Fig. 4

Effect of GW9508 given intrathecally on spinal β-endorphin expression on spinal microglia (a–f), astrocytes (g–l), and neurons (m–r) in neuropathic rats induced by spinal nerve ligation. Frozen sections of the spinal lumbar enlargements were obtained 1 h after intrathecal saline (10 μl) or GW9508 (30 μg) treatment. Immunofluorescence was double stained with β-endorphin/Iba-1, β-endorphin/GFAP, and β-endorphin/NeuN, and photomicrographs were taken from the entire spinal cord section (a, d, g, j, m, p: 500 μm) and amplified dorsal horn laminae I–V (b, c, e, f, h, i, k, l, n, o, q, r: 50 μm). Arrows indicate double immunostaining of β-endorphin with each cellular biomarker. Double immunolabeled surface areas of β-endorphin/Iba-1 (s), β-endorphin/GFAP (t), and β-endorphin/NeuN (u) from the spinal dorsal horn laminae I-V indicated in white lines were quantified using the ImageJ program. Data are presented as means ± SEM (N = 5~7 per group). *P < 0.05 vs. saline group; analyzed by unpaired and two-tailed Student’s t test