A Comprehensive Overview on Stress Neurobiology: Basic Concepts and Clinical Implications

Mitochondria and early-life adversity

Early-life adversity (ELA), which includes maltreatment, neglect, or severe trauma in childhood, increases the life-long risk for negative health outcomes. Mitochondria play a key role in the stress response and may be an important mechanism by which stress is transduced into biological risk for disease. By responding to cues from stress-signaling pathways, mitochondria interact dynamically with physiological stress responses coordinated by the central nervous, endocrine, and immune systems. Preclinical evidence suggests that alterations in mitochondrial function and structure are linked to both early stress and systemic biological dysfunction. Early clinical studies support that increased mitochondrial DNA content and altered cellular energy demands may be present in individuals with a history of ELA. Further research should investigate mitochondria as a potential therapeutic target following ELA.

The impact of a stress-reducing protocol on the quality of pre-anaesthesia in cats

INTRODUCTION

Transport to the clinic is a major source of stress for cats. The process involves being put into a carrier, driven in a car and handled. Cats are therefore removed from the safe-haven of their territory and experience many stressful stimuli and interactions.

METHODS

In the present study, 31 cats were transported to the clinic following a low-stress transport protocol and compared with a control group of 36 cats whose owners did not follow the protocol. This protocol involved preparing a cat carrier basket with F3 pheromone and keeping it covered and stable during the car journey from the home to the clinic. Pre-anaesthesia information was recorded for cardiac rate, respiratory rate, tolerance to handling, time for sedation to be achieved and dose of propofol required for induction and endotracheal intubation.

RESULTS

The group exposed to the low-stress transport protocol took less time to reach sedation and needed a lower dose of propofol for induction than the control group.

CONCLUSION

These results suggest that, in cats, pre-anaesthetic and induction requirements are influenced by lower-stress transport and handling.

The environmental enrichment model revisited: A translatable paradigm to study the stress of our modern lifestyle

Mounting evidence shows that physical activity, social interaction and sensorimotor stimulation provided by environmental enrichment (EE) exert several neurobehavioural effects traditionally interpreted as enhancements relative to standard housing (SH) conditions. However, this evidence rather indicates that SH induces many deficits, which could be ameliorated by exposing animals to an environment vaguely mimicking some features of their wild habitat. Rearing rodents in social isolation (SI) can aggravate such deficits, which can be restored by SH or EE. It is not surprising, therefore, that most preclinical stress models have included severe and unnatural stressors to produce a stress response prominent enough to be distinguishable from SH or SI-frequently used as control groups. Although current stress models induce a stress-related phenotype, they may fail to represent the stress of our urban lifestyle characterized by SI, poor housing and working environments, sedentarism, obesity and limited access to recreational activities and exercise. In the following review, we discuss the stress of living in urban areas and how exposures to and performing activities in green environments are stress relievers. Based on the commonalities between human and animal EE, we discuss how models of housing conditions (e.g., SI-SH-EE) could be adapted to study the stress of our modern lifestyle. The housing conditions model might be easy to implement and replicate leading to more translational results. It may also contribute to accomplishing some ethical commitments by promoting the refinement of procedures to model stress, diminishing animal suffering, enhancing animal welfare and eventually reducing the number of experimental animals needed.

Neuroendocrine, neuroinflammatory and pathological outcomes of chronic stress: A story of microglial remodeling

Microglia, the resident macrophage cells of the central nervous system (CNS), are involved in a myriad of processes required to maintain CNS homeostasis. These cells are dynamic and can adapt their phenotype and functions to the physiological needs of the organism. Microglia rapidly respond to changes occurring in their microenvironment, such as the ones taking place during stress. While stress can be beneficial for the organism to adapt to a situation, it can become highly detrimental when it turns chronic. Microglial response to prolonged stress may lead to an alteration of their beneficial physiological functions, becoming either maladaptive or pro-inflammatory. In this review, we aim to summarize the effects of chronic stress exerted on microglia through the neuroendocrine system and inflammation at adulthood. We also discuss how these effects of chronic stress could contribute to microglial involvement in neuropsychiatric and sleep disorders, as well as neurodegenerative diseases.

Molecular characterization of the stress network in individuals at risk for schizophrenia

The biological mechanisms underlying inter-individual differences in human stress reactivity remain poorly understood. We aimed to identify the molecular underpinning of aberrant neural stress sensitivity in individuals at risk for schizophrenia. Linking mRNA expression data from the Allen Human Brain Atlas to task-based fMRI revealed 201 differentially expressed genes in cortex-specific brain regions differentially activated by stress in individuals with low (healthy siblings of schizophrenia patients) or high (healthy controls) stress sensitivity. These genes are associated with stress-related psychiatric disorders (e.g. schizophrenia and anxiety) and include markers for specific neuronal populations (e.g. ADCYAP1, GABRB1, SSTR1, and TNFRSF12A), neurotransmitter receptors (e.g. GRIN3A, SSTR1, GABRB1, and HTR1E), and signaling factors that interact with the corticosteroid receptor and hypothalamic-pituitary-adrenal axis (e.g. ADCYAP1, IGSF11, and PKIA). Overall, the identified genes potentially underlie altered stress reactivity in individuals at risk for schizophrenia and other psychiatric disorders and play a role in mounting an adaptive stress response in at-risk individuals, making them potentially druggable targets for stress-related diseases.

A review of potential biomarkers for assessing physical and psychological trauma in paediatric burns

Biological markers that evaluate physical healing as well as psychological impact of a burn are essential for effective treatment of paediatric burns. The objective of this review is to summarize the evidence supporting the use of biomarkers in children with burns. An extensive review of the literature was performed using PubMed. A total of 59 biomarkers were identified relating to burn presence, specifically relating to processes involved in inflammation, wound healing, growth and metabolism. In addition, biomarkers involved in the stress response cascade following a burn trauma were also identified. Although many biomarkers have been identified that are potentially associated with burn-related physical and psychological trauma, an understanding of burn biology is still lacking in children. We propose that future research in the field of children’s burns should be conducted using broad screening methods for identifying potential biomarkers, examine the biological interactions of different biomarkers, utilize child-appropriate biological fluids such as urine or saliva, and include a range of different severity burns. Through further research, the biological response to burn injury may be fully realized and clinically relevant diagnostic tests and treatment therapies utilizing these biomarkers could be developed, for the improvement of healing outcomes in paediatric burn patients.

How stress physically re-shapes the brain: Impact on brain cell shapes, numbers and connections in psychiatric disorders

Severe stress is among the most robust risk factors for the development of psychiatric disorders. Imaging studies indicate that life stress is integral to shaping the human brain, especially regions involved in processing the stress response. Although this is likely underpinned by changes to the cytoarchitecture of cellular networks in the brain, we are yet to clearly understand how these define a role for stress in human psychopathology. In this review, we consolidate evidence of macro-structural morphometric changes and the cellular mechanisms that likely underlie them. Focusing on stress-sensitive regions of the brain, we illustrate how stress throughout life may lead to persistent remodelling of the both neurons and glia in cellular networks and how these may lead to psychopathology. We support that greater translation of cellular alterations to human cohorts will support parsing the psychological sequalae of severe stress and improve our understanding of how stress shapes the human brain. This will remain a critical step for improving treatment interventions and prevention outcomes.

Integrative Review of Early Life Adversity and Cortisol Regulation in Pregnancy

OBJECTIVE

To synthesize published findings on the relationship between early life adversity and hypothalamic-pituitary-adrenal axis cortisol parameters in pregnant women.

DATA SOURCES

We searched PubMed, CINAHL, and PsycINFO databases using variants and combinations of the keywords early life adversity, pregnancy, hypothalamic-pituitary-adrenal axis, and cortisol.

STUDY SELECTION

We selected articles that included pregnant participants, included measures of cortisol and early life adversity, were published in English in a peer-reviewed journal, and were of sufficient methodologic quality. Date of publication was unrestricted through May 2020.

