Fig. 2

Immunofluorescence staining and quantification of CD11b/c protein. OX42 (CD11b/c protein) immunofluorescence to detect microglia in the dorsal horn (DH) of sections through L4–L5 spinal cord segments from naïve and sham-operated rats as well as sCCI-operated rats treated with ACSF or CD200Fc. Representative pictures of OX42 immunofluorescence in ipsilateral DH of the spinal cord from sham- (a) and CCI-operated (b, c) rats 5 h after ACSF (a, b) or CD200Fc (c) injection. Scale bars = 75 μm. A higher power magnification of OX42 immunofluorescence in DH of naïve (d) and sham-operated (h) rats and the ipsi- and contralateral DH (DH-ipsi, DH-contra) of sCCI-operated and ACSF-treated rats (e, i) as well as 5 (f, j) or 24 h (g, k) after injection with CD200Fc. Scale bars = 50 μm. Insets in d–f show typical shape of OX42-labeled microglia in DH of naïve, ACSF-, and CD200Fc-treated rats, respectively. Scale bars for insets = 33 μm. l Bar graph shows quantification of OX42 immunostaining area in DH of L4–L5 spinal cord segments from naïve and sham-operated rats as well as sCCI-operated rats for 7 days and 5 or 24 h after administration of CD200Fc or ACSF. m Western blot shows increased CD11b/c protein level in the spinal cord of sCCI-operated in comparison to naïve or sham-operated rats, whereas CD200Fc administration reduced this elevation. The data represent the mean ± SD optical density normalized to tubulin from six animals in each group. *p < 0.05 when compared to DH of naïve or sham-operated rats; #p < 0.05 when compared to DH of sCCI + ACSF rats; ++p < 0.05 when compared to 5-h treatment. Mann-Whitney U test