SCOPOLAMINE PRODUCES LOCOMOTOR STEREOTYPY IN AN OPEN-FIELD BUT APOMORPHINE DOES NOT

Both dopaminergic and nondopaminergic drugs produce hyperlocomotion in rats. Dopaminergic drugs also produce focused stereotypy (absence of locomotion and intense sniffing or licking/biting of a restricted area of the environment). Some drugs produce repetitive routes of locomotion; this phenomenon might represent a combination of hyperlocomotion and stereotypy. Scopolamine (an acetylcholine antagonist) and apomorphine (a dopamine agonist) both produce hyperlocomotion in rats; apomorphine also produces focused stereotypy but scopolamine does not. This research determines whether these drugs also produce locomotor stereotypy as measured by γ. Scopolamine (0.5 and 2.0 mg/kg) produced locomotor stereotypy at both doses. Apomorphine (1.0, 2.0, and 3.0 mg/kg) failed to reliably produce locomotor stereotypy. Thus, there is not necessarily a relationship between the ability of a drug to produce focused stereotypy and the ability of the drug to produce locomotor stereotypy. © 1990.