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Allostasis: A New Paradigm to Explain Arousal Pathology
Abstract and Figures
homeostasis versus allostasis
mechanisms of allostasis
allostatic regulation of the immune response
regulation of arousal
pathology from chronic arousal
definitions of health and approaches to therapeutics
hypertension / psychoneuriommunology / iatrogenesis / health (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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... Moreover, the stress response is an energy-demanding process, and chronic stress renders energy unavailable for important life processes including growth, digestion, immunity and reproduction (Schreck and Tort, 2016). The attempt to rectify this situation is termed 'allostasis', wherein physiological and behavioral set points of regulatory mechanisms are adjusted to optimize organismal performance under predicted environmental demands at minimal cost (Schreck, 2010;Schreck and Tort, 2016;Sterling and Eyer, 1988). As such, low allostatic load (or eustress) can improve the performance of the animal, whereas allostatic overload (or distress) encountered during chronic stress can become a pathophysiological condition (Schreck and Tort, 2016). ...
Stress and elevated plasma cortisol in salmonids have been linked with pathological remodeling of the heart and deterioration of fitness and welfare. However, these associations were based on biomarkers that fail to provide a retrospective view of stress. This study is the first whereby the association of long-term stress, using scale cortisol as chronic stress biomarker, with cardiac morphology and growth performance of wild Atlantic salmon (Salmo salar) is made. Growth, heart morphology, plasma and scale cortisol levels, and expression of genes involved in cortisol regulation of the hypothalamic-pituitary-interrenal axis of undisturbed fish (CONTROL) were compared with fish exposed daily to stress (STRESS) for 8 weeks. Though scale cortisol levels showed a time-dependent accumulation in both groups, plasma and scale cortisol levels of STRESS fish were 29.1% and 25.0% lower than CONTROL, respectively. These results correlated with the overall upregulation of stress-axis genes involved in the systemic negative feedback of cortisol, and local via 11β-hydroxysteroid dehydrogenases, glucocorticoid-, and mineralocorticoid receptors in the STRESS treatment at hypothalamus and pituitary level. These lower cortisol levels were, however, counterintuitive to the growth performance as STRESS fish grew 33.7% slower than CONTROL which likely influenced the 8.4% increase in relative ventricle mass in STRESS. Though compact myocardium area between the treatments was comparable, these parameters showed significant linear correlations with scale cortisol levels indicating the involvement of chronic stress in cardiac remodeling. These findings underscore the importance of scale cortisol as biomarker when associating chronic stress with long-term processes including cardiac remodeling.
... More recently, the understanding of individual-level stress has been enabled by the development of a major conceptual advance in stress-related research. Allostasis, a new model of physiological regulation that complements homeostasis, was proposed by Peter Sterling and Joseph Eyer in 1988 [3]. Unlike the rigid constancy of homeostasis, allostasis suggests that physiological stability is achieved through variation and is distinguished by predictive regulation orchestrated by the brain. ...
... Evolúciós értelemben e folyamat hasznos, hiszen a változás kulcsfontosságú tényező a túlélés és az alkalmazkodás érdekében. A fennmaradást elősegítő fiziológiai változás folyamata az allosztázis [27]. Az allosztázis alapvető feltétele a külső környezeti és a belső fiziológiás változás felismerésének képessége és az erre adott válasz. ...
Az alkoholizmus és következményei világszerte, így Magyarországon is jelentős közegészségügyi problémát jelentenek. Súlyosbítja a helyzetet, hogy a kezelésbe kerülési ráta alacsony, kezelés esetén pedig a páciensek nagy számban idő előtt befejezik a terápiát. A visszaesési ráta is nagy, a páciensek akár több mint fele a kezelést követő első pár hónapot követően már nem tudja tartani absztinenciáját. Bár az addiktológiai ellátórendszerben a legnagyobb számban 35 év fölött jelennek meg a betegek, az alkoholhasználati zavar kialakulásának okai gyakran már a kora gyermekkori tapasztalatokból eredeztethetők. A gyermekkorban átélt tartós traumák szignifikáns összefüggést mutatnak a későbbi életszakaszokban kialakuló szomatikus és mentális egészségi problémákkal, a szerhasználattal, beleértve az alkoholfüggőséget is. A közlemény az alkoholfüggőség prevalenciájának áttekintésével, illetve a gyermekkori rossz bánásmód és az ártalmas gyermekkori élmények definiálásával indul, majd az ártalmas gyermekkori élmények hatását és hatásmechanizmusait tárgyalja a felnőttkori alkoholhasználati zavar kialakulásának és szerény kezelési rátájának tükrében. A közlemény további célja, hogy felhívja a figyelmet a traumafókuszú gondolkodás és a traumainformált megközelítés jelentőségére az egészségügyi ellátórendszerben, az addiktológiai intervenciók és szolgáltatások tervezésében. Orv Hetil. 2023; 164(41): 1628–1636.
A significant number of persons engage in paradoxical behaviors, such as extreme food restriction (up to starvation) and non-suicidal self-injuries, especially during periods of rapid changes, such as adolescence. Here, we contextualize these and related paradoxical behavior within an active inference view of brain functions, which assumes that the brain forms predictive models of bodily variables, emotional experiences, and the embodied self and continuously strives to reduce the uncertainty of such models. We propose that not only in conditions of excessive or prolonged uncertainty, such as in clinical conditions, but also during pivotal periods of developmental transition, paradoxical behaviors might emerge as maladaptive strategies to reduce uncertainty—by “acting on the body”— soliciting salient perceptual and interoceptive sensations, such as pain or excessive levels of hunger. Although such strategies are maladaptive and run against our basic homeostatic imperatives, they might be functional not only to provide some short-term reward (e.g. relief from emotional distress)—as previously proposed—but also to reduce uncertainty and possibly to restore a coherent model of one’s bodily experience and the self, affording greater confidence in who we are and what course of actions we should pursue.
