Glial fibrillary acidic protein and Alzheimer-type senile dementia.

Glial fibrillary acidic protein (GFAP), a protein that is associated with 9-nm filaments of astrocytes, was observed to be increased in the astrocytes surrounding senile plaques in patients with Alzheimer dementia and in aged subjects without dementia. A few GFAP-positive fibers were seen in the centers of plaques. These results emphasized the selectivity of senile changes; whereas some cells seemed to undergo degeneration or dysfunction, other cells--astrocytes--maintain their capacity for reaction and may increase the formation of at least one protein, GFAP.