Mastering A&P Neurophysiology Practice Test

A local hyperpolarization refers to an increase in the membrane's potential, making the inside of the neuron more negative relative to the outside. This change in the membrane potential moves it further away from the threshold level needed to initiate an action potential, thus decreasing the likelihood of neuronal firing.

The term "inhibitory postsynaptic potential" (IPSP) is used to describe this effect. When a neuron experiences hyperpolarization, it is generally due to the influx of negatively charged ions (like chloride ions) or the efflux of positively charged ions (like potassium ions). This creates an inhibitory effect on the postsynaptic neuron, making it less likely to reach the threshold for an action potential.

In contrast, a stable resting potential would indicate no significant change in membrane potential. An excitatory postsynaptic potential would instead involve depolarization, bringing the neuron closer to the threshold for firing. An action potential represents a rapid depolarization followed by repolarization, which is not consistent with a hyperpolarization event. Therefore, the correct answer, indicating that hyperpolarization typically leads to an inhibitory postsynaptic potential, reflects the fundamental principles of neurophysiology concerning membrane potentials.