Immune modulation of the hypothalamic-pituitary-adrenal (HPA) axis during viral infection

The association between hair cortisol and burnout is moderated by age, psychosocial, and immunological markers

Background

Exhaustion and depersonalization are the core symptoms of the occupational burnout. However, burnout is not an all-or-nothing phenomenon, but can occur in a milder to moderate form in otherwise healthy employees. In the last two decades hair cortisol concentrations (HCC) were increasingly related to the cumulative effect of psychosocial stress at work. We analyzed data of the Dortmund Vital Study (Clinicaltrials.gov: NCT05155397) to explore the relationship of HCC and burnout symptoms. Moreover, we asked whether the HCC - burnout association was moderated by work ability, chronic stress, neuroticism, depressive symptoms, and stress-related immunological biomarkers such as T cell concentration, CD4/CD8 cell ratio, and proinflammatory cytokines TNF- α, IL-6, and IL-18.

Methods

Burnout was assessed by the Oldenburg Burnout Inventory (OLBI), and the Maslach Burnout Inventory (MBI-D) in 196 working adults aged between 20 and 65 years (mean age 42.2 years). Several self-reported variables and biomarkers were collected.

Results

The results showed an association between HCC and the burnout measures. A series of moderator analyses revealed that the association between HCC and burnout symptoms was substantial for low work ability, high chronic stress level, high neuroticism level, and mild to moderate depressive symptoms. Immunological markers moderated the HCC - burnout association for high concentrations of T cells, low CD4/CD8 ratio and low IL-6, IL-18 and TNF-α concentrations. These interactions were moderated by age showing the largest impact in middle-aged to older individuals.

Conclusions

The present findings shed light on the complex interaction between burnout symptoms and work ability, chronic stress, personality, and the endocrinological and immunological responses across the working lifespan. These parameters should be considered when assessing the risk for developing burnout and validating the diagnosis of burnout.

Trial registration

ClinicalTrials.gov NCT05155397; https://clinicaltrials.gov/ct2/show/NCT05155397.

Traumatic brain injury: Symptoms to systems in the 21st century

Severe traumatic brain injury (TBI) is a devastating injury with a mortality of ∼ 25-30 %. Despite decades of high-quality research, no drug therapy has reduced mortality. Why is this so? We argue two contributing factors for the lack of effective drug therapies include the use of specific-pathogen free (SPF) animals for translational research and the flawed practice of single-nodal targeting for drug design. A revolution is required to better understand how the whole body responds to TBI, identify new markers of its progression, and discover new system-acting drugs to treat it. In this review, we present a brief history of TBI, discuss its system's pathophysiology and propose a new research strategy for the 21st century. TBI progression develops from injury signals radiating from the primary impact, which can cause local ischemia, hemorrhage, excitotoxicity, cellular depolarization, immune dysfunction, sympathetic hyperactivity, blood-brain barrier breach, coagulopathy and whole-body dysfunction. Metabolic reprograming of immune cells drives neuroinflammation and secondary injury processes. We propose if sympathetic hyperactivity and immune cell activation can be corrected early, cardiovascular function and endothelial-glycocalyx-mitochondrial coupling can be restored, and secondary injury minimized with improved patient outcomes. The therapeutic goal is to switch the injury phenotype to a healing phenotype by restoring homeostasis and maintaining sufficient tissue O2 delivery. We have been developing a small-volume fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat TBI and have shown that it blunts the CNS-stress response, supports cardiovascular function and reduces secondary injury. Future research will investigate its suitability for human translation.

Mechanisms behind the high mortality rate in chronic Chagas cardiomyopathy: Unmasking a three-headed monster

Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Chronic Chagas cardiomyopathy (CCC), the most severe form of target organ involvement in Chagas disease, is characterized by a complex pathophysiology and a unique phenotype that differentiates it from other cardiomyopathies, highlighting its worse prognosis compared to other aetiologies of heart failure. The three pathophysiological mechanisms with the largest impact on this differential mortality include rapidly progressive heart failure, a high incidence of stroke, and a high burden of ventricular arrhythmias. However, despite significant advances in understanding the unique molecular circuits underlying these mechanisms, the new knowledge acquired has not been efficiently translated into specific diagnostic and therapeutic approaches for this unique cardiomyopathy. The lack of dedicated clinical trials and the limited CCC-specific risk stratification tools available are evidence of this reality. This review aims to provide an updated perspective of the evidence and pathophysiological mechanisms associated with the higher mortality observed in CCC compared to other cardiomyopathies and highlight opportunities in the diagnostic and therapeutic approaches of the disease.

A Glucocorticoid-Mediated Immunoregulatory Circuit Integrated at Brain Levels: Our Early Studies and a Present View

BACKGROUND

It was known since the 1940s that pharmacological administration of glucocorticoids can inhibit inflammatory and immune processes, and these hormones are still today among the most widely used therapeutic tools to treat diseases with immune components. However, it became clear later that endogenous glucocorticoids can either support or restrain immune processes.

SUMMARY

Early studies showed that (a) endogenous levels of glucocorticoids can modulate immune cell activity; (b) the immune response itself can stimulate the hypothalamus-pituitary-adrenal (HPA) axis to release glucocorticoids to levels that can exert immunoregulatory effects; (c) immune products, later identified as cytokines, mediate this effect. On these bases, the existence of a glucocorticoid-mediated immunoregulatory circuit was proposed. It was also shown that increased levels of endogenous glucocorticoids exert protective effects during infections and other diseases with immune components. However, it was found in animal models and in humans that these effects can be blunted in several immune-linked diseases by defects at several levels, for example, by glucocorticoid resistance or by adrenal insufficiency. Evidence was later provided that the glucocorticoid-mediated immunoregulatory circuit can also be activated by cytokines produced not only as consequence of immune stimulation but also following psycho/sensorial and physical stimuli. Thus, this circuit can be integrated at brain levels and, besides stimulating the HPA axis, cytokines can also affect synaptic plasticity, most likely via a tripartite synapse, with astrocytes as neuro-immune cells acting as the third component.

KEY MESSAGES

It is now well established that the glucocorticoid-mediated immunoregulatory circuit plays a central role in maintaining health. However, several variables can condition the efficacy of the effect of endogenous glucocorticoids. Furthermore, since cytokines and other immune products have many other neuroendocrine and metabolic effects, other neuroendocrine-immune circuits could simultaneously operate or become predominant during different pathologies. The consideration of these aspects might help to implement strategies to eventually decrease therapeutic doses of exogenous glucocorticoids.

Prenatal depression outcomes in the next generation: A critical review of recent DOHaD studies and recommendations for future research

Prenatal depression, a common pregnancy-related risk with a prevalence of 10-20 %, may affect in utero development and socioemotional and neurodevelopmental outcomes in the next generation. Although there is a growing body of work that suggests prenatal depression has an independent and long-lasting effect on offspring outcomes, important questions remain, and findings often do not converge. The present review examines work carried out in the last decade, with an emphasis on studies focusing on mechanisms and leveraging innovative technologies and study designs to fill in gaps in research. Overall, the past decade of research continues to suggest that prenatal depression increases risk for offspring socioemotional problems and may alter early brain development by affecting maternal-fetal physiology during pregnancy. However, important limitations remain; lack of diversity in study samples, inconsistent consideration of potential confounders (e.g., genetics, postnatal depression, parenting), and restriction of examination to narrow time windows and single exposures. On the other hand, exciting work has begun uncovering potential mechanisms underlying transmission, including alterations in mitochondria functioning, epigenetics, and the prenatal microbiome. We review the evidence to date, identify limitations, and suggest strategies for the next decade of research to detect mechanisms as well as sources of plasticity and resilience to ensure this work translates into meaningful, actionable science that improves the lives of families.

Implications of Dysnatremia and Endocrine Disturbances in COVID-19 Patients

Sodium imbalance is a common electrolyte disturbance in COVID-19, often linked to disruptions in hormonal regulation. This review explores the relationship between sodium dysregulation and endocrine disturbances, particularly focusing on primary and secondary hypothyroidism, hypocortisolism, and the renin-angiotensin-aldosterone system (RAAS). Hypocortisolism in COVID-19, due to adrenal insufficiency or secondary to pituitary dysfunction, can lead to hyponatremia through inadequate cortisol levels, which impair renal free water excretion and enhance antidiuretic hormone (ADH) secretion. Similarly, hypothyroidism is associated with decreased renal blood flow and the glomerular filtration rate (GFR), which also increases ADH activity, leading to water retention and dilutional hyponatremia. Furthermore, COVID-19 can disrupt RAAS (primarily through its interaction with the angiotensin-converting enzyme 2 (ACE2) receptor), diminishing aldosterone secretion and further contributing to sodium loss and hyponatremia. These hormonal disruptions suggest that sodium imbalance in COVID-19 is multifactorial and warrants further investigation into the complex interplay between COVID-19, endocrine function, and sodium homeostasis. Future research should focus on understanding these mechanisms to develop management algorithms that address both sodium imbalance and underlying hormonal disturbances in order to improve prognosis and outcomes in COVID-19 patients.