DATA EXTRACTION

Twenty-five articles met the inclusion criteria and were evaluated for quality and risk of bias. Sources of cortisol included saliva, hair, plasma, and amniotic fluid.

DATA SYNTHESIS

We categorized findings according to four physiologically distinct cortisol output parameters: diurnal (daily pattern), phasic (in response to an acute stressor), tonic (baseline level), and pregnancy-related change. Preliminary evidence suggests that early adversity may be associated with elevated cortisol awakening response (diurnal) and blunted response to acute stressors (phasic), irrespective of other psychosocial symptoms or current stress. For women with high levels of current stress or psychological symptoms, early adversity was associated with higher baseline (tonic) cortisol levels.

CONCLUSION

Early life adversity in women is linked with alterations in cortisol regulation that are apparent during pregnancy. Researchers should examine how variations in each cortisol parameter differentially predict pregnancy health risk behaviors, maternal mental health, and neonatal health outcomes.

Brief mindfulness-based training and mindfulness trait attenuate psychological stress in university students: a randomized controlled trial

BACKGROUND

Psychological distress in University settings has grown and became a public health concern. In this context, contemplative practices such as mindfulness have been proposed as a strategy to help students on stress management.

METHODS

Forty university students (20 female), aged between 18 to 30 years (mean = 24.15; SD = 3.56), with no previous experience with meditation or yoga were recruited at the Federal University of Rio Grande do Norte and randomized to a mindfulness training (MT) or active control (AC) groups. We analyzed measures of anxiety, affect, stress, as well as state and trait mindfulness in order to evaluate the effects of trait mindfulness and a brief mindfulness intervention in forty healthy young students. Participants were classified as Low (n = 27, females = 13) or High (n = 13, females = 7) Trait Mindfulness by k-means clustering and compared between them using Wilcoxon sum rank test. Furthermore, the sample was randomly allocated to an AC (n = 20, females = 10) or a MT (n = 20, females = 10) group, and mixed analysis of variance was performed to analyze the effect of interventions. The mechanisms and role of trait mindfulness in the intervention was assessed by a moderated mediation analysis.

RESULTS

We found that High Trait individuals have lower anxiety trait, anxiety state and perceived stress levels. Only the MT group reduced their anxiety state and perceived stress after the intervention and increased their state mindfulness. Both groups reduced negative affect and cortisol, and no change was found in positive affect. Moderated mediation analysis showed that the training-induced change in state mindfulness mediated the increase in positive affect and the decrease in perceived stress and cortisol, regardless of trait mindfulness. For anxiety state the decrease only occurred in individuals with High Trait Mindfulness.

CONCLUSIONS

Together, these results suggest that higher trait mindfulness is associated with low levels of psychological distress and that a brief mindfulness-based intervention seems to be useful to reduce distress measures in university students.

TRIAL REGISTRATION

ReBEC, U1111-1194-8661. Registered 28 March 2017-Retrospectively registered, http://www.ensaiosclinicos.gov.br/rg/RBR-7b8yh8.

Chronological Impact of Earthquakes on Blood Pressure: A Literature Review and Retrospective Study of Hypertension in Haiti Before and After the 2010 Earthquake

Objective: We review prior studies on the incidence of hypertension (HTN) after earthquakes and present a retrospective analysis of HTN after the 2010 earthquake in Haiti. Methods: Prior reports on HTN incidence were reviewed and a retrospective chart review for diagnosis of HTN in 4,308 patient charts was performed over a 7 year period (five clinics). A retrospective cohort study (RCS) was then performed on 11 patients with linear follow-up. Results: The Literature review revealed a significant increase in acute and subacute HTN following earthquakes. However, the chronic effects of earthquakes varied. Our chart review uncovered no significant difference in diagnosed HTN in a Fort-Liberté clinic 128 kilometers (km) distant and 4 weeks post-event. A secondary linear RCS for 11 individuals, prior to and after the earthquake, also did not detect a significant change in HTN prevalence. Conclusion: Prior studies demonstrate acute and subacute, increases in HTN after earthquakes, but late changes have varied. Retrospective studies in the Fort-Liberté clinic, 128 km distant and 4 weeks post-event, revealed no significant change in HTN, confirming prior findings that changes in HTN after earthquakes are early and local events. Further work examining HTN after earthquakes is needed to improve early health care after natural disasters.

Biometric Data as Real-Time Measure of Physiological Reactions to Environmental Stimuli in the Built Environment

The physiological and cognitive effects of environmental stimuli from the built environment on humans have been studied for more than a century, over short time frames in terms of comfort, and over long-time frames in terms of health and wellbeing. The strong interdependence of objective and subjective factors in these fields of study has traditionally involved the necessity to rely on a number of qualitative sources of information, as self-report variables, which however, raise criticisms concerning their reliability and precision. Recent advancements in sensing technology and data processing methodologies have strongly contributed towards a renewed interest in biometric data as a potential high-precision tool to study the physiological effects of selected stimuli on humans using more objective and real-time measures. Within this context, this review reports on a broader spectrum of available and advanced biosensing techniques used in the fields of building engineering, human physiology, neurology, and psychology. The interaction and interdependence between (i) indoor environmental parameters and (ii) biosignals identifying human physiological response to the environmental stressors are systematically explored. Online databases ScienceDirect, Scopus, MDPI and ResearchGate were scanned to gather all relevant publications in the last 20 years, identifying and listing tools and methods of biometric data collection, assessing the potentials and drawbacks of the most relevant techniques. The review aims to support the introduction of biomedical signals as a tool for understanding the physiological aspects of indoor comfort in the view of achieving an improved balance between human resilience and building resilience, addressing human indoor health as well as energetic and environmental building performance.

Toxic Effects of Methamphetamine on Perivascular Health: Co-morbid Effects of Stress and Alcohol Use Disorders

Methamphetamine (Meth) abuse presents a global problem and commonly occurs with stress and/or alcohol use disorders. Regardless, the biological causes and consequences of these comorbidities are unclear. Whereas the mechanisms of Meth, stress, and alcohol abuse have been examined individually and well-characterized, these processes overlap significantly and can impact the neural and peripheral consequences of Meth. This review focuses on the deleterious cardio- and cerebrovascular effects of Meth, stress, alcohol abuse, and their comorbid effects on the brain and periphery. Points of emphasis are on the composition of the blood-brain barrier and their effects on the heart and vasculature. The autonomic nervous system, inflammation, and oxidative stress are specifically highlighted as common mediators of the toxic consequences to vascular and perivascular health. A significant portion of the Meth abusing population also presents with stress and alcohol use disorders, prompting a need to understand the mechanisms underlying their comorbidities. Little is known about their possible convergent effects. Therefore, the purpose of this critical review is to identify shared mechanisms of Meth, chronic stress, and alcohol abuse that contributes to the dysfunction of vascular health and underscores the need for studies that directly address their interactions.

The counteracting effects of (-)-Epigallocatechin-3-Gallate on the immobilization stress-induced adverse reactions in rat pancreas

Many studies suggest that Epigallocatechin-3-Gallate (EGCG) has many protective effects. But little is known about its protective effects against chronic restraint stress-induced damage in rats. The aim was to demonstrate the potential protective effects of EGCG against harmful pancreatic damage to the immobilization stress in the rat model. Forty rats, 2 months old, were divided into four groups (n = 10): control group; EGCG group, rats received EGCG by gavage (100 mg/kg /day) for 30 days; stressed group, rats exposed to immobilization stress; and stressed with EGCG group, rats exposed to immobilization stress and received EGCG for 30 days. Glycemic status parameters, corticosterone, and inflammatory markers were investigated on the first day, 15th day, and the 30th day of the experiment. Pancreatic oxidative stress markers and cytokines were evaluated. Histological, immunohistological, and statistical studies were performed. On the 15th day, fasting blood glucose (FBG), fasting plasma insulin (FPI), homeostatic model assessment for insulin resistance (HOMA-IR), and fasting plasma corticosterone were significantly higher in the stressed group when compared with first and 30th day in the same group as well as when compared with control and stressed with EGCG groups. The stressed group revealed significantly higher pancreatic IL-1β, IL-6, TNF-α, MDA, and NO, serum amylase and serum lipase, and significantly lower GSH, SOD, and CAT when compared to control and stressed with EGCG groups. EGCG treatment attenuated the pancreatic stress-induced cellular degeneration, leucocytic infiltration, and cytoplasmic vacuolations; significantly decreased area percentage of collagen fibers; and significantly increased mean area percentage of insulin immunopositive cell as compared with stressed group. EGCG is a protective agent against immobilization stress because of its anti-diabetic, anti-inflammatory, and and anti-oxidative stress properties, as confirmed by biochemical and histological alterations.

