HSPA5 and psychosocial stress measurement: Spinal nerve ligation induced Grp78 (sham vs. SNL7d, p = 0.006; sham vs. SNL14d, p = 0.001; F = 9.338) high expression in L3–L5 spinal cord (Figures 2B,D), suggesting that ER stress participates in nociceptive ascending modulation system.