Repeated cocaine administration does not affect 5-HT receptor subtypes (5-HT1A, 5-HT2) in several rat brain regions.
In order to examine whether cocaine-induced behavioral sensitization is modulated by changes in serotonin receptor subtypes, we measured the binding of [3H]8-hydroxy-2-(di-n-propylamino)tetralin ([3H]8-OH-DPAT) to 5-HT1A receptors and of [3H]-ketanserin to 5-HT2 receptors in various brain regions of cocaine-treated and saline-treated (control) rats. As previously reported, repeated administration of cocaine resulted in behavioral sensitization. Stereotypic scores with the cocaine challenge were significantly (P < 0.05) higher in cocaine-pretreated animals than in the saline-pretreated group. Neither acute nor chronic cocaine administration significantly altered the number (Bmax) or the affinity (KD) of either [3H]8-OH-DPAT or [3H]ketanserin binding sites in any of the brain regions examined. These results suggest that the enhanced functional sensitivity of 5-HT1A or 5-HT2 receptor subtypes seen with cocaine may be associated with alterations in processes distal to receptors rather than changes in the number or the affinity of the receptors.
Javaid
J I
JI
Illinois State Psychiatric Institute, Chicago 60651.
Sahni
S K
SK
Pandey
S C
SC
Davis
J M
JM
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007650:Ketanserin / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D013239:Stereotyped Behavior / Q000187:drug effects*
D011985:Receptors, Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007650:Ketanserin; D003042:Cocaine