The spontaneously diabetic Wistar-BB rat manifests altered grooming and catalepsy responses: implications of impaired...

1. The purpose of this study was to investigate the hypothesis that the grooming and catalepsy behaviors, believed to be mediated predominantly by the D1 and D2 dopamine receptor based mechanism(s), respectively, are altered in the Spontaneously Diabetic Wistar-BB Rat (SDR). 2. The insulin treated male SDR (5-6 months diabetic) and a genetically matched Non-Diabetic (NDR) control group were monitored for pharmacologically-induced catalepsy as well as stress-induced grooming. 3. Results obtained indicated that the SDR manifested an increased sensitivity to i) the cataleptogenic effects of haloperidol (0.3-1.0 mg/kg; s.c.) and ii) to the grooming response elicited by a mild stressor (novel environment), when compared to the NDR group. However, under more stressful conditions, the NDR groomed as much as the SDR. The altered behavioral sensitivity of the SDR may be a consequence of impaired dopaminergic neurotransmission and the subsequent upregulation of D1 receptors.