[Changes in the synaptic activity in sciatic nerve-extensor digitorum longus (preparations induced by ethanol)].

The aim of this research is the study of the modification of synaptic activity caused by ethanol in the rat sciatic nerve-extensor digitorum longus (EDL) muscle preparation. For such a purpose, intracellular recordings have been carried out, keeping the muscle immersed in normal Ringer solution and in Ringer solutions containing ethanol at different concentrations up to 0,8 M. Therefore, the resting potential of muscle cells and the frequency of m.e.p.p.s were measured. Qualitative observations of m.e.p.p.s shape were also carried out. Ethanol increases the frequency of m.e.p.p.s in the rat sciatic nerve - EDL muscle preparation. The logarithm of relative frequency (frequency in Ringer solution with ethanol/frequency in normal Ringer solution) is linear with respect to the concentration of ethanol, with a slope of 1.44. Furthermore, ethanol increases the amplitude and lengthens the time course of m.e.p.p.s. The muscle cells undergo a hyperpolarization of about 2-3% at the lowest concentrations of ethanol tested.