Our study provides novel evidence that the brain of neonate Ts65Dn mice exhibits defective functional activities of MRC complexes, i.e., complex I and ATP synthase, similar to the fibroblasts and lymphoblastoid cells from DS subjects [17,18,19] as well as Ts65Dn-derived hippocampal NPCs [21,22] and brain cortex of Ts16 mice [47]. The gene discussed is CD200; the disease is Dravet syndrome.