ON THE QUESTION OF APOPTOSIS IN THE PARKINSONIAN SUBSTANTIA-NIGRA

Apoptosis has been postulated as a mechanism of nerve cell death in Pa rkinson's disease. In the present study, the substantia nigra of 22 ne uropathologically confirmed Parkinson cases and 8 control brains was s tudied using the in situ end-labeling (TUNEL) method. About 50% of par kinsonian brains showed a small number of TUNEL-positive glial cells i n the substantia nigra, whereas no neurons showed convincing TUNEL pos itivity or any morphological signs of apoptosis. No correlation was ob served between the number of TUNEL-positive glial cells and microglial activation. Our results fail to demonstrate apoptosis as a mechanism of cell death in Parkinson's disease.