Figure 9

Changes in spherule-containing cells during radial nerve cord regeneration. The number of morula cells and spherulocytes increases in the regenerating radial nerve cord following transection. Morulas were detected using Toluidene blue (see Fig. 1). Quantitative analysis show that (A) the number of morulas peak between 2 and 6 dpi in the proximal nerve stumps and at 12 dpi in the regenerating cord that is forming at the injury site. Few changes are observed distal to the injury site. (B-C) Spherulocytes (green, arrows) were detected using the Sph2 antibody, a monoclonal antibody that recognizes the spherulocyte population. Longitudinal sections of animals at (B) 12 and (C) 28 dpi show the presence of spherulocytes within the nerve cord in early but not in late regenerating stages. Sections were also labeled with anti-galanin (red) and Hoeschst nuclear dye (blue). X's denote the injury site (D) Quantitative analysis show that the number of spherulocytes peaks at 6 dpi in the proximal stumps and at 12 dpi at the injury site, with little change at distal sites. Regenerated tissues in the injured area do not appear until 12-dpe. Each point represents the mean ± S.E. of five animals. When compared to distal, significant differences are observed at various stages in the proximal and injured areas *p < .05, **p < .01.