Allostasis – Wikipedia

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Allostasis – Wikipedia

Allostasis

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Allostasis proposes that efficient regulation requires anticipating needs and preparing to satisfy them before they arise,[1] as opposed to homeostasis, in which the goal is a steady state.

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Etymology[edit]

Allostasis /ˌɑːloʊˈsteɪsɪs/ from the Greek prefix ἄλλοςállos, “other,” “different” + the suffix στάσιςstasis, “standing still”.

Nature of concept[edit]

The concept was named by Sterling and Eyer in 1988. Allostasis was coined from the Greek allo, which means “variable;” thus, “remaining stable by being variable”.[2][3] Allostatic regulation reflects, at least partly, cephalic involvement in primary regulatory events, in that it is anticipatory to systemic physiological regulation.[2][4] This is different from homeostasis, which occurs in response to subtle ebb and flow. Both homeostasis and allostasis are endogenous systems responsible for maintaining the internal stability of an organism. Homeostasis is formed from the Greek adjective homoios, meaning “similar,” and the noun stasis, meaning “standing;” thus, “standing at about the same level.”[2]

The term heterostasis is also used in place of allostasis, particularly where state changes are finite in number and therefore discrete (e.g. computational processes).[5]

Wingfield states:

The concept of allostasis, maintaining stability through change, is a fundamental process through which organisms actively adjust to both predictable and unpredictable events… Allostatic load refers to the cumulative cost to the body of allostasis, with allostatic overload… being a state in which serious pathophysiology can occur… Using the balance between energy input and expenditure as the basis for applying the concept of allostasis, two types of allostatic overload have been proposed.[6]

Sterling (2004) proposed six interrelated principles that underlie allostasis:[7]

  1. Organisms are designed to be efficient
  2. Efficiency requires reciprocal trade-offs
  3. Efficiency also requires being able to predict future needs
  4. Such prediction requires each sensor to adapt to the expected range of input
  5. Prediction also demands that each effector adapt its output to the expected range of demand
  6. Predictive regulation depends on behavior whilst neural mechanisms also adapt.

continues

Allostasis – Wikipedia