Figure 4.

BDNF levels control motor coordination in mutant htt mice. A-D, The decrease of bdnf in mutant htt mice produces an uncoordinated walking footprint pattern. We analyzed the following four parameters of footprints: A, the number of steps; B, the distance between two consecutive steps; C, D, the distance between right and left frontbase and hindbase path, respectively. bDM shows differences in the number and distance of steps (A, B) and in the frontbase width (C). No differences were found in the hindbase pattern (D). ^*p < 0.05, ^**p < 0.005, and ^***p < 0.001 compared with wt mice (bdnf^+/+ htt^wt); ⁺p < 0.05 and ⁺⁺⁺p < 0.001 compared with R6/1 mice (bdnf^+/+ htt^m); ^#p < 0.05, ^##p < 0.005, and ^###p < 0.001 compared with bdnfheterozygous mice (bdnf^{+/ -} htt^wt). E, The levels of BDNF do not affect the mouse's ability to walk on a wire rod. Although we did not find statistical differences between groups, animals with mutant htt and with normal or lower levels of BDNF had a higher tendency to fall off the rod. The distance covered by the animals on the rod also shows the same effect, with shorter runs in those animals expressing mutant htt.