The immunology of sickness metabolism

Everyone knows that an infection can make you feel sick. Although we perceive infection-induced changes in metabolism as a pathology, they are a part of a carefully regulated process that depends on tissue-specific interactions between the immune system and organs involved in the regulation of systemic homeostasis. Immune-mediated changes in homeostatic parameters lead to altered production and uptake of nutrients in circulation, which modifies the metabolic rate of key organs. This is what we experience as being sick. The purpose of sickness metabolism is to generate a metabolic environment in which the body is optimally able to fight infection while denying vital nutrients for the replication of pathogens. Sickness metabolism depends on tissue-specific immune cells, which mediate responses tailored to the nature and magnitude of the threat. As an infection increases in severity, so do the number and type of immune cells involved and the level to which organs are affected, which dictates the degree to which we feel sick. Interestingly, many alterations associated with metabolic disease appear to overlap with immune-mediated changes observed following infection. Targeting processes involving tissue-specific interactions between activated immune cells and metabolic organs therefore holds great potential for treating both people with severe infection and those with metabolic disease. In this review, we will discuss how the immune system communicates in situ with organs involved in the regulation of homeostasis and how this communication is impacted by infection.

Recurrent COVID-19-related psychotic disorder with neuro-immuno-endocrine dysfunction as a possible underlying mechanism: A case report from China

Background

SARS-CoV-2, first identified in Wuhan, China, in December 2019, has been gradually spreading worldwide since 2020. The relationship between SARS-CoV-2 infection and psychotic disorders has received much attention, and several studies have described the direct/indirect mechanisms of its effects on the brain, but no mechanism has been found to explain recurrent episodes of COVID-19-related psychotic symptoms.

Case

We report the case of an 18-year-old female patient with no family or personal psychotic disorder history with multiple hospital admissions with symptoms such as disorganized speech and behavior, hyperactivity, restlessness, and impulsive aggression during the COVID-19 recovery period. Relevant tests revealed longitudinal changes such as persistent IL-6 and IL-10 elevation, abnormal discharges on EEG, and brain and hippocampal MRI abnormal signals. The patient was treated with antipsychotics, MECT, combination therapy of hormones and antivirals, then discharged after multiple treatment rounds.

Conclusion

The case presented here outlines the possibility that the COVID-19 recovery period may be a critical period for acute psychotic episodes and that the patient's recurrent psychotic symptoms may be associated with neuro-immuno-endocrine dysfunction mediated by sustained cytokine synthesis, further causing structural and functional brain damage. Routine psychiatric evaluation and related screening should be performed at all stages of the illness to better identify, prevent, and effectively intervene in psychiatric disorders following COVID-19. Because many outcomes require long-term assessment, a clearer understanding of the impact of the COVID-19 epidemic on mental health is likely to emerge in the future.

Electrical stimulation of the dorsal motor nucleus of the vagus in male mice can regulate inflammation without affecting the heart rate

BACKGROUND

The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN), as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications. However, the anti-inflammatory effectiveness of electrical stimulation of the DMN (eDMNS) and the possible heart rate (HR) alterations associated with this approach have not been investigated. Here, we examined the effects of eDMNS on HR and cytokine levels in mice administered with lipopolysaccharide (LPS, endotoxin) and in mice subjected to cecal ligation and puncture (CLP) sepsis.

METHODS

Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (500, 250 or 50 μA at 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 μA or 50 μA was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24 h after CLP. CLP survival was monitored for 14 days.

RESULTS

Either left or right eDMNS at 500 μA and 250 μA decreased HR, compared with baseline pre-stimulation. This effect was not observed at 50 μA. Left side eDMNS at 50 μA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and was not associated with serum corticosterone alterations. Right side eDMNS in endotoxemic mice suppressed serum TNF and increased serum IL-10 levels but had no effects on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice.

CONCLUSIONS

For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation. These eDMNS anti-inflammatory effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.

Dynamic stress- and inflammatory-based regulation of psychiatric risk loci in human neurons

The prenatal environment can alter neurodevelopmental and clinical trajectories, markedly increasing risk for psychiatric disorders in childhood and adolescence. To understand if and how fetal exposures to stress and inflammation exacerbate manifestation of genetic risk for complex brain disorders, we report a large-scale context-dependent massively parallel reporter assay (MPRA) in human neurons designed to catalogue genotype x environment (GxE) interactions. Across 240 genome-wide association study (GWAS) loci linked to ten brain traits/disorders, the impact of hydrocortisone, interleukin 6, and interferon alpha on transcriptional activity is empirically evaluated in human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons. Of ~3,500 candidate regulatory risk elements (CREs), 11% of variants are active at baseline, whereas cue-specific CRE regulatory activity range from a high of 23% (hydrocortisone) to a low of 6% (IL-6). Cue-specific regulatory activity is driven, at least in part, by differences in transcription factor binding activity, the gene targets of which show unique enrichments for brain disorders as well as co-morbid metabolic and immune syndromes. The dynamic nature of genetic regulation informs the influence of environmental factors, reveals a mechanism underlying pleiotropy and variable penetrance, and identifies specific risk variants that confer greater disorder susceptibility after exposure to stress or inflammation. Understanding neurodevelopmental GxE interactions will inform mental health trajectories and uncover novel targets for therapeutic intervention.

Rotavirus Sickness Symptoms: Manifestations of Defensive Responses from the Brain

Rotavirus is infamous for being extremely contagious and for causing diarrhea and vomiting in infants. However, the symptomology is far more complex than what could be expected from a pathogen restricted to the boundaries of the small intestines. Other rotavirus sickness symptoms like fever, fatigue, sleepiness, stress, and loss of appetite have been clinically established for decades but remain poorly studied. A growing body of evidence in recent years has strengthened the idea that the evolutionarily preserved defensive responses that cause rotavirus sickness symptoms are more than just passive consequences of illness and rather likely to be coordinated events from the central nervous system (CNS), with the aim of maximizing the survival of the individual as well as the collective group. In this review, we discuss both established and plausible mechanisms of different rotavirus sickness symptoms as a series of CNS responses coordinated from the brain. We also consider the protective and the harmful nature of these events and highlight the need for further and deeper studies on rotavirus etiology.

Sports and Immunity, from the recreational to the elite athlete

The pivotal role of the immune system in physical activity is well-established. While interactions are complex, they tend to constitute discrete immune responses. Moderate intensity exercise causes leukocytosis with a mild anti-inflammatory cytokine profile and immunoenhancement. Above a threshold of intensity, lactate-mediated IL-6 release causes a proinflammatory state followed by a depressed inflammatory state, which stimulates immune adaptation and longer term cardiometabolic enhancement. Exercise-related immune responses are modulated by sex, age and immunonutrition. At all ability levels, these factors collectively affect the immune balance between enhancement or overload and dysfunction. Excessive training, mental stress or insufficient recovery risks immune cell exhaustion and hypothalamic pituitary axis (HPA) stress responses causing immunodepression with negative impacts on performance or general health. Participation in sport provides additional immune benefits in terms of ensuring regularity, social inclusion, mental well-being and healthier life choices in terms of diet and reduced smoking and alcohol, thereby consolidating healthy lifestyles and longer term health. Significant differences exist between recreational and professional athletes in terms of inherent characteristics, training resilience and additional stresses arising from competition schedules, travel-related infections and stress. Exercise immunology examines the central role of immunity in exercise physiology and straddles multiple disciplines ranging from neuroendocrinology to nutrition and genetics, with the aim of guiding athletes to train optimally and safely. This review provides a brief outline of the main interactions of immunity and exercise, some influencing factors, and current guidance on maintaining immune health.

Is membrane androgen and estrogen receptor signaling imperative in the governing function of the adrenal cortex in the Eurasian beaver (Castor fiber L.)?

There is a need to fully know the physiology of Eurasian beaver due to its essential role in environmental homeostasis. However, a "human factor" impacts this, including stress conditions and environmental pollution. Adrenal glands protect these all. The regulation of endocrine processes by nonclassical androgen and estrogen signaling, the first and fastest control, is still a matter of research. The specific analyses performed here in mature female and male beaver adrenals contained: anatomical and histological examinations, expression and localization of membrane androgen receptor (zinc transporter, Zinc- and Iron-like protein 9; ZIP9) and membrane estrogen receptor coupled with G protein (GPER), and measurement of zinc (Zn2+) and copper (Ca2+) ion levels and corticosterone levels. We revealed normal anatomical localization, size, and tissue histology in female and male beavers, respectively. Equally, ZIP9 and GPER were localized in the membrane of all adrenal cortex cells. The protein expression of these receptors was higher (p < 0.001) in male than female adrenal cortex cells. Similarly, Zn2+ and Ca2+ ion levels were higher (p < 0.05, p < 0.01) in male than female adrenal cortex. The increased corticosterone levels (p < 0.001) were detected in the adrenal cortex of females when compared to males. The present study is the first to report the presence of nonclassical androgen and estrogen signaling and its possible regulatory function in the adrenal cortex of Eurasian beavers. We assume that this first-activated and fast-transmitted regulation can be important in the context of the effect of environmental physical and chemical stressors especially on adrenal cortex cells. The beaver adrenals may constitute an additional supplementary model for searching for universal mechanisms of adrenal cortex physiology and diseases.

