A comparison between lick or lever-pressing contingent reward and the effects of neuroleptics thereon.
Rats implanted with an electrode in the lateral hypothalamus were trained to obtain brain-stimulation by either pressing a lever or by licking a steel drinking tube in subsequent 15-min sessions. Half of the rats began the sessions with lever-pressing, the other half began with licking. After stabilization of the response rates, rats were run in saline- or drug-sessions. During the drug sessions rats were treated with 4 doses of the following neuroleptics: haloperidol, pimozide, pipamperone, azaperone. These neuroleptics dose-relatedly inhibited licking for brain-stimulation but suppressed lever-pressing only at the highest dose tested. The lick response was thus inhibited at lower doses than lever-pressing. This differential sensitivity to neuroleptics appears not to be due to a difference in baseline response rates, schedule differences or to the motor activity involved in both responses, but rather to the different thresholds of reinforcement produced by licking and lever-pressing for brain-stimulation.
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D007033:Hypothalamus, Middle / Q000502:physiology; D008297:Male; D051381:Rats; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects / Q000502:physiology*
D014150:Antipsychotic Agents