Effects of Certain Indole Amines on Electrical Activity of the Nervous System

Abstract

Lysergic acid diethylamide (LSD), 5-hydroxytryptamine, and adrenochrome were shown to have properties similar to epinephrine in their effects on the spontaneous electrical activity in the brain of the albino rat. The effects of these drugs were shown to be determined by the type of anesthetic used. In Pentothal-anesthetized animals, profound reduction of the electrical activity in both frequency and amplitude was found in response to these drugs, while in ether-anesthetized animals there was no significant effect. There was a tendency for LSD to increase electrical activity when injected following recovery from anesthesia. The significance of this differential response is discussed with respect to structures in the central nervous system primarily affected by ether and Pentothal, and it is suggested that the site of action of these compounds is in Pentothal-sensitive nonspecific pathways. The site of the depressive action of these drugs with Pentothal is further defined by the fact that both cortical and subcortical structures were equally affected, while respiratory and cardio-regulatory centers were not significantly depressed. This implicates one of the lower nonspecific centers with widespread cortical and subcortical projections.