A neuron normally fires when
A) its sodium-potassium pumps are stimulated.
B) there is an EPSP.
C) there is an IPSP.
D) the degree of depolarization on the axon adjacent to the hillock exceeds the threshold of excitation.
E) its buttons are stimulated.

Question

Quizplus · Accepted Answer

The correct choice is D because neurons communicate with each other by generating electrical signals called action potentials. An action potential occurs when the depolarization of a neuron's cell membrane exceeds the threshold of excitation. This depolarization triggers the opening of voltage-gated sodium channels and the influx of sodium ions, which in turn cause the membrane potential to become even more positive. This positive feedback loop leads to a rapid depolarization of the cell membrane and the generation of an action potential.

A Neuron Normally Fires When