Drug-Induced Motor Behavior

It is hoped that elucidation of the mechanisms of drug-induced locomotor activity can provide clues as to how some of these other factors might affect locomotor behavior.

Abstract

The property of directed movement which most animals possess is a major difference between them and other living things and is largely responsible for their ability to manipulate their environment. In fact, active motor behavior appears to be crucial for perceptual development and learning (Held and Hein, 1963). Here we consider some of the neural mechanisms which underly three types of drug-induced motor behavior. The first of these, locomotor activity, is influenced not only by drugs but by a wide variety of genetic, developmental, hormonal, environmental, motivational, and endogenous rhythmic factors. It is hoped that elucidation of the mechanisms of drug-induced locomotor activity can provide clues as to how some of these other factors might affect locomotor behavior. The second type of activity, stereotyped behavior, is rarely seen in the undrugged animal but is reported to be a striking feature of human schizophrenic behavior (Bleuler, 1950). The third type of behavior, drug-induced circling, is generally studied in animals with some type of unilateral lesion but can be induced in the intact animal (Glick et al., 1976). The behavior is closely related to asymmetric dopaminergic activity in the corpora striata, and its study may reveal functional relationships within the basal ganglia and between them and other brain structures. For reasons of consistency the experiments considered here are mainly restricted to those performed on the rat.