Quantifying the prevalence and predictors of burnout in emergency medical services personnel

INTRODUCTION

Recently, burnout has amassed considerable attention because of deleterious effects on workers and the work environment. Frequently, EMS clinicians find themselves prone to experiencing burnout, yet little is known about etiologies in this population.

OBJECTIVE

To estimate prevalence and predictors of burnout in EMS clinicians.

METHODS

This was a cross-sectional survey study of nine EMS agencies from North Carolina selected based on geography and population. Emergency medical technicians (EMTs), advanced EMTs, and paramedics were included. Emergency medical responders and air medical personnel were excluded if those positions were a primary occupational function. The Professional Quality of Life (ProQOL) Scale was used to assess burnout. Parametric and nonparametric testing was used to assess factors potentially affecting burnout. Factors significant in univariate analyses were included in a hierarchical linear regression model to determine unique predictors of burnout while controlling for confounders. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used to determine model predictability.

RESULTS

A total of 686 EMS clinicians completed the survey. Overall, 57.3% (n = 393) were likely to have burnout. Of the 328 respondents who were likely to have burnout, 254 (77.4%) and 211 (75.1%) also were identified as likely to suffer from compassion fatigue or vicarious trauma, respectively. Overall, 152 (22.2%) were likely to suffer from all three stress disorders, 118 (56.5%) of which scored high enough to potentially produce immune system dysregulation. Prior suicidal thoughts ((sr2 = 0.042, p < 0.001), attempts (sr2 = 0.025, p < 0.001) or the presence of vicarious trauma (sr2 = 0.040, p < 0.001) accounted for 4.2%, 2.5%, and 4.0% of model variance, respectively. Years of field experience (sr2 = 0.035, p < 0.001) and credential level (sr2 = 0.011, p = 0.005) accounted for 4.6% of model variance. Finally, a respondent's experience or knowledge of debriefing (sr2 = 0.008, p = 0.023); experiencing adversity in childhood in the form of familial mental illness, depression, or suicide (sr2 = 0.009, p = 0.016); or the incarceration of a family member (sr2 = 0.010, p = 0.011) accounted for a combined 2.7% of model variance. Model predictability showed an AUCROC of 81.5%.

CONCLUSIONS

This study showed a nearly 60% prevalence of occupational burnout in the group of EMS clinicians surveyed, making burnout of considerable concern in this population. Further study is needed to address occupational factors that contribute to burnout in EMS clinicians.

Revolution in sepsis: a symptoms-based to a systems-based approach?

Severe infection and sepsis are medical emergencies. High morbidity and mortality are linked to CNS dysfunction, excessive inflammation, immune compromise, coagulopathy and multiple organ dysfunction. Males appear to have a higher risk of mortality than females. Currently, there are few or no effective drug therapies to protect the brain, maintain the blood brain barrier, resolve excessive inflammation and reduce secondary injury in other vital organs. We propose a major reason for lack of progress is a consequence of the treat-as-you-go, single-nodal target approach, rather than a more integrated, systems-based approach. A new revolution is required to better understand how the body responds to an infection, identify new markers to detect its progression and discover new system-acting drugs to treat it. In this review, we present a brief history of sepsis followed by its pathophysiology from a systems' perspective and future opportunities. We argue that targeting the body's early immune-driven CNS-response may improve patient outcomes. If the barrage of PAMPs and DAMPs can be reduced early, we propose the multiple CNS-organ circuits (or axes) will be preserved and secondary injury will be reduced. We have been developing a systems-based, small-volume, fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat sepsis and endotoxemia. Our early studies indicate that ALM therapy shifts the CNS from sympathetic to parasympathetic dominance, maintains cardiovascular-endothelial glycocalyx coupling, reduces inflammation, corrects coagulopathy, and maintains tissue O2 supply. Future research will investigate the potential translation to humans.

A cluster-randomized trial of water, sanitation, handwashing and nutritional interventions on stress and epigenetic programming

A regulated stress response is essential for healthy child growth and development trajectories. We conducted a cluster-randomized trial in rural Bangladesh (funded by the Bill & Melinda Gates Foundation, ClinicalTrials.gov NCT01590095) to assess the effects of an integrated nutritional, water, sanitation, and handwashing intervention on child health. We previously reported on the primary outcomes of the trial, linear growth and caregiver-reported diarrhea. Here, we assessed additional prespecified outcomes: physiological stress response, oxidative stress, and DNA methylation (N = 759, ages 1-2 years). Eight neighboring pregnant women were grouped into a study cluster. Eight geographically adjacent clusters were block-randomized into the control or the combined nutrition, water, sanitation, and handwashing (N + WSH) intervention group (receiving nutritional counseling and lipid-based nutrient supplements, chlorinated drinking water, upgraded sanitation, and handwashing with soap). Participants and data collectors were not masked, but analyses were masked. There were 358 children (68 clusters) in the control group and 401 children (63 clusters) in the intervention group. We measured four F2-isoprostanes isomers (iPF(2α)-III; 2,3-dinor-iPF(2α)-III; iPF(2α)-VI; 8,12-iso-iPF(2α)-VI), salivary alpha-amylase and cortisol, and methylation of the glucocorticoid receptor (NR3C1) exon 1F promoter including the NGFI-A binding site. Compared with control, the N + WSH group had lower concentrations of F2-isoprostanes isomers (differences ranging from -0.16 to -0.19 log ng/mg of creatinine, P < 0.01), elevated post-stressor cortisol (0.24 log µg/dl; P < 0.01), higher cortisol residualized gain scores (0.06 µg/dl; P = 0.023), and decreased methylation of the NGFI-A binding site (-0.04; P = 0.037). The N + WSH intervention enhanced adaptive responses of the physiological stress system in early childhood.

Early-life influenza A (H1N1) infection independently programs brain connectivity, HPA AXIS and tissue-specific gene expression profiles

Early-life adversity covers a range of physical, social and environmental stressors. Acute viral infections in early life are a major source of such adversity and have been associated with a broad spectrum of later-life effects outside the immune system or "off-target". These include an altered hypothalamus-pituitary-adrenal (HPA) axis and metabolic reactions. Here, we used a murine post-natal day 14 (PND 14) Influenza A (H1N1) infection model and applied a semi-holistic approach including phenotypic measurements, gene expression arrays and diffusion neuroimaging techniques to investigate HPA axis dysregulation, energy metabolism and brain connectivity. By PND 56 the H1N1 infection had been resolved, and there was no residual gene expression signature of immune cell infiltration into the liver, adrenal gland or brain tissues examined nor of immune-related signalling. A resolved early-life H1N1 infection had sex-specific effects. We observed retarded growth of males and altered pre-stress (baseline) blood glucose and corticosterone levels at PND42 after the infection was resolved. Cerebral MRI scans identified reduced connectivity in the cortex, midbrain and cerebellum that were accompanied by tissue-specific gene expression signatures. Gene set enrichment analysis confirmed that these were tissue-specific changes with few common pathways. Early-life infection independently affected each of the systems and this was independent of HPA axis or immune perturbations.

Clinical and Laboratory Characteristics of Fatigue-Dominant Long-COVID Subjects: A Cross-Sectional Study

BACKGROUND

Long COVID is defined by persistent symptoms following COVID-19 infection. Approximately 71% of individuals with long COVID experience ongoing fatigue, postexertional malaise, and cognitive impairments, which share pathological similarities with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This similarity has prompted studies to explore the characteristics of long COVID to gain a better understanding of ME/CFS. To gain insights, we investigated the clinical and laboratory characteristics of individuals with fatigue-dominant long COVID.

METHODS

We enrolled 100 subjects (36 males, 64 females) with long COVID who had a higher score than 60 in the modified Korean version of the Chalder Fatigue Scale (mKCFQ11) and higher than 5 in a fatigue-focused visual analogue scale. To investigate fatigue symptoms, the mKCFQ11, the Multidimensional Fatigue Inventory, a visual analogue scale for fatigue and brain fog, along with the Short-Form survey, were employed. We also measured 3 cytokines and cortisol levels for immunological and endocrinological indicators. As a cross-sectional observational study, the data were collected at a single point in time.

RESULTS

The mean scores on the measurements showed severe fatigue, and these scores were significantly correlated, with no differences based on sex, the post-COVID period, or age. Among the laboratory tests, plasma cortisol levels had a significant negative correlation with fatigue scores and a positive correlation with living quality. The negative correlation between cortisol levels and mKCFQ11 scores appeared to be more specific to mental fatigue than physical, which conflicted with other measurements.

CONCLUSION

Our findings provide the first insights into the characteristics of fatigue in individuals with long COVID, particularly in terms of fatigue severity and cortisol levels. These results serve as valuable reference data for clinicians dealing with fatigue symptoms in long-COVID patients and for researchers exploring postviral fatigue symptoms, including ME/CFS, in the future.

