eric kandel. and a ho word hughes medical investigator. >> we can discuss parkinson's disease and huntington's disease, two deagain rattive diseases of the nervous system that affect movement. what is interesting about these disorders is their history. if we consider autism, which is a program we did recently, that was discovered 60 years ago. we have had beautiful, detailed and insightful descriptions of parkinson's disease and huntington's disease that go back over 150 years. james parkinson in 1817 described six families that had what he called shaking palsy. the three defining features of the disease are that they have a tremored rest. they have an abnormallal posture and they have muscular weakness. this description was so detailed and so excellent that physicians soon were able to characterize the disease and see exactly what parkinson's saw and they renamed the disease from shaking palsy to parkinson's disease. but it was a long time before we began to understand what some of the mechanisms