Following longer exposure to vinblastine (7 days), we also observed the formation of neuritic swellings in tau-overexpressing cortical neurons, and quantified this effect (Fig. 7c and d). The number of these neuritic swellings was significantly increased in neurons overexpressing P301S tau when treated with 1 nM vinblastine, as compared to neurons expressing either WT or 2P tau (Fig. 7d).