What is the term for a reduction in the electric potential across the plasma membrane of a neuron?

The correct term for a reduction in the electric potential across the plasma membrane of a neuron is depolarization. Depolarization occurs when there is a decrease in the negative charge inside the neuron relative to the outside. This typically happens when sodium channels open, allowing sodium ions to flow into the cell, causing the inside of the neuron to become more positive. This shift in membrane potential is crucial for the generation and propagation of action potentials, which are essential for neuronal communication.

While resting potential refers to the stable, baseline state of a neuron when it is not actively transmitting signals, and hyperpolarization refers to an increase in negative charge, depolarization is specifically characterized by the reduction of the negative charge within the cell, moving it closer to zero. Repolarization is the process that occurs after depolarization, where the membrane potential returns to its resting state. Thus, depolarization is the most appropriate term for the described change in electric potential.