Aβ-induced deficits in axonal transport do not depend on interactions between tau and Fyn. (A) Diagram of 0N4R mouse tau indicating the Y18F point mutation that should prevent phosphorylation of tau by Fyn (Lee et al., 2004) and the PxxP to AxxA substitutions in the seventh proline-directed region (AxxA7) that should interfere with binding of tau to Fyn (Lee et al., 1998). Numbers in parentheses indicate corresponding amino acid positions in human 2N4R tau. (B) The percentage of moving mitochondria in the axons of Tau^−/− neurons transfected with empty plasmid or plasmids encoding the indicated tau constructs was measured before (baseline) and 10–60 min after adding Aβ_1–42 oligomers to the medium. Results are expressed relative to baseline (100%). n = 19–37 axons per construct recorded during three to five independent sessions at DIV 7–8. ##, P < 0.01 versus empty (Kruskal-Wallis ANOVA, Dunn’s test); ***, P < 0.001 versus corresponding baseline (paired t tests, Bonferroni). Data are means ± SEM.