Figure 3.

GÖ6976 promotes CST axonal regeneration across and beyond a lesion gap only when it was delivered into the motor cortex. Representative sagittal (A–G) and parasagittal (H–N, 200 μm lateral to the sagittal) sections of the rat spinal cords of 6 treatment groups at 7 weeks after C4 DH. CST axonal regeneration across and beyond a lesion gap was found only when GÖ6976 was delivered into the motor cortex (D, K, and Q). Greater CST axonal regeneration was found when cortical GÖ6976 delivery was combined with lesion site delivery of lenti-ChABC (E, L, and O). In all other 5 groups, including when GÖ6976 was delivered intrathecally (F and M) or intraperitoneally (G and N), CST axons failed to regenerate into the caudal cords, though among which lenti-ChABC alone (C and J) promote the CST growth toward lesion border compared with other 4 groups. (P and R) Statistical comparison of axon index at sagittal (P) and parasagittal (R) sections among 7 treatment groups at different distances from the lesion site (n = 6/group; error bars = SD). “*” and “#” denote significant differences (* and #, P < 0.05; ** and ##, P < 0.01) between cortical GÖ6976-delivered groups (GÖ6976 alone or in combination with lenti-ChABC) and the other 5 groups. “$” denotes significant differences ($, P < 0.05; $$, P < 0.01) between lenti-ChABC alone and the other 6 groups. “+” denotes significant differences (+, P < 0.05; ++, P < 0.01) between the group that received cortical GÖ6976 delivery alone and the combined treatment with cortically delivery of GÖ6976 and lesion site delivery of lenti-ChABC. Scale bars in A–L = 100 µm, in M and O = 200 µm.