KCNJ11 and Parkinson disease: Although in adult mice KATP channels in DA neurons of both SN and VTA are formed by the same subunits (four Kir6.2 subunits and four regulatory SUR1 subunits), the activation of nigral KATP channels of DA neurons was responsible for the selective degeneration of DA neurons in PD (Liss et al., 2005).