ABSTRACT
In a neuron, action potentials are initiated at the axon hillock because this region has the greatest density of Navs and so the lowest threshold. Hence the axon hillock is also 37called the spike initiation zone. Once generated, action potentials are actively propagated (conducted) with constant velocity down the axon without loss of amplitude. Thus, action potentials are undiminished in size even when conducted along peripheral axons that in humans may be up to one meter long. This is one of the features that makes action potentials reliable signals for information transmission. The details of conduction are a little different depending on whether the neuron is myelinated or not.
