Figure 5.

Transplanted embryonic stem (ES) cell-derived neurons extended axons in both rostral and caudal directions. (A–C): Reconstructed confocal micrographs demonstrate process profiles (GFP [A]) exhibiting the immunoreactivity (neurofilament [B] and merge [C]) of axons traversing the cyst glial scar (white dotted lines demarcate cyst barrier). (C): Merged view (orthogonal view outlined in blue is representative of demarcated blue line) demonstrates relatively few cells and numerous axons within this spatial pattern of robust outgrowth. (D): A GFP+ neuron extended its neurite (white arrows; white arrowhead represents neuronal cell body) through a relatively less dense CSPG zone, whereas it remained within the cyst cavity/transplantation site (GFP, green; CSPG, red). (E): Quantification of the number of GFP/Hoechst+ ES cell-derived cells relative to the number of GFP+ neurites within a 1-mm measurement box, comparing the inside and outside of the cyst cavity. The percentage is expressed in relation to the total number of axonal processes. Student’s t test was used. ∗, p < .05; ∗∗, p < .01. Transplanted cells shown here were derived from the B5 GFP ES cell line. Scale bars = 10 μm (A–C), 20 μm (D). Abbreviations: CSPG, chondroitin sulfate proteoglycan; G, gray matter; GFP, green fluorescent protein; W, white matter.