What occurs when the membrane potential is reduced to less than -70 mV?

When the membrane potential is reduced to less than -70 mV, hyperpolarization occurs. Hyperpolarization is characterized by an increase in the membrane's negativity beyond its resting potential, which is typically around -70 mV in neurons. This change can result from the influx of negatively charged ions or the efflux of positively charged ions, making the inside of the neuron more negative relative to the outside.

In contrast, depolarization involves a decrease in the negativity of the membrane potential, moving it closer to zero or into the positive range. This usually occurs during the initiation of an action potential when sodium channels open. Repolarization refers to the process of returning the membrane potential to its resting level after depolarization, and resting potential signifies the stable state of the neuron before any activity occurs. Understanding these concepts helps clarify the fundamental processes involved in neuronal signaling.