticotrophs are central components of the hypothalamic-pituitary-adrenal (HPA) axis, receiving input from hypothalamic neuropeptides corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP), while regulating glucocorticoid output from the adrenal cortex. The dynamic control of electrical excitability by CRH/AVP and glucocorticoids is critical for corticotroph function; however, whether corticotrophs contribute to sexually differential responses of the HPA axis, which might underlie differences in stress-related disorders, is very poorly understood. Using perforated patch clamp electrophysiology in corticotrophs from mice expressing green fluorescent protein under the control of the Pomc promoter, we characterized basal and secretagogue-evoked excitability. Both male and female corticotrophs show predominantly single-spike action potentials under basal conditions; however, males predominantly display spikes with small-amplitude (<20 mV) afterhyperpolarizations (B-type), whereas females displayed a mixture of B-type spikes and spikes with a large-amplitude (>25 mV) afterhyperpolarization (A-type). In response to CRH, or CRH/AVP, male cells almost exclusively transition to a predominantly pseudo-plateau bursting, whereas only female B-type cells display bursting in response to CRH±AVP. Treatment of male or female corticotrophs with 1 nM estradiol (E2) for 24-72 h has no effect on the proportion of cells with A- or B-type spikes in either sex. However, E2 results in the cessation of CRH-induced bursting in both male and female corticotrophs, which can be partially reversed by adding a BK current using a dynamic clamp. RNA-seq analysis of purified corticotrophs reveals extensive differential gene expression at the transcriptional level, including more than 71 mRNAs encoding ion channel subunits. Interestingly, there is a two-fold lower level (p < 0.01) of BK channel pore-forming subunit (Kcnma1) expression in females compared to males, which may partially explain the decrease in CRH-induced bursting. This study identified sex differences at the level of the anterior pituitary corticotroph ion channel landscape and control of both spontaneous and CRH-evoked excitability. Determining the mechanisms of sex differences of corticotroph and HPA activity at the cellular level could be an important step for better understanding, diagnosing, and treating stress-related disorders.

Age-Related Hormones Changes and Its Impact on Health Status and Lifespan

The increase in life expectancy is accompanied with an increased consultation of age-related pathologies including endocrine disorders. Two main areas are focusing the attention of medical and social research in older population: the diagnosis and care of this heterogeneous population, and the interventional measures potentially useful to mitigate age-related functional declines and to increase health and quality of lifespan. Thus, better understanding the physiopathology of aging and establishing accurate diagnostic and personalized approaches are a priority and currently an unmet need of the medical community. The endocrine system plays a major role in survival and lifespan through regulating vital processes such as energy consumption and optimizing the stress response among others. The aim of this paper is to review the physiological evolution of the main hormonal functions in aging and its clinical translation to improve our approach to the aging patient.

Adult age differences in the psychophysiological response to acute stress

Age-related differences in the psychophysiology of the acute stress response are poorly understood given the limited number of studies and the high heterogeneity of findings. The present study contributes by investigating age differences in both the psychological and physiological responses to acute stress in a sample of healthy younger (N = 50; 18-30; M_age = 23.06; SD = 2.90) and older adults (N = 50; 65-84; M_age = 71.12; SD = 5.02). Specifically, the effects of psychosocial stress (i.e., age-adapted Trier Social Stress Test) were investigated at numerous timepoints throughout the stress response phases (i.e., baseline, anticipation, reactivity, recovery) on cortisol, heart rate, subjective stress, and anticipatory appraisal of the stressful situation. The study was conducted in a between-subject (younger vs. older) cross-over (stress vs. control) design. Results revealed age-related differences in both physiological and psychological variables: older adults had overall lower salivary cortisol levels in the stress and control conditions and lower stress-induced cortisol increase (i.e., AUCi). In addition, older adults' cortisol reactivity was delayed compared to younger adults. Older adults showed a lower heart rate response in the stress condition while no age differences were observed in the control condition. Finally, older adults reported less subjective stress and a less negative stress appraisal during the anticipation phase than younger adults, which could potentially explain lower physiological reactivity in this age group. Results are discussed in relation to the existing literature, potential underlying mechanisms, and future directions for the field.

Cumulative trauma predicts hair cortisol concentrations and symptoms of depression and anxiety in pregnant women-an investigation of community samples from Greece, Spain and Perú

Exposure to traumatic experiences across lifespan shapes the functioning of the hypothalamic pituitary adrenal (HPA) axis and sets individuals at risk to develop symptoms of depression and anxiety. Particularly, HPA axis regulation and the psychological health of the expectant mother have been of interest, as the health of the unborn child may be affected through changes in gestational biology. The present study investigated the potential associations between lifetime trauma, current symptoms (depression and anxiety) and hair cortisol concentrations (HCC) in pregnant women. A total of 149 pregnant women were interviewed in public outpatient clinics with varying gestational age in Greece, Spain and Perú. Lifetime trauma exposure and current symptoms of depression and anxiety were assessed. HCC was measured in scalp-near hair segments (2 cm length) reflecting cumulative cortisol secretion of the past two months. Results showed that trauma load is negatively associated with HCC and higher symptoms of depression and anxiety. There was a negative association between HCC and symptoms. The present findings support the notion that cumulative trauma exposure exerts long-lasting effects on the expectant mother's HPA axis activity functioning and mental health and may thereby potentially create risk trajectories for the unborn child via changes in gestational biology.

Clinical Ageing

Ageing is generally characterised by the declining ability to respond to stress, increasing homeostatic imbalance, and increased risk of ageing-associated diseases . Mechanistically, the lifelong accumulation of a wide range of molecular and cellular impairments leads to organismal senescence. The aging population poses a severe medical concern due to the burden it places on healthcare systems and the general public as well as the prevalence of diseases and impairments associated with old age. In this chapter, we discuss organ failure during ageing as well as ageing of the hypothalamic-pituitary-adrenal axis and drugs that can regulate it. A much-debated subject is about ageing and regeneration. With age, there is a gradual decline in the regenerative properties of most tissues. The goal of regenerative medicine is to restore cells, tissues, and structures that are lost or damaged after disease, injury, or ageing. The question arises as to whether this is due to the intrinsic ageing of stem cells or, rather, to the impairment of stem-cell function in the aged tissue environment. The risk of having a stroke event doubles each decade after the age of 55. Therefore, it is of great interest to develop neurorestorative therapies for stroke which occurs mostly in elderly people. Initial enthusiasm for stimulating restorative processes in the ischaemic brain with cell-based therapies has meanwhile converted into a more balanced view, recognising impediments related to survival, migration, differentiation, and integration of therapeutic cells in the hostile aged brain environment. Therefore, a current lack of understanding of the fate of transplanted cells means that the safety of cell therapy in stroke patients is still unproven. Another issue associated with ischaemic stroke is that patients at risk for these sequels of stroke are not duly diagnosed and treated due to the lack of reliable biomarkers. However, recently neurovascular unit-derived exosomes in response to Stroke and released into serum are new plasma genetic and proteomic biomarkers associated with ischaemic stroke. The second valid option, which is also more economical, is to invest in prevention.

