Question Detail
Question
Which one of the following is the most fundamental characteristic of the excitatory post-synaptic potential?
Correct Answer
Option C is the correct answer.
Detailed Explanation
The most fundamental characteristic of an excitatory postsynaptic potential (EPSP) is the depolarization of the postsynaptic membrane. This depolarization is typically caused by the opening of ligand-gated ion channels (often for Na+), making the membrane potential less negative and bringing it closer to the threshold for firing an action potential. The increased ion permeability (B) is the cause, but depolarization (C) is the defining characteristic of an EPSP.
Hint
What is the primary change in membrane potential that makes a neuron more likely to fire?