Figure 4.

Axons lacking BDNF do not significantly regenerate into BDNF-lacking grafts regardless of the training. A) The cumulative histograms of axon profile lengths of SLICK∷BDNF^f/f and SLICK∷BDNF^f/w axons growing into tam-Cre∷BDNF^f/f Tx grafts are shifted significantly to the left of those of controls, suggesting that these axons are significantly shorter than those growing in WT grafts (p ≤ 0.04). B) The median axon profile lengths are significantly shorter into BDNF^f/f grafts compared to WT (*p ≤ 0.009; ** p ≤ 0.0001). C) The cumulative histogram of the lengths of axon profiles of YFP⁺ SLICK∷BDNF^f/f axons is significantly shifted to the left when nerves are repaired with BDNF^f/f grafts and hosts are treadmill trained for two weeks post-repair (p ≤ 0.01). D) The median axon profile length of SLICK∷BDNF^f/f axons growing into BDNF^f/f grafts remains significantly decreased after treadmill training compared to SLICK∷BDNF^f/f axons growing into a WT graft (p ≤ 0.0001). E) Low magnification images of representative nerves from trained and untrained SLICK∷BDNF^f/f hosts two weeks after nerve repair. The white bar across the nerve indicates the site of surgical repair.