Temperature Extreme Events Decrease Endocrine and Immune Reactive Scope in Bullfrogs (Lithobates catesbeianus)

Currently, effects of increased atmospheric temperature, in the context of ongoing climate change, have been investigated in multiple organisms and levels of biological organization. While there has been a focus on the impacts of increased mean temperature, an emergent and equally important point is the consequences of recurrent exposure to extreme temperature events, simulating heat waves. This study investigated the effects of serial exposure to high temperatures on immune and endocrine variables before and after exposure to an acute secondary stressor in bullfrogs (Lithobates catesbeianus). Adult males were divided into three groups and subjected to three thermal regimes: control (c; constant 22°C); experimental 1 (E1; kept at 22°C and exposed to 4 days of 30°C every 16 days); and experimental 2 (E2; kept at 22°C and exposed to 4 days of 30°C every 6 days). Blood samples were collected on the last day of key extreme heat events. Two weeks after the last extreme heat event, animals were subjected to restraint stress (1 h) and sampled again. Blood samples were used to determine neutrophil: lymphocyte ratio, plasma bacterial killing ability, as well as, corticosterone and plasma testosterone levels. Overall, we found exposure to extreme heat events did not affect immune and endocrine variables over time. Meanwhile, the previous exposure to extreme heat events modulated the responsiveness to restraint. The amplitude of increased corticosterone plasma levels and neutrophil: lymphocyte ratio in response to restraint decreased with the number of previous exposures to extreme heat events. These results suggest that exposure to extreme climatic events has hidden effects on bullfrog's stress response, expressed as diminished reactive scope to a novel stressor. This represents a highly deleterious facet of climate change since diminished responsiveness prevents proper coping with wildlife challenges.

Modulation of Muscarinic Signalling in the Central Nervous System by Steroid Hormones and Neurosteroids

Muscarinic acetylcholine receptors expressed in the central nervous system mediate various functions, including cognition, memory, or reward. Therefore, muscarinic receptors represent potential pharmacological targets for various diseases and conditions, such as Alzheimer's disease, schizophrenia, addiction, epilepsy, or depression. Muscarinic receptors are allosterically modulated by neurosteroids and steroid hormones at physiologically relevant concentrations. In this review, we focus on the modulation of muscarinic receptors by neurosteroids and steroid hormones in the context of diseases and disorders of the central nervous system. Further, we propose the potential use of neuroactive steroids in the development of pharmacotherapeutics for these diseases and conditions.

Forgetful, sad and old: Do vascular cognitive impairment and depression share a common pre-disease network and how is it impacted by ageing?

Vascular cognitive impairment (VCI) and depression frequently coexist in geriatric populations and reciprocally increase disease risks. We assert that a shared pre-disease state of the psycho-immune-neuroendocrine (PINE) network model mechanistically explains bidirectional associations between VCI and depression. Five pathophysiological sub-networks are identified that are shared by VCI and depression: neuroinflammation, kynurenine pathway imbalance, hypothalamic-pituitary-adrenal (HPA) axis overactivity, impaired neurotrophic support and cerebrovascular dysfunction. These do not act independently, and their complex interactions necessitate a systems biology approach to better define disease pathogenesis. The PINE network is already established in the context of non-communicable diseases (NCDs) such as depression, hypertension, atherosclerosis, coronary heart disease and type 2 diabetes mellitus. We build on previous literature to specifically explore mechanistic links between MDD and VCI in the context of PINE pathways and discuss key mechanistic commonalities linking these comorbid conditions and identify a common pre-disease state which precedes transition to VCI and MDD. We expand the model to incorporate bidirectional interactions with biological ageing. Diathesis factors for both VCI and depression feed into this network and the culmination of shared mechanisms (on an ageing substrate) lead to a critical network transition to one or both disease states. A common pre-disease state underlying VCI and depression can provide clinicians a unique opportunity for early risk assessment and intervention in disease development. Establishing the mechanistic elements and systems biology of this network can reveal early warning or predictive biomarkers together with novel therapeutic targets. Integrative studies are recommended to elucidate the dynamic networked biology of VCI and depression over time.

Race moderates the association between adult attachment avoidance and the cortisol awakening response among young sexual minority men

Adult attachment, or the ways in which individuals develop and maintain trusting and loving relationships with peers and romantic partners, has been demonstrated to influence hypothalamic-pituitary-adrenal (HPA) axis functioning among young sexual minority men (YSMM). Theory and preliminary evidence suggest that differences in the lived experiences of White and Black sexual minority young adults may influence the way in which adult attachment influences the HPA-axis functioning. We sought to further this field of inquiry by examining if race moderates the association between adult attachment insecurity (i.e., avoidance and anxiety) and HPA-axis functioning among YSMM. Sixty-three YSMM participated in a 5-day daily diary study in which they completed a baseline survey to assess adult attachment orientation and provided saliva samples 4 times per day over a 5-day period in order to measure cortisol across the day. Three-level hierarchical linear modeling was used to examine the association between adult attachment, the cortisol awakening response (CAR), diurnal cortisol, and the moderating effect of race. We found no main effect of attachment anxiety or avoidance on HPA-axis functioning. However, we found that race moderated the association between adult attachment avoidance and the CAR such that Black YSMM with higher attachment avoidance had a lower CAR as compared to White YSMM. Results suggest that there may be key differences between White and Black YSMM men's lived experiences that should be explored in future research.