Evaluation of the HPA Axis' Response to Pharmacological Challenges in Experimental and Clinical Early-Life Stress-Associated Depression

Early-life stress (ELS) is associated with a higher risk of psychopathologies in adulthood, such as depression, which may be related to persistent changes in the hypothalamic-pituitary-adrenal (HPA) axis. This study aimed to evaluate the effects of ELS on the functioning of the HPA axis in clinical and experimental situations. Clinically, patients with current depressive episodes, with and without ELS, and healthy controls, composed the sample. Subjects took a capsule containing placebo, fludrocortisone, prednisolone, dexamethasone or spironolactone followed by an assessment of plasma cortisol the morning after. Experimentally, male Wistar rats were submitted to ELS protocol based on variable, unpredictable stressors from postnatal day (PND)1 to PND21. On PND65 animals were behaviorally evaluated through the forced-swimming test (FST). At PND68, pharmacological challenges started, using mifepristone, dexamethasone, spironolactone, or fludrocortisone, and corticosterone levels were determined 3 h after injections. Cortisol response of the patients did not differ significantly from healthy subjects, regardless of their ELS history, and it was lower after fludrocortisone, prednisolone, and dexamethasone compared with placebo, indicating the suppression of plasma cortisol by all these treatments. Animals exposed to ELS presented altered phenotype as indicated by an increased immobility time in the FST when compared with control, but no significant long-lasting effects of ELS were observed on the HPA axis response. Limitations on the way the volunteers were sampled may have contributed to the lack of ELS effects on the HPA axis, pointing out the need for further research to understand these complex phenomena.

The Biobehavioral Family Model: An Evidence-Based Approach to Biopsychosocial Research, Residency Training, and Patient Care

Engel's biopsychosocial model, based in systems theory, assumes the reciprocal influence of biological, psychological, and social factors on one another and on mental and physical health. However, the model's application to scientific study is limited by its lack of specificity, thus constraining its implementation in training and healthcare environments. The Biobehavioral Family Model (BBFM) is one model that can facilitate specification and integration of biopsychosocial conceptualization and treatment of illness. The model identifies specific pathways by which family relationships (i.e., family emotional climate) impact disease activity, through psychobiological mechanisms (i.e., biobehavioral reactivity). Furthermore, it is capable of identifying positive and negative effects of family process in the same model, and can be applied across cultural contexts. The BBFM has been applied to the study of child health outcomes, including pediatric asthma, and adult health, including for underserved primary care patients, minoritized samples, and persons with chronic pain, for example. The BBFM also serves as a guide for training and clinical practice; two such applications are presented, including the use of the BBFM in family medicine residency and child and adolescent psychiatry fellowship programs. Specific teaching and clinical approaches derived from the BBFM are described in both contexts, including the use of didactic lecture, patient interview guides, assessment protocol, and family-oriented care. Future directions for the application of the BBFM include incorporating temporal dynamics and developmental trajectories in the model, extending testable theory of family and individual resilience, examining causes of health disparities, and developing family-based prevention and intervention efforts to ameliorate contributing factors to disease. Ultimately, research and successful applications of the BBFM could inform policy to improve the lives of families, and provide additional support for the value of a biopsychosocial approach to medicine.

Neuroimmune connections between corticotropin-releasing hormone and mast cells: novel strategies for the treatment of neurodegenerative diseases

Corticotropin-releasing hormone is a critical component of the hypothalamic–pituitary–adrenal axis, which plays a major role in the body’s immune response to stress. Mast cells are both sensors and effectors in the interaction between the nervous and immune systems. As first responders to stress, mast cells can initiate, amplify and prolong neuroimmune responses upon activation. Corticotropin-releasing hormone plays a pivotal role in triggering stress responses and related diseases by acting on its receptors in mast cells. Corticotropin-releasing hormone can stimulate mast cell activation, influence the activation of immune cells by peripheral nerves and modulate neuroimmune interactions. The latest evidence shows that the release of corticotropin-releasing hormone induces the degranulation of mast cells under stress conditions, leading to disruption of the blood-brain barrier, which plays an important role in neurological diseases, such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, autism spectrum disorder and amyotrophic lateral sclerosis. Recent studies suggest that stress increases intestinal permeability and disrupts the blood-brain barrier through corticotropin-releasing hormone-mediated activation of mast cells, providing new insight into the complex interplay between the brain and gastrointestinal tract. The neuroimmune target of mast cells is the site at which the corticotropin-releasing hormone directly participates in the inflammatory responses of nerve terminals. In this review, we focus on the neuroimmune connections between corticotropin-releasing hormone and mast cells, with the aim of providing novel potential therapeutic targets for inflammatory, autoimmune and nervous system diseases.

Stress Markers for Mental States and Biotypes of Depression and Anxiety: A Scoping Review and Preliminary Illustrative Analysis

Depression and anxiety disrupt daily function and their effects can be long-lasting and devastating, yet there are no established physiological indicators that can be used to predict onset, diagnose, or target treatments. In this review, we conceptualize depression and anxiety as maladaptive responses to repetitive stress. We provide an overview of the role of chronic stress in depression and anxiety and a review of current knowledge on objective stress indicators of depression and anxiety. We focused on cortisol, heart rate variability and skin conductance that have been well studied in depression and anxiety and implicated in clinical emotional states. A targeted PubMed search was undertaken prioritizing meta-analyses that have linked depression and anxiety to cortisol, heart rate variability and skin conductance. Consistent findings include reduced heart rate variability across depression and anxiety, reduced tonic and phasic skin conductance in depression, and elevated cortisol at different times of day and across the day in depression. We then provide a brief overview of neural circuit disruptions that characterize particular types of depression and anxiety. We also include an illustrative analysis using predictive models to determine how stress markers contribute to specific subgroups of symptoms and how neural circuits add meaningfully to this prediction. For this, we implemented a tree-based multi-class classification model with physiological markers of heart rate variability as predictors and four symptom subtypes, including normative mood, as target variables. We achieved 40% accuracy on the validation set. We then added the neural circuit measures into our predictor set to identify the combination of neural circuit dysfunctions and physiological markers that accurately predict each symptom subtype. Achieving 54% accuracy suggested a strong relationship between those neural-physiological predictors and the mental states that characterize each subtype. Further work to elucidate the complex relationships between physiological markers, neural circuit dysfunction and resulting symptoms would advance our understanding of the pathophysiological pathways underlying depression and anxiety.

Correlates of Psychological Distress in Patients with Parkinson's Disease During the COVID-19 Outbreak

BACKGROUND

Following the severe consequences of the COVID-19 outbreak, on March 9, 2020, the Italian government implemented extraordinary measures to limit viral transmission, including restrictive quarantine measures. This resulted in a rapid and profound change of people's daily lives.

OBJECTIVE

We assessed the psychological impact of the 40-day quarantine in a large cohort of patients with Parkinson's disease (PD) and caregivers. Moreover, we analyzed whether prelockdown clinical features may be associated with subjective response of patients with PD to this traumatic event.

METHODS

A total of 94 patients with PD were enrolled in the study. The Impact of Event Scale-Revised, the Kessler Psychological Distress Scale, and the 12-item Zarit Burden Inventory were obtained from patients and caregivers by email. A multivariate regression analysis was performed to determine whether prelockdown clinical motor and nonmotor features were associated with the psychological impact of lockdown.

