FIG. 7.

Optogenetic stimulation of motor cortex (MC) activated more c-Fos–expressing neurons in red nucleus (RN) in SCI mice than in sham-injured mice. (A and B) At 6 weeks after sham injury or moderated SCI, optogenetic stimulation of the motor cortex using a blue LED for 30 min resulted in significant increases in the numbers of c-Fos–positive neurons per section in the motor cortex in both groups. However, the numbers of c-Fos–positive neurons per section were similar in the sham and SCI groups after optogenetic stimulation. (C and D) In contrast, cortical optogenetic stimulation activated a greater number of c-Fos–positive neurons per section in red nucleus of the SCI group than that of the sham group. Scale bars, 50 μm for low-power images of (A) and (C); 20 um for enlarged image of (C); n = 5 mice in each group. *p < 0.05; **p < 0.01, Student's t-test. DAPI, 4’,6-diamidino-2-phenylindole; LED, light-emitting diode; SCI, spinal cord injury. Color image is available online at www.liebertpub.com/neu