Computerized rotometer apparatus for recording circling behavior.

A computerized rotometer for recording rotational behavior in rats is described. The digital pulses derived from the infrared photocell detector induced by animal rotations were input directly to a 20-megabyte microcomputer for on-line recording and were processed further to the Digital Equipment Corporation's VAX computer with the SAS software system for statistical and graphical analysis. The typical results obtained with drugs (apomorphine and amphetamine) eliciting contralateral and ipsilateral rotation in rats with unilateral 6-hydroxydopamine (6-OHDA)-induced lesions of the nigrostriatal dopamine pathway were presented. The effect of catechol-O-methyltransferase (COMT) inhibitor, OR-611, on the potentiation of L-dopa-induced contralateral rotation in 6-OHDA-lesioned rats was also studied. The automation of rotometer apparatus and the speed of data analysis facilitate screening novel antiparkinsonian drugs in rats with unilateral lesions of 6-OHDA.