GAP43-IR in L4 primary sensory neurons of JNK KO mice following STN. Percentage of GAP-43-positive primary sensory neurons in L4 DRG in wilde type (A), JNK1 (B), JNK2 (C) and JNK3 (D) KO mice. GAP43 is constitutively expressed in primary sensory neurons of unoperated mice of each group (white bars). Seventy-two hours post lesion, GAP43-IR upregulation, which occurs in wt (A) and JNK2 KO (C) mice is absent both in JNK1 (B) and JNK3 (D) KO mice. #, £, $ p < 0.05, **p < 0.01 by tTest; n = 6 mice/group.