Involvement of microglial cells in synaptic remodeling in the lumbar motor region following thoracic spinal cord injury.

<p>(A-I) Representative images of transverse spinal cord sections from sham operated animals (A, D, G), animals at 3 weeks (3W) after injury (B, E, H), and animals at 3W after injury with treadmill training (TMT) (C, F, I). (A-C) Sections were stained with antibodies against CD11b (subunit of complement receptor 3). (D-F) Sections were stained with antibodies against C3 (complement component 3). Asterisks indicate cell bodies of ventral motor neurons. (G-I) Representative images of sections colabeled with Iba1 (red) and synaptotagmin (Syn; green). Each image consists of only a single optical plane. Double-labeled punctate signals (yellow) were considered as engulfed synaptic puncta (indicated by white arrows). The diagram inset in (A) shows the approximate location of regions of interest (red-boxed region within the ventral horn) for all the images. All scale bars represent 10 µm. (J) Quantification of the number of colocalized synaptic puncta per microglia. N = 5 animals for each group. *** represents <i>p</i><0.001 by one-way ANOVA followed by Tukey's post-hoc analysis. Error bars represent SEM.