Automated analysis of stereotypic behavior induced by psychomotor stimulants

A newly developed rotation sensing device has been applied to the continuous monitoring of animal movement. Animals treated with morphine, amphetamine or apomorphine display different stereotypic movements which can be distinguished by the apparatus. Initial studies have indicated that the apparatus is able not only to identify but also to quantitate some measures of stereotypic behavior. For example, the number and direction of rotations (a measure of motor asymmetry), frequency of changes in movement direction (a measure of stereotypic movement) and periods of cessation of movement are affected differentially with acute morphine, apomorphine or amphetamine treatment. Moreover, using this apparatus, morphine was shown to increase the degree of rotational asymmetry of normal animals and of animals with unilateral lesions of the nigrostriatal pathway.