Which of the following describes an excitatory postsynaptic potential (EPSP)?

An excitatory postsynaptic potential (EPSP) is characterized as a transient depolarization of the postsynaptic membrane. This occurs when excitatory neurotransmitters bind to receptors on the postsynaptic neuron, leading to an increase in the permeability of the membrane to sodium ions (Na+). As Na+ ions flow into the neuron, they cause the internal charge of the neuron to become more positive, moving the membrane potential closer to the threshold required for action potential generation. This process enhances the likelihood of the neuron firing an action potential in response to subsequent stimuli, thereby playing a critical role in neural communication.

In this context, recognizing the specific nature of EPSPs is essential for understanding how synaptic transmission occurs and how signals propagate through the nervous system. The transient nature of EPSPs also emphasizes their role as a temporary change in membrane potential that facilitates neuronal communication without permanent alterations in the membrane's resting state.