SELECTIVE PATTERNS OF EXPRESSION OF G-PROTEIN ALPHA-SUBUNITS DURING IN-VITRO DEVELOPMENT OF HYPOTHALAMIC NEURONS

Expression of different alpha subunits of G proteins was studied in hy pothalamic primary cultures grown in defined medium and enriched in ei ther neurons or glial (astrocyte) cells. In parallel, the cellular dis tribution of Gi, Gs, and GoA subunits was visualized by in situ hybrid ization. Immunoblots using specific antisera and hybridization of mRNA s with specific oligonucleotide probes allowed us to characterize Gs, Gi2, and GoA as major neuronal G proteins in the hypothalamus, whereas the glial cells expressed mostly Gs, Gi2, and GoB forms. Gi was found to be expressed very early and transiently in the culture, whereas ex pression of Gs and GoA increased regularly with time.