TRPV1 Channel Activated by the PGE2/EP4 Pathway Mediates Spinal Hypersensitivity in a Mouse Model of Vertebral Endplate Degeneration

Figure 4

EP4 and TRPV1 expressed in CGRP⁺ nerves and in CGRP⁺ DRG neurons of LSI mice, respectively. (a) Representative images of the coimmunostaining of CGRP and EP4 in L4-L5 caudal endplates in the LSI or sham group at 8 weeks. (b) Representative images of the coimmunostaining of CGRP and TRPV1 in L4-L5 caudal endplates in the LSI or sham group at 8 weeks. (c) Representative images of the coimmunostaining of CGRP and EP4 in L2 DRGs in the LSI or sham group at 8 weeks. (d) The percentage of the EP4⁺CGRP⁺ area relative to the CGRP⁺ area in the LSI or sham group. (e) Representative images of the coimmunostaining of CGRP and TRPV1 in L2 DRGs in the LSI or sham group at 8 weeks. (f) The percentage of the TRPV1⁺CGRP⁺ area relative to the CGRP⁺ area in the LSI or sham group. Scale bars, 50 μm (a, b, c, e). vs. sham group. per group (d, f).