RESULTS

Regression analyses showed that prelockdown levels of anxiety, treatment-related motor complications, patients' quality of life, and lockdown hours per day were significantly associated with psychological impact measures of the 40-day quarantine. In addition, we showed that caregiver burden was correlated with overall patient autonomy and attention/memory impairment.

CONCLUSIONS

We identified specific PD motor and nonmotor features potentially predisposing to higher psychological impact of stressful situations, such as quarantine. This may help guide postpandemic interventions and preventive strategies to avoid further impairment of psychological well-being in patients with PD.

Neuroendocrine Response to Psychosocial Stressors, Inflammation Mediators and Brain-periphery Pathways of Adaptation

Threats, challenging events, adverse experiences, predictable or unpredictable, namely stressors, characterize life, being unavoidable for humans. The hypothalamus-pituitary-adrenal axis (HPA) and the sympathetic nervous system (SNS) are well-known to underlie adaptation to psychosocial stress in the context of other interacting systems, signals and mediators. However, much more effort is necessary to elucidate these modulatory cues for a better understanding of how and why the "brain-body axis" acts for resilience or, on the contrary, cannot cope with stress from a biochemical and biological point of view. Indeed, failure to adapt increases the risk of developing and/or relapsing mental illnesses such as burnout, post-traumatic stress disorder (PTSD), and at least some types of depression, even favoring/worsening neurodegenerative and somatic comorbidities, especially in the elderly. We will review here the current knowledge on this area, focusing on works presenting the main brain centers responsible for stressor interpretation and processing, together with those underscoring the physiology/biochemistry of endogenous stress responses. Autonomic and HPA patterns, inflammatory cascades and energy/redox metabolic arrays will be presented as allostasis promoters, leading towards adaptation to psychosocial stress and homeostasis, but also as possible vulnerability factors for allostatic overload and non-adaptive reactions. Besides, the existence of allostasis buffering systems will be treated. Finally, we will suggest promising lines of future research, particularly the use of animal and cell culture models together with human studies by means of high-throughput multi-omics technologies, which could entangle the biochemical signature of resilience or stress-related illness, a considerably helpful facet for improving patients' treatment and monitoring.

Blink rate as a measure of stress and attention in the domestic horse (Equus caballus)

Measuring animal stress is fundamentally important for assessing animal emotional state and welfare. Conventional methods of quantifying stress (cortisol levels, heart rate/heart rate variability) require specialist equipment and are not instantly available. Spontaneous blink rate (SBR) has previously been used to measure stress responses in humans and may provide a non-invasive method for measuring stress in other animal species. Here we investigated the use of SBR as a measure of stress in the domestic horse. SBR was measured before and during a low-stress event (sham clipping) and compared with heart rate variability and salivary cortisol. For the entire sample, there was a reduction in SBR (startle response) during the first minute of clipping. For horses reactive to clipping, the initial reduction in SBR was followed by an increase above baseline whereas the SBR of the non-reactive horses quickly returned to baseline. For the entire sample, SBR correlated with heart rate variability and salivary cortisol. We have demonstrated that SBR is a valid fast alternative measure of stress in horses, but the initial 'startle' response must be considered when using this parameter as a measure of animal stress.

Context Matters: Situational Stress Impedes Functional Reorganization of Intrinsic Brain Connectivity during Problem-Solving

Extensive research has established a relationship between individual differences in brain activity in a resting state and individual differences in behavior. Conversely, when individuals are engaged in various tasks, certain task-evoked reorganization occurs in brain functional connectivity, which can consequently influence individuals' performance as well. Here, we show that resting state and task-dependent state brain patterns interact as a function of contexts engendering stress. Findings revealed that when the resting state connectome was examined during performance, the relationship between connectome strength and performance only remained for participants under stress (who also performed worse than all other groups on the math task), suggesting that stress preserved brain patterns indicative of underperformance whereas non-stressed individuals spontaneously transitioned out of these patterns. Results imply that stress may impede the reorganization of a functional network in task-evoked brain states. This hypothesis was subsequently verified using graph theory measurements on a functional network, independent of behavior. For participants under stress, the functional network showed less topological alterations compared to non-stressed individuals during the transition from resting state to task-evoked state. Implications are discussed for network dynamics as a function of context.

Calming Effects of Touch in Human, Animal, and Robotic Interaction-Scientific State-of-the-Art and Technical Advances

Small everyday gestures such as a tap on the shoulder can affect the way humans feel and act. Touch can have a calming effect and alter the way stress is handled, thereby promoting mental and physical health. Due to current technical advances and the growing role of intelligent robots in households and healthcare, recent research also addressed the potential of robotic touch for stress reduction. In addition, touch by non-human agents such as animals or inanimate objects may have a calming effect. This conceptual article will review a selection of the most relevant studies reporting the physiological, hormonal, neural, and subjective effects of touch on stress, arousal, and negative affect. Robotic systems capable of non-social touch will be assessed together with control strategies and sensor technologies. Parallels and differences of human-to-human touch and human-to-non-human touch will be discussed. We propose that, under appropriate conditions, touch can act as (social) signal for safety, even when the interaction partner is an animal or a machine. We will also outline potential directions for future research and clinical relevance. Thereby, this review can provide a foundation for further investigations into the beneficial contribution of touch by different agents to regulate negative affect and arousal in humans.

Chronic unpredictable stress-induced inflammation and quantitative analysis of neurons of distinct brain regions in Wistar rat model of comorbid depression

Background and Aim:

Depression and anxiety are the most prominent neuropsychiatric disease and have been considered as the most burdensome diseases of society. The hippocampus and prefrontal cortex have a prominent role in stress-induced neurological disorders. Chronic unpredictable stress exposed rats are a perfect model in understanding comorbid depression and anxiety disorders. The inflammatory response occurring in the body has been linked to C-reactive protein (CRP) in many diseased conditions. The present research primarily focus on the possible correlation of Cortisol, CRP level and neuronal assay in different regions of hippocampus, dentate gyrus (DG), and prefrontal cortex.

Materials and Methods:

The control group of rats (n=6) was not exposed to any stress. Whereas, the experimental stress group (n=6) of rats was exposed to various stressors for 15 days. After the experimentation procedures, the blood samples were collected and brain dissection was done. The neurons in the prefrontal cortex, the DG along with various hippocampal regions was counted. Statistical analysis was performed using student’s t-test and p<0.05 was expressed as statistically significant.

Results:

Animals exposed to chronic unpredictable stressors showed a significant (p<0.0001) decrease in the neuronal count in prefrontal cortex and hippocampus. A significant rise in the serum cortisol (p<0.0001) and CRP (p<0.001) was witnessed in the stressed group.

Conclusion:

Our results demonstrate that chronic unpredictable stress exposure has affected neurogenesis in prefrontal cortex and hippocampal regions. Decreased neurogenesis was well in coordinance with the increase in cortisol and CRP. The chronic unpredictable stress-induced inflammatory response correlated to various brain regions might provoke insights into a variety of new drugs targeting neurogenesis.

An in-depth neurobehavioral characterization shows anxiety-like traits, impaired habituation behavior, and restlessness in male Cryptochrome-deficient mice

Many psychiatric disorders, for example, anxiety, are accompanied by disturbances of circadian rhythms, including disturbed sleep/wake cycles, changes in locomotor activity, and abnormal endocrine function. Conversely, alternations of circadian rhythms are a risk factor for the development of psychiatric disorders. This assumption is supported by animals with clock gene mutations which often display behaviors that resemble human psychiatric disorders. In this study, we performed an in-depth behavioral analysis with male mice lacking the central clock genes Cryptochrome 1 and 2 (Cry1/2^-/- ), which are thus unable to express endogenous circadian rhythms. With wild-type and Cry1/2^-/- mice, we performed an extensive behavioral analysis to study their cognitive abilities, social behavior, and their expression of depression-like and anxiety-like behavior. While Cry1/2^-/- mice showed only mild abnormalities at cognitive and social behavioral levels, they were consistently more anxious than wildtype mice. Anxiety-like behavior was particularly evident in reduced mobility in new environments, altered ability to habituate, compensatory behavior, and consistent restless behavior across many behavioral tests. In line with their anxiety-like behavioral phenotype, Cry1/2^-/- mice have higher c-Fos activity in the amygdala after exposure to an anxiogenic stressor than wild-type mice. In our study, we identified Cry1/2^-/- mice as animals that qualify as a translational mouse model for anxiety disorder in humans because of its consistent behavior of restlessness, increased immobility, and dysfunctional habituation in new environments.

