The effect of n-alkanols on the stationary current voltage behavior and action potential of myelinated nerve.

Stationary current voltage characteristics and the action potential of single myelinated nerve fibres were measured to examine the effect of n-alkanols (methanol to octanol) on the electrophysiological function of the axon membrane. K+-depolarized membranes show alkanol-dependent shifts of VTr, the membrane transition voltage, whereas in veratridine-depolarized membranes such VTr-shifts are not observed. In the latter case, n-alkanols reduce both the stationary Na+ current and the conductivity step between the high- and low-ohmic conductivity state of the membrane. Action potential amplitude, however, is less affected by the alkanols as is the stationary Na+ current. The results are compared with the alkanol-dependent changes of the thermotropic phase transition in phospholipid bilayers.