Publication Date:
1983-06-17
Description:
Animals with a history of receiving daily injections of +-amphetamine in a specific environment showed a placebo effect (enhanced activity) when injected with saline and placed there; control animals with similar but dissociated drug histories and experience with the test chamber failed to show the effect. The dopamine receptor blocker pimozide antagonized the establishment of conditioning. However, the same dose of pimozide, when given to previously conditioned animals on the placebo test day, failed to antagonize the expression of conditioned activity. Thus, during conditioning dopaminergic neurons mediated a change that subsequently influenced behavior even when dopaminergic systems were blocked. Although schizophrenia may be related to hyperfunctioning of dopamine, neuroleptic drugs, which block dopamine receptors on their first administration, do not have therapeutic effects for a number of days. The results of the pimozide experiments may resolve this paradox.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Beninger, R J -- Hahn, B L -- New York, N.Y. -- Science. 1983 Jun 17;220(4603):1304-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6857251" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Conditioning (Psychology)/*drug effects/physiology
;
Dextroamphetamine/antagonists & inhibitors/*pharmacology
;
Humans
;
Male
;
Pimozide/*pharmacology
;
Rats
;
Rats, Inbred Strains
;
Receptors, Dopamine/physiology
;
Reinforcement (Psychology)
;
Schizophrenia/physiopathology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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