Under neuro-pathological conditions, much evidence has suggested that AQP4 participates in the onset and progression of patho-physiological disorders, such as Parkinson disease [4,24], depression [24], neuro-myelitis optical [24], Alzheimer disease [4,50,52], ischemia [50], K+ spatial buffering system [4,50], epilepsy, cerebral edema [4,47,50,52], stroke [4], and drug addiction [54]. This evidence concerns the gene AQP4 and Parkinson disease.