MAPT and tauopathy: Based on the positive correlation between NFT-burden and microglial-burden in brains of tauopathy patients (Ishizawa and Dickson, 2001) and as reported by us in NFT-Tg mice (Boimel et al., 2009), as well as the finding that microglial activation precede tangles in a tauopathy mouse model (Yoshiyama et al., 2007), we were interested to see whether the increase of tau pathology following the exposure to 3NP of DM-Tau-tg mice as well as the generation de novo of NFTs in the non-tg mice after 3NP exposure is associated with a microglial response.