BV injection evoked p38 phosphorylation in rat dorsal horn. (A) p-p38 immunostaining in an L4/5 spinal cord section (16 μm) in a control and at the indicated time points after intraplantar BV injection (200 μg/50 μl). Immunohistochemistry shows a gradual increase in the number of p-p38 immunoreactive cells in the ipsilateral spinal cord. (B) Time course of BV-evoked p-p38 labeled cells in the lamina I-II of L4/5 dorsal horn (n = 4 or 5 each time point, ** p < 0.001; *p < 0.05; compared with control; one-way ANOVA). Scale bars, 100 μm; cont, control.