The HPA and immune axes in stress: the involvement of the serotonergic system

2005 ◽  
Vol 20 (S3) ◽  
pp. S302-S306 ◽  
Author(s):  
B.E. Leonard
Keyword(s):  
Stress Response ◽  
Chronic Stress ◽  
Hpa Axis ◽  
Feedback Inhibition ◽  
Critical Role ◽  
Serotonergic System ◽  
Anxiety And Depression ◽  
Acute And Chronic Stress ◽  
The Impact ◽  
The Brain

AbstractThe impact of acute and chronic stress on the hypothalamic-pituitary-adrenal (HPA) axis is reviewed and evidence presented that corticotrophin releasing factor (CRF) is the stress neurotransmitter which plays an important role in the activation of the central sympathetic and serotonergic systems. The activity of CRF is expressed through specific receptors (CRF 1 and 2) that are antagonistic in their actions and widely distributed in the limbic regions of the brain, as well as in the hypothalamus, and on immune cells.The mechanism whereby chronic stress, via the CRF induced activation of the dorsal raphe nucleus, can induce a change in the serotonergic system, involves an increase in the 5HT2A and a decrease in the 5HT1A receptor mediated function. Such changes contribute to the onset of anxiety and depression. In addition, the hypersecretion of glucocorticoids that is associated with chronic stress and depression desensitises the central glucocorticoid receptors to the negative feedback inhibition of the HPA axis. This indirectly results in the further activation of the HPA axis.The rise in pro-inflammatory cytokines that usually accompanies the chronic stress response results in a further stimulation of the HPA axis thereby adding to the stress response. While CRF would appear to play a pivotal role, evidence is provided that simultaneous changes in the serotonergic and noradrenergic systems, combined with the activation of peripheral and central macrophages that increase the pro-inflammatory cytokine concentrations in the brain and blood, also play a critical role in predisposing to anxiety and depression. Neurodegenerative changes in the brain that frequently occur in the elderly patient with major depression, could result from the activation of indoleaminedioxygenase (IDO), a widely distributed enzyme that converts tryptophan via the kynenine pathway to for the neurotoxic end product quinolinic acid.

Pengaruh Stres Kronik terhadap Otak: Kajian Biomolekuler Hormon Glukokortikoid dan Regulasi Brain-Derived Neurotrophic Factor (BDNF) Pascastres di Cerebellum

2017 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Desby Juananda ◽  
Dwi Cahyani Ratna Sari ◽  
Djoko Prakosa2, ◽  
Nur Arfian ◽  
Mansyur Romi
Keyword(s):  
Chronic Stress ◽  
Brain Plasticity ◽  
Critical Role ◽  
Synaptic Function ◽  
Bdnf Expression ◽  
Acute And Chronic Stress ◽  
Repetitive Stress ◽  
Central Organ ◽  
The Impact ◽  
The Brain

The brain is the central organ of stress adaptation, and is also a target of stress. Chronic stress may result in abnormalchanges in brain plasticity; include dendritic retraction, neuronal toxicity, and suppression of neurogenesis andaxospinous synaptic plasticity. Repetitive stress exposure will gradually change the electrical characteristic, morphologyand proliferative capacity of neurons. Among brain region, the cerebellum is known to be severely affected by oxidativedamage associated with glucocorticoids level. It is believed due to the highest levels of glucocorticoid receptorslocalized in the external granular layer. BDNF, a member of neurotrophin family, is known to be a strong survivalpromoting factor, and plays a critical role in cell proliferation and differentiation, neuronal protection, and the regulationof synaptic function in the central nervous system. BDNF is highly expressed in the cerebellum, mainly in granulecells. Both acute and chronic stress change BDNF expression in the brain. Although the impact of stress on BDNFlevels showed the different results, BDNF is believed to protect neurons from injuries caused by stress.

scholarly journals Steroid Receptor Coactivator-1-Deficient Mice Exhibit Altered Hypothalamic-Pituitary-Adrenal Axis Function

