Neuronal BDNF Signaling Is Necessary for the Effects of Treadmill Exercise on Synaptic Stripping of Axotomized Motoneurons

Figure 3

The mean (+SEM) percent of motoneuron somata and proximal dendrites that are contacted by structures immunoreactive for VGLUT1 (a) and GAD67 (b) in WT mice and for WT and KO cells in tamoxifen-treated SLICK:: mice are shown. Separate groups of three bars are shown in each panel for data from intact mice (left), unexercised mice two weeks after sciatic nerve transection (center), and two weeks after nerve transection and five days per week exercise (right) (, 4, and 3 mice, resp.). The left group of results shows that synaptic coverage is significantly reduced in BDNF KO cells compared to WT mouse and WT cells in intact mice. Following nerve transection, synaptic coverage is significantly decreased in all cells, but coverage in BDNF KO cells is not changed from those seen in the intact animal. Exercise following transection restores synaptic coverage in all cells except the BDNF KO cells.

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