Expression and distribution of CXCL12 protein in the spinal cord after TCI in rats. (A) Western blot analysis shows time course of CXCL12 expression in sham and TCI rats. Five spinal cord segments were included in each group. Representative bands are shown on the top; data summary is shown on the bottom. *P < 0.05, **P < 0.01 versus sham control. (B) Immunofluorescence shows expression of CXCL12 protein (green) in rat spinal cord at different time points. Tissues were collected at day 3, 5, 10, 14 after TCI. Original magnification: 200× for all the confocal images showing the dorsal horn ipsilateral to TCI (bar = 100 μm).