Figure 3.

Motor impairment in GFAP/tau Tg mice. A, Both strains of tau Tg and non-Tg mice at the ages indicated were tested on the accelerating rotarod after 2 weeks of training. Latency to fall was recorded for each of 12 trials over 2 weeks. n = 12-14 animals per group at 4 months of age; n = 6-9 animals per group at 12, 16, and 20 months. Impaired performance was observed in both GFAP/tauWT (WT) and GFAP/tauP301L (PL) Tg mice relative to age-matched controls (one-way ANOVA, Bonferroni's post hoc test; ^*p < 0.001). At 12 months of age, the GFAP/tauP301L Tg mice also manifest impaired performance relative to the GFAP/tauWT Tg animals (one-way ANOVA, Bonferroni's post hoc test; ^*p < 0.001). Latency to fall, Mean of 12 trials. Error bars indicate SEM. B, GFAP/tau Tg and control mice at the ages indicated were assessed for neuromuscular strength using the wire-hang test. Animals were suspended from a wire, and the latency to fall from the wire was recorded as hanging time in seconds. Each mouse was tested four times over 2 d with an intertrial interval of 2 h. n = 11-14 mice per group at 6 months of age and 6-9 animals per group at 15 months. At 4 months of age, there was no difference in performance between both the strains of tau Tg and non-Tg mice. In contrast, both GFAP/tauWT (WT) and GFAP/tauP301L (PL) mice were significantly impaired at 15 months of age with 65% impairment relative to non-Tg mice (one-way ANOVA, Bonferroni's post hoc test; ^*p < 0.001). Hanging time, Mean of four trials. Error bars indicate SEM.