Silent Infections are not So Silent: The Emerging Role of Combined Infections, Inflammation, and Vitamin Levels in OCD

Objective

Recent evidence highlights that different agents may trigger immune-mediated processes involved in the pathophysiology of different neuropsychiatric conditions. Given the limited information on obsessive-compulsive disorder (OCD), the present study aimed at assessing current/past infections and plasma levels of vitamin D, vitamin B12, folic acid, homocysteine and common peripheral inflammatory markers in a group of OCD outpatients.

Method

The sample included 217 adult outpatients with an OCD diagnosis according to the DSM-5 criteria. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was used to assess the clinical phenotype and symptom severity. Laboratory blood tests measured levels of vitamin D, vitamin B12, folic acid, homocysteine, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), blood count and antibodies titers for cytomegalovirus (CMV), Epstein Barr virus (EBV), Toxoplasma gondii and antistreptolysin titer.

Results

Sixty-one patients had a previous EBV infection, 46 were seropositive for CMV IgG, 24 showed positive antistreptolysin titer, 14 were seropositive for Toxoplasma gondii IgG, and four for CMV IgM. More than a half of patients showed vitamin D insufficiency. Compared to seronegative patients, patients with a past EBV infection displayed significantly higher scores on the Y-BOCS total score and compulsion subscale, and other symptoms. Vitamin D was negatively correlated with both the Y-BOCS total score and the subscales scores. Folic acid was negatively correlated with the Y-BOCS total and obsessions subscale score.

Conclusions

The findings of our study show an association between Epstein-Barr infection and hypovitaminosis D and the overall severity and specific symptom patterns of OCD. The laboratory measures used in this study are useful, cheap and easy parameters that should be routinely assessed in patients with OCD. Further studies are needed to clarify their role in OCD pathophysiology and outcomes, as well as the potential therapeutic impact of vitamins and antibiotics/immunomodulatory agents in OCD and other psychiatric conditions.

The exploration of neuroinflammatory mechanism by which CRHR2 deficiency induced anxiety disorder

Inflammation stimulates the hypothalamic-pituitary adrenal (HPA) axis and triggers glial neuroinflammatory phenotypes, which reduces monoamine neurotransmitters by activating indoleamine 2,3-dioxygenase enzyme. These changes can induce psychiatric diseases, including anxiety. Corticotropin releasing hormone receptor 2 (CRHR2) in the HPA axis is involved in the etiology of anxiety. Omega(n)-3 polyunsaturated fatty acids (PUFAs) can attenuate anxiety through anti-inflammation and HPA axis modulation. However, the underlying molecular mechanism by CRHR2 modulates anxiety and its correlation with neuroinflammation remain unclear. Here, we first constructed a crhr2 zebrafish mutant line, and evaluated anxiety-like behaviors, gene expression associated with the HPA axis, neuroinflammatory response, neurotransmitters, and PUFAs profile in crhr2+/+ and crhr2-/- zebrafish. The crhr2 deficiency decreased cortisol levels and up-regulated crhr1 and down-regulated crhb, crhbp, ucn3l and proopiomelanocortin a (pomc a) in zebrafish. Interestingly, a significant increase in the neuroinflammatory markers, translocator protein (TSPO) and the activation of microglia M1 phenotype (CD11b) were found in crhr2-/- zebrafish. As a consequence, the expression of granulocyte-macrophage colony-stimulating factor, pro-inflammatory cytokines vascular endothelial growth factor, and astrocyte A1 phenotype c3 were up-regulated. While microglia anti-inflammatory phenotype (CD206), central anti-inflammatory cytokine interleukin-4, arginase-1, and transforming growth factor-β were downregulated. In parallel, crhr2-deficient zebrafish showed an upregulation of vdac1 protein, a TSPO ligand, and its downstream caspase-3. Furthermore, 5-HT/5-HIAA ratio was decreased and n-3 PUFAs deficiency was identified in crhr2-/- zebrafish. In conclusion, anxiety-like behavior displayed by crhr2-deficient zebrafish may be caused by the HPA axis dysfunction and enhanced neuroinflammation, which resulted in n-3 PUFAs and monoamine neurotransmitter reductions.

From biological aging to functional decline: Insights into chronic inflammation and intrinsic capacity

Intrinsic capacity is the sum of an individual's physical and mental capacities, which helps determine functional ability. Intrinsic capacity decline is an important predictor of adverse health outcomes and can identify individuals at higher risk of functional decline. Aging is characterized by a decrease in physiological reserves and functional abilities. Chronic inflammation, a mechanism of aging, is associated with decreased intrinsic capacity, which may mirror the broader relationship between aging and functional ability. Therefore, it is crucial for maintaining functional ability and promoting healthy aging to study the mechanisms of intrinsic capacity decline, identify easily available markers, and make targets for intervention from the perspective of chronic inflammation. We reviewed the current research on chronic inflammation, inflammation-related markers, and intrinsic capacity. To date, there is still no inflammatory markers with high specificity and sensitivity to monitor intrinsic capacity decline. Interleukin-6, C-reactive protein, and tumor necrosis factor-alpha may potentially indicate changes in intrinsic capacity, but their results with intrinsic capacity or each intrinsic capacity domain are inconsistent. Considering the variations in individual responses to changes in inflammatory markers, it may be beneficial to explore the use of multiple analytes instead of relying on a single marker. This approach could be valuable in monitoring the decline of intrinsic capacity in the future.

A Review on the Protective Effects of Probiotics against Alzheimer's Disease

This review summarizes the protective effects of probiotics against Alzheimer's disease (AD), one of the most common neurodegenerative disorders affecting older adults. This disease is characterized by the deposition of tau and amyloid β peptide (Aβ) in different parts of the brain. Symptoms observed in patients with AD include struggles with writing, speech, memory, and knowledge. The gut microbiota reportedly plays an important role in brain functioning due to its bidirectional communication with the gut via the gut-brain axis. The emotional and cognitive centers in the brain are linked to the functions of the peripheral intestinal system via this gut-brain axis. Dysbiosis has been linked to neurodegenerative disorders, indicating the significance of gut homeostasis for proper brain function. Probiotics play an important role in protecting against the symptoms of AD as they restore gut-brain homeostasis to a great extent. This review summarizes the characteristics, status of gut-brain axis, and significance of gut microbiota in AD. Review and research articles related to the role of probiotics in the treatment of AD were searched in the PubMed database. Recent studies conducted using animal models were given preference. Recent clinical trials were searched for separately. Several studies conducted on animal and human models clearly explain the benefits of probiotics in improving cognition and memory in experimental subjects. Based on these studies, novel therapeutic approaches can be designed for the treatment of patients with AD.

Activity behaviors and relative changes in activity patterns recorded by precision technology were associated with diarrhea status in individually housed calves

The objective of this case-control study was to quantify any association of daily activity behaviors and relative changes in activity patterns (lying time, lying bouts, step count, activity index) with diarrhea status in preweaning dairy calves. Individually housed calves sourced from auction were health-scored daily for signs of diarrhea (fecal consistency loose or watery for 2 consecutive days) for the 28 d after arrival. Calves with diarrhea were pair-matched with healthy controls (n = 13, matched by arrival date, arrival weight, and diagnosis days to diarrheic calves). Mixed linear regression models were used to evaluate the association of diarrhea status, and the diarrhea status by day interaction with activity behaviors (d -3 to d 4) and relative changes in activity patterns (d -3 to d 4) relative to diagnosis of a diarrhea bout. The serum Brix percentage at arrival and daily temperature-humidity index from the calf barn were explored as quantitative covariates, with day as a repeated measure. The baseline for relative changes in activity patterns was set at 100% on d 0. Diarrheic calves were less active; they averaged fewer steps (119.1 ± 18.81 steps/d) than healthy calves (227.4 ± 18.81 steps/d, LSM ± SEM). Diarrheic calves also averaged lower activity indices (827.34 ± 93.092 daily index) than healthy calves (1,396.32 ± 93.092 daily index). We also found also a diarrhea status by day interaction for lying time on d -3, with diarrheic calves spending more time lying (20.80 ± 0.300 h/d) than healthy calves (19.25 ± 0.300 h/d). For relative changes in activity patterns, a diarrhea status by day interaction was detectable on d -2, where diarrheic calves had greater relative changes in step counts (diarrhea 634.85 ± 87.581% vs. healthy 216.51 ± 87.581%) and activity index (diarrhea 316.83 ± 35.692% vs. healthy 150.68 ± 35.692%). Lying bouts were not associated with diarrhea status. These results show that diarrheic calves were more lethargic, and they had relative changes in activity patterns 2 d before clinical signs of diarrhea. Future research should explore the potential of an activity alert that positively indicates an individually housed calf at risk for a diarrhea bout using deviations from relative changes in individual calf activity patterns.

