Question

As you increase the stimulation voltage to a nerve would you expect to first see large extracellular action potentials or small ones? Explain.

Answer 1

There are ranges of stimulus intensity that evoke different amount of depolarisations in compound action potential nerve.

A subthreshold stimulus is at which none of the nerves get stimulated.

A threshold stimulus is that which is just enough to depolarize the nerve. At this point not all the neurons reach action potential so a little recording is seen in compound action potential.

If we apply an intense stimulus that could depolarize all the nerves , a strong compound action potential is recorded.

If the stimulus is increased beyond this point then there will be no change because already all the neurons have reached there action potential.