Fig. 4.
The expression of ERK1/2 (A, B) and p-ERK1/2 (C, D) in the L4-L5 spinal dorsal horn in the comorbid pain condition. The expression of ERK1/2 in the E2 + CFA + FS group (n = 4) did not significantly change compared with the oil + saline + non-FS group (n = 6). The expression of p-ERK1/2 in the E2 + CFA + FS group significantly increased compared with the oil + saline + non-FS group. Data were normalized to the oil + saline + non-FS group. *P < 0.05 vs. the oil + saline + non-FS group.