IMMUNOFLUORESCENT STUDIES ON THE LOCALIZATION OF TYROSINE HYDROXYLASE AND DOPAMINE-β-HYDROXYLASE IN THE MES-, DI-, AND TELENCEPHALON OF THE RAT USING UNPERFUSED FRESH FROZEN SECTIONS

Abstract

Distributions of tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH) in the rat brain were examined using immunofluorescent staining on unperfused fresh frozen sections. TH-positive and DBH-negative dopaminergic neurons were observed in the anterior hypothalamic nucleus. In other hypothalamic nuclei such as ventromedialis, dorsomedialis, and posterior hypothalamic nuclei, a few dopaminergic neurons were also observed.Our immunofluorescent results with unperfused fresh frozen sections indicated that TH or DBH was mainly localized in the cell bodies of catecholaminergic neurons and that small amounts of the enzymes were distributed in the nerve terminals. Although it had been reported that the amine enzymes existed in nerve terminals as well as in the cell bodies by using paraformaldehyde perfused sections, the fluorescence observed in nerve terminals might be produced not only by the amine enzymes but also by amines themselves.