What is the first step in the sequence of events that occur during an action potential?

The first step in the sequence of events that occur during an action potential is when a local potential arrives at the axon hillock. This localized change in membrane potential is crucial because it is at this point where the neuron integrates incoming signals from synapses. If the depolarization reaches a certain threshold at the axon hillock, it triggers the opening of voltage-gated sodium channels, leading to the rapid depolarization characteristic of an action potential.

This step sets the stage for the subsequent events that follow. Without the arrival of the local potential to initiate this series of actions, an action potential cannot occur. The local potential must accumulate and reach the threshold for the action potential to be generated, illustrating the critical role this first step plays in neuronal signaling.