Localization of glial fibrillary acidic protein, CGB, and SgII in astrocytes of brain tissues.

Expression of glial fibrillary acidic proteins in the intermediate filaments of astrocytes that contain secretory granules was examined by double immunogold labeling using the antibodies specific for GFAP and either CGB (A) or SgII (B). (A) The GFAP-labeling gold particles (10 nm) and the CGB-labeling gold particles (15 nm) are marked by black and white arrows, respectively. Notice that the GFAP-labeling gold particles are exclusively localized in the filaments (fm) whereas the CGB-labeling particles are limited to secretory granules (SG). (B) The GFAP-labeling gold particles (10 nm) and the SgII-labeling gold particles (15 nm) are marked by black and white arrows, respectively. Again the GFAP-labeling gold particles are exclusively localized in the filaments (fm) whereas the SgII-labeling gold particles are localized in secretory granules (SG), but not in mitochondria (M) and axon (ax). Bar = 200 nm.