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1322-1332 ◽  
Author(s):  
Jonathon N. Winnay ◽  
Jianming Xu ◽  
Bert W. O’Malley ◽  
Gary D. Hammer
Keyword(s):  
Chronic Stress ◽  
Hpa Axis ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Feedback Inhibition ◽  
Steroid Receptor ◽  
Serum Glucose ◽  
Compensatory Mechanism ◽  
Hypothalamic Pituitary Adrenal ◽  
Steroid Receptor Coactivator ◽  
Acute And Chronic Stress

Steroidogenic factor-1 (SF-1), has emerged as a critical nuclear receptor regulating development and differentiation at several levels of the hypothalamic-pituitary-steroidogenic axis. Although many coregulatory factors have been shown to physically and functionally interact with SF-1, the relative importance of these interactions in SF-1 target tissues has not been thoroughly established. In this study we assessed roles of steroid receptor coactivator-1 (SRC-1) in hypothalamic-pituitary-adrenal (HPA) axis function using SRC-1-deficient (SRC-1−/−) mice in the absence or presence of SF-1 haploinsufficiency. Surprisingly, SRC-1 deficiency did not alter baseline HPA axis function or the acute rise in corticosterone after ACTH administration and failed to exacerbate adrenocortical dysfunction in SF-1+/− mice. However, after exposure to paradigms of acute and chronic stress, SRC-1−/− mice exhibited an elevation in serum corticosterone despite normal (nonsuppressed) ACTH, suggesting an increase in adrenal sensitivity as well as a concomitant defect in glucocorticoid-mediated feedback inhibition of the HPA axis. An examination of potential compensatory mechanism(s) revealed an increase in adrenal weight, selective elevation of melanocortin 2 receptor mRNA, and a coincident increase in SRC-2 and SRC-3 expression in SRC-1−/− adrenals. A reduction in blood glucose was observed in SRC-1−/− mice after chronic stress, consistent with a generalized state of glucocorticoid resistance. Dexamethasone suppression tests confirmed a weakened ability of glucocorticoids to 1) elevate serum glucose levels and induce hepatic phosphoenolpyruvate carboxykinase transcription and 2) suppress pituitary proopiomelanocortin transcript levels in SRC-1−/− animals. Collectively, these data are consistent with an indispensable role for SRC-1 in mediating actions of glucocorticoids in pituitary and liver.

scholarly journals Protective and damaging effects of stress mediators: central role of the brain

2006 ◽  
Vol 8 (4) ◽  
pp. 367-381 ◽  
Keyword(s):  
Prefrontal Cortex ◽  
Chronic Stress ◽  
Allostatic Load ◽  
The Body ◽  
Stressful Events ◽  
Whole Body ◽  
Acute And Chronic Stress ◽  
The Mind ◽  
The Impact ◽  
The Brain

The mind involves the whole body and two-way communication between the brain and the cardiovascular, immune, and other systems via neural and endocrine mechanisms. Stress is a condition of the mind-body interaction, and a factor in the expression of disease that differs among individuals. It is notjust the dramatic stressful events that exact their toll, but rather the many events of daily life that elevate and sustain activities of physiological systems and cause sleep deprivation, overeating, and other health-damaging behaviors, producing the feeling of being "stressed out." Over time, this results in wear and tear on the body which is called "allostatic load," and it reflects not only the impact of life experiences but also of genetic load, individual lifestyle habits reflecting items such as diet, exercise, and substance abuse, and developmental experiences that set life-long patterns of behavior and physiological reactivity. Hormones associated with stress and allostatic load protect the body in the short run and promote adaptation by the process known as allostasis, but in the long run allostatic load causes changes in the body that can lead to disease. The brain is the key organ of stress, allostasis, and allostatic load, because it determines what is threatening and therefore stressful, and also determines the physiological and behavioral responses. Brain regions such as the hippocampus, amygdala, and prefrontal cortex respond to acute and chronic stress by undergoing structural remodeling, which alters behavioral and physiological responses. Translational studies in humans with structural and functional imaging reveal smaller hippocampal volume in stress-related conditions, such as mild cognitive impairment in aging and prolonged major depressive illness, as well as in individuals with low self-esteem. Alterations in amygdala and prefrontal cortex are also reported. Besides pharmaceuticals, approaches to alleviate chronic stress and reduce allostatic load and the incidence of diseases of modern life include lifestyle change, and policies of government and business that would improve the ability of individuals to reduce their own chronic stress burden.

