CGRP-IR following injury in L4 primary sensory neurons of JNK KO Mice. Percentage of CGRP-positive primary sensory neurons in L4 DRG in wt (A), JNK1 (B), JNK2 (C) and JNK3 (D) KO mice. CGRP is constitutively expressed in primary sensory neurons of unoperated mice of each group (white bars). Seventy-two hours post lesion, CGRP-IR , which is downregulated in wt (A) and JNK3 KO (D) mice, is unchanged both in JNK1 and JNK2 KO mice (B, C). ** and ##, p < 0.01 and ***p < 0.001 by tTest; n = 6 mice/group.