Effects of Ringer's solution with different concentrations of alcohol on biphasic compound action potentials of frog sciatic nerve trunk

Abstract

To quantitatively investigate the effects of Ringer's solution with different concentrations of alcohol (1%～80%) on biphasic compound action potentials (AP) from frog sciatic nerve trunk, and their recoveries from alcohol effects. Individual segments of frog sciatic nerve trunk with a length of 6 to 8 cm were prepared. Ringer's solution with different concentrations of alcohol (0%, 1%, 2%, 4%, 8%, 16%, 32%, 48%, 64% and 80%) was applied onto the segment of the trunk between the stimulus and ground electrodes via an agent reservoir which was newly armed in a nerve trunk shielded chamber for 5 minutes. The nerve trunk was respectively electro-stimulated to generate the biphasic compound AP which was recorded using the experimental system of BL-420F. This was followed by 5 times washout plus 5 min administration with Ringer's solution before recovery recording of AP. Compared to normal Ringer's solution, Ringer's solution with alcohol at ≤4% did not have dramatic impacts on the AP amplitude and conduction velocity, while Ringer's solution with alcohol at ≥8% there was significant decrease in these two parameters. Ringer's solution with alcohol at the conentrations of 16%, 32% and ≥48% could prevent a small proportion (30%), a large proportion (90%) and all (100%) of sciatic nerve trunks, respectively, from generating AP. Washout with normal Ringer's solution after alcohol application at the concentration of ≤32%, AP could totally recover to normal status. While alcohol at the concentration of 48%, 64% and 80%, the probabilities to regenerate APs were 90%, 40% and 0%, and the AP amplitudes were decreased to 60%, 36% and 0%, respectively. After washout, AP conduction velocity showed no difference with alcohol at the concentration of ≤8% when compared with that before washout, while it could not be recovered to normal under alcohol at ≥16%. Ringer's solution with different concentrations of alcohol exerts different effects on biphasic compound AP amplitude and conduction velocity. Hopefully, our findings could be helpful for the alcoholic usage and its recovery from alcoholic damage.