Growth differentiation factor-15 stimulates the synthesis of corticotropin-releasing factor in hypothalamic 4B cells

Growth differentiation factor-15 (GDF15) is a stress-activated cytokine that regulates cell growth and inflammatory and stress responses. We previously reported the role and regulation of GDF15 in pituitary corticotrophs. Dexamethasone increases Gdf15 gene expression levels and production. GDF15 suppresses adrenocorticotropic hormone synthesis in pituitary corticotrophs and subsequently mediates the negative feedback effect of glucocorticoids. Here, we analyzed corticotropin-releasing factor (Crf) promoter activity in hypothalamic 4B cells transfected with promoter-driven luciferase reporter constructs. The effects of time and GDF15 concentration on Crf mRNA levels were analyzed using quantitative real-time polymerase chain reaction. Glial cell-derived neurotrophic factor family receptor α-like (GFRAL) protein is expressed in 4B cells. GDF15 increased Crf promoter activity and Crf mRNA levels in 4B cells. The protein kinase A and C pathways also contributed to the GDF15-induced increase in Crf gene expression. GDF15 stimulates GFRAL, subsequently increasing the phosphorylation of AKT, an extracellular signal-related kinase, and the cAMP response element-binding protein. Therefore, GDF15-dependent pathways may be involved in regulating Crf expression under stressful conditions in hypothalamic cells.

Effects of the COVID-19 Infection on Women's Menstrual Cycle: A Retrospective Study at Latifa Hospital, Dubai, United Arab Emirates

Background The COVID-19 pandemic has affected all of us in one way or another. The menstrual cycle is a reflection of the female reproductive system, and it is influenced by various factors including stress and infections. Although there is little information available about how the COVID-19 pandemic has affected women's reproductive health, it has had a significant impact on women. Objective The main objective of our study is to identify if there are any menstrual disturbances following COVID-19 infection in women. Study design Our study is a retrospective study wherein 700 women recovering from COVID-19 infection were asked about any new menstrual disturbances after the infection. We collected the data using questionnaires and analyzed the data using Statistical Product and Service Solutions (SPSS, version 26) (IBM SPSS Statistics for Windows, Armonk, NY). Results Our study showed no dysmenorrhea in 90% of the participants, 81% reported no change in menstrual flow rate, a vast majority (93%) denied experiencing amenorrhea, only 4% reported a new onset of intermenstrual bleeding, and 1% reported postmenopausal bleeding. Conclusion There was no significant change in the participants' menstrual cycle following COVID-19 infection.

Linking stress with urocortin in rats

The corticotropin-releasing factor neuropeptides (CRH and UCN-1,2,3), as well as spexin, contribute to the control of energy balance and limit food intake in mammals. However, the role of these neuropeptides in chronic variable stress remains unknown. The effect of chronic varied stress on circulating corticosterone levels and urocortin expression levels in the brains of experimental rats was studied in this study. Rats were subjected with 28 days long term stress protocol, end of stress protocol experimental and control animal organs isolated, brain urocorcortin-1,2,3 expression by RT-PCR and serum corticosterone by ELISA method. UCN levels in the brain were altered in rats subjected to prolonged varied stress. Furthermore, corticosterone levels were elevated as a result of the same urocortin expression pattern, indicating that urocortin expression is controlled by glucocorticoids via a glucocorticoid-responsive element (GRE). Thus, data shows that hypothalamus-pituitary-adrenal (HPA) axis, also known as the LHPA axis, and limbic system are both stimulated by stress, which is reflected in the form of elevated corticosterone levels, according to the genes UCN1, 2, and 3.

Prevalence of Hypocortisolemia in Patients with Sepsis or Septic Shock (The HIS Study) Presenting to the Emergency Department

Background

Cortisol response to stressors (hypothalamic-pituitary-adrenal axis, autonomic nervous system, and immune system) plays a vital role in maintaining stable metabolic homeostasis. This study was done to assess the prevalence of hypocortisolemia in patients presenting to ED with sepsis and/or septic shock.

Methods

This prospective observational study was done from July 2020 to April 2021. Serum cortisol levels were measured in patients with sepsis and septic shock, and their clinical and laboratory profile was categorized, coded, and analyzed.

Results

Ninety-eight patients were included, of which serum Cortisol <10 μg/dl was noted in 7 (7.2%) patients. The cohort's mean age was 52.9 (SD: 15.3) years with a male predominance (n-61; 62.2%). Most common presenting complaint was fever (n-52; 53.1%), followed by abdominal pain (n-24; 24.5%), and breathing difficulty (n-14; 14.3%). Systolic blood pressure <90 mmHg and tachycardia were seen in 63 patients (64.3%). Assessment of diet and native medication use did not demonstrate a predisposition to hypocortisolemia. The median (IQR) arterial lactate values were lower in the hypocortisolemic group: 2.2 (1.2-2.5) as compared to the non-hypocortisolemic group: 3.7 (2.2-8.0). Patients with septic shock without hypocortisolemia were noted to have a higher mean lactate level (2.6 ± 1.3 Vs 5.4 ± 3.9) and lower platelet counts compared to those with low cortisol levels. Patients with normal cortisol levels (n-38; 38.8%) still had low ACTH values.

Conclusion

The prevalence of hypocortisolemia was lower when compared to other Indian studies. Diet and native medication use do not predispose Indians to hypocortisolemia.

Correlation analysis of salivary cytokines and hormones with resiliency

BACKGROUND

Frequent exposure to acute stress increases risk of suicide, posttraumatic stress disorder, and other stress-related disorders. Neuroendocrine and immunologic dysregulation associated with stress may underlie predispositions to psychological disorders and inflammatory disease processes in individuals, such as first-responders and other healthcare professionals, who function in high stress situations. The Hardiness Resilience Gauge (HRG) can be used to psychometrically measure resilience, a psychological modifier of the stress response. Using the HRG alongside salivary biomarker profiling, may help to identify low resilience phenotypes and allow mitigation and early therapeutic interventions. There is a paucity of knowledge regarding biomarkers of resilience. This study aims to evaluate the relationship between factors of resilience with salivary biomarker levels and fluctuations during and following acute stress.

METHODS

Sixty-three first responders underwent a standardized stress-inducing training exercise, providing salivary samples before (prestress), immediately after (post-stress), and 1 hour after the event (recovery). The HRG was administered before (initial) and after (final) the event. Multiplex ELISA panels quantified 42 cytokines and 6 hormones from the samples, which were analyzed for relationships to psychometric factors of resilience measured by the HRG.

RESULTS

Several biomarkers correlated with psychological resilience following the acute stress event. The HRG scores correlated ( p < 0.05) with a select set of biomarkers with moderate-to-strong correlations (|r| > 0.3). These included EGF, GROα, PDGFAA, TGFα, VEGFA, interleukin (IL)1Ra, TNFα, IL18, cortisol, FGF2, IL13, IL15, and IL6. Interestingly, fluctuations of EGF, GROα, and PDGFAA in post-stress compared with recovery were positively correlated with factors of resilience, which were negatively correlated from the pre-stress to post-stress period.

CONCLUSION

This exploratory analysis discovered a small subset of salivary biomarkers that are significantly correlated with acute stress and resilience. Further investigation of their specific roles in acute stress and associations with resiliency phenotypes is warranted.

Paternal deprivation induces vigilance-avoidant behavior and accompanies sex-specific alterations in stress reactivity and central proinflammatory cytokine response in California mice (Peromyscus californicus)

RATIONALE

Early-life stress (ELS) can increase anxiety, reduce prosocial behaviors, and impair brain regions that facilitate emotional and social development. This knowledge greatly stems from assessing disrupted mother-child relationships, while studies investigating the long-term effects of father-child relationships on behavioral development in children are scarce. However, available evidence suggests that fathers may uniquely influence a child's behavioral development in a sex-specific manner. Rodent models examining mother-offspring interaction demonstrate relationships among ELS, neuroinflammatory mediators, and behavioral development; yet, the role paternal care may play in neuroimmune functioning remains unreported.

OBJECTIVES

Using the biparental California mouse (Peromyscus californicus), we examined to what extent paternal deprivation impairs social and anxiety-like behaviors, augments peripheral corticosterone (CORT) response, and alters central proinflammatory cytokine production following an acute stressor in adulthood.

METHODS

Biparentally reared and paternally deprived (permanent removal of the sire 24 h post-birth) adult mice were assessed for sociability, preference for social novelty, social vigilance, and social avoidance behaviors, followed by novelty-suppressed feeding (NSF) testing for general anxiety-like behavior. Following an acute stressor, circulating CORT concentrations and region-specific proinflammatory cytokine concentrations were determined via radioimmunoassay and Luminex multianalyte analysis, respectively.

RESULTS

In response to a novel same-sex conspecific, social vigilance behavior was associated with reduced sociability and increased avoidance in paternally deprived mice-an effect not observed in biparentally reared counterparts. Yet, in response to a familiar same-sex conspecific, social vigilance persisted but only in paternally deprived females. The latency to consume during NSF testing was not significantly altered by paternal deprivation. In response to an acute physical stressor, lower circulating CORT concentrations were observed in paternally deprived females. Compared to control-reared males, paternal deprivation increased hypothalamic interleukin-1β, but decreased hippocampal IL-6 protein concentration.

CONCLUSION

Greater social vigilance behavior was demonstrated in paternally deprived mice while they avoided social interaction with a novel same-sex conspecific; however, in response to a familiar same-sex conspecific, paternal deprivation increased social vigilance behavior but only in females. It is possible that different neurobiological mechanisms underlie these observed behavioral outcomes as sex-specific central proinflammatory cytokine and stress responsivity were observed in paternally deprived offspring.

