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

2006 ◽  
Vol 8 (4) ◽  
pp. 367-381 ◽  

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.

2004 ◽  
Vol 16 (9) ◽  
pp. 4
Author(s):  
B. McEwen

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 and a factor in the expression of disease that differs among individuals. A broader view is that it is not just the dramatic stressful events that exact their toll but rather the many events of daily life that elevates activities of physiological systems so as to cause some measure of wear and tear. We call this wear and tear 'allostatic load', and it reflects not only the impact of life experiences but also genetic load' individual life-style habits reflecting items such as diet, exercise and substance abuse' and developmental experiences that set life-long patterns of behavior and physiological reactivity (1). Hormones associated with stress and allostatic load protect the body in the short-run and promote adaptation, but the long run allostatic load causes changes in the body that lead to disease. This will be illustrated for the immune system and brain regions involved in stress, fear and cognition (e.g. hippocampus, amygdala and prefrontal cortex). Besides developmental influences associated with mother–infant interactions, the most potent of stressors in adult life are those arising from competitive interactions between animals of the same species, leading to the formation of dominance hierarchies. Psychosocial stress of this type not only impairs cognitive function of lower ranking animals, but it can also promote disease (e.g. atherosclerosis) among those vying for the dominant position, as well as depressive illness. Social ordering in human society is also associated with gradients of disease, with an increasing frequency or mortality and morbidity as one descends the scale of socioeconomic status (SES) that reflects both income and education. Although the causes of these gradients of health are very complex, they are likely to reflect, with increasing frequency at the lower end of the scale, the cumulative burden of coping with limited resources and negative life events as well as differences in life style, and the allostatic load that this burden places on the physiological systems involved in adaptation and coping. (1) McEwen, B.S. (1998) Protective and damaging effects of stress mediators. New England J. Med. 238, 171–179.


Author(s):  
Bruce S. McEwen

The response to the social and physical environment involves two-way communication between the brain and the body and epigenetic adaptation (‘allostasis’) via mediators of the cardiovascular, immune, metabolic, neuroendocrine, and neural mechanisms. Chronic stress causes wear and tear on the brain and body (‘allostatic load and overload’), reflecting also the impact of health-damaging behaviours and lasting effects of early life experiences interacting with genetic predispositions. Hormonal and other mediators of allostasis promote adaptation in the short run but cause allostatic load/overload when they are overused or dysregulated. The brain is key because it determines what is threatening and the physiological and behavioural responses, while showing structural remodelling that affects its function. Besides pharmaceuticals, there are ‘top–down’ interventions, like physical activity, that engage ‘the wisdom of the body’ to change itself, as well as the impact of policies of government and business that encourage individuals to manage their own lives and promote increased ‘healthspan’.


2015 ◽  
Vol 31 (2) ◽  
pp. 452
Author(s):  
Mariantonia Lemos

The attachment bond has been proven to be a vulnerability factor for chronic diseases. This article seeks to clarify this relationship by the theory of allostasis. Allostasis theory refers to the regulation of complex physiological processes by systemic response in the body maintaining physiological stability when a person is confronted by challenges. The insecure attachments confront children from his first years with stressful events, by failing to provide security, fundamental purpose of attachment. In this way insecure attachments could impact the calibration of the stress system in the early age and would be factors that increases the allostatic load by a larger number of stressful life events compare to people with secure attachment, a cognitive appraisal of threat that leads to the development of hypervigilance and the impact on stress regulation systems in the body.


2017 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Desby Juananda ◽  
Dwi Cahyani Ratna Sari ◽  
Djoko Prakosa2, ◽  
Nur Arfian ◽  
Mansyur Romi

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.


2005 ◽  
Vol 20 (S3) ◽  
pp. S302-S306 ◽  
Author(s):  
B.E. Leonard

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.


2007 ◽  
Vol 87 (3) ◽  
pp. 873-904 ◽  
Author(s):  
Bruce S. McEwen

The brain is the key organ of the response to stress because it determines what is threatening and, therefore, potentially stressful, as well as the physiological and behavioral responses which can be either adaptive or damaging. Stress involves two-way communication between the brain and the cardiovascular, immune, and other systems via neural and endocrine mechanisms. Beyond the “flight-or-fight” response to acute stress, there are events in daily life that produce a type of chronic stress and lead over time to wear and tear on the body (“allostatic load”). Yet, hormones associated with stress protect the body in the short-run and promote adaptation (“allostasis”). The brain is a target of stress, and the hippocampus was the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. Stress and stress hormones produce both adaptive and maladaptive effects on this brain region throughout the life course. Early life events influence life-long patterns of emotionality and stress responsiveness and alter the rate of brain and body aging. The hippocampus, amygdala, and prefrontal cortex undergo stress-induced structural remodeling, which alters behavioral and physiological responses. As an adjunct to pharmaceutical therapy, social and behavioral interventions such as regular physical activity and social support reduce the chronic stress burden and benefit brain and body health and resilience.