scholarly journals Impact of Carcinogenic Chromium on the Cellular Response to Proteotoxic Stress

2019 ◽  
Vol 20 (19) ◽  
pp. 4901 ◽  
Author(s):  
Leonardo M. R. Ferreira ◽  
Teresa Cunha-Oliveira ◽  
Margarida C. Sobral ◽  
Patrícia L. Abreu ◽  
Maria Carmen Alpoim ◽  
...  
Keyword(s):  
Stress Response ◽  
Health Effects ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Chemical Properties ◽  
Adverse Health Effects ◽  
Proteotoxic Stress ◽  
Adverse Health ◽  
The Impact

Worldwide, several million workers are employed in the various chromium (Cr) industries. These workers may suffer from a variety of adverse health effects produced by dusts, mists and fumes containing Cr in the hexavalent oxidation state, Cr(VI). Of major importance, occupational exposure to Cr(VI) compounds has been firmly associated with the development of lung cancer. Counterintuitively, Cr(VI) is mostly unreactive towards most biomolecules, including nucleic acids. However, its intracellular reduction produces several species that react extensively with biomolecules. The diversity and chemical versatility of these species add great complexity to the study of the molecular mechanisms underlying Cr(VI) toxicity and carcinogenicity. As a consequence, these mechanisms are still poorly understood, in spite of intensive research efforts. Here, we discuss the impact of Cr(VI) on the stress response—an intricate cellular system against proteotoxic stress which is increasingly viewed as playing a critical role in carcinogenesis. This discussion is preceded by information regarding applications, chemical properties and adverse health effects of Cr(VI). A summary of our current understanding of cancer initiation, promotion and progression is also provided, followed by a brief description of the stress response and its links to cancer and by an overview of potential molecular mechanisms of Cr(VI) carcinogenicity.

scholarly journals Stress and Growth in children and adolescents

2021 ◽  
Author(s):  
Maria Mousikou ◽  
Andreas Kyriakou ◽  
Nicos Skordis
Keyword(s):  
Growth Hormone ◽  
Stress Response ◽  
Chronic Stress ◽  
Early Life ◽  
Stress System ◽  
Childhood And Adolescence ◽  
Conservation Of Energy ◽  
Targeted Interventions ◽  
The Impact

The infantile, childhood, and adolescent periods of growth and development represent times of increased vulnerability to stressors. The rate of growth in each period depends on the interplay of genetic, environmental, dietary, socioeconomic, developmental, behavioral, nutritional, metabolic, biochemical, and hormonal factors. A stressor may have an impact on growth directly through modulation of the growth hormone axis or indirectly through modulation of other factors. The adaptive response to stressors culminates in behavioral, physiological, and biochemical responses, which together support survival and conservation of energy. The process begins within seconds and involves activation of sympathetic nervous system and Hypothalamic-Pituitary-Adrenal axis. The time-limited stress response is at once anti-growth, anti-reproductive and catabolic with no lasting adverse consequences. However, chronic activation of the stress system and hypercortisolism have consequential negative impacts on growth, thyroid function, reproduction-puberty, and metabolism. They suppress Growth Hormone-Insulin like growth factor 1, Hypothalamic-Pituitary-Gonadal and Thyroid axes and can be responsible for an increase in visceral adiposity, a decrease in lean mass, suppression of osteoblastic activity with risk of osteoporosis, and induction of insulin resistance. Early life adversities, emotional or physical, have been associated with long-term negative physical and mental health outcomes. There are many models of chronic stress that corroborate that early life adversities affect optimal growth and have consequences throughout the lifespan. Targeted interventions to reduce stress during infancy, childhood and adolescence can have far reaching benefits to long-term health as well as attaining adequate growth. In this review we describe the neuroendocrinology of the stress response, the factors influencing growth, and the impact of chronic stress on growth during critical periods of infancy, childhood, and puberty with reference to each of growth, thyroid, and gonadal axis.

