What does depolarization in neurons involve?

Depolarization in neurons primarily involves a loss of electrical potential across the neuron's membrane. Under resting conditions, a neuron maintains a negative internal charge compared to the outside of the cell, primarily due to the distribution of ions, with higher concentrations of sodium ions outside the cell and potassium ions inside.

During depolarization, there is a rapid influx of sodium ions (Na+) into the neuron through voltage-gated sodium channels. This influx results in a decrease in the negative charge inside the cell, leading to a net positive charge briefly. The electrical potential moves toward zero and can even become positive for a short time, which constitutes the depolarization phase of an action potential.

The idea of losing electrical potential directly relates to the movement of ions during this process. Other options, while they have elements of truth regarding different aspects of neuronal function, do not capture the essence of depolarization in the same direct way. For instance, an increase in negative charge would describe hyperpolarization rather than depolarization, and the concept of restoring balance typically refers to the subsequent steps in an action potential, like repolarization.