IN-SITU HYBRIDIZATION HISTOCHEMISTRY OF C-ERBA-ALPHA-2 MESSENGER-RNA IN THE HYPOTHALAMUS AND ITS SURROUNDING STRUCTURES IN THE ADULT MALE-RAT

In order to detect the localization of c-erbA alpha 2 mRNA in the hypothalamus and its surrounding structures, in situ hybridization histochemistry was performed in the adult male rat. Sections through the hypothalamus were hybridized with a [H-3]-labeled RNA probe complementary to c-erbA alpha 2 mRNA and then coated with photographic emulsion. Autoradiograms were then developed and localization of the hybridization signal was detected under a light microscope. Hybridization signal was detected throughout the hypothalamic and extrahypothalamic structures such as the paraventricular hypothalamic nucleus (PVN), ventromedial nucleus (VMN), arcuate nucleus (Arc), amygdala (Am), habenula (Hb), paraventricular thalamic nucleus (PVT) and hippocampus (Hipp). No hybridization signal was detected in the section which was hybridized with the sense probe. These results not only confirm previous findings in the PVN, Hb, PVT and Hipp, but also extend the finding to the VMN, Arc and Am, in which cells expressing c-erbA alpha 2 primary transcript were concentrated. These new findings may provide an important aid to the understanding of the roles of thyroid hormone in the function of the central nervous system.