Nerve injury reduced spinal Hes1 expression accompanied with behavioral allodynia. (a) Representative Western blot and statistical analyses (normalized to GAPDH) demonstrating, when compared with the sham operation (Sham), that spinal nerve ligation (SNL) decreased the expression of Hes1 in the ipsilateral (I and IPSI) but not the contralateral (C and CONTRA) dorsal horn at days 3, 7, 14, and 21 after surgery. IB, Immunoblotting. Two-way ANOVA with repeated measures over time, treatment, F (3,20) = 116.6, p < 0.0001; time, F (4,80) = 6.258, p = 0.0002; treatment × time, F(12,80) = 9.003, p < 0.0011. ** p < 0.01 vs. Sham IPSI. ## p < 0.01 vs. SNL day –1. n = 6. (b) Von Frey test demonstrating, when compared with the sham operation, that SNL decreased the tactile withdrawal threshold of the ipsilateral but not the contralateral hind-paw at days 3, 7, 14, and 21 after surgery. Two-way ANOVA with repeated measures over time, treatment, F (3,24) = 59.37, p < 0.0001; time, F(4,96) = 4.514, p = 0.0022; treatment × time, F(12,96) = 6.427, p < 0.0001. ** p < 0.01 vs. Sham IPSI. ## p < 0.01 vs. SNL day –1. n = 7. (c,d) Immunofluorescence images showing, when compared with the sham operation (c), that SNL (d) decreased the number and distribution of Hes1-positive neurons (red) in the ipsilateral dorsal horn (left) of spinal cord slice harvested at day 7 (7D) after surgery. Dashed lines indicate the margin of the dorsal horn. The lower images (II, III) are magnifications of the upper images (I); and the inset images at the bottom of the lower image are further amplified images, with arrows marking the Hes1-positive neurons. Scale bar = 50 μm; Thickness = 30 μm.