Cytokine fluctuation during acute stress is correlated to life trauma

BACKGROUND

Multiple studies have demonstrated that human neurobiology and behavior are inextricably linked to the activity of our immune systems. Trauma is associated with a multitude of immune system changes; reflecting this, posttraumatic stress disorder (PTSD) is often comorbid with immune-related conditions such as autoimmune disorders. To further investigate this phenomenon, we tested our hypothesis that cytokine fluctuations during and after an acute stress response correlates with experienced life trauma.

METHODS

Using a prospective observational approach, this cohort study measured biomarker profiles in firefighter participants (n = 63), with 9 participants having prior PTSD diagnoses and 54 without prior PTSD diagnoses. In addition, life trauma scores were determined from all participants using the Life Events Checklist 5 (LEC-5) survey. Baseline salivary biomarker concentrations were determined, along with levels immediately before, immediately after, and 1 hour following a standardized stressful training event. Biomarkers measured using these salivary samples included 42 cytokines and 6 steroid and thyroid hormones. The concentrations of these markers were then correlated, using Pearson correlation coefficients, with the participants' LEC-5 scores. t Tests were also performed to compare cytokine values between the populations with and without prior PTSD diagnosis.

RESULTS

Included in the cytokine panel were interleukin (IL)-8, IL-10, IL-1B, GCSF, IL1-Ra, Groα, IFNa2, PDGFAA, and VEGF, all of which demonstrated positive correlation at various time points in individuals with increased severity of LEC-5 scores (and thus increased experienced life trauma). Concentrations of Groα, PDGFAA, IL1-Ra, IL-1a, Mip1a, IL-1a, IL-6, Mip1b, TNFα, and TGFα were also found to be significantly altered at various time points in participants with prior PTSD diagnoses, demonstrating some overlap with the LEC-5 Pearson correlations.

CONCLUSION

The results support our hypothesis and demonstrate that LEC-5 scores are indeed significantly correlated to cytokine concentrations and fluctuations surrounding a stress test.

LEVEL OF EVIDENCE

Diagnostic Tests or Criteria; Level IV.

Molecular consequences of peripheral Influenza A infection on cell populations in the murine hypothalamus

Infection with Influenza A virus (IAV) causes the well-known symptoms of the flu, including fever, loss of appetite, and excessive sleepiness. These responses, mediated by the brain, will normally disappear once the virus is cleared from the system, but a severe respiratory virus infection may cause long-lasting neurological disturbances. These include encephalitis lethargica and narcolepsy. The mechanisms behind such long lasting changes are unknown. The hypothalamus is a central regulator of the homeostatic response during a viral challenge. To gain insight into the neuronal and non-neuronal molecular changes during an IAV infection, we intranasally infected mice with an H1N1 virus and extracted the brain at different time points. Using single-nucleus RNA sequencing (snRNA-seq) of the hypothalamus, we identify transcriptional effects in all identified cell populations. The snRNA-seq data showed the most pronounced transcriptional response at 3 days past infection, with a strong downregulation of genes across all cell types. General immune processes were mainly impacted in microglia, the brain resident immune cells, where we found increased numbers of cells expressing pro-inflammatory gene networks. In addition, we found that most neuronal cell populations downregulated genes contributing to the energy homeostasis in mitochondria and protein translation in the cytosol, indicating potential reduced cellular and neuronal activity. This might be a preventive mechanism in neuronal cells to avoid intracellular viral replication and attack by phagocytosing cells. The change of microglia gene activity suggest that this is complemented by a shift in microglia activity to provide increased surveillance of their surroundings.

PDT-Induced Activation Enhanced by Hormone Response to Treatment

Photodynamic therapy (PDT) is a medical treatment with the use of a photosensitizing agent (PS), which, when activated by light, results in selective tissue damage with a cytotoxic effect on tumor cells. PDT leads to the induction of an acute-phase response, which results in the involvement of adrenal glucocorticoid (GC) hormones. PDT, by activating the hormonal response, affects the treatment of cancer. GC release is observed due to adrenal activity, which is driven by changes in the hypothalamic pituitary-adrenal axis triggered by stress signals emanating from the PDT treated tumor. The hormones released in this process in the context of the PDT-induced acute-phase response perform many important functions during anticancer therapy. They lead, among other things, to the systemic mobilization of neutrophils and the production of acute-phase reagents, and also control the production of immunoregulatory proteins and proteins that modulate inflammation. GCs can radically affect the activity of various inflammatory and immune cells, including the apoptosis of cancer cells. A better understanding of the modulation of GC activity could improve the outcomes of cancer patients treated with PDT.

Substances of abuse and their effect on SAR-CoV-2 pathogenesis

Following the emergence of SARS-CoV-2, various reports suggest that there has been a significant increase in substance abuse due to social distancing and related issues. Several reports have suggested the impact of chronic substance use on individuals' physiological and psychological health. Therefore, there is a need to know the impact of SARS-CoV-2 on persons with substance use disorders. Individuals with substance use disorders are the most vulnerable groups and are at a high risk of SARS-CoV-2 infection due to their already existing health issues associated with substance use. This review discusses some of the molecular and systemic/organic effects chronic substance use such as alcohol, nicotine, marijuana (cannabis), opioids, methamphetamine, and cocaine have on SARS-CoV-2 infectivity and its potential cause for worsened disease outcomes in persons with substance use disorder. This will provide healthcare providers, public health policies, and researchers with the needed knowledge to address some of the many challenges faced during the Covid-19 pandemic to facilitate treatment strategies for persons with substance use disorders.

Signalling cognition: the gut microbiota and hypothalamic-pituitary-adrenal axis

Cognitive function in humans depends on the complex and interplay between multiple body systems, including the hypothalamic-pituitary-adrenal (HPA) axis. The gut microbiota, which vastly outnumbers human cells and has a genetic potential that exceeds that of the human genome, plays a crucial role in this interplay. The microbiota-gut-brain (MGB) axis is a bidirectional signalling pathway that operates through neural, endocrine, immune, and metabolic pathways. One of the major neuroendocrine systems responding to stress is the HPA axis which produces glucocorticoids such as cortisol in humans and corticosterone in rodents. Appropriate concentrations of cortisol are essential for normal neurodevelopment and function, as well as cognitive processes such as learning and memory, and studies have shown that microbes modulate the HPA axis throughout life. Stress can significantly impact the MGB axis via the HPA axis and other pathways. Animal research has advanced our understanding of these mechanisms and pathways, leading to a paradigm shift in conceptual thinking about the influence of the microbiota on human health and disease. Preclinical and human trials are currently underway to determine how these animal models translate to humans. In this review article, we summarize the current knowledge of the relationship between the gut microbiota, HPA axis, and cognition, and provide an overview of the main findings and conclusions in this broad field.

Cues associated with repeated ethanol exposure facilitate the corticosterone response to ethanol and immunological challenges in adult male Sprague Dawley rats: implications for neuroimmune regulation

Background: We previously found a conditioned increase in central neuroinflammatory markers (Interleukin 6; IL-6) following exposure to alcohol-associated cues. Recent studies suggest (unconditioned) induction of IL-6 is entirely dependent on ethanol-induced corticosterone.Objectives: The goals of these present studies were to test whether alcohol-paired cues facilitated the hypothalamic-pituitary-adrenal (HPA) axis response to either a subthreshold priming alcohol dose or an immune or psychological stress challengeMethods: In Experiment 1 (N = 64), adult male Sprague Dawley rats were trained (paired or unpaired, four pairings total) with  either vehicle or 2 g/kg alcohol [intragastric (i.g.) or intraperitoneal (i.p.)] injections. In Experiments 2 (N = 28) and 3 (N = 30), male rats were similarly trained but with 4 g/kg alcohol i.g. intubations. On test day, all rats were either administered a 0.5 g/kg alcohol dose (i.p. or i.g. Experiment 1), a 100 µg/kg i.p. lipopolysaccharide (LPS) challenge (Experiment 2), or a restraint challenge (Experiment 3), and exposed to alcohol-associated cues. Blood plasma was collected for analysis.Results: Alcohol-associated cues facilitated the plasma corticosterone response to a subthreshold dose of alcohol (F1,28 = 4.85, p < .05) and an immune challenge (F8,80 = 6.23, p < .001), but not a restraint challenge (F2,27 = 0.18, p > .05).Conclusion: These findings reveal that the impact of the cues associated with alcohol intoxication on the HPA axis may be context-specific. This work illustrates how HPA axis learning processes form in the early stages of alcohol use and has important implications for how the HPA and neuroimmune conditioning may develop in alcohol use disorder in humans and facilitate the response to a later immune challenge.

Evaluation of the stress-reducing effect of trace mineral injection in beef calves

BACKGROUND

Little is known about the effects of trace mineral supplementation on the stress response in beef calves.

OBJECTIVES

To investigate the effect of injectable trace mineral supplementation (ITM) on the stress response in beef calves exposed to different types of stress.

ANIMALS

Thirty weaned Angus and Angus crossbred calves.