Evaluation of salivary vasopressin as an acute stress biomarker in healthy dogs with stress due to noise and environmental challenges

Background

Stress is associated with various detrimental changes in physiological health that affect an animal’s quality of life. The hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adreno-medullar (SAM) axis are two main physiological pathways that constitute the stress response of an organism. Arginine vasopressin (AVP) is a mediator of the HPA axis and is known to be related to social behaviours and stress. The serum concentration of AVP is higher in more aggressive dogs and humans with post-traumatic stress disorder. Salivary biomarker analysis is a non-invasive method to assess stress. The purpose of this study was to evaluate the possibility of using salivary AVP as an acute stress biomarker in dogs. Salivary AVP concentration was measured before and after exposure to all relevant environmental stimuli (i.e. car trip to the lab, physical examination by the veterinarian, and sampling procedure,) and then after 30 min of vacuum noise exposure. Behavioural assessments, physiologic parameter assessments, and serum cortisol analysis were conducted in combination. Statistical analysis was conducted separately in the total study population, the less stressed group, and the more stressed group, respectively.

Results

Based on stress behaviour analysis scores, 28 dogs were classified into less or more stressed groups. All four physiologic parameters (blood pressure, body temperature, heart rate, and respiratory rate) were significantly increased after noise and environmental challenges, in the more stressed group. Serum cortisol did not show any significant change. Salivary AVP significantly decreased after noise and environmental stimulation in the more stressed group but not in the less stressed group. Salivary AVP and blood pressure changes were negatively correlated in the more stressed group.

Conclusion

Salivary AVP may be a potential acute stress biomarker in dogs.

Effects of elevated corticosterone on humoral innate and antibody-mediated immunity in southern leopard frog (Lithobates sphenocephalus) tadpoles

As a free-living larval stage of a vertebrate, tadpoles are good subjects for the study of the development of physiological systems and the study of evolutionarily conserved, context-dependent responses to variable environments. While the basic components of innate and adaptive immune defenses in tadpoles are known, the impact of glucocorticoids on immune defenses in tadpoles is not well-studied. We completed four experiments to assess effects of elevation of corticosterone on humoral innate defenses and antibody-mediated immunity in southern leopard frog tadpoles (Lithobates sphenocephalus). To test humoral innate defense within the tadpoles exposed to short-term and long-term elevation of glucocorticoids, we exposed tadpoles to exogenous corticosterone for different lengths of time in each experiment (0-84 days). We used bacterial killing assays to assess humoral innate immune defense. To test antibody-mediated immune responses, we again exposed tadpoles to exogenous corticosterone, while also exposing them to Aeromonas hydrophila. We used A. hydrophila ELISA comparing IgM and IgY responses among groups. Plasma from corticosterone-dosed tadpoles killed more A. hydrophila than control tadpoles each following a short-term (14 day) and long-term (56 day) exposure to exogenous corticosterone. Conversely, corticosterone-dosed tadpoles had significantly lower IgM and IgY against A. hydrophila after 12 weeks. Our fourth experiment revealed that the lower IgY response is a product of weaker, delayed isotype switching compared with controls. These results show that elevated corticosterone has differential effects on innate and acquired immunity in larval southern leopard frogs, consistent with patterns in more derived vertebrates and in adult frogs.

Large-Scale Phenotyping of Livestock Welfare in Commercial Production Systems: A New Frontier in Animal Breeding

Genomic breeding programs have been paramount in improving the rates of genetic progress of productive efficiency traits in livestock. Such improvement has been accompanied by the intensification of production systems, use of a wider range of precision technologies in routine management practices, and high-throughput phenotyping. Simultaneously, a greater public awareness of animal welfare has influenced livestock producers to place more emphasis on welfare relative to production traits. Therefore, management practices and breeding technologies in livestock have been developed in recent years to enhance animal welfare. In particular, genomic selection can be used to improve livestock social behavior, resilience to disease and other stress factors, and ease habituation to production system changes. The main requirements for including novel behavioral and welfare traits in genomic breeding schemes are: (1) to identify traits that represent the biological mechanisms of the industry breeding goals; (2) the availability of individual phenotypic records measured on a large number of animals (ideally with genomic information); (3) the derived traits are heritable, biologically meaningful, repeatable, and (ideally) not highly correlated with other traits already included in the selection indexes; and (4) genomic information is available for a large number of individuals (or genetically close individuals) with phenotypic records. In this review, we (1) describe a potential route for development of novel welfare indicator traits (using ideal phenotypes) for both genetic and genomic selection schemes; (2) summarize key indicator variables of livestock behavior and welfare, including a detailed assessment of thermal stress in livestock; (3) describe the primary statistical and bioinformatic methods available for large-scale data analyses of animal welfare; and (4) identify major advancements, challenges, and opportunities to generate high-throughput and large-scale datasets to enable genetic and genomic selection for improved welfare in livestock. A wide variety of novel welfare indicator traits can be derived from information captured by modern technology such as sensors, automatic feeding systems, milking robots, activity monitors, video cameras, and indirect biomarkers at the cellular and physiological levels. The development of novel traits coupled with genomic selection schemes for improved welfare in livestock can be feasible and optimized based on recently developed (or developing) technologies. Efficient implementation of genetic and genomic selection for improved animal welfare also requires the integration of a multitude of scientific fields such as cell and molecular biology, neuroscience, immunology, stress physiology, computer science, engineering, quantitative genomics, and bioinformatics.

Chronic stress and endothelial dysfunction: mechanisms, experimental challenges, and the way ahead

Although chronic stress is an important risk factor for cardiovascular diseases (CVD) onset, the underlying mechanisms driving such pathophysiological complications remain relatively unknown. Here, dysregulation of innate stress response systems and the effects of downstream mediators are strongly implicated, with the vascular endothelium emerging as a primary target of excessive glucocorticoid and catecholamine action. Therefore, this review article explores the development of stress-related endothelial dysfunction by focusing on the following: 1) assessing the phenomenon of stress and complexities surrounding this notion, 2) discussing mechanistic links between chronic stress and endothelial dysfunction, and 3) evaluating the utility of various preclinical models currently employed to study mechanisms underlying the onset of stress-mediated complications such as endothelial dysfunction. The data reveal that preclinical models play an important role in our efforts to gain an increased understanding of mechanisms underlying stress-mediated endothelial dysfunction. It is our understanding that this provides a good foundation going forward, and we propose that further efforts should be made to 1) more clearly define the concept of stress and 2) standardize protocols of animal models with specific guidelines to better indicate the mental complications that are simulated.

Paternal effects in a wild-type zebrafish implicate a role of sperm-derived small RNAs

While the importance of maternal effects has long been appreciated, a growing body of evidence now points to the paternal environment having an important influence on offspring phenotype. Indeed, research on rodent models suggests that paternal stress leaves an imprint on the behaviour and physiology of offspring via nongenetic information carried in the spermatozoa; however, fish have been understudied with regard to these sperm-mediated effects. Here, we investigated whether the zebrafish was subjected to heritable influences of paternal stress by exposing males to stressors (conspecific-derived alarm cue, chasing and bright light) before mating and assessing the behavioural and endocrine responses of their offspring, including their behavioural response to conspecific-derived alarm cue. We found that after males are exposed to stress, their larval offspring show weakened responses to stressors. Small RNA sequencing subsequently revealed that the levels of several small noncoding RNAs, including microRNAs, PIWI-interacting RNAs and tRNA-derived small RNAs, were altered in the spermatozoa of stressed fathers, suggesting that stress-induced alterations to the spermatozoal RNA landscape may contribute to shaping offspring phenotype. The work demonstrates that paternal stress should not be overlooked as a source of phenotypic variation and that spermatozoal small RNAs may be important intergenerational messengers in fish.

