Activity analysis of operant behavior following methylphenidate administration.

13 male Long-Evans hooded rats were tested on a CRF-50 reinforcement schedule. Total response time as well as time and total activity responses away from the bar were significantly influenced by injections of methylphenidate (1.2 mg/kg I.P.). In general, the data supported previous findings of reduced response rate to the drug. However, methylphenidate (a CNS stimulant) increased activity that was not related to bar pressing. Analysis of activity response to drug should include total time and activity as well as operant rates.