Attenuation of normeperidine's suppressing effect on schedule-controlled behavior.

The purpose of the present study was to compare several central nervous system (CNS) depressant drugs in their ability to attenuate the suppressant effects of normeperidine on the responding of pigeons under a multiple fixed-ratio, fixed-interval schedule of grain presentation. The effects of pentobarbital (3 and 10 mg/kg i.m.), diazepam (1-10 mg/kg p.o.), clonazepam (0.03-3 mg/kg p.o.), aminooxyacetic acid (1-10 mg/kg i.m.), baclofen (5 and 10 mg/kg i.m.) and ethanol (0.5-2 g/kg p.o.) were determined alone and in the presence of 17.5 mg/kg (p.o.) of normeperidine, a dose which almost completely eliminates responding. Pentobarbital, diazepam and clonazepam attenuated the normeperidine-induced suppression of behavior, whereas aminooxyacetic acid, baclofen and ethanol failed to attenuate the effects of normeperidine. The results indicate that in the pigeon the non-opioid effects of normeperidine and related analogs are related to proconvulsive actions.