[Effect of some psychotropic drugs on spontaneous electromyographic activity in the stressed rat]

Electromyographic registration of a skeletal muscle allows to point out not only the phasic activation but also the tonic activity which otherwise is difficult to value. We registered the spontaneous electromyographic activity of the gastrocnemius muscle in stressed rats. The intensity of the electromyographic signal is measured by electronic rectification and integration. We studied the dose-effect correlation of some neurotropic drugs: Pentobarbital, Meprobamate, Chlorpromazine, Sulpiride, Amitriptyline, D-Amphetamine. Chlorpromazine progressively reduces the spontaneous mioelectric activity until the whole abolition. At the studied doses Meprobamate doesn't reduce completely the spontaneous activity. At small doses of Pentobarbitral the spontaneous activity increases while at high doses it's abolished. At small doses Amitriptyline becomes an exciting drug while at higher doses it reduces the spontaneous mioelectric activity. Sulpiride at small doses inhibits the spontaneous activity while at high doses it seems to increase it. At all tested doses D-amphetamine remarkably increases the spontaneous mioelectric activity.