What occurs during depolarization in a neuron?

During depolarization in a neuron, the membrane potential becomes less negative, moving towards zero and sometimes even becoming positive. This process occurs mainly due to the influx of sodium ions (Na+) through sodium channels that open in response to a stimulus, leading to a rapid change in membrane potential.

When considering the correct choice, it is clear that during depolarization the resting potential difference, which is typically around -70 mV in a neuronal cell, is effectively reversed temporarily. This means that the inside of the neuron becomes more positive compared to the outside, which is a critical step in the generation of an action potential.

Depolarization is essential for the conduction of nerve impulses, and without it, signals would not be transmitted efficiently. The other options do not accurately describe the changes that occur during depolarization; for instance, the membrane does not become more negative, the neuron becomes more responsive as it is activated, and repolarization is a subsequent phase that occurs after depolarization, not during it.