GABARAPL1 and Parkinsonism: In the brain, a decrease in gabarapl1 transcript levels have been observed in both the cortex of macaques treated with MPTP (1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine), a neurotoxin which mimics the effect of the development of Parkinson's disease in animal models, and in the substantia nigra neurons of human Parkinson's patients [16], [17].