Regional neuroleptic microinjections indicate a role for nucleus accumbens in lateral hypothalamic self-stimulation reward.
Bilateral microinjections of the neuroleptic, cis-flupenthixol, were made into 56 forebrain targets distributed across various dopamine (DA) terminal fields in the forebrain. Drug effects on medial forebrain bundle (MFB) stimulation-produced reward were assessed with a rate-frequency procedure implemented in a runway paradigm in a discrete-trial fashion. This method generated independent measures of drug-induced changes in the MFB stimulation reward and operant motor/performance capacity. Control experiments were run with the inactive isomer, trans-flupenthixol. Results indicate a major role for accumbens DA in MFB reward, but not for the DA in caudate and medial frontal cortex. Few drug-induced motor/performance deficits were found at any site. In 14 selected subjects, 6-OHDA-induced chronic DA lesions were made at the same site as neuroleptic microinjection. These results confirmed the reward effects of acute DA receptor blockade, but produced a greater associated motor/performance impairment. Both behavioral effects of the lesion recovered within 2 weeks in many, but not all subjects.
Stellar
J R
JR
Department of Psychology, Northeastern University, Boston, MA 02115.
Corbett
D
D
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D005475:Flupenthixol / Q000494:pharmacology*; D006892:Hydroxydopamines / Q000494:pharmacology; D007026:Hypothalamic Area, Lateral / Q000187:drug effects / Q000502:physiology*; D007536:Isomerism; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D009928:Organ Specificity; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects*; D012686:Septal Nuclei / Q000502:physiology*; D013892:Thioxanthenes / Q000494:pharmacology*
D006892:Hydroxydopamines; D013892:Thioxanthenes; D016627:Oxidopamine; D005475:Flupenthixol