MAOB and Alzheimer disease: Although it is considered that reduction of [11C]DED binding is probably due to astrocytic dysfunction and atrophy by a downstream effect of the early MAO-B upregulation and a reflection of chronic neuroinflammation (Carter et al., 2019a), it remains unclear because many postmortem studies demonstrated the elevation of MAO-B levels in AD (Jossan et al., 1991b; Saura et al., 1994; Gulyas et al., 2011; Marutle et al., 2013; Ni et al., 2021).