Hodgkin Cycle
Encyclopedia
The Hodgkin cycle represents a positive feedback
loop in which an initial membrane depolarization leads to uncontrolled deflection of the membrane potential to near VNa. The initial depolarization must reach or surpass threshold in order to activate voltage-gated Na+ channels. Opening of Na+ channels allows Na+ inflow which, in turn, further depolarizes the membrane. Additional depolarization activates additional Na+ channels. This cycle leads to a very rapid rise in Na+ conductance (gNa), which moves the membrane potential close to VNa.
Created by Alan Lloyd Hodgkin
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Positive feedback
Positive feedback is a process in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system that responds to a perturbation in a way that reduces its effect is...
loop in which an initial membrane depolarization leads to uncontrolled deflection of the membrane potential to near VNa. The initial depolarization must reach or surpass threshold in order to activate voltage-gated Na+ channels. Opening of Na+ channels allows Na+ inflow which, in turn, further depolarizes the membrane. Additional depolarization activates additional Na+ channels. This cycle leads to a very rapid rise in Na+ conductance (gNa), which moves the membrane potential close to VNa.
Created by Alan Lloyd Hodgkin
Alan Lloyd Hodgkin
Sir Alan Lloyd Hodgkin, OM, KBE, PRS was a British physiologist and biophysicist, who shared the 1963 Nobel Prize in Physiology or Medicine with Andrew Huxley and John Eccles....
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