scholarly journals NG2 glia regulate brain innate immunity via TGF-β2/TGFBR2 axis

BMC Medicine ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Shu-zhen Zhang ◽  
Qin-qin Wang ◽  
Qiao-qiao Yang ◽  
Huan-yu Gu ◽  
Yan-qing Yin ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Diphtheria Toxin ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Normal Brain ◽  
Sequencing Analysis ◽  
Brain Functions ◽  
Lps Challenge ◽  
The Impact ◽  
The Brain

Abstract Background Brain innate immunity is vital for maintaining normal brain functions. Immune homeostatic imbalances play pivotal roles in the pathogenesis of neurological diseases including Parkinson’s disease (PD). However, the molecular and cellular mechanisms underlying the regulation of brain innate immunity and their significance in PD pathogenesis are still largely unknown. Methods Cre-inducible diphtheria toxin receptor (iDTR) and diphtheria toxin-mediated cell ablation was performed to investigate the impact of neuron-glial antigen 2 (NG2) glia on the brain innate immunity. RNA sequencing analysis was carried out to identify differentially expressed genes in mouse brain with ablated NG2 glia and lipopolysaccharide (LPS) challenge. Neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice were used to evaluate neuroinflammatory response in the presence or absence of NG2 glia. The survival of dopaminergic neurons or glial cell activation was evaluated by immunohistochemistry. Co-cultures of NG2 glia and microglia were used to examine the influence of NG2 glia to microglial activation. Results We show that NG2 glia are required for the maintenance of immune homeostasis in the brain via transforming growth factor-β2 (TGF-β2)-TGF-β type II receptor (TGFBR2)-CX3C chemokine receptor 1 (CX3CR1) signaling, which suppresses the activation of microglia. We demonstrate that mice with ablated NG2 glia display a profound downregulation of the expression of microglia-specific signature genes and remarkable inflammatory response in the brain following exposure to endotoxin lipopolysaccharides. Gain- or loss-of-function studies show that NG2 glia-derived TGF-β2 and its receptor TGFBR2 in microglia are key regulators of the CX3CR1-modulated immune response. Furthermore, deficiency of NG2 glia contributes to neuroinflammation and nigral dopaminergic neuron loss in MPTP-induced mouse PD model. Conclusions These findings suggest that NG2 glia play a critical role in modulation of neuroinflammation and provide a compelling rationale for the development of new therapeutics for neurological disorders.

scholarly journals Facilitation of the HPA Axis to a Novel Acute Stress Following Chronic Stress Exposure Modulates Histone Acetylation and the ERK/MAPK Pathway in the Dentate Gyrus of Male Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 2942-2952 ◽  
Author(s):  
Chantelle L. Ferland ◽  
Erin P. Harris ◽  
Mai Lam ◽  
Laura A. Schrader
Keyword(s):  
Dentate Gyrus ◽  
Histone Acetylation ◽  
Chronic Stress ◽  
Hpa Axis ◽  
Acute Stress ◽  
Male Rats ◽  
Stress Exposure ◽  
Erk Activation ◽  
Acute And Chronic Stress ◽  
Acute Stressor

