Quantitative assessment of amphetamine induced behavioural changes in rhesus monkeys, Macaca mulatta

Graded dose of amphetamine (AMP; 1-4 mg/kg, im) induced suppression of approach, contact, body jerk, grooming and food forage, hypervigilance (checking), stereotyped behaviour and oral hyperkinesia in rhesus monkeys. Pretreatment with haloperidol--a dopamine receptor blocking agent (0.04 mg/kg, im)--significantly suppressed the AMP induced hypervigilance, stereotypy and oral hyperkinesia but was unable to reverse other AMP induced behavioural effects in the monkeys. Haloperidol (0.01-0.04 mg/kg, im) per se produced decrease in social and solitary behaviour and marked cataleptic posture. The results suggest that dopamine may be playing an important role in the mediation of many AMP induced behavioural changes in primates.