TSPO and Alzheimer disease: Considering the early stage of the pathology in our study, i.e. the absence of CD68 (marker of activated microglia), of STAT3 (marker of the reactivity of astrocytes), of extracellular Aβ-deposits and of cognitive effect, it can be hypothesized that microglia TSPO from microglia is not a key player as astrocyte TSPO in early AD.