EFFECTS OF PSYCHOTROPIC DRUGS ON THE SPONTANEOUS MOTOR ACTIVITY IN MICE

Abstract

Changes in the spontaneous motor activity of mice induced by psychotropic drugs have been measured by a set of methods which were constructed for a differential observation in various aspects of behaviour. These observations consisted in a running activity measured by a revolving cage with counting device, small movements recorded by a electrical method reported by Utena and the auther, and a rating scale of motor activity as a whole.
The drugs used were central stimulants (Methamphetamine, Pipradrol, Methylphenidate, Caffeine), central depressants (Chlorpromazine, Reserpine, Phenobarbital), and LSD-derivatives (LSD-25, BOL-148, LAE-32).
For evaluating the stimulating effect on running activity were used the following criteria, i. e., the time course, the mean and maximum increase in number of revolution and the daily amount of revolution subsequent to the drug administration. Distinct qualitative difference in stimulating effects between the stimulants was evidenced in the time-revolution curve and in the recording of small movements, even in the doses which give the same mean increase in running activity. Methamphetamine was peculiar in its marked after-depression in spontaneous motor activity, which persisted for several days after the administration.
Among the three kinds of central depressants, reserpine was much slow acting than the others. It was revealed that chlorpromazine was effective to extinguish response behaviour to external stimuli, this was demonstrated by the recordings of responsive movements.
LSD-derivaties gave rise to bi-phasic effect on spontaneous motor activity, stimulating for a short duration and depressing slightly afterwards.