Parkinsonian-like tremor induced by a combined application of chlorpromazine and pentobarbitone in cats with left-paw preference.

A Parkinsonian-like tremor can be induced by a combined application of chlorpromazine and pentobarbitone in cats. Interestingly enough, only cats with left-paw preference were found to have a predisposition to this drug-induced tremor. The cats with ambidexterity and right-preference in paw use did not show any visible tremorogenic action of these drugs. Especially the proximal muscles of all four extremities showed oscillations with a frequency of about 12 per second in all animals tested, which completely disappeared after i.v. application of lioresal, atropine and biperiden. It was suggested that this new drug-induced tremor model may reflect an impairment within the cortico-striato-pallido-thalamo-cortical feedback loop. It was also concluded that left-handers may have an increased predisposition to centrally acting drugs than nonleft-handers.