Question

Why is it easier to record the electrical activity of single axons in invertebrate nerves than in vertebrate nerves?

Answer 1

1.Axons are the main neural elements activated by stimulation , with smaller diameter axons having higher threshold than large axons.

2.Axons of invertebrates are unmylinated which describes all invertebrates axons and small axons of vertebrates typically axons below micro metre.

3The unmylineted axon is usually surrounded by glial cell or in some cases such as parallel fibres in the cerebellar molecular layer which is not covered by glial cell.

4.The speed of action potential of unmyelinated axon is proportional to the square root of the axon diameter.

5.Thus invertebrates have large diameter axons for signals that need to be propagated rapidly