Dopamine D(4) receptors in rat forebrain: unchanged with amphetamine-induced behavioral sensitization.
Dopamine D(2) receptors are implicated in stimulant-induced behavioral sensitization.(7,10) Studies using selective receptor antagonists also implicate the D(4) receptor, a member of the dopamine D(2)-like receptor family.(3) Accordingly, dopamine D(4) and D(2)-like receptor levels in rat forebrain were examined by computed autoradiography after repeated (+)-amphetamine treatment that induced behavioral sensitization. Receptor binding was quantified in critical brain regions including caudate-putamen, nucleus accumbens septi, medial prefrontal cortex and hippocampus. No significant differences in D(4) or D(2)-like receptor levels were detected among rats sensitized to amphetamine, those exposed to amphetamine but killed before behavioral sensitization emerged or vehicle-treated controls. The findings indicate that expression of amphetamine-induced behavioral sensitization is not associated with altered D(4) (or D(2)) receptor density in rat forebrain.
Zhang
K
K
Mailman Research Center, McLean Division of Massachusetts General Hospital, Belmont, MA 02478, USA. kz@mclean.harvard.edu
Tarazi
F I
FI
Baldessarini
R J
RJ
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001345:Autoradiography; D001549:Benzamides / Q000493:pharmacokinetics; D002421:Caudate Nucleus / Q000378:metabolism; D018492:Dopamine Antagonists / Q000493:pharmacokinetics; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism; D017397:Prefrontal Cortex / Q000378:metabolism; D016548:Prosencephalon / Q000378:metabolism*; D011699:Putamen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism*; D050638:Receptors, Dopamine D4; D014316:Tritium
D001549:Benzamides; D018492:Dopamine Antagonists; C493601:Drd4 protein, rat; D017448:Receptors, Dopamine D2; D014316:Tritium; D050638:Receptors, Dopamine D4; D000661:Amphetamine; C030265:nemonapride