Differential response control by isopropamide: a peripherally induced discriminative cue.

The peripherally acting anticholinergic drug isopropamide (0.02 mg/kg s.c.) is shown to produce a discriminative stimulus complex in rats. In rats trained to discriminate isopropamide from saline, dexetimide and methylscopolamine were generalized with isopropamide treatment. The results indicate that drug discrimination learning does not necessarily require a central drug action.