Action potentials are normally generated at the axon hillock and propagated down the axon away from the cell body. If you experimentally depolarized an axon to the threshold level at a point halfway down the axon, what would happen?
A) An action potential would be generated that would travel to the synapse with the next neuron.
B) An action potential would be generated that would travel back towards the cell body.
C) No action potential could be generated at this location.
D) Answers A and B both apply.

Question

Quizplus · Accepted Answer

Action potentials can propagate in both directions from the point of initiation. If an axon is experimentally depolarized to threshold at a midpoint, an action potential would be generated and could travel both towards the synapse (down the axon) and back towards the cell body. Normally, action potentials are unidirectional due to the refractory period of the membrane just passed, but in this experimental scenario, both directions are equally viable starting points.

Action Potentials Are Normally Generated at the Axon Hillock and Propagated