Etiology of Parkinson's disease: Genetics and environment revisited

摘要

Idiopathic Parkinson's disease (PD) is the second most common neurodegen-erative disorder and affects more than 1 million Americans over the age of 55. The disease selectively affects dopaminergic neurons of the substantia nigra pars com-pacta, culminating in their demise. After ≈50% of the dopamine neurons and 75-80% of striatal dopamine is lost, patients start to exhibit the classical symptoms of PD including bradykinesia, postural reflex impairment, resting tremor, and rigidity (1, 2). Although there are several treatments that are effective for a number of years, their usefulness wanes over time and is accompanied by unacceptable side effects. New therapies are clearly needed for this disorder.