Effects of intrastriatal and intracortical scopolamine on behavior in rats

The anticholinergic drug scopolamine (20 micrograms, 30 micrograms, 40 micrograms) or its vehicle was injected unilaterally into the dorsal anterior striatum or overlying rostral neocortex in rats in order to examine the role of each region in contralateral postural deviation and stereotyped rearing. Scopolamine-induced contralateral deviation was observed in all subjects with striatal injections (p less than 0.01), and was of the same magnitude at all dose levels. Intracortical scopolamine did not induce contralateral deviation. However, stereotyped rearing was elicited from both the striatum and neocortex (p less than 0.01) at the two highest dose levels of scopolamine. Thus the mechanisms for contralateral deviation and stereotyped rearing differ both with respect to brain region and drug sensitivity.