Financial Awards and Their Effect on Football Players' Anxiety and Coping Skills

OBJECTIVE

Financial awards can be an important factor affecting athletes' mental preparation and various skills to manage stress. Since such a link has not yet been studied, the study has been designed to evaluate the moderation effect of financial awards in relation to football players' anxiety and coping skills.

METHODS

The study consists of 110 male football players aged 18-32 years old (mean ± SD: 23.98 ± 3.01 years) who were divided into two groups: financial awarded (n = 48) and financial unawarded for sports performance (n = 62). The anxiety of football players was measured by the Sport Anxiety Scale SAS-2. Coping strategies to manage stress were assessed by the Athletic Coping Skills Inventory ACSI-28. The effect of financial awards in relation to football players' anxiety and coping skills was evaluated by the mediators' model using the PROCESS software (Hayes, 2018).

RESULTS

The results suggest that financial awards are important factors that influence football players' anxiety and coping skills. The financial awards increase the motivation of football players to better prepare for sports performance, which has been proven, through better setting of performance goals and more careful mental preparation. Financially awarded football players seem to respect the coach and follow his instructions to a greater extent than unawarded football players, which may be due to the financial benefits and the commitment they have confirmed by signing to the football club. In another aspect, the financial awards are likely to increase the cognitive trait of the anxiety of football players. It seems that financial players are more concerned about the failure of the match, which increases their anxiety, especially since it is a cognitive part and affects their sports performance.

CONCLUSION

For this reason, we encourage sports organizations to focus more on the mental preparation of football players. It is important to provide football players the opportunity to graduate from short- or long-term mental training conducted by a trained sports psychologist not only at the time of the athlete's failure but also as a preventive measure against increasing cognitive anxiety. We recommend sports organizations to train coaches in the field of mental training, preferably through annual short training sessions with a sports psychologist, to influence the development of desirable athletes' coping skills.

Computationally Guided Intracerebral Drug Delivery via Chronically Implanted Microdevices

Treatments for neurologic diseases are often limited in efficacy due to poor spatial and temporal control over their delivery. Intracerebral delivery partially overcomes this by directly infusing therapeutics to the brain. Brain structures, however, are nonuniform and irregularly shaped, precluding complete target coverage by a single bolus without significant off-target effects and possible toxicity. Nearly complete coverage is crucial for effective modulation of these structures. We present a framework with computational mapping algorithms for neural drug delivery (COMMAND) to guide multi-bolus targeting of brain structures that maximizes coverage and minimizes off-target leakage. Custom-fabricated chronic neural implants leverage rational fluidic design to achieve multi-bolus delivery in rodents through a single infusion of radioactive tracer (Cu-64). The resulting spatial distributions replicate computed spatial coverage with 5% error in vivo, as detected by positron emission tomography. COMMAND potentially enables accurate, efficacious targeting of discrete brain regions.

Pathophysiological Basis of Endometriosis-Linked Stress Associated with Pain and Infertility: A Conceptual Review

Women with endometriosis are often under stress due to the associated pain, infertility, inflammation-related and other comorbidities including cancer. Additionally, these women are also under stress due to taboos, myths, inter-personal troubles surrounding infertility and pain of the disease as well as due to frequent incidences of missed diagnosis and treatment recurrence. Often these women suffer from frustration and loss of valuable time in the prime phase of life. All these complexities integral to endometriosis posit a hyperstructure of integrative stress physiology with overt differentials in effective allostatic state in women with disease compared with disease-free women. In the present review, we aim to critically examine various aspects of pathophysiological basis of stress surrounding endometriosis with special emphasis on pain and subfertility that are known to affect the overall health and quality of life of women with the disease and promising pathophysiological basis for its effective management.

Elevated Circulating Th2 Cells in Women With Asthma and Psychological Morbidity: A New Asthma Endotype?

PURPOSE

Psychological stress shifts the immune system toward the production of T-helper (Th)-2-mediated cytokines and eosinophilia, increases the risks for both asthma and depression, and can precipitate asthma exacerbations. Th2-mediated inflammation is a characteristic of allergic asthma. We have shown that the levels of CD4⁺ Th2 cells in the peripheral blood of patients with asthma are associated with severity and/or control of the disease. To improve our understanding of the interactions between stress and asthma symptoms, we evaluated the effects of psychological comorbidity on Th2-mediated inflammation in patients with asthma.

METHODS

Sixty-six asthmatic patients were recruited from the University of Alberta Asthma Clinic after they gave informed consent. Stress-related effects on asthma and psychological morbidity were assessed using the Asthma Control Questionnaire, completed by the patients at recruitment. Venous blood was collected at recruitment and Th2-mediated immunity evaluated by flow cytometry, quantitative real-time reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay.

FINDINGS

Patients with stress-triggered asthma (n = 12) had higher percentage of CD4⁺ T cells (P = 0.006) and Th2 cells (CD4⁺CRTh2⁺ T cells; P = 0.002) in peripheral blood compared to patients with asthma who did not experience stress-related worsening of disease (n = 54). The same was true when we analyzed patients with any form of psychological comorbidity (n = 19) compared to those without psychological comorbidities (n = 47). These differences were evident among women, but not among men. Women with psychological comorbidity also required higher doses of inhaled and oral corticosteroids compared to those without psychological comorbidity.

IMPLICATIONS

Asthma involving psychological morbidity associates with an elevated level of circulating Th2 cells and increased corticosteroid usage, and may be more prevalent in women. Larger-scale prospective studies are required for assessing whether these women constitute a new endotype of Th2-high asthma responsive to treatments aimed to improve psychological comorbidities.

[Indicated Stress Prevention for Adolescents in the Group Setting - A manual based on Acceptance- and Commitment-Therapy]

Indicated Stress Prevention for Adolescents in the Group Setting - A manual based on Acceptance- and Commitment-Therapy Stress in adolescence has become a topic of interest in recent years. Long-term exposure to stress can play a significant role in the development and maintenance of mental disorders. Previous studies have shown that especially the more severely stressed adolescents benefit from targeted interventions. However, evidence-based treatment concepts targeting this group are scarce. In this article we introduce the first German-language treatment manual for indicated stress prevention, addressing adolescents based on Acceptance and Commitment Therapy (ACT). ACT is part of the third wave of behavioral therapies, designed for treatment across disorders, which makes it suitable for the treatment of chronic stress symptoms. Previous studies show good efficacy of the ACT-approach in the treatment of adult stress and first promising successes in treatment of adolescents in non-German-speaking countries. The focus of our training lies in practical exercises based on ACT which are conveyed by the use of metaphors, art therapy techniques, role plays and group discussions. The concept is complemented by psychoeducation on stress, mindfulness exercises and training in problem solving. Worksheets and tasks for the week facilitate the transfer into everyday life. Alongside the presentation of the treatment manual, first experiences in the implementation of the program are discussed.

