Immunohistochemical analysis of the spinal cord ventral horn stained with glial fibrillary acid protein (GFAP), 4 and 12 weeks following ventral root avulsion and repair. No significantly further increase in astrogliosis after reimplantation was observed. (a-b, e-f, and i-j) Ipsilateral and contralateral sides, 4 weeks after lesion. (c-d, g-h, and k-l) Ipsilateral and contralateral sides, 12 weeks after lesion. (m) Mean integrated density of pixels obtained ipsi and contralateral to the lesion side, 4 weeks after injury. (n) The ratio IL/CL (ipsi/contralateral sides) of the integrated density of pixels at lamina IX, 4 weeks after lesion. (o) Mean integrated density of pixels obtained ipsi and contralateral to the lesion side, 12 weeks after injury. (p) The ratio IL/CL (ipsi/contralateral sides) of the integrated density of pixels at lamina IX, 12 weeks after lesion. Scale bar = 50 μm. Mean ± SE.