METHODS

The enrolled calves were randomly assigned to 2 groups: ITM, 15 calves received modified-live virus vaccine (MLV) and ITM SC and 15 calves received MLV and saline SC (CONT). The calves were exposed to 3 types of stress: the stress of MLV vaccination (d0), nasal aerosol with bovine viral diarrhea virus-2 (BVDV-2) challenge (d5), and liver biopsy (d26). The calves' body weights and health status were monitored. Leukocyte counts, serum cortisol concentration ([cort]), BVDV-2 serum neutralizing antibodies (SNA), and percentages of CD4⁺ , CD8⁺ , WC1⁺ _, and CD25⁺ T-lymphocytes were measured.

RESULTS

Serum cortisol concentration ([cort]) showed strong associations with the percentage of CD8⁺ (r_s  = .50), BVDV2-SNA (r_s  = -.43), and WC1CD25⁺ (r_s  = .41) cells, and rectal temperature (r_s  = .40). The highest [cort] was reported 3 days after aerosol BVDV-2 challenge. Serum [cort] was decreased in ITM-treated calves 3 days post-BVDV-2 challenge, compared with CONT calves, with an average decrease of 18.5 ng/μL (95% confidence interval [CI], -6.07 to -31.3). The ITM-treated calves were heavier and healthier (P < .01) than the CONT calves.

CONCLUSIONS AND CLINICAL IMPORTANCE

Trace mineral supplementation appears to have stress mitigation effects in beef cattle that may reflect positively on growth and health performance. Viral exposure is associated with a high degree of stress, which is considered a major welfare concern.

Glucocorticoid Hormones as Modulators of the Kynurenine Pathway in Chronic Pain Conditions

The pathogenesis of chronic pain entails a series of complex interactions among the nervous, immune, and endocrine systems. Defined as pain lasting or recurring for more than 3 months, chronic pain is becoming increasingly more prevalent among the US adult population. Pro-inflammatory cytokines from persistent low-grade inflammation not only contribute to the development of chronic pain conditions, but also regulate various aspects of the tryptophan metabolism, especially that of the kynurenine pathway (KP). An elevated level of pro-inflammatory cytokines exerts similar regulatory effects on the hypothalamic-pituitary-adrenal (HPA) axis, an intricate system of neuro-endocrine-immune pathways and a major mechanism of the stress response. As the HPA axis counters inflammation through the secretion of endogenous cortisol, we review the role of cortisol along with that of exogenous glucocorticoids in patients with chronic pain conditions. Considering that different metabolites produced along the KP exhibit neuroprotective, neurotoxic, and pronociceptive properties, we also summarize evidence rendering them as reliable biomarkers in this patient population. While more in vivo studies are needed, we conclude that the interaction between glucocorticoid hormones and the KP poses an attractive venue of diagnostic and therapeutic potential in patients with chronic pain.

Post-traumatic Stress Disorder: Focus on Neuroinflammation

Post-traumatic stress disorder (PTSD), gaining increasing attention, is a multifaceted psychiatric disorder that occurs following a stressful or traumatic event or series of events. Recently, several studies showed a close relationship between PTSD and neuroinflammation. Neuroinflammation, a defense response of the nervous system, is associated with the activation of neuroimmune cells such as microglia and astrocytes and with changes in inflammatory markers. In this review, we first analyzed the relationship between neuroinflammation and PTSD: the effect of stress-derived activation of the hypothalamic-pituitary-adrenal (HPA) axis on the main immune cells in the brain and the effect of stimulated immune cells in the brain on the HPA axis. We then summarize the alteration of inflammatory markers in brain regions related to PTSD. Astrocytes are neural parenchymal cells that protect neurons by regulating the ionic microenvironment around neurons. Microglia are macrophages of the brain that coordinate the immunological response. Recent studies on these two cell types provided new insight into neuroinflammation in PTSD. These contribute to promoting comprehension of neuroinflammation, which plays a pivotal role in the pathogenesis of PTSD.

A review of cytokine-based pathophysiology of Long COVID symptoms

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with "brain fog," arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines. There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

Activation of Mast Cells by Neuropeptides: The Role of Pro-Inflammatory and Anti-Inflammatory Cytokines

Mast cells (MCs) are tissue cells that are derived from bone marrow stem cells that contribute to allergic reactions, inflammatory diseases, innate and adaptive immunity, autoimmunity, and mental disorders. MCs located near the meninges communicate with microglia through the production of mediators such as histamine and tryptase, but also through the secretion of IL-1, IL-6 and TNF, which can create pathological effects in the brain. Preformed chemical mediators of inflammation and tumor necrosis factor (TNF) are rapidly released from the granules of MCs, the only immune cells capable of storing the cytokine TNF, although it can also be produced later through mRNA. The role of MCs in nervous system diseases has been extensively studied and reported in the scientific literature; it is of great clinical interest. However, many of the published articles concern studies on animals (mainly rats or mice) and not on humans. MCs are known to interact with neuropeptides that mediate endothelial cell activation, resulting in central nervous system (CNS) inflammatory disorders. In the brain, MCs interact with neurons causing neuronal excitation with the production of neuropeptides and the release of inflammatory mediators such as cytokines and chemokines. This article explores the current understanding of MC activation by neuropeptide substance P (SP), corticotropin-releasing hormone (CRH), and neurotensin, and the role of pro-inflammatory cytokines, suggesting a therapeutic effect of the anti-inflammatory cytokines IL-37 and IL-38.

Secondary trauma response in emergency services systems (STRESS) project: quantifying and predicting vicarious trauma in emergency medical services personnel

Introduction

There is a lack of literature exploring vicarious trauma (VT) in emergency medical services (EMS) personnel. VT is emotional countertransference that occurs between the clinician and patient. The presence of trauma- or stressor-related disorders could be a factor in the rising suicide rate in these clinicians.

Methods

This was a cross-sectional statewide study of American EMS personnel, using one-stage area sampling. Nine EMS agencies were selected to participate based on geographic area, who then provided data about annual call volume and mix. The Impact of Event Scale-Revised was used to quantify VT. Univariate analyses used chi-square and ANOVA to evaluate the relationship between VT and various psychosocial and demographic characteristics. Factors significant in the univariate analyses were included in a logistic regression to determine predictors of VT while controlling for potential confounders.

Results

A total of 691 respondents participated in the study, of which 44.4% were female and 12.3% were minorities. Overall, 40.9% had VT. Of those, 52.5% scored high enough to potentially illicit immune system modulation. Compared to those without VT, more than four times as many EMS professionals with VT self-reported as currently in counselling (9.2% v. 2.2%; p < 0.01). Approximately one in four EMS professionals (24.0%) had considered suicide, while nearly half (45.0%) knew an EMS provider who had died by suicide. There were multiple predictors of VT, including female sex (odds ratio [OR] 1.55; p = 0.02) and childhood exposure to emotional neglect (OR 2.28; p < 0.01) or domestic violence (OR 1.91; p = 0.05). Those with other stress syndromes, such as burnout or compassion fatigue, were 2.1 and 4.3 times more likely to have VT, respectively.

Conclusions

Among study participants, 41% suffered from VT, and 24% had considered suicide. As a largely understudied phenomenon in EMS professionals, additional research on VT should focus on causality and the mitigation of sentinel events experienced in the workplace.

The influence of COVID-19 infection-associated immune response on the female reproductive system†

Coronavirus disease 2019 (COVID-19) is a multi-system disease that has led to a pandemic with unprecedented ramifications. The pandemic has challenged scientists for the past 2 years and brought back previously abandoned research topics. COVID-19 infection causes a myriad of symptoms ranging from mild flu-like symptoms to severe illness requiring hospitalization. Case reports showed multiple systemic effects of COVID-19 infection, including acute respiratory distress syndrome, fibrosis, colitis, thyroiditis, demyelinating syndromes, and mania, indicating that COVID-19 can affect most human body systems. Unsurprisingly, a major concern for women all over the globe is whether a COVID-19 infection has any long-term effects on their menstrual cycle, fertility, or pregnancy. Published data have suggested an effect on the reproductive health, and we hypothesize that the reported reproductive adverse effects are due to the robust immune reaction against COVID-19 and the associated cytokine storm. While the COVID-19 receptor (angiotensin converting enzyme, ACE2) is expressed in the ovaries, uterus, vagina, and placenta, we hypothesize that it plays a less important role in the adverse effects on the reproductive system. Cytokines and glucocorticoids act on the hypothalamo-pituitary gonadal axis, arachidonic acid pathways, and the uterus, which leads to menstrual disturbances and pregnancy-related adverse events such as preterm labor and miscarriages. This hypothesis is further supported by the apparent lack of long-term effects on the reproductive health in females, indicating that when the cytokine storm and its effects are dampened, the reproductive health of women is no longer affected.

