Fig. 4

Expression change of ERα and ERβ to different estrogen pretreatment regimes. Expression of a ERα and b ERβ positive neurons in rat spinal cord at the last day of estrogen substitution. ER positive neurons mainly concentrated in the laminae I~II of the spinal cord, pictures are shown at × 20 magnification, scale bar represents 100 μm. c, d Histographs show one-way ANOVA analysis of the difference of ER expression among groups. Data are shown as mean ± SD. *P < 0.05 when compared with the OVX group, ^&P < 0.05 when compared with the E-decrease group. e Expression ratio of ERα to ERβ of each group