Effects of chronic heat stress on the immunophenotyping of lymphocytes in immune organs of growing pigs

This study aimed to investigate the effects of chronic heat stress on the immunophenotyping of lymphocytes in immune organs of growing pigs. A single-factor randomized block design was used, and 15 healthy growing large white barrows (5 litters, 3 pigs/litter) with similar body weight (40.8 kg) were assigned into 3 groups (5 pigs in each group). Groups were: control group (Con, in 23 °C environmental control chamber, fed ad libitum), heat stress group (HS, in 33 °C environmental control chamber, fed ad libitum), and pair-fed group (PF, in 23 °C environmental control chamber, fed diets according to the feed intake of HS group). After a 7-d adaption, the experiment lasted for 21 d. The results showed as follows: (1) activated T cells in the thymus of HS pigs were higher than those in PF pigs (P < 0.05). Monocytes and dendritic cells in the thymus of HS pigs were significantly higher than that in Con and PF pigs (P < 0.05), while the proportions of these 2 lymphocytes in the thymus of Con pigs did not differ from PF pigs (P > 0.05). Compared with Con pigs, the proportion of CD4+ (P < 0.05) and CD8+ T cells (P < 0.10) in the thymus was increased in HS pigs, while the proportion of CD4+ and CD8+ T cells in PF pigs did not differ from Con pigs (P > 0.05). (2) Compared with Con pigs, significantly decreased T cells, increased B cells and monocytes were found in the spleen of pigs exposed to heat stress (P < 0.05); the proportions of these 3 types of lymphocytes were not significantly different between Con and PF pigs (P > 0.05). The proportions of CD4+ T cells and Treg cells in the spleen of pigs exposed to heat stress tended to be lower than those in the Con pigs (P < 0.10). (3) The proportion of lymphocytes in the tonsils of pigs exposed to heat stress did not differ from Con pigs (P > 0.05); compared with PF pigs, the proportion of Treg cells was significantly decreased in HS pigs (P < 0.05). In conclusion, chronic heat stress stimulates the development and maturation of T cells in the pig thymus toward CD4+ and CD8+ T cells and increases the proportion of monocytes and dendritic cells; under the condition of chronic heat stress, the immune response process in the spleen of pigs is enhanced, but chronic heat stress impairs the survival of CD4+ T cells in the spleen.

Oxytocin and oxygen: the evolution of a solution to the ‘stress of life’

Oxytocin (OT) and the OT receptor occupy essential roles in our current understanding of mammalian evolution, survival, sociality and reproduction. This narrative review examines the hypothesis that many functions attributed to OT can be traced back to conditions on early Earth, including challenges associated with managing life in the presence of oxygen and other basic elements, including sulfur. OT regulates oxidative stress and inflammation especially through effects on the mitochondria. A related nonapeptide, vasopressin, as well as molecules in the hypothalamic–pituitary–adrenal axis, including the corticotropin-releasing hormone family of molecules, have a broad set of functions that interact with OT. Interactions among these molecules have roles in the causes and consequence of social behaviour and the management of threat, fear and stress. Here, we discuss emerging evidence suggesting that unique properties of the OT system allowed vertebrates, and especially mammals, to manage over-reactivity to the ‘side effects’ of oxygen, including inflammation, oxidation and free radicals, while also supporting high levels of sociality and a perception of safety.

This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.

Rutland C. Equine Stress: Neuroendocrine Physiology and Pathophysiology

This review presents new aspects to understanding the neuroendocrine regulation of equine stress responses, and their influences on the physiological, pathophysiological, and behavioral processes. Horse management, in essence, is more frequently confirmed by external and internal stress factors, than in other domestic animals. Regardless of the nature of the stimulus, the equine stress response is an effective and highly conservative set of interconnected relationships designed to maintain physiological integrity even in the most challenging circumstances (e.g., orthopedic injuries, abdominal pain, transport, competitions, weaning, surgery, and inflammation). The equine stress response is commonly a complementary homeostatic mechanism that provides protection (not an adaptation) when the body is disturbed or threatened. It activates numerous neural and hormonal networks to optimize metabolic, cardiovascular, musculoskeletal, and immunological functions. This review looks into the various mechanisms involved in stress responses, stress-related diseases, and assessment, prevention or control, and management of these diseases and stress. Stress-related diseases can not only be identified and assessed better, given the latest research and techniques but also prevented or controlled.

Blood hormones and suicidal behaviour: A systematic review and meta-analysis

This study was to evaluate the relationship between blood hormone levels and suicidal behaviour. We reviewed Web of Science, PubMed and Embase for literature published up to 10 April 2022. Studies were restricted to English-language articles. Studies measuring blood hormone levels in suicidal and non-suicidal subjects were eligible. Standardized mean differences (SMDs) were applied to evaluate group differences. Overall, 57 studies were eligible, of which 51 evaluated suicide attempts, and 9 assessed suicidal ideation. Random-effects meta-analysis indicated that levels of thyrotropin stimulating hormone (TSH) (SMD = 0.50; 95% CI, 0.27-0.72), leptin (SMD = -1.16; 95% CI, -1.94 to -0.38) and dehydroepiandrosterone sulfate (DHEAS) (SMD = -0.67; 95% CI, -1.13 to -0.21) were related to suicide attempts, whereas progesterone levels (SMD = 0.22; 95% CI, 0.03-0.41) were related to suicidal ideation. This analysis offers evidence linking abnormalities of blood hormones with suicidal behaviour, which may be essential for identifying individuals with suicide attempts and suicidal ideation. Large prospective studies are needed for further clarification of roles of hormones in suicidal behaviour.

Environmental enrichment and the aging brain: is it time for standardization?

Aging entails a progressive decline of cognitive abilities. However, since the brain is endowed with considerable plasticity, adequate stimulation can delay or partially compensate for age-related structural and functional impairment. Environmental enrichment (EE) has been reported to determine a wide range of cerebral changes. Although most findings have been obtained in young and adult animals, research has recently turned to aged individuals. Notably, EE can contribute identifying key lifestyle factors whose change can help extend the "mind-span", i.e., the time an individual lives in a healthy cognitive condition. Here we discuss specific methodological issues that can affect the outcomes of EE interventions applied to aged rodents, summarize the main variables that would need standardization (e.g., timing and duration, enrichment items, control animals and setting), and offer some suggestions on how this goal may be achieved. Reaching a consensus on EE experiment design would significantly reduce differences between and within laboratories, enable constructive discussions among researchers, and improve data interpretation.

Multiple events case-control study in a prospective cohort to identify systemic, cellular, and molecular biomarkers of obesity-induced accelerated aging in 30-years-olds: the ObAGE study protocol

Background

Aging is characterized by a progressive loss of capacities linked to fundamental alterations/damage in multiple cellular and molecular pathways. It is the most significant risk factor for all non-communicable diseases (NCDs). Another contributing factor to the rise in NCDs is obesity. It has been suggested that obesity not only accelerates the onset of metabolic imbalances but also decreases lifespan and impacts cellular and molecular processes in a manner similar to aging. Obesity might accelerate the pace of aging. Guided by a lifecourse approach, we will explore how exposure to obesity in critical developmental stages disrupt homeostatic resilience mechanisms that preserve physiological integrity, inducing an early expression of aging phenotypes. Also, we will determine whether exposure to early psychosocial adversity influences vulnerability to obesity as a risk factor for accelerated aging.

