What is the term for the potential difference that occurs across a nerve cell's plasma membrane when stimulated?

The potential difference that occurs across a nerve cell's plasma membrane when it is stimulated is referred to as the action potential. This is a rapid fluctuation in membrane potential that occurs when a nerve cell is activated by a stimulus strong enough to reach a threshold. During an action potential, there is a significant influx of sodium ions into the cell, leading to depolarization, where the inside of the neuron becomes more positively charged relative to the outside.

The action potential is characterized by a series of voltage changes that allow the nerve signal to be propagated along axons to communicate information. After the peak of the action potential, the membrane undergoes repolarization to return to its resting state, and this process is crucial for the nerve cell to be able to fire again. Understanding the mechanics behind the action potential is fundamental to comprehending how nerve cells function and transmit signals, making it a key concept in neurobiology.