Evidence suggests that when presented with novel acute stress, animals previously exposed to chronic homotypic or heterotypic stressors exhibit normal or enhanced hypothalamic-pituitary-adrenal (HPA) response compared with animals exposed solely to that acute stressor. The molecular mechanisms involved in this effect remain unknown. The extracellular signal-regulated kinase (ERK) is one of the key pathways regulated in the hippocampus in both acute and chronic stress. The aim of this study was to examine the interaction of prior chronic stress, using the chronic variable stress model (CVS), with exposure to a novel acute stressor (2,5-dihydro-2,4,5-trimethyl thiazoline; TMT) on ERK activation, expression of the downstream protein BCL-2, and the glucocorticoid receptor co-chaperone BAG-1 in control and chronically stressed male rats. TMT exposure after chronic stress resulted in a significant interaction of chronic and acute stress in all 3 hippocampus subregions on ERK activation and BCL-2 expression. Significantly, acute stress increased ERK activation, BCL-2 and BAG-1 protein expression in the dentate gyrus (DG) of CVS-treated rats compared with control, CVS-treated alone, and TMT-only animals. Furthermore, CVS significantly increased ERK activation in medial prefrontal cortex, but acute stress had no significant effect. Inhibition of corticosterone synthesis with metyrapone had no significant effect on ERK activation in the hippocampus; therefore, glucocorticoids alone do not mediate the molecular effects. Finally, because post-translational modifications of histones are believed to play an important role in the stress response, we examined changes in histone acetylation. We found that, in general, chronic stress decreased K12H4 acetylation, whereas acute stress increased acetylation. These results indicate a molecular mechanism by which chronic stress-induced HPA axis plasticity can lead to neurochemical alterations in the hippocampus that influence reactivity to subsequent stress exposure. This may represent an important site of dysfunction that contributes to stress-induced pathology such as depression, anxiety disorders, and posttraumatic stress disorder.

scholarly journals The Anteroventral Bed Nucleus of the Stria Terminalis Differentially Regulates Hypothalamic-Pituitary-Adrenocortical Axis Responses to Acute and Chronic Stress

Endocrinology ◽  
2007 ◽  
Vol 149 (2) ◽  
pp. 818-826 ◽  
Author(s):  
Dennis C. Choi ◽  
Nathan K. Evanson ◽  
Amy R. Furay ◽  
Yvonne M. Ulrich-Lai ◽  
Michelle M. Ostrander ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Hpa Axis ◽  
Paraventricular Nucleus ◽  
Restraint Stress ◽  
Body Weight Gain ◽  
Stria Terminalis ◽  
Thymic Involution ◽  
Bed Nucleus ◽  
Acute And Chronic Stress

The anteroventral region of the bed nucleus of the stria terminalis (BST) stimulates hypothalamic-pituitary-adrenocortical (HPA) axis responses to acute stress. However, the role of the anterior BST nuclei in chronic drive of the HPA axis has yet to be established. Therefore, this study tests the role of the anteroventral BST in physiological responses to chronic drive, using a chronic variable stress (CVS) model. Male Sprague-Dawley rats received either bilateral ibotenate lesions, targeting the anteroventral BST, or vehicle injection into the same region. Half of the lesion and control rats were exposed to a 14-d CVS paradigm consisting of twice-daily exposure to unpredictable, alternating stressors. The remaining rats were nonhandled control animals that remained in home cages. On the morning after the end of CVS exposure, all rats were exposed to a novel restraint stress challenge. CVS induced attenuated body weight gain, adrenal hypertrophy, thymic involution, and enhanced CRH mRNA in hypophysiotrophic neurons of the hypothalamic paraventricular nucleus, none of which were affected by anteroventral BST lesions. In the absence of CVS, lesions attenuated the plasma corticosterone and paraventricular nucleus c-fos mRNA responses to the acute restraint stress. In contrast, lesions of the anteroventral BST elevated plasma ACTH and corticosterone responses to novel restraint in the rats previously exposed to CVS. These data suggest that the anterior BST plays very different roles in integrating acute stimulation and chronic drive of the HPA axis, perhaps mediated by chronic stress-induced recruitment of distinct BST cell groups or functional reorganization of stress-integrative circuits.