The knowledge perspective of Descartes’s Method was revolutionary, but rather skewed. The Cartesian view of reality explains change exclusively in reductionist-deterministic terms: the whole is the sum of its parts; the past (cause) determines the present (effect). Left out was the realization that life, in all its embodiments (from the simplest mono-cell to the complex human being) is goal driven.
Opioid use disorder is characterized by excessive use of opioids, inability to control its use, a withdrawal syndrome upon discontinuation of opioids, and long-term likelihood of relapse. The behavioral stages of opioid addiction correspond with affective experiences that characterize the opponent process view of motivation. In this framework, active involvement is accompanied by positive affective experiences which gives rise to “reward craving,” whereas the opponent process, abstinence, is associated with the negative affective experiences that produce “relief craving.” Relief craving develops along with a hypersensitization to the negatively reinforcing aspects of withdrawal during abstinence from opioids. These negative affective experiences are hypothesized to stem from neuroadaptations to a network of affective processing called the “extended amygdala.” This negative valence network includes the three core structures of the central nucleus of the amygdala (CeA), the bed nucleus of the stria terminalis (BNST), and the nucleus accumbens shell (NAc shell), in addition to major inputs from the basolateral amygdala (BLA). To better understand the major components of this system, we have reviewed their functions, inputs and outputs, along with the associated neural plasticity in animal models of opioid withdrawal. These models demonstrate the somatic, motivational, affective, and learning related models of opioid withdrawal and abstinence. Neuroadaptations in these stress and motivational systems are accompanied by negative affective and aversive experiences that commonly give rise to relapse. CeA neuroplasticity accounts for many of the aversive and fear-related effects of opioid withdrawal via glutamatergic plasticity and changes to corticotrophin-releasing factor (CRF)-containing neurons. Neuroadaptations in BNST pre-and post-synaptic GABA-containing neurons, as well as their noradrenergic modulation, may be responsible for a variety of aversive affective experiences and maladaptive behaviors. Opioid withdrawal yields a hypodopaminergic and amotivational state and results in neuroadaptive increases in excitability of the NAc shell, both of which are associated with increased vulnerability to relapse. Finally, BLA transmission to hippocampal and cortical regions impacts the perception of conditioned aversive effects of opioid withdrawal by higher executive systems. The prevention or reversal of these varied neuroadaptations in the extended amygdala during opioid withdrawal could lead to promising new interventions for this life-threatening condition.
I identify and then aim to resolve a tension between the psychological and existential conceptions of boredom. The dominant view in psychology is that boredom is an emotional state that is adaptive and self-regulatory. In contrast, in the philosophical phenomenological tradition, boredom is often considered as an existentially important mood. I leverage the predictive processing framework to offer an integrative account of boredom that allows us to resolve these tensions. This account explains the functional aspects of boredom-as-emotion in the psychological literature, offering a principled way of defining boredom’s function in terms of prediction-error-minimisation. However, mediated through predictive processing, we can also integrate the phenomenological view of boredom as a mood; in this light, boredom tracks our grip on the world – revealing a potentially fundamental (mis)attunement.
Modern capitalist social organization, through intensified, con flicted work and the destruction of cooperative, supportive forms of social com munity, causes a large excess mortality among adults in developed countries. This excess mortality is most strikingly evident in the comparison of vital rates for advanced capitalist societies whith those of undisrupted hunter-gatherers.
Angiotensin II and aldosterone increase in response to sodium deficiency to promote sodium and water conservation. In addition, they may act synergistically to arouse a sodium appetite. If so, then blockade of endogenous angiotensin should decrease the appetite. In experiments reported here, captopril (SQ 14,225) was given peripherally to rats to block conversion of angiotensin I to angiotensin II. It both enhanced and suppressed sodium depletion-induced sodium appetite. The appetite was suppressed when captopril was given in high doses, which block conversion centrally as well as peripherally. The same doses of captopril had no effect on urinary sodium excretion or on sodium appetite aroused by mineralocorticoid treatment. Low doses, which block conversion only in the periphery, enhanced salt intake elicited by depletion, and the enhancement was abolished by captopril given directly into the brain. Therefore the enhancement was probably due to a captopril-induced increase of peripheral angiotensin I, which gained access to the brain and was converted there to angiotensin II.
Truisms are, of course, self evident. In spite of their obviousness we need to reconsider some in order to appreciate understanding that we take for granted and to remind ourselves of the value of particular approaches we use in our research on brain function. It seems evident to me that understanding behavior and higher order brain function reduces to knowing the rules governing the flow of information in neural networks. Biochemical, molecular, cellular and pharmocological events affect brain function by rising to modulate this flow of infomation in neural circuits. Given these axioms it is, therefore, important to learn the organization of the brain’s neural networks.
The author presents a discussion of the steady states (homeostases) of the body, with the explanation, so far as such is possible, of the mechanisms controlling such conditions. The account is closed with analogies between the regulation of the body and the regulation of social processes. Brief bibliography. (PsycINFO Database Record (c) 2012 APA, all rights reserved)