Methods

Multiple events case–control study embedded in a prospective cohort of Chileans at 30-31y, 50% females, of low- to-middle socioeconomic status, who participated in nutrition research since birth. At 23y, 25% had obesity and cardiometabolic risk was high. We will use a multi-layer approach including: anthropometric assessment; DXA scan for body composition; abdominal ultrasound of the liver; stool samples collection and sequencing of the ribosomal RNA 16S gene to characterize the gut microbiome; determination of age-related pro-inflammatory cytokynes and anti-inflammatory miokynes. For the first time in Chile, we will address age-related epigenetic changes using the Horvath´s epigenetic clock. In a subset we will conduct a controlled physical challenge to characterize physical resilience (autophagy).

Discussion

ObAGE is in an excellent position to: approach aging as a process whose expression involves multiple factors from the early stages of a person's life; understand how longitudinal changes in health trajectories impact the biological mechanisms of aging; identify potential resilience mechanisms that help prevent unhealthy aging. Because SLS participants are still young, our research setting combined with advanced scientific techniques may identify individuals or groups at risk of early onset health issues. Results from ObAGE may pave the way to address the contribution of obesity to aging through lifespan from cells to systems and might be instrumental to developing interventions to improve health span in the Chilean population.

Trial registration

The proposed study does not consider any health care intervention on human participants.

Vitamin D in Osteosarcopenic Obesity

Osteosarcopenic obesity is a unique clinical condition where low bone and muscle mass coexist in individuals with obesity. Alterations in adipose tissue, skeletal muscle and bone are strictly interconnected, and vitamin D plays key roles in several metabolic pathways that are involved in maintaining musculoskeletal health and glucose homeostasis. We reviewed the available literature on mechanisms underlying osteosarcopenic obesity, with a focus on the role of vitamin D in the pathogenesis and treatment of the condition. We found that, although evidence from large observational studies and pre-clinical experiments strongly supports a role of vitamin D deficiency in the pathogenesis of osteosarcopenic obesity, the common belief that vitamin D improves musculoskeletal health lacks solid clinical evidence, as trials specifically aimed at assessing the effects of vitamin D supplementation in patients with osteosarcopenic obesity are not available, and trials that investigated the role of vitamin D on muscle and bone health in other patient populations either showed no or even detrimental effects. We conclude that large observational and interventional studies including individuals with osteosarcopenic obesity representative of different sex, age and race are needed to better define the role of vitamin D in the pathogenesis and treatment of this condition.

An anxious relationship between Autism Spectrum Disorder and Gut Microbiota: A tangled chemistry?

Autism spectrum disorder (ASD) is a serious multifactorial neurodevelopmental disorder often accompanied by strained social communication, repetitive behaviour, immune dysregulation, and gastrointestinal (GI) issues. Recent studies have recorded a link between dysbiosis in the gut microbiota (gm) and the primary stages of ASD. A bidirectional connection (also called microbiota-gut-brain-axis) exchanges information between the gut bacteria and central nervous system. When the homeostasis of the microenvironment of the gut is dysregulated, it causes oxidative stress, affecting neuronal cells and neurotransmitters, thereby causing neurodevelopmental disorders. Studies have confirmed a difference in the constitution of gut bacteria among ASD cases and their controls. Numerous studies on animal models of ASD have shown altered gm and its association with abnormal metabolite profile and altered behaviour phenotype. This process happens due to an abnormal metabolite production in gm, leading to changes in the immune system, especially in ASD. Hence, this review aims to question the current knowledge on gm dysbiosis and its related GI discomforts and ASD behavioural symptoms and shed light on the possible therapeutic approaches available to deal with this situation. Thereby, though it is understood that more research might be needed to prove an association or causal relationship between gm and ASD, therapy with the microbiome may also be considered as an effective strategy to combat this issue.

Neuroprotective and Antioxidant Effects of Riparin I in a Model of Depression Induced by Corticosterone in Female Mice

BACKGROUND

Depression is a common, chronic, and often recurrent serious mood disorder. Conventional antidepressants present limitations that stimulate the search for new drugs. Antioxidant and neuroprotective substances are potential antidepressant agents. In this context, riparin I (RIP I) has presented promising results, emerging as a potential source of a new therapeutic drug. In this study, the antidepressant effect of RIP I was evaluated in an animal model of depression induced by corticosterone (CORT). The involvement of neuroprotective and antioxidant mechanisms in the generation of this effect was also assessed.

METHODS

Female mice were submitted to CORT for 21 days and treated with RIP I in the last 7 days. Behavioral and neurochemical analyses were performed.

RESULTS

The administration of RIP I reversed the depressive and psychotic-like behavior, as well as the cognitive impairment caused by CORT, in addition to regulating oxidative stress parameters and BDNF levels in depression-related brain areas.

CONCLUSION

These findings suggest that RIP I can be a strong candidate for drugs in the treatment of depression.

The Role of OXT, OXTR, AVP, and AVPR1a Gene Expression in the Course of Schizophrenia

Schizophrenia is a serious and chronic mental illness, the symptoms of which usually appear for the first time in late adolescence or early adulthood. To date, much research has been conducted on the etiology of schizophrenia; however, it is still not fully understood. Oxytocin and vasopressin as neuromodulators that regulate social and emotional behavior are promising candidates for determining the vulnerability to schizophrenia. The aim of this study was to evaluate the expression of OXT, OXTR, AVP, and AVPR1a genes at the mRNA and protein levels in patients with schizophrenia. Due to the neurodegenerative nature of schizophrenia, the study group was divided into two subgroups, namely, G1 with a diagnosis that was made between 10 and 15 years after the onset of the illness, and G2 with a diagnosis made up to two years after the onset of the illness. Moreover, the relationship between the examined genes and the severity of schizophrenia symptoms, assessed using PANSS (Positive and Negative Syndrome Scale) and CDSS scales (Clinical Depression Scale for Schizophrenia) was evaluated. The analysis of the expression of the studied genes at the mRNA and protein levels showed statistically significant differences in the expression of all the investigated genes. OXT and AVPR1a gene expression at both the mRNA and protein levels were significantly lower in the schizophrenia group, and OXTR and AVP gene expression at both the mRNA and protein levels was higher in the schizophrenia subjects than in the controls. Furthermore, a significant correlation of OXT gene expression at the mRNA and protein levels with the severity of depressive symptoms in schizophrenia as assessed by CDSS was found.

