APOPTOSIS IN NEURODEGENERATIVE DISORDERS

Although the exact mechanism of nigral cell death in Parkinson's disea se (PD) is not known, increasing evidence suggests the presence of apo ptotic cell death in PD. When we applied the TUNEL method to detect DN A fragmentation, four out of seven late onset sporadic patients with P D showed TUNEL-positive neurons. The percentages of those neurons amon g the remaining melanin containing neurons were 0.6 to 4.8% (average 2 .1%). But TUNEL-positive neurons could not be detected in control subj ects as well as four patients with young onset (under 40 years of the age) PD. Numbers of nigral toxins such as MPTP, complex I inhibitors, and mitochondrial respiratory inhibitors have been reported to induced apoptotic cell death. These findings suggest that apoptosis is involv ed in nigral cell death in PD at least in part and warrant further stu dies on apoptosis-related substances in PD.