Motility and stereotyped behaviour induced by amphetamine and apomorphine on hypophysectomized and on thyroidectomized rats.

The reduction of the hypermotility and stereotyped behaviour induced by amphetamine and apomorphine was used as a criterion for the effectiveness of neuroleptics. Considering the impact of neuroleptics on the hypophysis as well as the relationship between the hypophysis and the thyroid, motility and stereotyped behaviour induced by amphetamine and apomorphine was studied in both hypophysectomized and thyroidectomized rats. In the hypophysectomized rat, amphetamine-induced hypermotility, observed between 1 and 3 hours after administration, was almost 3 times greater than in normal animals. Thyroidectomy resulted in a reversal of the motility effect induced by amphetamine. The stereotyped behaviour induced by apomorphine was practically abolished in both hypophysectomized and thyroidectomized animals.