A MEN1 Patient Presenting With Multiple Parathyroid Adenomas and Transient Hypercortisolism: A Case Report and Literature Review

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary endocrine syndrome caused by mutations in MEN1 tumor suppressor gene.

CASE PRESENTATION

A 53-year-old Chinese female was admitted to Division of Endocrinology, Tongji Hospital, for hypercalcemic crisis. Increased level of parathyroid hormone (PTH) was confirmed by laboratory tests, and imaging examination showed multiple parathyroid adenomas. Based on gene analysis, the patient was diagnosed as MEN1 associated hyperparathyroidism (HPT) by gene analysis with c.1378C>T (p.Arg460Ter) mutation in MEN1 gene. Her condition was complicated by transient hypercortisolism, mammary mass and uterine leiomyoma. After subtotal parathyroidectomy, PTH and serum calcium levels returned to normal.

CONCLUSION

HPT with multiple parathyroid adenomas is an indication of MEN1 gene mutation. Serum cortisol and its circadian rhythm can be abnormal in the presence of hypercalcemia and high PTH. These parameters can return to normal after parathyroidectomy.

Stress research during the COVID-19 pandemic and beyond

The COVID-19 pandemic confronts stress researchers in psychology and neuroscience with unique challenges. Widely used experimental paradigms such as the Trier Social Stress Test feature physical social encounters to induce stress by means of social-evaluative threat. As lockdowns and contact restrictions currently prevent in-person meetings, established stress induction paradigms are often difficult to use. Despite these challenges, stress research is of pivotal importance as the pandemic will likely increase the prevalence of stress-related mental disorders. Therefore, we review recent research trends like virtual reality, pre-recordings and online adaptations regarding their usefulness for established stress induction paradigms. Such approaches are not only crucial for stress research during COVID-19 but will likely stimulate the field far beyond the pandemic. They may facilitate research in new contexts and in homebound or movement-restricted participant groups. Moreover, they allow for new experimental variations that may advance procedures as well as the conceptualization of stress itself. While posing challenges for stress researchers undeniably, the COVID-19 pandemic may evolve into a driving force for progress eventually.

Mental health trajectories of individuals and families following the COVID-19 pandemic: Study protocol of a longitudinal investigation and prevention program

Introduction

Many adults, adolescents and children are suffering from persistent stress symptoms in the face of the COVID-19 pandemic. This study aims to characterize long-term trajectories of mental health and to reduce the transition to manifest mental disorders by means of a stepped care program for indicated prevention.

Methods and analysis

Using a prospective-longitudinal design, we will assess the mental strain of the pandemic using the Patient Health Questionnaire, Strength and Difficulties Questionnaire and Spence Child Anxiety Scale. Hair samples will be collected to assess cortisol as a biological stress marker of the previous months. Additionally, we will implement a stepped-care program with online- and face-to-face-interventions for adults, adolescents, and children. After that we will assess long-term trajectories of mental health at 6, 12, and 24 months follow-up. The primary outcome will be psychological distress (depression, anxiety and somatoform symptoms). Data will be analyzed with general linear model and machine learning. This study will contribute to the understanding of the impact of the COVID-19 pandemic on mental health. The evaluation of the stepped-care program and longitudinal investigation will inform clinicians and mental health stakeholders on populations at risk, disease trajectories and the sufficiency of indicated prevention to ameliorate the mental strain of the pandemic.

Ethics and dissemination

The study is performed according to the Declaration of Helsinki and was approved by the Ethics Committee of the Department of Psychology at the Humboldt Universität zu Berlin (no. 2020-35).

Trial registration number

DRKS00023220.

Characterizing the postnatal hypothalamic-pituitary-adrenal axis response of in utero heat stressed pigs at 10 and 15 weeks of age

In utero heat stress alters postnatal physiological and behavioral stress responses in pigs. However, the mechanisms underlying these alterations have not been determined. The study objective was to characterize the postnatal hypothalamic–pituitary–adrenal axis response of in utero heat-stressed pigs. Pigs were subjected to a dexamethasone suppression test followed by a corticotrophin releasing hormone challenge at 10 and 15 weeks of age. Following the challenge, hypothalamic, pituitary, and adrenal tissues were collected from all pigs for mRNA abundance analyses. At 10 weeks of age, in utero heat-stressed pigs had a reduced (P < 0.05) cortisol response to the corticotrophin releasing hormone challenge versus controls. Additionally, the cortisol response tended to be greater overall (P < 0.10) in 15 versus 10-week-old pigs in response to the dexamethasone suppression test. The cortisol response tended to be reduced overall (P < 0.10) in 15 versus 10-week-old pigs in response to the corticotrophin releasing hormone challenge. Hypothalamic corticotropin releasing hormone mRNA abundance tended to be greater (P < 0.10) in in utero heat-stressed versus control pigs at 15-weeks of age. In summary, in utero heat stress altered some aspects of the hypothalamic–pituitary–adrenal axis related to corticotropin releasing hormone signaling, and age influenced this response.

Complementary Role of Oxytocin and Vasopressin in Cardiovascular Regulation

The neurons secreting oxytocin (OXY) and vasopressin (AVP) are located mainly in the supraoptic, paraventricular, and suprachiasmatic nucleus of the brain. Oxytocinergic and vasopressinergic projections reach several regions of the brain and the spinal cord. Both peptides are released from axons, soma, and dendrites and modulate the excitability of other neuroregulatory pathways. The synthesis and action of OXY and AVP in the peripheral organs (eye, heart, gastrointestinal system) is being investigated. The secretion of OXY and AVP is influenced by changes in body fluid osmolality, blood volume, blood pressure, hypoxia, and stress. Vasopressin interacts with three subtypes of receptors: V1aR, V1bR, and V2R whereas oxytocin activates its own OXTR and V1aR receptors. AVP and OXY receptors are present in several regions of the brain (cortex, hypothalamus, pons, medulla, and cerebellum) and in the peripheral organs (heart, lungs, carotid bodies, kidneys, adrenal glands, pancreas, gastrointestinal tract, ovaries, uterus, thymus). Hypertension, myocardial infarction, and coexisting factors, such as pain and stress, have a significant impact on the secretion of oxytocin and vasopressin and on the expression of their receptors. The inappropriate regulation of oxytocin and vasopressin secretion during ischemia, hypoxia/hypercapnia, inflammation, pain, and stress may play a significant role in the pathogenesis of cardiovascular diseases.

Aging, Social Distancing, and COVID-19 Risk: Who is more Vulnerable and Why?