2018 ◽  
Vol 32 (1) ◽  
pp. 30-42 ◽  
Author(s):  
Claudia Traunmüller ◽  
Kerstin Gaisbachgrabner ◽  
Helmut Karl Lackner ◽  
Andreas R. Schwerdtfeger

Abstract. In the present paper we investigate whether patients with a clinical diagnosis of burnout show physiological signs of burden across multiple physiological systems referred to as allostatic load (AL). Measures of the sympathetic-adrenergic-medullary (SAM) axis and the hypothalamic-pituitary-adrenal (HPA) axis were assessed. We examined patients who had been diagnosed with burnout by their physicians (n = 32) and were also identified as burnout patients based on their score in the Maslach Burnout Inventory-General Survey (MBI-GS) and compared them with a nonclinical control group (n = 19) with regard to indicators of allostatic load (i.e., ambulatory ECG, nocturnal urinary catecholamines, salivary morning cortisol secretion, blood pressure, and waist-to-hip ratio [WHR]). Contrary to expectations, a higher AL index suggesting elevated load in several of the parameters of the HPA and SAM axes was found in the control group but not in the burnout group. The control group showed higher norepinephrine values, higher blood pressure, higher WHR, higher sympathovagal balance, and lower percentage of cortisol increase within the first hour after awakening as compared to the patient group. Burnout was not associated with AL. Results seem to indicate a discrepancy between self-reported burnout symptoms and psychobiological load.


Philosophies ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Fiorella Battaglia

Moral issues arise not only when neural technology directly influences and affects people’s lives, but also when the impact of its interventions indirectly conceptualizes the mind in new, and unexpected ways. It is the case that theories of consciousness, theories of subjectivity, and third person perspective on the brain provide rival perspectives addressing the mind. Through a review of these three main approaches to the mind, and particularly as applied to an “extended mind”, the paper identifies a major area of transformation in philosophy of action, which is understood in terms of additional epistemic devices—including a legal perspective of regulating the human–machine interaction and a personality theory of the symbiotic connection between human and machine. I argue this is a new area of concern within philosophy, which will be characterized in terms of self-objectification, which becomes “alienation” following Ernst Kapp’s philosophy of technology. The paper argues that intervening in the brain can affect how we conceptualize the mind and modify its predicaments.


2017 ◽  
Vol 118 (4) ◽  
pp. 2499-2506 ◽  
Author(s):  
A. Pomante ◽  
L. P. J. Selen ◽  
W. P. Medendorp

The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.


2021 ◽  
Vol 4 (2) ◽  
pp. 245-250
Author(s):  
Lidya Ariyanti ◽  
Redia Indira Putrianti ◽  
Setiawati Setiawati

ABSTRAK Kosentrasi merupakan keadaan pikiran atau asosiasi terkondisi yang diaktifkan oleh sensasi di dalam tubuh. Cara mengaktifkan sensasi di dalam tubuh adalah dengan membuat tubuh berada dalam keadaan yang rileks dan suasana yang menyenangkan, karena dalam keadaan yang tegang seseorang tidak akan dapat menggunakan otaknya dengan maksimal oleh karena pikiran menjadi kosong. Fenomena yang terjadi di lapangan diketahui bahwa penurunan konsentrasi belajar pada anak belum mendapatkan penanganan yang maksimal. Selama ini teknik yang digunakan memiliki kelemahan tersendiri yang tentunya tujuan dari peningkatan konsentrasi belajar belum dapat dirasakan oleh semua siswa, seharusnya teknik peningkatan konsentrasi belajar di buat lebih mudah dan efektif. Salah satunya adalah teknik Brain Gym. Tujuan setelah diberikan terapi senam otak diharapkan dapat meningkatkan konsentrasi belajar pada anak. Adapun kegiatan yang dilakukan berupa penyuluhan dan demonstrasi terapi senam otak. Terdapat peningkatan konsentrasi belajar pada anak setelah diberikan terapi senam otak di Desa Rawajitu Selatan. Dengan demikian, pemberian terapi senam otak efektif dalam meningkatkan konsentrasi belajar. Kata Kunci: Konsentrasi, Senam Otak, Peningkatan Konsentrasi Belajar  ABSTRACT Concentration is a state of mind or conditioned association that is activated by sensations in the body. How to activate sensations in the body is to make the body in a relaxed state and pleasant atmosphere, because in a tense situation a person will not be able to use his brain to the maximum because the mind becomes empty. The phenomenon that occurs in the field is known that the reduction in the concentration of learning in children has not gotten the maximum treatment. During this time the technique used has its own weaknesses which of course the purpose of increasing concentration of learning can not be felt by all students, the technique of increasing the concentration of learning should be made easier and more effective. One of them is the Brain Gym technique. The goal after being given brain exercise therapy is expected to increase the concentration of learning in children. The activities carried out in the form of counseling and demonstration of brain exercise therapy. There is an increase in the concentration of learning in children after being given brain exercise therapy at Rawajitu Selatan Village. Thus, the administration of brain exercise therapy is effective in increasing concentration of learning. Keywords: Concentration, Brain Exercise, Increased Learning Concentration


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