The "Undershoot" Phase of After-Hyperpolarization is Due To

Question

The "undershoot" phase of after-hyperpolarization is due to
A)slow opening of voltage-gated sodium channels.
B)sustained opening of voltage-gated potassium channels.
C)rapid opening of voltage-gated calcium channels.
D)slow restorative actions of the sodium-potassium ATPase.
E)ions that move away from their open ion channels.

Accepted Answer

During the after-hyperpolarization phase, there is a prolonged opening of voltage-gated potassium channels, which allows potassium ions to move out of the neuron leading to a more negative resting membrane potential. This leads to an undershoot phase as the membrane potential becomes more negative than the resting potential. Therefore, sustained opening of voltage-gated potassium channels is responsible for the undershoot phase of after-hyperpolarization.