Perceived social support represents an important predictor of healthy aging. The global COVID-19 pandemic has dramatically changed the face of social relationships and revealed elderly to be particularly vulnerable to the effects of social isolation. Social distancing may represent a double-edged sword for older adults, protecting them against COVID-19 infection while also sacrificing personal interaction and attention at a critical time. Here, we consider the moderating role of social relationships as a potential influence on stress resilience, allostatic load, and vulnerability to infection and adverse health outcomes in the elderly population. Understanding the mechanisms how social support enhances resilience to stress and promotes mental and physical health into old age will enable new preventive strategies. Targeted social interventions may provide effective relief from the impact of COVID-19-related isolation and loneliness. In this regard, a pandemic may also offer a window of opportunity for raising awareness and mobilizing resources for new strategies that help build resilience in our aging population and future generations.

Empowerment, Stress, and Depressive Symptoms Among Female Survivors of Intimate Partner Violence Attending Personal Empowerment Programs

Intimate partner violence (IPV) affects one in three women and can have long-lasting psychological effects, with abuse survivors typically exhibiting elevated stress and depressive symptoms. However, women with greater personal empowerment resources (i.e., self-care, agency, self-efficacy) and who practice relaxation techniques generally exhibit lower stress and depressive symptoms. The present study investigated the effectiveness of Personal Empowerment Programs (PEP) and practicing relaxation techniques in promoting empowerment and lowering stress and depressive symptoms. Ninety women were recruited from PEP classes conducted at domestic violence agencies in Orange County, California. Salivary cortisol and affect were assessed before and after one PEP class. Perceived stress, depressive symptoms, empowerment, and relaxation techniques were also assessed. Practicing relaxation techniques correlated with more empowerment. For women without sexual abuse experiences only, having completed more classes (>5 classes) in the program was associated with greater empowerment, less stress, and fewer depressive symptoms. Implications extend to future studies and interventions for IPV survivors.

Aging-Dependent Downregulation of SUV39H1 Histone Methyltransferase Increases Susceptibility to Stress-Induced Depressive Behavior

Aging induces cellular and molecular changes including gene expression alteration in the brain, which might be associated with aging-induced decrease in stress coping ability. In the present study, we investigate how aging changes the ability to cope with stress and increases sensitivity to stress. Aged mice show decreased expression of SUV39H1 histone methyltransferase and increased expression of Mkp-1 in the hippocampus. The siRNA-mediated knockdown of SUV39H1 increases Mkp-1 expression and suppresses p-CREB and Bdnf expression in HT22 cells and in the hippocampus of mice. Chromatin immunoprecipitation assays indicate that the levels of SUV39H1 and methylated histone-H3 bound to the promoter of the Mkp-1 in the hippocampus are reduced in aged mice. Aged mice exhibit depression-like behavior following weak stress that does not induce depressive behavior in young mice. Rosmarinic acid, a phenolic compound that increases SUV39H1 expression, reverses stress-induced changes of SUV39H1, Mkp-1, and Bdnf expression in the hippocampus via an overlapping but distinct mechanism from those of fluoxetine and imipramine and produces anti-depressive effects. These results suggest that aging increases susceptibility to stress via downregulation of SUV39H1 and resulting changes in SUV39H1-regulated signaling pathways in the hippocampus.

Stress and Loss of Ovarian Function: Novel Insights into the Origins of Sex-Based Differences in the Manifestations of Respiratory Control Disorders During Sleep

The respiratory system of women and men develops and functions in distinct neuroendocrine milieus. Despite differences in anatomy and neural control, homeostasis of arterial blood gases is ensured in healthy individuals regardless of sex. This convergence in function differs from the sex-based differences observed in many respiratory diseases. Sleep-disordered breathing (SDB) results mainly from episodes of upper airway closure. This complex and multifactorial respiratory disorder shows significant sexual dimorphism in its clinical manifestations and comorbidities. Guided by recent progress from basic research, this review discusses the hypothesis that stress is necessary to reveal the sexual dimorphism of SDB.

Effects of CRH and ACTH exposure during in vitro maturation on competence of pig and mouse oocytes

Although it is known that stresses on females damage oocytes with increased production of stress hormones, whether corticotrophin-releasing hormone (CRH) or adrenocorticotropic hormone (ACTH) harm oocytes directly are largely unknown. We demonstrated that CRH exposure during in vitro maturation impaired competence of both pig and mouse cumulus-oocyte-complexes (COCs), and it impaired competence and induced apoptosis in pig cumulus-denuded oocytes (DOs) but not in mouse DOs. CRH receptor 1 was expressed in pig DOs and in cumulus cells (CCs) of both species but not in mouse DOs. In the presence of CRH, whereas mouse CCs underwent apoptosis, pig CCs did not. While pig CCs did, mouse CCs did not express CRH-binding protein. ACTH did not affect competence of either pig or mouse COCs or DOs although they all expressed ACTH receptor. Both pig and mouse CCs expressed steroidogenic acute regulatory protein (StAR), and ACTH enhanced their progesterone production while alleviating their apoptosis. Neither pig nor mouse DOs expressed StAR, but ACTH inhibited maturation-promoting factor and decelerated meiotic progression of DOs suggesting activation of protein kinase A (PKA). In conclusion, CRH impaired pig and mouse oocyte competence by interacting with CRH receptor and inducing CCs apoptosis, respectively. ACTH activated PKA in both DOs and CCs although it showed no effect on oocyte competence.

Glucocorticoid-Dependent Mechanisms of Brain Tolerance to Hypoxia

Adaptation of organisms to stressors is coordinated by the hypothalamic-pituitary-adrenal axis (HPA), which involves glucocorticoids (GCs) and glucocorticoid receptors (GRs). Although the effects of GCs are well characterized, their impact on brain adaptation to hypoxia/ischemia is still understudied. The brain is not only the most susceptible to hypoxic injury, but also vulnerable to GC-induced damage, which makes studying the mechanisms of brain hypoxic tolerance and resistance to stress-related elevation of GCs of great importance. Cross-talk between the molecular mechanisms activated in neuronal cells by hypoxia and GCs provides a platform for developing the most effective and safe means for prevention and treatment of hypoxia-induced brain damage, including hypoxic pre- and post-conditioning. Taking into account that hypoxia- and GC-induced reprogramming significantly affects the development of organisms during embryogenesis, studies of the effects of prenatal and neonatal hypoxia on health in later life are of particular interest. This mini review discusses the accumulated data on the dynamics of the HPA activation in injurious and non-injurious hypoxia, the role of the brain GRs in these processes, interaction of GCs and hypoxia-inducible factor HIF-1, as well as cross-talk between GC and hypoxic signaling. It also identifies underdeveloped areas and suggests directions for further prospective studies.

