Comparison of immunocytochemical and Holzer's methods for detection of acute and chronic gliosis in human postmortem material

Immunocytochemical staining for glial fibrillary acidic protein (GFAP) allows more specific identification of astrocytes and their processes than classical histochemical techniques and has therefore recently been used by some investigators to quantify gliosis. However, although the immunocytochemical method is superior for delineation of reactive astrocytes, the examples presented here and previous work by others demonstrate that chronic fibrillary gliosis may be best detected by Holzer's method and not by GFAP immunocytochemistry. The authors' studies indicate that if, as in a recent study of gliosis in schizophrenia, computer-assisted densitometry is to be used to measure gliosis, the immunoperoxidase method may not be a sensitive technique to demonstrate glial changes in human postmortem material.