The terminal myelin segments of afferent axons to cutaneous mechanoreceptors.

The present study documents reductions in thickness of the myelin sheath without change in axonal diameter in a series of fortuitous longitudinal sections of axons innervating mechanoreceptors. These findings are interpreted to mean that we must indicate that caution should be expressed in the evaluation of quantitative data on myelinated axons in close proximity to their termination as sensory receptors.