PARKINSONS-DISEASE - BIOLOGY AND ETIOLOGY

The cause of dopamine cell death, thought to be the primary neurocytol ogic defect in idiopathic Parkinson's disease, remains unknown, Mitoch ondrial oxidative dysfunction causes premature cell death, and may be linked to accelerated apoptosis, excessive free and toxic radicals, de ficient neurotrophic factors or combinations of these detrimental fact ors, Neurochemical imbalances result both in the substantia nigra and neostriatum, resulting in compensatory mechanisms that make this chron ic neurodegenerative disease difficult to evaluate. Acute parkinsonism models have limitations when compared with chronic disease states, an d caution should be present when comparing 'parkinsonism' data with hu man disease, Better understanding of classical neurotransmitters, neur oactive peptides and neurotrophic factors, will hopefully lead to more rational treatment approaches, cellular support strategies, and an un derstanding of the causes of this disease, Glial derived neurotrophic factor looks the most promising neurotrophic candidate so far tested i n culture and in vivo. The result of clinical trials utilizing neurotr ophic factors, both as mesencephalic implant support strategies and as definitive treatment of idiopathic Parkinson's disease, are awaited w ith cautious optimism.