DOPAMINE TRANSPORTER IMMUNOHISTOCHEMISTRY IN MEDIAN-EMINENCE, AMYGDALA, AND OTHER AREAS OF THE RAT-BRAIN

In an extension of our previous work, an antibody directed against a p eptide from the N-terminal region of DAT was used to localize specific dopamine transporter immunoreactivity (DAT-IR) in several regions of rat brain. Apparent axons and varicosities were found in the zona ince rta, external layer of the median eminence, various nuclei of the amyg dala, the cortex-amygdala transition zone, and in periglomerular regio ns in the olfactory bulb. Apparent stained neuronal perikarya and dend rites were observed in the arcuate nucleus and olfactory bulb. These r egions are known to have dopaminergic neurons and innervations, althou gh there was not a perfect correspondence between DAT-IR and the known distribution of dopaminergic neurons. A possible explanation is that different dopamine containing cell groups express different levels of DAT mRNA and protein, as we have previously shown. Also in the tuberoi nfundibular neurons, for example, DAT-IR was preferentially localized to distal axons in the median eminence, suggesting intracellular compa rtmentation. (C) 1996 wiley-Liss, Inc.