Fig. 7. Scatter diagram showing the reversibility of the effect of Endo N treatment on OPC chemotaxis. Before the migration assay in Dunn chamber, cultures were treated with Endo N in the presence of Ara-C (5x10^–6 M) and PDGF (5 ng/ml) for 24 hours, subsequently washed and further cultured in normal medium with PDGF (5 ng/ml), NT3 (10 ng/ml) and Ara-C for 16 hours. The migration assay was performed as described in Materials and Methods. The final positions of cells after 6 hours of migration were indicated with the starting point for each cell at (0, 0), with the source of PDGF (100 ng/ml) at the top. Note that cells have normal chemotactic responses to PDGF gradient in contrast to cells kept in the presence of Endo N (Fig. 4). Data from four independent experiments are shown. Speed and FMI represent the mean ± s.e.m. from these four independent experiments.