Expression of Fas antigen in the normal mouse brain

The Fas antigen (Fas/Apo-1/CD95) is a cell surface receptor protein that me diates apoptosis-inducing signals and plays an important role in the immune system. In the central nervous system, during the period of naturally occu rring cell death many neurons appear to die by apoptosis. We investigated t he involvement of Fas in these events. The expression of Fas transcripts an d protein was examined in the juvenile mouse brain. By RT-PCR analysis, Fas mRNA was detected in the cerebrum, cerebellum, and hippocampus of the brai n. By immunohistochemistry, we found Fas in neurons localized in the CA2 an d CA3 sectors of the hippocampus and in the cortical III layer of the cereb rum, but not neurons in the cerebellum. Furthermore, Fas was expressed on t he primary cultured hippocampal and cerebral cells using immunofluorescence and flow cytometry. These results suggest that Fas is specifically express ed on neurons in the mouse brain during postnatal development. (C) 1998 Aca demic Press.