Fiber composition of the posterior lateral-line nerve of goldfish, investigated by electrophysiological and microscopical techniques.

Abstract

AbstractThe trunk of the posterior lateral‐line nerve of goldfish was stimulated electrically, and the evoked compound spike potential was recorded from the proximal cut end of the nerve. The spike potential consisted of four components which were distinguished from each other by differences of excitability, refractory period and conduction velocity. They were named F‐1, F‐2, F‐3 and S, in the order of decreasing conduction velocity. All of these components could generally be elicited by stimulation of the small nerve branches innervating canal organs.By means of light‐ and electron‐microscopical examination, the fiber diameter spectrum of the posterior lateral‐line nerve was obtained. The observed compound spike potentials were reconstructed successfully from this fiber spectrum. It is concluded that the three subgroups, F‐1, F‐2 and F‐3 components are thick myelinated fibers and the S component is thin myelinated fibers.