MAPT and Anxiety: To determine the role of neuronal Lag3 in mediating behavioral deficits induced by Tau PFF, we performed several behavioral tests as described.[19] We assessed anxiety‐related behavior by analyzing time spent in the center zone versus the peripheral zone using the open field test.[20] The results show that there is no significant difference in total horizontal activity in the Lag3L/L‐YFP mice between the PBS and Tau PFF inoculated groups (Figure 5h), which is consistent with a prior study[19], indicating that hippocampal injection of Tau PFF cannot cause motor dysfunction.