Individual-Level Interventions for Decreasing Job-Related Stress and Enhancing Coping Strategies Among Nurses: A Systematic Review

Background: Nurses are facing unprecedented amounts of pressure because of the ongoing global health challenges. Improving nurses' resilience to job-related stress and enhancing their strategies to cope effectively with stressors are key issues facing many health care institutions during the COVID-19 pandemic. This literature review aimed to: a) provide a thorough overview of individual-level interventions for stress management among nurses, b) identify measurement tools utilized to evaluate nurses' stress level, and c) provide the best evidence-based recommendations for future research and practice adapted to the current restrictions. Design: Systematic review. Data Sources: Studies published between January 2000 and October 2020 were retrieved from the following sources: EBSCOhost, Dortmund University Library, PubMed, Medline, Google Scholar, Applied Nursing Research, and reference lists from relevant articles. Review methods: Individual-level interventions with a control group or a placebo intervention were included in the final sample. Primary outcome was defined as a change in individual stress level or stress symptoms which were measured by objective or subjective instruments with evidence of validity. Articles published in English or German were included in the present review. Results: In total, 27 relevant studies were included into the current review. There are some indications that technology-delivered interventions with relaxation and stress management interventions comprising cognitive-behavioral components might be effective in decreasing stress among nurses and improving their well-being. Furthermore, although there were some attempts to collect objectively measured parameters for assessing the primary outcome of stress, the majority of the interventions utilized self-reported stress scales. Conclusion: A wide range of interventions are available for nurses. However, it is of utmost importance to develop and implement stress management programs that are conveniently accessible in the workplace and above all, meet the current restrictions for minimizing human contacts. To this end, innovative interventions delivered through digital technology, such as virtual reality, seem to be a promising solution for combating the detrimental impact of stress on nurses. Special attention should be also paid to applying standardized objective measurement tools to allow the assessment of sensitive physiological indices and the generalizability of scientific knowledge.

Neuropeptides of the human magnocellular hypothalamus

Hypothalamic magnocellular nuclei with their large secretory neurons are unique and phylogenetically conserved brain structures involved in the continual regulation of important homeostatic and autonomous functions in vertebrate species. Both canonical and newly identified neuropeptides have a broad spectrum of physiological activity at the hypothalamic neuronal circuit level located within the supraoptic (SON) and paraventricular (PVN) nuclei. Magnocellular neurons express a variety of receptors for neuropeptides and neurotransmitters and therefore receive numerous excitatory and inhibitory inputs from important subcortical neural areas such as limbic and brainstem populations. These unique cells are also densely innervated by axons from other hypothalamic nuclei. The vast majority of neurochemical maps pertain to animal models, mainly the rodent hypothalamus, however accumulating preliminary anatomical structural studies have revealed the presence and distribution of several neuropeptides in the human magnocellular nuclei. This review presents a novel and comprehensive evidence based evaluation of neuropeptide expression in the human SON and PVN. Collectively this review aims to cast a new, medically oriented light on hypothalamic neuroanatomy and contribute to a better understanding of the mechanisms responsible for neuropeptide-related physiology and the nature of possible neuroendocrinal interactions between local regulatory pathways.

The Long-Term Public Health Impact of Social Distancing on Brain Health: Topical Review

Social distancing has been a critical public health measure for the COVID-19 pandemic, yet a long history of research strongly suggests that loneliness and social isolation play a major role in several cognitive health issues. What is the true severity and extent of risks involved and what are potential approaches to balance these competing risks? This review aimed to summarize the neurological context of social isolation and loneliness in population health and the long-term effects of social distancing as it relates to neurocognitive aging, health, and Alzheimer's disease and related dementias. The full scope of the underlying causal mechanisms of social isolation and loneliness in humans remains unclear partly because its study is not amenable to randomized controlled trials; however, there are many detailed experimental and observational studies that may provide a hypothesis-generating theoretical framework to better understand the pathophysiology and underlying neurobiology. To address these challenges and inform future studies, we conducted a topical review of extant literature investigating associations of social isolation and loneliness with relevant biological, cognitive, and psychosocial outcomes, and provide recommendations on how to approach the need to fill key knowledge gaps in this important area of research.

Differential stress response to psychological and physical stressors in children using spatial versus response-dependent navigation strategies

Previous work from our lab has shown that basal cortisol levels are different between healthy young adults who spontaneously use caudate nucleus-dependent response strategies compared to young adults who use hippocampus-dependent spatial navigation strategies. Young adults who use caudate nucleus dependent strategies display lower basal cortisol levels compared to those who use hippocampus-dependent strategies. In the current study, we assessed navigation strategies in children using a virtual navigation task and measured cortisol at baseline as well as cortisol reactivity to both a psychological and to a physical stressor. Replicating what is observed in adults, we found that children who used caudate nucleus-dependent navigation strategies displayed lower cortisol levels at baseline compared to those who used hippocampus-dependent strategies. The psychological stressor, knowledge that a blood draw would be performed by a nurse, caused a significant increase in cortisol uniquely in response learners. The physical stressor, the actual blood draw, produced a significant increase in cortisol amongst spatial learners that was then comparable to levels observed in response learners. Lower baseline cortisol and higher cortisol psychological stress response observed amongst children who used response strategies may therefore reflect early biological changes during development which may have an impact later in life when considering risk for neuropsychiatric disorders.

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Both adults and children rely of different navigation strategies to learn new environments.

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Cortisol levels differ between people dependent on spontaneous navigation strategy.

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We show a differential cortisol stress response in children dependent on navigational strategy.

Hypothalamic aging and hormones

It is the heterogeneous changes of hypothalamic functions that determine the chronological sequence of aging in mammals. Recently, it was hypothesized by Cai the decrease in slow-wave sleep (SWS) resulting from skin aging as responsible for the degeneration of hypothalamic suprachiasmatic nucleus (SCN). It was soon hypothesized by the European people in television that the increase in body fat as responsible for the degeneration of male preoptic sexually dimorphic nucleus (SDN-POA), via the aromatase converting testosterone to estradiol as proposed by Cohen. It is the hypothalamic paraventricular nucleus (PVN) that remains unchanged in neuron number during aging for psychological stress. In this chapter, it is briefly reviewed more manifestations of hypothalamic related mammalian aging processes, including (1) the aging of ovary by lipid, estradiol and hypothalamus; (2) the aging of muscle, stomach, intestine, thymus, and the later aging of brain, regulated by growth hormone/insulin-like growth factor 1(GH/IGF1); (3) the cardiovascular hypertension from PVN activation, the bone and other peripheral aging by psychological stress, and that of kidney by vasopressin. It is classified these aging processes by the primary regulation from one of the three hypothalamic nuclei, although still necessary to investigate and supplement their secondary regulation by the hypothalamic nuclei in future. It is the hypothalamic structural changes that shift the functional balance among these three hypothalamic systems toward aging.

