THE EFFECT OF ETHANOL ON THE STEADY-STATE ELECTRICAL-ACTIVITY OF AN INTERMITTENTLY STRETCHED MECHANORECEPTOR

The experiments reported here continue the development of the neurons of the Muscle Receptor Organ (MRO) of the crayfish as a pharmacologica l model for studying the effects of ethanol on the electrical activity of isolated neurons. Previous work showed that ethanol caused a reduc ed firing rate in statically stretched MRO neurons (Macmillan et al., 1991) whereas it increased the firing during stretch episodes (Walsh e t al., 1994). Its effect on the activity of fully adapted MRO neurons between stretch episodes is unknown. We report here results showing th at when ethanol (120mM) was applied to MRO neurons subjected tb a stai rcase extension regime, the firing rate increased in the interpull int ervals, even though the MRO neuron was allowed to adapt fully. The imp lications of this for interpretations of the effect of ethanol on the neuronal membrane and for further identification of the critical eleme nts are discussed.