Hedgehog (Hh) signaling pathway is conserved in a wide range of species from drosophila to human and plays a key role in regulating organogenesis. The sonic hedgehog (Shh), a member of Hh family, is an essential factor for central nervous system development. Shh stimulates differentiation of neural stem cells into motor neurons or interneuron in the neural tube and proliferation of immature cells in cerebellum and retina. Hh signaling molecules are also found in the adult brain, implying that Hh signaling functions in the mature nervous system. In the present study, focusing the function of Hh signaling in the adult mouse brain, we first examined expression of Hh signaling molecules in the adult mouse brain by in-situ hybridization. Patched 1, which is a receptor of Hh family members, was expressed in S100 positive astrocytes and Shh mRNA was expressed in HuC/D-positive neurons in the adult mouse cerebellum. These results suggest that Hh is involved in neuron-glia interaction. We further confirmed that the Hh signal molecules were expressed in cultured astrocytes using RT-PCR. We next examined whether or not recombinant Shh N-terminal (rShh-N) activates Hh signaling pathway and regulates astrocytic functions in vitro. Treatment with rShh-N induced expression of not only Gli-1, a representative downstream factor of Hh pathway, but also GLAST, an astrocytic glutamate transporter, in cultured astrocytes. These findings suggest that Hh signal pathway regulates astrocytic GLAST expression and thereby modulates extracellular glutamate concentration.