Cellular investigations of behavioral reinforcement.
Using the hippocampal-slice preparation, we attempted to demonstrate operant conditioning of pyramidal cell activity using local micropressure applications of transmitters and drugs as reinforcement; the same injections administered independently of bursting provided a control for direct pharmacological stimulation or facilitation of firing. The results suggested that the spontaneous bursting of individual CA1 pyramidal neurons may be reinforced with activity-contingent injections of dopamine and cocaine, whereas, CA3-bursting responses may be reinforced with contingently-applied dynorphin A. We sought to confirm these indications of cellular reinforcement at the behavioral level in studies of hippocampal self-administration (despite the fact that the hippocampus has been ignored as a brain site for chemical self-administration experiments). The results suggested that dynorphin A is a powerful reinforcer of hippocampal self-administration behavior when injected in the CA3 field; experiments still in progress suggest that dopamine can reinforce self-administration behavior when injected in the CA1 field. Successful prediction of new behavioral data from operant-conditioning data at the cellular level helps to validate the cellular data by providing suggestive evidence of interrelationship between cellular and behavioral operant conditioning processes.
Stein
L
L
Department of Pharmacology, College of Medicine, University of California, Irvine 92717.
Belluzzi
J D
JD
D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology; D003216:Conditioning, Operant / Q000502:physiology; D004298:Dopamine / Q000008:administration & dosage; D015259:Dopamine Agents / Q000008:administration & dosage / Q000494:pharmacology; D004399:Dynorphins / Q000008:administration & dosage / Q000494:pharmacology; D004558:Electric Stimulation; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011954:Receptors, Dopamine / Q000502:physiology; D011957:Receptors, Opioid / Q000502:physiology; D012054:Reinforcement, Psychology; D012646:Self Administration; D012653:Self Stimulation / Q000502:physiology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology
D015259:Dopamine Agents; D011954:Receptors, Dopamine; D011957:Receptors, Opioid; D013764:Tetrahydronaphthalenes; D013876:Thiophenes; D004399:Dynorphins; C047508:rotigotine; D003042:Cocaine; D004298:Dopamine