Altered dopamine D2 receptor function and binding in obese OLETF rat

Andras Hajnal, Wojciech M. Margas, Mihai Covasa

Research output: Contribution to journalArticle

33 Scopus citations

Abstract

A decrease in D2-like receptor (D2R) binding in the striatum has been reported in obese individuals and drug addicts. Although natural and drug rewards share neural substrates, it is not clear whether such effects also contribute to overeating on palatable meals as an antecedent of dietary obesity. Therefore, we investigated receptor density and the effect of the D2R agonist quinpirole (0.05, 0.5 mg/kg, S.C.) on locomotor activity and sucrose intake in a rat model of diet-induced obesity, the CCK-1 receptor-deficient Otsuka Long Evans Tokushima Fatty (OLETF) rat. Compared to age-matched lean controls (LETO), OLETF rats expressed significantly lower [125I]-iodosulpride binding in the accumbens shell (-16%, p < 0.02). Whereas the high dose of quinpirole increased motor activity in both strains equally, the low dose reduced activity more in OLETF. Both doses significantly reduced sucrose intake in OLETF but not LETO rats. These findings demonstrate an altered D2R signaling in obese OLETF rats similar to drug-induced sensitization and suggest a link between this effect and avidity for sucrose in this model.

Original languageEnglish (US)
Pages (from-to)70-76
Number of pages7
JournalBrain Research Bulletin
Volume75
Issue number1
DOIs
StatePublished - Jan 31 2008

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

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