Neuron—glia interactions: effect of serotonin on the astroglial expression of GFAP and of its encoding message

Abstract The trophic effect of serotonin on the glial fibrillary acidic protein (GFAP) expression was investigated in rat brainstem astrocytes in primary culture. GFAP immunolabelling decreased and gliofilaments appeared localized in the cytoplasm periphery. GFAP protein level decreased in parallel with a decrease in its encoding message. Serotonin may act as an inhibitor of GFAP expression either on the transcription or on the stability of the GFAP-mRNA.