The pathological and neurotransmitter basis of PD is not all dopaminergic, other transmitter systems such as cholinergic, noradrenergic, and serotonergic system are involved; nondopaminergic neurons, including the locus coeruleus and raphe area, are selectively vulnerable during the spreading of pathological alpha‐synuclein (Braak et al., 2003). This evidence concerns the gene SNCA and Parkinson disease.