APOPTOSIS AND AUTOPHAGY IN NIGRAL NEURONS OF PATIENTS WITH PARKINSONS-DISEASE

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive cell loss confined mostly to dopaminergic neurons of t he substantia nigra. Several factors, including oxidative stress, and decreased activity of complex I mitochondrial respiratory chain, are i nvolved in the degenerative process. Yet, the underlying mechanisms le ading to dopaminergic cell loss remain elusive. Morphological assessme nt for different modes of cell death: apoptosis, necrosis or autophagi c degeneration, can contribute significantly to the understanding of t his neuronal loss. Ultrastructural examination revealed characteristic s of apoptosis and autophagic degeneration in melanized neurons of the substantia nigra in PD patients. The results suggest that even at the final stage of the disease, the dopaminergic neurons are undergoing a ctive process of cell death.