VISUALIZATION OF G(O-ALPHA)-SUBTYPE GUANINE-NUCLEOTIDE-BINDING REGULATORY PROTEIN IN THE MEDULLA-OBLONGATA AND PONS OF THE RAT

This study reports on the visualization of G(o) protein in the medulla oblongata and pons of Sprague-Dawley rats, using a commercially avail able selective polyclonal antiserum against a 39-kDa protein correspon ding to the alpha subunit of G(o). Specific immunofluorescent-staining was widely distributed in neuropils and neuronal cell bodies but disp layed regional heterogeneity. The immunoreactive product exhibited a p unctate appearance and was most pronounced in the cell membrane and cy toplasm of the perikarya and proximal dendrites whereas the nucleus re mained unstained. Positive immunoreactivity of G(oalpha) was present i n nucleus reticularis gigantocellularis, nucleus reticularis paramedia lis, nucleus tractus solitarii, nucleus nervi hypoglossi, nucleus raph e pallidus, locus coeruleus, nucleus tractus mesencephali nervi trigem ini and nucleus cuneatus. These results provided anatomic evidence to support the participation of G(o) protein. in both sensory and motor f unctions that originate from the medulla oblongata and pons of the rat .