Figure 2.

Progressive motor deficit in 5-htt−/− mice. a–c, BG-dependent motor behavior in 5-htt−/− mice as a function of age was assessed using the rotarod test (a), the beam-walking test (b), and the clasping test (c). a, Rotarod performance progressively worsened with age in 5-htt−/− mice compared to 5-htt+/+ control mice in a longitudinal study (20 rpm; top; n = 17 per group). Four independent cohorts of mice were tested at 12 weeks of age (n = 29–29 mice per group), 16 weeks of age (n = 29–29 per group), 38 weeks of age (n = 15–17 per group), and 56 weeks of age (n = 6–16 mice per group) at 20 rpm as indicated (bottom). No effect was detected at 12 weeks of age. An effect of genotype was detected at 16, 38, and 56 weeks of age, and effect sizes increase with age. b, Beam-walking performance progressively worsened with age in 5-htt−/− mice compared to 5-htt+/+ control mice (n = 14–17 per group). c, Clasping behavior progressively increased with age in 5-htt−/− mice compared to 5-htt+/+ control mice (n = 22–27 per group). The dotted line indicates reduced n compared to previous ages. *p < 0.05; **p < 0.01; ***p < 0.001.