FIG. 2.

Morphometric analysis of the connections between the segments caudal to the lesion and various parts of the central nervous system cranial to that. (A) Numbers of neurons retrograde labeled from the right L3 hemisegment. Note the significantly higher numbers of labeled cells in the grafted animals compared with their controls, especially in the brainstem. The greatest number of retrograde labeled cells was always found in the intraspinally treated animals. (B) Retrograde labeling results in the raphe nuclei (left panel) and serotonergic immunochemical densities (right panel) expressed as fold increase caudal to the lesion normalized to the uninjured level. Note the considerable number of retrograde labeled raphe neurons and the lack of sprouting in the NE4C-1w-isp animals. Data are expressed as mean ± standard error of the mean. *, significant difference between the intraspinally or intravenously grafted animals with the control ones.