BV induced p38 phosphorylation in both neurons and microglia in the rat L4/5 spinal dorsal horn. (A-I) Double immunofluorescence in the dorsal horn of L4/5 spinal cord sections (16 μm) at 3 d after BV-injection, for p-p38 (green) and GFAP, an astrocyte marker (red; B, C); NeuN, a neuronal marker (red; E, F); and Iba1, a microglia marker (red; H, I) (40×). (A-C) p-p38-IR was not co-expressed with GFAP-IR. (D-F) Double immunofluorescence for p-p38 and NeuN indicated partial colocalization of p-p38 and NeuN (F, white arrow). There were many p-p38-IR cells that are not co-expressed with NeuN in the dorsal horn after BV injection (F, white arrow head). (G-I) p-p38-IR which is not co-expressed with NeuN colocalized with Iba1 (I, white arrow head). Scale bars, 50 μm (A-I).