Fig. 9
Ankle joint immobilization suppressed microglial activation. a Unilateral arthrodesis of the right side was performed to immobilize the ankle joint (i.e., left = non-arthrodesis side). Clear microglial accumulation was observed in the L5 spinal cord in the medial region of the dorsal horn and the dorsal region of the ventral horn (non-arthrodesis side), whereas no such accumulation was observed on the arthrodesis side (arthrodesis side). b Quantification of microglial cell number/unit area (10,000 μm2) in the medial region of the L5 dorsal horn. c Quantification of microglial cell number/unit area (10,000 μm2) in the dorsal region of the L5 ventral horn. d Quantification of microglial occupied area/unit area in the medial region of the L5 dorsal horn. e Quantification of microglial occupied area/unit area in the dorsal region of the L5 ventral horn. f ATF3 immunoreactivity (green) was observed in ChAT-positive cells (motor neurons, red) in the rectangular inset region of the non-arthrodesis side in a. g ATF3 immunoreactivity was not observed in ChAT-positive cells (motor neurons, red) in the inset region of the arthrodesis side in a. h Expression of ATF3 (green) was observed in the L5 dorsal root ganglion (DRG) of the non-arthrodesis side. i Expression of ATF3 was suppressed in the L5 DRG of the arthrodesis side. Scale bar 200 μm. j ATF3 expression was significantly suppressed in the L5 DRG of the arthrodesis side. k Changes in the pressure pain threshold of the muscle after CS on the non-arthrodesis and arthrodesis sides. The pain threshold increased on the arthrodesis side. n = 4. *p < 0.05. **p < 0.01. ***p < 0.001. Paired t test