SEROTONIN, DOPAMINE AND NOREPINEPHRINE TRANSPORTER MESSENGER-RNAS - HETEROGENEITY OF DISTRIBUTION AND RESPONSE TO BINGE COCAINE ADMINISTRATION

Quantitative in situ hybridization was utilized to map the distributio n and abundance of the serotonin, dopamine and norepinephrine transpor ter (SERT, DAT and NET, respectively) mRNAs. SERT mRNA was quantified within the dorsal raphe (DR) and the median raphe (MR), DAT mRNA withi n the ventral tegmental area substantia nigra (VTA-SN) region and NET mRNA within the locus coenuleus (LC). SERT mRNA expression within the raphe complex was organized into distinct subregional domains with the rank order of mRNA abundance: ventromedial (vm) DR > dorsomedial (dm) DR > MR > dorsolateral (dl) DR. The relative abundance of DAT mRNA al so varied across subregions: SN pars compacta > the parabrachial pigme ntosis (PBP) > the intrafascicular (IF). The effects of a 'binge' para digm of cocaine administration on SERT, DAT and NET mRNA abundance wer e compared in the brains of behaviorally sensitized rats. Cocaine sign ificantly decreased the abundance of the SERT mRNA within the dlDR and DAT mRNA abundance within the SNc and the PBP, and increased the abun dance of the NET mRNA within the LC. Finally, correlational analysis i ndicated that post-cocaine levels of DAT, SERT and NET mRNAs were not associated with cocaine-induced sensitization. (C) 1997 Elsevier Scien ce B.V.