Summary.
Rats received haloperidol (1.0 mg/kg i.p.) or clozapine (10 mg/kg i.p.), twice daily for 4 weeks: vacuous chewing -recorded 26 h after the final injection- similarly increased in both groups. Three h later, the rats were challenged with dopaminomimetics, and automatically recorded jaw movements were analysed. Both apomorphine and a mixture of D1 and D2 receptor agonists (SKF 38393 resp. quinpirole) increased jaw movements in haloperidol-treated, but not clozapine-treated rats; SKF 38393 or quinpirole remained ineffective, when given alone. A fixed dose of quinpirole together with increasing doses of SKF 38393, but not a fixed dose of SKF 38393 together with increasing doses of quinpirole, produced a dose-dependent increase in jaw movements in otherwise non-treated rats, suggesting that the noted haloperidol-induced increase was due to a shift in the D1–D2 receptor balance towards a predominance of D1 receptors. This study presents a new animal model of tardive dyskinesia with predictive validity, good reliability and, especially, great efficiency.
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Received March 4, 1999; accepted May 22, 1999
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Ikeda, H., Adachi, K., Hasegawa, M. et al. Effects of chronic haloperidol and clozapine on vacuous chewing and dopamine-mediated jaw movements in rats: evaluation of a revised animal model of tardive dyskinesia. J Neural Transm 106, 1205–1216 (1999). https://doi.org/10.1007/s007020050234
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DOI: https://doi.org/10.1007/s007020050234