THE EFFECT OF ETHANOL ON THE DYNAMIC-RESPONSE OF A MECHANORECEPTOR NEURON

This report describes the acute effects of ethanol on the electrical o utput of a stretch-sensitive neuron during periods of intermittent, no n-synaptic, stretch stimulation. The firing rate of the neuron of the tonic muscle receptor organ (MRO) of the crayfish, Cherax destructor, was monitored during intermittent stretch before and after the applica tion of 100mM or 140mM ethanol, concentrations that cause reversible b ehavioural intoxication in the crayfish. Application of 100mM ethanol resulted in a trend towards an increased rate of firing during subsequ ent pull episodes, a trend which became statistically significant afte r 25 minutes. At an ethanol concentration of 140mM the effect was more marked and occurred sooner, suggesting that it is concentration depen dent. The same concentrations of ethanol applied to the statically str etched neuron have been shown previously to cause a decrease in firing rate. The present result provides evidence that the effect of ethanol on the tonic neuron of the MRO depends on its level of activity.