DNM1L and Alzheimer disease: In contrast to the well-established aberrant elevation of mitochondrial fission due to increased Drp1 that has been reported in AD, PD, and HD,13,35,38,39 we did not observe a change in Drp1 or its activated form of phospho-Drp1 on serine 616 (S616) 24 h, 1 week, or 2 weeks after TBI (Figures 1A and S1A–S1C).