HTT and juvenile Huntington disease: For example, immunoblotting and immunocytochemical analyses revealed reduced Drp1 protein levels in hippocampal tissues of Alzheimer’s patients compared with age-matched healthy individuals (Wang et al, 2009), whereas Huntington’s disease patients were found to have increased Drp1 enzymatic activity mediated by interaction with mutant Huntingtin (Htt) aggregates, resulting in abnormal mitochondrial dynamics, including defective anterograde mitochondrial movement and synaptic deficiencies (Song et al, 2011; Shirendeb et al, 2012).