The Endocannabinoid System as a Potential Therapeutic Target for HIV-1-Associated Neurocognitive Disorder

Background: Despite the successful introduction of combined antiretroviral therapy, the prevalence of mild to moderate forms of HIV-associated neurocognitive disorders (HAND) remains high. It has been demonstrated that neuronal injury caused by HIV is excitotoxic and inflammatory, and it correlates with neurocognitive decline in HAND. Endocannabinoid system (ECS) protects the body from excitotoxicity and neuroinflammation on demand and presents a promising therapeutic target for treating HAND. Here, we firstly discuss the potential pathogenesis of HAND. We secondly discuss the structural and functional changes in the ECS that are currently known among HAND patients. We thirdly discuss current clinical and preclinical findings concerning the neuroprotective and anti-inflammatory properties of the ECS among HAND patients. Fourth, we will discuss the interactions between the ECS and neuroendocrine systems, including the hypothalamic-pituitary-adrenocortical (HPA) and hypothalamic-pituitary-gonadal (HPG) axes under the HAND conditions. Materials and Methods: We have carried out a review of the literature using PubMed to summarize the current state of knowledge on the association between ECS and HAND. Results: The ECS may be ideally suited for modulation of HAND pathophysiology. Direct activation of presynaptic cannabinoid receptor 1 or reduction of cannabinoid metabolism attenuates HAND excitotoxicity. Chronic neuroinflammation associated with HAND can be reduced by activating cannabinoid receptor 2 on immune cells. The sensitivity of the ECS to HIV may be enhanced by increased cannabinoid receptor expression in HAND. In addition, indirect regulation of the ECS through modulation of hormone-related receptors may be a potential strategy to influence the ECS and also alleviate the progression of HAND due to the reciprocal inhibition of the ECS by the HPA and HPG axes. Conclusions: Taken together, targeting the ECS may be a promising strategy to alleviate the inflammation and neurodegeneration caused by HIV-1 infection. Further studies are required to clarify the role of endocannabinoid signaling in HIV neurotoxicity. Strategies promoting endocannabinoid signaling may slow down cognitive decline of HAND are proposed.

Physiological Corticosterone Attenuates gp120-Mediated Microglial Activation and Is Associated with Reduced Anxiety-Like Behavior in gp120-Expressing Mice

Despite the benefits of combinatorial antiretroviral therapies (cART), virotoxic HIV proteins are still detectable within the central nervous system. Approximately half of all cART-treated patients contend with neurological impairments. The mechanisms underlying these effects likely involve virotoxic HIV proteins, including glycoprotein 120 (gp120). Glycoprotein-120 is neurotoxic due to its capacity to activate microglia. Corticosterone has been found to attenuate neuronal death caused by gp120-induced microglial cytokine production in vitro. However, the concentration-dependent effects of corticosterone on microglial activation states and the associated behavioral outcomes are unclear. Herein, we conducted parallel in vitro and in vivo studies to assess gp120-mediated effects on microglial activation, motor function, anxiety- and depression-like behavior, and corticosterone's capacity to attenuate these effects. We found that gp120 activated microglia in vitro, and corticosterone attenuated this effect at an optimal concentration of 100 nM. Transgenic mice expressing gp120 demonstrated greater anxiety-like behavior on an elevated plus maze, and a greater duration of gp120 exposure was associated with motor deficits and anxiety-like behavior. Circulating corticosterone was lower in gp120-expressing males and diestrous females. Greater circulating corticosterone was associated with reduced anxiety-like behavior. These findings may demonstrate a capacity for glucocorticoids to attenuate gp120-mediated neuroinflammation and anxiety-like behavior.

Viruses and Endocrine Diseases

Viral infections have been frequently associated with physiological and pathological changes in the endocrine system for many years. The numerous early and late endocrine complications reported during the current pandemic of coronavirus disease 2019 (COVID-19) reinforce the relevance of improving our understanding of the impact of viral infections on the endocrine system. Several viruses have been shown to infect endocrine cells and induce endocrine system disturbances through the direct damage of these cells or through indirect mechanisms, especially the activation of the host antiviral immune response, which may lead to the development of local or systemic inflammation or organ-specific autoimmunity. In addition, endocrine disorders may also affect susceptibility to viral infections since endocrine hormones have immunoregulatory functions. This review provides a brief overview of the impact of viral infections on the human endocrine system in order to provide new avenues for the control of endocrine diseases.

Anti-Inflammatory Therapy as a Promising Target in Neuropsychiatric Disorders

This chapter analyzes the therapeutic potential of current anti-inflammatory drugs in treating psychiatric diseases from a neuro-immunological perspective. Based on the bidirectional brain-immune system relationship, the rationale is that a dysregulated inflammation contributes to the pathogenesis of psychiatric and neurological disorders, while the immunology function is associated with psychological variables like stress, affective disorders, and psychosis. Under certain social, psychological, and environmental conditions and biological factors, a healthy inflammatory response and the associated "sickness behavior," which are aimed to resolve a physical injury and microbial threat, become harmful to the central nervous system. The features and mechanisms of the inflammatory response are described across the main mental illnesses with a special emphasis on the profile of cytokines and the function of the HPA axis. Next, it is reviewed the potential clinical utility of immunotherapy (cytokine agonists and antagonists), glucocorticoids, unconventional anti-inflammatory agents (statins, minocycline, statins, and polyunsaturated fatty acids (PUFAs)), the nonsteroidal anti-inflammatory drugs (NSAIDs), and particularly celecoxib, a selective cyclooxygenase-2 (Cox-2) inhibitor, as adjuvants of conventional psychiatric medications. The implementation of anti-inflammatory therapies holds great promise in psychiatry. Because the inflammatory background may account for the etiology and/or progression of psychiatric disorders only in a subset of patients, there is a need to elucidate the immune underpinnings of the mental illness progression, relapse, and remission. The identification of immune-related bio-signatures will ideally assist in the stratification of the psychiatric patient to predict the risk of mental disease, the prognosis, and the response to anti-inflammatory therapy.

SARS-CoV-2 (COVID-19) as a possible risk factor for neurodevelopmental disorders

Pregnant women constitute one of the most vulnerable populations to be affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of coronavirus disease 2019. SARS-CoV-2 infection during pregnancy could negatively impact fetal brain development via multiple mechanisms. Accumulating evidence indicates that mother to fetus transmission of SARS-CoV-2 does occur, albeit rarely. When it does occur, there is a potential for neuroinvasion via immune cells, retrograde axonal transport, and olfactory bulb and lymphatic pathways. In the absence of maternal to fetal transmission, there is still the potential for negative neurodevelopmental outcomes as a consequence of disrupted placental development and function leading to preeclampsia, preterm birth, and intrauterine growth restriction. In addition, maternal immune activation may lead to hypomyelination, microglial activation, white matter damage, and reduced neurogenesis in the developing fetus. Moreover, maternal immune activation can disrupt the maternal or fetal hypothalamic-pituitary-adrenal (HPA) axis leading to altered neurodevelopment. Finally, pro-inflammatory cytokines can potentially alter epigenetic processes within the developing brain. In this review, we address each of these potential mechanisms. We propose that SARS-CoV-2 could lead to neurodevelopmental disorders in a subset of pregnant women and that long-term studies are warranted.

Reduced Steroid Metabolites Identify Infection-Prone Children in Two Independent Pre-Birth Cohorts

Recurrent respiratory infections are a leading cause of morbidity and mortality in early life, but there is no broadly accepted means to identify infection-prone children during this highly vulnerable period. In this study, we investigated associations between steroid metabolites and incident respiratory infections in two pre-birth cohorts to identify novel metabolomic signatures of early infection proneness. Children from the Vitamin D Antenatal Asthma Reduction Trial and the Copenhagen Prospective Studies on Asthma in Childhood were included, and profiling was performed on plasma samples collected at ages 1 and 6 years. Both cohorts recorded incidence of lower respiratory infections, upper respiratory infections, ear infections, and colds. Poisson regression analysis assessed the associations between 18 steroid metabolites and the total number of respiratory infections that occurred in offspring during follow-up. We found that steroid metabolites across androgenic, corticosteroid, pregnenolone, and progestin classes were reduced in children that suffered more infections, and these patterns persisted at age 6 years, generally reflecting consistency in direction of effect and significance. Our analysis suggested steroid metabolite measurement may be useful in screening for infection proneness during this critical developmental period. Future studies should clinically evaluate their potential utility as a clinical screening tool.

Linking Puberty and the Gut Microbiome to the Pathogenesis of Neurodegenerative Disorders

Puberty is a critical period of development marked by the maturation of the central nervous system, immune system, and hypothalamic-pituitary-adrenal axis. Due to the maturation of these fundamental systems, this is a period of development that is particularly sensitive to stressors, increasing susceptibility to neurodevelopmental and neurodegenerative disorders later in life. The gut microbiome plays a critical role in the regulation of stress and immune responses, and gut dysbiosis has been implicated in the development of neurodevelopmental and neurodegenerative disorders. The purpose of this review is to summarize the current knowledge about puberty, neurodegeneration, and the gut microbiome. We also examine the consequences of pubertal exposure to stress and gut dysbiosis on the development of neurodevelopmental and neurodegenerative disorders. Understanding how alterations to the gut microbiome, particularly during critical periods of development (i.e., puberty), influence the pathogenesis of these disorders may allow for the development of therapeutic strategies to prevent them.