Author: Thomas B. Morgan
The current study examined in 2-h sessions the effects of intraperitoneal injections of dextromethorphan (DM) (0.0, 40.0, 60.0, and 80.0 mg/kg) on the acquisition of lever-press responding
in rats that were exposed to a two-lever procedure in which responses on the
reinforcement lever (RL) were reinforced with food after a 15-s resetting delay and responses on the cancellation lever cancelled a scheduled reinforcer. Response acquisition was observed at all drug doses. A decrease in RL responses, food deliveries, and the number of subjects that acquired responding was observed at the highest dose of DM. All doses of DM increased latency to respond relative to the
control group. The results of…
