Tolerance for the decrease in nerve conduction velocity and for the motor impairment produced by ethanol in mice: differential development during chronic ethanol consumption.

C57BL/6J/BOM mice were given 15% (w/v) ethanol solution as their sole drinking fluid. Nerve conduction velocities (NCV) and motor coordination (ataxia) of the unanesthetized animals were examined after a single IP injection of 3.0 g ethanol/kg body weight at 6, and 9 months after the start of drinking and after 3 months of abstinence. During chronic consumption of ethanol, tolerance for relative conduction time (RCT) change developed in six months. This tolerance was not observed after 9 months of ethanol treatment. The tolerance for ataxia persisted throughout the period of ethanol treatment. After a three month's abstinence, no differences between the controls and the animals previously on ethanol were observed regarding responses to acute ethanol administration. These observations suggest that different mechanisms underlie the development of tolerance for the effect of ethanol on peripheral nerve conductance and for the ataxia from ethanol in the central nervous system.