They are, in order of distance from Neptune: Naiad (48,227 km), Thalassa (50,074 km), Despina (52,526 km), Galatea (61,953 km), Larissa (73,548 km), S/2004 N 1 (105,300 Â± 50 km), and Proteus (117,646 km).
In this article. Font Size. A. A. A. Parkinson's disease is caused by the progressive impairment or deterioration of neurons (nerve cells) in an area of the brain known as the substantia nigra. When functioning normally, these neurons produce a vital brain chemical known as dopamine.here is considerable controversy surrounding the possibility of a genetic cause of Parkinson's disease. In a small number of families, specific genetic abnormalities leading to the illness have been identified.
The motor symptoms of Parkinson's disease result from the death of dopamine-generating cells in the substantia nigra, a region of the midbrain. The causes of this cell death are poorly understood.he disease can be either primary or secondary. Primary Parkinson's disease is referred to as idiopathic (having no known cause), although some atypical cases have a genetic origin, while secondary parkinsonism is due to known causes like toxins.