Gut microbiota in dementia. Critical review of novel findings and their potential application

There is a great deal of impetus for the comprehensive understanding of the complete pathological function, genetic information, and functional diversity of the gut microbiota that favors the development of dementia. It has been reported that patients with mild cognitive impairment and Alzheimer's disease present with several metabolic and immune-inflammatory alterations. The recently highlighted aspects of human health linked to cognitive decline include insulin-resistance, obesity, and chronic low-grade inflammation. Gut microbiota is known to produce neurotransmitters, such as GABA, acetylcholine, dopamine or serotonin, vitamins, intestinal toxins, and modulate nerve signaling - with emphasis on the vagus nerve. Additionally, gut dysbiosis results in impaired synthesis of signaling proteins affecting metabolic processes relevant to the development of Alzheimer's disease. Due to numerous links of gut microbiota to crucial metabolic and inflammatory pathways, attempts aimed at correcting the gut microflora composition may affect dementia pathology in a pleiotropic manner. Taking advantage of the metabolic effects of cold exposure on organisms by the introduction of whole-body cryostimulation in dementia patients could lead to alterations in gut microbiota and, therefore, decrease of an inflammatory response and insulin resistance, which remain one of the critical metabolic features of dementia. Further studies are needed in order to explore the potential application of recent findings and ways of achieving the desired goals.

The supraoptic and paraventricular nuclei in healthy aging and neurodegeneration

The supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus undergo structural and functional changes over the course of healthy aging. These nuclei and their connections are also heterogeneously affected by several different neurodegenerative diseases. This chapter reviews the involvement of the SON and PVN, the hypothalamic-pituitary axes, and the peptide hormones produced in both nuclei in healthy aging and in neurodegeneration, with a focus on Alzheimer's disease (AD), frontotemporal dementia (FTD), amyotrophic lateral sclerosis, progressive supranuclear palsy, Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy, and Huntington's disease. Although age-related changes occur in several regions of the hypothalamus, the SON and PVN are relatively preserved during aging and in many neurodegenerative disorders. With aging, these nuclei do undergo some sexually dimorphic changes including changes in size and levels of vasopressin and corticotropin-releasing hormone, likely due to age-related changes in sex hormones. In contrast, oxytocinergic cells and circulating levels of thyrotropin-releasing hormone remain stable. A relative resistance to many forms of neurodegenerative pathology is also observed, in comparison to other hypothalamic and brain regions. Mirroring the pattern observed in aging, pathologic hallmarks of AD, and some subtypes of FTD are observed in the PVN, though to a milder degree than are observed in other brain regions, while the SON is relatively spared. In contrast, the SON appears more vulnerable to alpha-synuclein pathology of DLB and PD. The consequences of these alterations may help to inform several of the physiologic changes observed in aging and neurodegenerative disease.

Interplay between hormones and exercise on hippocampal plasticity across the lifespan

The hippocampus is a brain structure known to play a central role in cognitive function (namely learning and memory) as well as mood regulation and affective behaviors due in part to its ability to undergo structural and functional changes in response to intrinsic and extrinsic stimuli. While structural changes are achieved through modulation of hippocampal neurogenesis as well as alterations in dendritic morphology and spine remodeling, functional (i.e., synaptic) changes can be noted through the strengthening (i.e., long-term potentiation) or weakening (i.e., long-term depression) of the synapses. While age, hormone homeostasis, and levels of physical activity are some of the factors known to module these forms of hippocampal plasticity, the exact mechanisms through which these factors interact with each other at a given moment in time are not completely understood. It is well known that hormonal levels vary throughout the lifespan of an individual and it is also known that physical exercise can impact hormonal homeostasis. Thus, it is reasonable to speculate that hormone modulation might be one of the various mechanisms through which physical exercise differently impacts hippocampal plasticity throughout distinct periods of an individual's life. The present review summarizes the potential relationship between physical exercise and different types of hormones (namely sex, metabolic, and stress hormones) and how this relationship may mediate the effects of physical activity during three distinct life periods, adolescence, adulthood, and senescence. Overall, the vast majority of studies support a beneficial role of exercise in maintaining hippocampal hormonal levels and consequently, hippocampal plasticity, cognition, and mood regulation.

In Silico Studies on Anti-Stress Compounds of Ethanolic Root Extract of Hemidesmus indicus L

BACKGROUND

Alternative medicine is available for those diseases which cannot be treated by conventional medicine. Ayurveda and herbal medicines are important alternative methods in which the treatment is done with extracts of different medicinal plants. This work is concerned with the evaluation of anti-stress bioactive compounds from the ethanolic root extract of Hemidesmus indicus.

METHODS

Gas chromatography and Mass Spectrum studies are used to identify the compounds present in the ethanolic extract based on the retention time, area. In order to perform docking studies, Vasopressin model is generated using modeling by Modeller 9v7. Vasopressin structure is developed based on the crystal structure of neurophysin-oxytocin from Bos taurus (PDB ID: 1NPO_A) collected from the PDB data bank. Using molecular dynamics simulation methods, the final predicted structure is obtained and further analyzed by verifying 3D and PROCHECK programs, confirmed that the final model is reliable. The identified compounds are docked to vasopressin for the prediction of anti-stress activity using GOLD 3.0.1 software.

RESULTS

The predicted model of Vasopressin structure is stabilized and confirmed that it is a reliable structure for docking studies. The results indicated ARG4, THR7, ASP9, ASP26, ALA32, ALA 80 in Vasopressin are important determinant residues in binding as they have strong hydrogen bonding with phytocompounds. Among the 21 phytocompounds identified and docked, molecule Deoxiinositol, pentakis- O-(trimethylsilyl) showed the best docking results with Vasopressin.

CONCLUSION

The identified compounds were used for anti-stress activity by insilico method with Vasopressin which plays an important role in causing stress and hence selected for inhibitory studies with phytocompounds. The phytocompounds are inhibiting vasopressin through hydrogen bodings and are important in protein-ligand interactions. Docking results showed that out of twenty-one compounds, Deoxiinositol, pentakis-O-(trimethylsilyl) showed best docking energy to the Vasopressin.