Short and long-term changes in dopamine and serotonin receptor binding sites in amphetamine-sensitized rats: a quantitative autoradiographic study.
The biochemical changes in DA and 5HT systems were investigated in amphetamine (AMPH)-sensitized rats, 1 and 15 days after cessation of treatment (5 mg/kg AMPH, i.p., twice a day for 6 days). At both times, AMPH-treated rats exhibited behavioral sensitization, as revealed by an enhancement of the stereotypic response to a challenge dose of 2 mg/Kg, ip. AMPH. Basal dopamine (DA) and serotonin (5-HT) metabolism was not significantly modified in different brain areas of AMPH-sensitized rats. Quantitative autoradiographic analysis of DA and serotonin 5-HT receptor subtypes was performed in the following brain regions: medial prefrontal cortex, nucleus accumbens, striatum, substantia nigra, ventral tegmental area, dorsal and median raphe nuclei. A significant increase of [3H]SCH 23390 binding to D1 DA receptors was observed in the substantia nigra pars reticulata 1 day but not 15 days after the cessation of AMPH treatment, whereas [3H]8-OH-DPAT binding to 5-HT1A sites was found to be significantly enhanced in the dorsal raphe nucleus at both time points. No change in D2 DA nor in 5-HT1B or 5-HT2A receptors was found in any of the brain structures examined at either time point. The obtained results suggest that DA and 5-HT systems are differently and time-dependently involved in AMPH-induced behavioral sensitization.
Bonhomme
N
N
INSERM U. 259, Université de Bordeaux II, France.
Cador
M
M
Stinus
L
L
Le Moal
M
M
Spampinato
U
U
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001522:Behavior, Animal / Q000187:drug effects; D001552:Benzazepines / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology
D001552:Benzazepines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D011985:Receptors, Serotonin; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D003913:Dextroamphetamine; D004298:Dopamine