The effect of DDD on single ranvier nodes of Xenopus laevis

Abstract

Membrane potentials of single Ranvier nodes of myelinated nerve fibres were measured. DDD suppressed the rising phase of the action potential, probably by a reduction of the inward sodium current. This effect is in sharp contrast to that of DDT, which does not affect the rising phase but slows down the falling phase of the action potential by prolonging the inward sodium current.