scholarly journals Neuroendocrine Function After Hypothalamic Depletion of Glucocorticoid Receptors in Male and Female Mice

Endocrinology ◽  
2015 ◽  
Vol 156 (8) ◽  
pp. 2843-2853 ◽  
Author(s):  
Matia B. Solomon ◽  
Matthew Loftspring ◽  
Annette D. de Kloet ◽  
Sriparna Ghosal ◽  
Ryan Jankord ◽  
...  
Keyword(s):  
Chronic Stress ◽  
Hpa Axis ◽  
Glucocorticoid Receptors ◽  
Acute Stress ◽  
Feedback Inhibition ◽  
Forced Swim Test ◽  
Feedback Regulation ◽  
Signaling Mechanism ◽  
Cell Groups ◽  
Neuroendocrine Responses

Abstract Glucocorticoids act rapidly at the paraventricular nucleus (PVN) to inhibit stress-excitatory neurons and limit excessive glucocorticoid secretion. The signaling mechanism underlying rapid feedback inhibition remains to be determined. The present study was designed to test the hypothesis that the canonical glucocorticoid receptors (GRs) is required for appropriate hypothalamic-pituitary-adrenal (HPA) axis regulation. Local PVN GR knockdown (KD) was achieved by breeding homozygous floxed GR mice with Sim1-cre recombinase transgenic mice. This genetic approach created mice with a KD of GR primarily confined to hypothalamic cell groups, including the PVN, sparing GR expression in other HPA axis limbic regulatory regions, and the pituitary. There were no differences in circadian nadir and peak corticosterone concentrations between male PVN GR KD mice and male littermate controls. However, reduction of PVN GR increased ACTH and corticosterone responses to acute, but not chronic stress, indicating that PVN GR is critical for limiting neuroendocrine responses to acute stress in males. Loss of PVN GR induced an opposite neuroendocrine phenotype in females, characterized by increased circadian nadir corticosterone levels and suppressed ACTH responses to acute restraint stress, without a concomitant change in corticosterone responses under acute or chronic stress conditions. PVN GR deletion had no effect on depression-like behavior in either sex in the forced swim test. Overall, these findings reveal pronounced sex differences in the PVN GR dependence of acute stress feedback regulation of HPA axis function. In addition, these data further indicate that glucocorticoid control of HPA axis responses after chronic stress operates via a PVN-independent mechanism.

scholarly journals Differential Impact of Acute and Chronic Stress on CA1 Spatial Coding and Gamma Oscillations

2021 ◽  
Vol 15 ◽  
Author(s):  
Anupratap Tomar ◽  
Denis Polygalov ◽  
Thomas J. McHugh
Keyword(s):  
Chronic Stress ◽  
Cognitive Processing ◽  
Structural Integrity ◽  
Spatial Information ◽  
Acute Stress ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Spatial Coding ◽  
Acute And Chronic Stress ◽  
The Impact

Chronic and acute stress differentially affect behavior as well as the structural integrity of the hippocampus, a key brain region involved in cognition and memory. However, it remains unclear if and how the facilitatory effects of acute stress on hippocampal information coding are disrupted as the stress becomes chronic. To examine this, we compared the impact of acute and chronic stress on neural activity in the CA1 subregion of male mice subjected to a chronic immobilization stress (CIS) paradigm. We observed that following first exposure to stress (acute stress), the spatial information encoded in the hippocampus sharpened, and the neurons became increasingly tuned to the underlying theta oscillations in the local field potential (LFP). However, following repeated exposure to the same stress (chronic stress), spatial tuning was poorer and the power of both the slow-gamma (30–50 Hz) and fast-gamma (55–90 Hz) oscillations, which correlate with excitatory inputs into the region, decreased. These results support the idea that acute and chronic stress differentially affect neural computations carried out by hippocampal circuits and suggest that acute stress may improve cognitive processing.

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