Question

Place the following phases of the action potential in the order that they would occur at the axon hillock:

1. Resting Vm
2.EPSPs are summed
3. Membrane potential becomes more positive
4.Membrane potential stops depolarizing
5.Membrane potential becomes more negative
6.Membrane potential is more negative than resting membrane potential
7.Membrane potential becomes more positive to reach resting membrane potential

Answer 1

The order of action potential stages at the axon hillock begins with the resting membrane potential, then the excitatory postsynaptic potentials leading to depolarization, followed by repolarization, hyperpolarization, and finally restoration to the resting potential.

The sequence of phases of an action potential at the axon hillock is:

1. Resting Vm.
2. EPSPs are summed.
3. Membrane potential becomes more positive (depolarization).
4. Membrane potential stops depolarizing as Na+ channels inactivate.
5. Membrane potential becomes more negative (beginning of repolarization).
6. Membrane potential is more negative than resting membrane potential (hyperpolarization).
7. Membrane potential becomes more positive to reach resting membrane potential (restoration).

This order reflects the process from the neuron resting state through excitement, the peak of action, and recovery back to the resting state.