Decompaction of CNS myelin leads to a reduction of the conduction velocity of action potentials in optic nerve.

The conduction velocity of action potentials in nerve fibres is proportional to degree of myelination. Here we studied the influence of myelin ultrastructure on the compound action potential conduction velocity in optic nerves of the proteolipid protein (PLP)-deficient mouse model, which displays loose myelination in central fibres. We show that a myelin decompaction leads to a suboptimal conduction velocity. The significance of myelin ultrastructure for conduction of action potential in the optic nerve is discussed.