Immunohistochemical observation of GRP78. GRP78-immunoreactivity (ir) in the mPFC of SPS rats in different groups (A-D, magnification × 400). A: the control group; B: the SPS1d group; C: the SPS4d group; D: the SPS7d group; E: the quantity of GRP78-ir expression (OD). n = 5 for each group, scale bar = 30 um, and statistical analysis was carried out by Tukey test. *P < 0.05 versus control.