Differential Tau spreading between WT and mutated Tau species. LVs encoding hTau46WT (n = 5, sacrificed at 2 months; n = 5, sacrificed at 8 months) (a), V5-hTau46WT (n = 3, sacrificed at 8 months) (b) or hTau46P301L (n = 5, sacrificed at 8 months) (c) were bilaterally injected into the CA1 layer of rat brains. After sacrifice, the whole brain was processed for immunohistochemical analysis using AT8, MC1 or AT100 phosphorylated Tau antibodies. Among the positive rats, the rostralmost and caudalmost brain coordinates (from bregma) labeled by each antibody were determined for each brain. The figures represent the mean values +/-SEM of the rostralmost of caudalmot brain coordinates. These data showed that whereas hTau46P301L diffusion is restricted to the vicinity of the IS, hTau46WT has spread throughout the brain. Numbers of immunopositive rats per group are indicated on the right of each mapping.