Hypothalamic Crh/Avp, Plasmatic Glucose and Lactate Remain Unchanged During Habituation to Forced Exercise

It has been demonstrated that physical activity contributes to a healthier life. However, there is a knowledge gap regarding the neural mechanisms producing these effects. One of the keystones to deal with this problem is to use training programs with equal loads of physical activity. However, irregular motor and stress responses have been found in murine exercise models. Habituation to forced exercise facilitates a complete response to a training program in all rodents, reaching the same load of physical activity among animals. Here, it was evaluated if glucose and lactate - which are stress biomarkers - are increased during the habituation to exercise. Sprague-Dawley rats received an 8-days habituation protocol with progressive increments of time and speed of running. Then, experimental and control (non-habituated) rats were subjected to an incremental test. Blood samples were obtained to determine plasmatic glucose and lactate levels before, immediately after and 30 min after each session of training. Crh and Avp mRNA expression was determined by two-step qPCR. Our results revealed that glucose and lactate levels are not increased during the habituation period and tend to decrease toward the end of the protocol. Also, Crh and Avp were not chronically activated by the habituation program. Lactate and glucose, determined after the incremental test, were higher in control rats without previous contact with the wheel, compared with habituated and wheel control rats. These results suggest that the implementation of an adaptive phase prior to forced exercise programs might avoid non-specific stress responses.

Neurobehavioral Effects of Restricted and Unpredictable Environmental Enrichment in Rats

To study how motivational factors modulate experience-dependent neurobehavioral plasticity, we modify a protocol of environmental enrichment (EE) in rats. We assumed that the benefits derived from EE might vary according to the level of incentive salience attributed to it. To enhance the rewarding properties of EE, access to the EE cage varied randomly from 2 to 48 h for 30 days (REE). The REE group was enriched only 50% of the time and was compared to standard housing and continuous EE (CEE) groups. As behavioral readout, we analyzed the spontaneous activity and the ultrasonic vocalizations (USVs) within the EE cage weekly, and in the open field test at the end of the experiment. In the cage, REE increased the utilization of materials, physical activity, and the rate of appetitive USVs. In the OF, the CEE-induced enhancements in novelty habituation and social signaling were equaled by the REE. At the neural level, we measured the expression of genes related to neural plasticity and epigenetic regulations in different brain regions. In the dorsal striatum and hippocampus, REE upregulated the expression of the brain-derived neurotrophic factor, its tropomyosin kinase B receptor, and the DNA methyltransferase 3A. Altogether, our results suggest that the higher activity within the cage and the augmented incentive motivation provoked by the REE boosted its neurobehavioral effects equaling or surpassing those observed in the CEE condition. As constant exposures to treatments or stimulating environments are virtually impossible for humans, restricted EE protocols would have greater translational value than traditional ones.

Decision making under stress: mild hypoxia leads to increased risk-taking

People tend to take more risks under stressful conditions. In the present study, we examined the effect of mild hypoxia, an unconscious and ongoing stressor, on decisions under uncertainty where probabilities are unknown. Participants completed the Balloon Analogue Risk Taking task (BART) in both a normoxic (20.9% oxygen concentration) and a mildly hypoxic (14.1% oxygen concentration) environment. The results indicate that people take more risks in a mildly hypoxic than in a normoxic environment. Despite inducing significant changes in physiological parameters, the oxygen manipulation remained undetected by participants allowing us to rule out a cognitive appraisal account for the effect. Moreover, the stressor was ongoing allowing us to discount possible post-stress reaction explanations. The current findings extend previous ones about the effect of stress on risk-taking and demonstrate that undetected stressors can increase risk-taking in decision making under ambiguity.

Modifiable Cardiovascular Risk, Hematopoiesis, and Innate Immunity

Unhealthy diet, lack of exercise, psychosocial stress, and insufficient sleep are increasingly prevalent modifiable risk factors for cardiovascular disease. Accumulating evidence indicates that these risk factors may fuel chronic inflammatory processes that are active in atherosclerosis and lead to myocardial infarction and stroke. In concert with hyperlipidemia, maladaptive immune system activities can contribute to disease progression and increase the probability of adverse events. In this review, we discuss recent insight into how the above modifiable risk factors influence innate immunity. Specifically, we focus on pathways that raise systemic myeloid cell numbers and modulate immune cell phenotypes, reviewing hematopoiesis, leukocyte trafficking, and innate immune cell accumulation in cardiovascular organs. Often, relevant mechanisms that begin with lifestyle choices and lead to cardiovascular events span multiple organ systems, including the central nervous, endocrine, metabolic, hematopoietic, immune and, finally, the cardiovascular system. We argue that deciphering such pathways provides not only support for preventive interventions but also opportunities to develop biomimetic immunomodulatory therapeutics that mitigate cardiovascular inflammation.

Clinical characteristics of hospitalised patients with schizophrenia who were suspected to have coronavirus disease (COVID-19) in Hubei Province, China

Background

Since the outbreak of COVID-19, no data have been available for hospitalised psychiatric patients who are suspected to have COVID-19. We performed a comprehensive investigation of the clinical features of hospitalised patients with schizophrenia with or without suspected COVID-19 in Hubei Province, China.

Aim

To explore the clinical characteristics of hospitalised patients with schizophrenia with suspected COVID-19 in Hubei Province, China.

Methods

21 hospitalised patients with schizophrenia with suspected COVID-19 (COVID-19 suspected group) in the isolation ward of a mental health hospital in Wuhan and 30 hospitalised patients with schizophrenia (clean group) in the general ward of another mental health hospital in Yichang were recruited. We retrospectively reviewed their clinical characteristics, laboratory findings and chest CT results before 21 February 2020. We also compared the emotional and mental symptoms between the two groups.

Results

Medical records revealed that 21 COVID-19 suspected patients were transferred to the isolation ward between 30 January 2020 and 15 February 2020. The mean age (SD) of COVID-19 suspected patients was 43.1 (2.6). 12 (57.1%) patients showed abnormalities on chest CT before onset of respiratory symptoms. 14 (66.7%) patients had psychiatric medications adjustment after detection of abnormal chest CT findings. By 21 February, one patient was confirmed to have COVID-19. Even though the remaining 20 (95.2%) were negative for at least two reverse transcription PCR tests, 11 (52.4%) patients met the diagnostic criteria for clinically confirmed cases. Compared with patients in the clean group, patients in the suspected COVID-19 group showed significantly higher stress, depression and anxiety levels and poorer sleep quality.

Conclusion

Setting up an independent isolation ward for hospitalised psychiatric patients who are suspected to have symptoms of COVID-19 helped control the spread of the epidemic. Patients with schizophrenia suspected to have COVID-19 showed increased stress and mood and sleep disturbances, which should be appropriately managed.

Corticotropin-Releasing Factor Family: A Stress Hormone-Receptor System's Emerging Role in Mediating Sex-Specific Signaling

No organ in the body is impervious to the effects of stress, and a coordinated response from all organs is essential to deal with stressors. A dysregulated stress response that fails to bring systems back to homeostasis leads to compromised function and ultimately a diseased state. The components of the corticotropin-releasing factor (CRF) family, an ancient and evolutionarily conserved stress hormone-receptor system, helps both initiate stress responses and bring systems back to homeostasis once the stressors are removed. The mammalian CRF family comprises of four known agonists, CRF and urocortins (UCN1–3), and two known G protein-coupled receptors (GPCRs), CRF₁ and CRF₂. Evolutionarily, precursors of CRF- and urocortin-like peptides and their receptors were involved in osmoregulation/diuretic functions, in addition to nutrient sensing. Both CRF and UCN1 peptide hormones as well as their receptors appeared after a duplication event nearly 400 million years ago. All four agonists and both CRF receptors show sex-specific changes in expression and/or function, and single nucleotide polymorphisms are associated with a plethora of human diseases. CRF receptors harbor N-terminal cleavable peptide sequences, conferring biased ligand properties. CRF receptors have the ability to heteromerize with each other as well as with other GPCRs. Taken together, CRF receptors and their agonists due to their versatile functional adaptability mediate nuanced responses and are uniquely positioned to orchestrate sex-specific signaling and function in several tissues.

