Behavioral effects of neurotensin: operant responding and assessment of 'anhedonia'.

Neurotensin and antipsychotic drugs share certain properties. This study investigates whether neurotensin and neuroleptics share the ability to produce 'anhedonia'. A dose-response curve for the effect of neurotensin on continuously reinforced behavior was obtained in Experiment 1. Centrally administered neurotensin reduced food-reinforced responding. Based on the results of Experiment 1, a dose of neurotensin (0.95 micrograms) was chosen which had minimal effects on food-reinforced operant responding. To test for anhedonia, repeated presentations of this dose were given. Because response rates did not decrease over repeated testing, no evidence for anhedonia was found.