MAPT and Alzheimer disease: The LC exhibits prodromal accumulation of hyperphosphorylated of tau in AD (Braak et al., 2011; Pletnikova et al., 2018) and α-synuclein aggregation in PD (Tredici et al., 2013), often well before other areas that are canonically associated with these disorders such as the hippocampus, cortex (AD), and basal ganglia (PD).