Stress and Psychiatric Disorders: The Role of Mitochondria

In seeking to understand mental health and disease, it is fundamental to identify the biological substrates that draw together the experiences and physiological processes that underlie observed psychological changes. Mitochondria are subcellular organelles best known for their central role in energetics, producing adenosine triphosphate to power most cellular processes. Converging lines of evidence indicate that mitochondria play a key role in the biological embedding of adversity. Preclinical research documents the effects of stress exposure on mitochondrial structure and function, and recent human research suggests alterations constituting recalibrations, both adaptive and nonadaptive. Current research suggests dynamic relationships among stress exposure, neuroendocrine signaling, inflammation, and mitochondrial function. These complex relationships are implicated in disease risk, and their elucidation may inform prevention and treatment of stress- and trauma-related disorders. We review and evaluate the evidence for mitochondrial dysfunction as a consequence of stress exposure and as a contributing factor to psychiatric disease.

Co-expression Network of mRNAs and lncRNAs Regulated by Stress-Linked Behavioral Assays

RATIONALE

Mood-related behavioral assays, designed typically on rodents' natural aversion to certain threats, are useful in studying the mechanisms of mood and in discovering effective treatments for neuropsychiatric disorders.

OBJECTIVES

Although reasonable attention has been paid to the conducted sequence, few studies address the argument whether a behavioral assay itself affects the intrinsic signaling, gene expression, and the subsequent performance of mice.

METHODS

We examined the short- (1 day) and long-term effects (7 and 14 days) of commonly used behavioral assays for anxiety and depression, including the elevated plus maze test (EPM), forced swimming test (FST), and tail suspension test (TST), on behaviors. We also investigated the effects of repeated behavioral assays on behaviors. The alterations in the expression profiles in the hippocampus experienced behavioral assays were explored via the integrative analysis of mRNA and lncRNA transcriptomes generated by RNA sequencing.

RESULTS

We found that one FST or TST can induce anxiety-related behaviors, while repeated FST or TST resulted in depression-related behaviors in mice. The altered behaviors were associated with extensive transcriptional alterations in the FST and TST hippocampus of mice. KEGG pathway analyses indicated that differentially expressed genes (DEGs) in the FST and TST hippocampus were enriched in anxiety- and metabolic-related pathways, respectively. Moreover, differentially expressed lncRNAs, showing correlations with DEGs, were linked to anxiety-related pathways in the FST hippocampus and metabolic-related pathways in the TST hippocampus.

CONCLUSIONS

Our study identified the unique and shared mRNAs and lncRNAs regulated by mood-related behavioral assays, emphasizing the importance of the sequence of and intervals between them.

[Modern views on the relationship between psychoemotional state and the bioelectrical activity of facial muscles]

The paper presents a review of the literature data reflecting the relevance and current views on the problem of facial feedback. It considers the relationship between the bioelectric activity of facial muscles and neuropsychic stress. The modern issues dedicated to the study of the correlation between the indicators assessing the tonic activity of facial muscles and psycho-emotional stress are highlighted. Particular emphasis is placed on the scientific concept of emotional proprioception, according to which facial muscle activity through the trigeminal and facial nerves affects the emotional centers of the brain, by improving or worsening the emotional state. The currently known methods for the correction of psychoemotional states, which are based on the feedback mechanism, are analyzed. The possibilities of using neuromuscular relaxation of the facial muscles to correct psychoemotional conditions are considered.

The aetiology of social deficits within mental health disorders: The role of the immune system and endogenous opioids

The American National Institute for Mental Health (NIMH) has put out a set of research goals that include a long-term plan to identify more reliable endogenous explanations for a wide variety of mental health disorders (Insel, 2013). In response to this, we have identified a major symptom that underlies multiple mental health disorders - social bonding dysfunction. We suggest that endogenous opioid abnormalities can lead to altered social bonding, which is a symptom of various mental health disorders, including depression, schizophrenia and ASD. This article first outlines how endogenous opioids play a role in social bonding. Then we show their association with the body's inflammation immune function, and review recent literature linking inflammation to mental health 'immunophenotypes'. We finish by explaining how these immunophenotypes may be caused by alterations in the endogenous opioid system. This is the first overview of the role of inflammation across multiple disorders where we provide a biochemical explanation for why immunophenotypes might exist across diagnoses. We propose a novel mechanism of how the immune system may be causing 'sickness-type' behaviours (fatigue, appetite change, social withdrawal and inhibited motivation) in those who have these immunophenotypes. We hope that this novel aetiology can be used as a basis for future research in mental health.

Non-Coding RNAs in Psychiatric Disorders and Suicidal Behavior

It is well known that only a small proportion of the human genome code for proteins; the rest belong to the family of RNAs that do not code for protein and are known as non-coding RNAs (ncRNAs). ncRNAs are further divided into two subclasses based on size: 1) long non-coding RNAs (lncRNAs; >200 nucleotides) and 2) small RNAs (<200 nucleotides). Small RNAs contain various family members that include microRNAs (miRNAs), small interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and small nuclear RNAs (snRNAs). The roles of ncRNAs, especially lncRNAs and miRNAs, are well documented in brain development, homeostasis, stress responses, and neural plasticity. It has also been reported that ncRNAs can influence the development of psychiatric disorders including schizophrenia, major depressive disorder, and bipolar disorder. More recently, their roles are being investigated in suicidal behavior. In this article, we have comprehensively reviewed the findings of lncRNA and miRNA expression changes and their functions in various psychiatric disorders including suicidal behavior. We primarily focused on studies that have been done in postmortem human brain. In addition, we have briefly reviewed the role of other small RNAs (e.g. piwiRNA, siRNA, snRNA, and snoRNAs) and their expression changes in psychiatric illnesses.

Exploring the Stress Impact in the Paternal Germ Cells Epigenome: Can Catecholamines Induce Epigenetic Reprogramming?

Spermatogenesis is characterized by unique epigenetic programs that enable chromatin remodeling and transcriptional regulation for proper meiotic divisions and germ cells maturation. Paternal lifestyle stressors such as diet, drug abuse, or psychological trauma can directly impact the germ cell epigenome and transmit phenotypes to the next generation, pointing to the importance of epigenetic regulation during spermatogenesis. It is established that environmental perturbations can affect the development and behavior of the offspring through epigenetic inheritance, including changes in small non-coding RNAs, DNA methylation, and histones post-translational modifications. But how male germ cells react to lifestyle stressors and encode them in the paternal epigenome is still a research gap. Most lifestyle stressors activate catecholamine circuits leading to both acute and long-term changes in neural functions, and epigenetic mechanisms show strong links to both long-term and rapid, dynamic gene expression regulation during stress. Importantly, the testis shares a molecular and transcriptional signature with the brain tissue, including a rich expression of catecholaminergic elements in germ cells that seem to respond to stressors with similar epigenetic and transcriptional profiles. In this minireview, we put on stage the action of catecholamines as possible mediators between paternal stress responses and epigenetic marks alterations during spermatogenesis. Understanding the epigenetic regulation in spermatogenesis will contribute to unravel the coding mechanisms in the transmission of the biological impacts of stress between generations.

Chronic Stress and Diabetes Mellitus: Interwoven Pathologies

Stress threatens the homeostasis and mobilizes a plethora of adaptive physiological and behavioral changes via the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. The HPA axis influences the pituitary gland, hypothalamus and adrenal gland via a complex set of positive and negative feedback system. The feedback system operates in a well regulated neuroendocrine manner to reestablish the threatened body equilibrium. The HPA axis secreted major product is a glucocorticoid (cortisol) which is kept within a physiologically optimal range and serves to accomplish the various physiological functions crucial for survival. In chronically stressed individuals dishabituation of HPA axis is followed by increased release of glucocorticoids and catecholamines. Higher secretion of glucocorticoids influences glucose metabolism by promoting gluconeogenesis in the liver, suppressing glucose uptake (adipocytes and skeletal muscles), promoting lipolysis in adipocytes, suppressing insulin secretion, inflicting insulin resistance and inflammation. These biological changes alter neuroendocrine mechanisms and lead to maladaptive congregation of events that form the underlying cause of development of Type 2 diabetes (T2D). The currently reviewed evidences advocate that targeting stress mediated hypersecretion of glucocorticoids may be a viable approach for the treatment of T2D and to reinstate glucose homeostasis.