AbstractAstrocytes derived from the mouse brain mesencephalon and striatum regulate neuronal morphogenesis in a region‐specific manner in vitro. To begin defining molecular mechanisms that may underlie this functional heterogeneity, lectin probes were used to compare surface glycoproteins expressed by astrocytes from different brain regions. These experiments demonstrated marked differences in surface glycoproteins depending on the anatomic origin of the astrocytes. In particular, mesencephalic and cerebellar astrocytes express a fucosylated glycoprotein with and apparent molecular weight of 190 kD that is absent or rarely expressed by striatal or cortical astrocytes. These findings raise the possibility that carbohydrate diversity of astrocyte surface molecules may play a role in the heterogeneity of region‐specific neuron‐glial interac