Fig. 7. Quantitative analysis of the effect of SDF-1-expressing COS cells on the morphology of CXCR4-GFP-transfected hippocampal neurons. Hippocampal neurons transfected with CXCR4-GFP were co-cultured for 16-20 hours with SDF-1-transfected COS cells. For morphometric analysis, CXCR4-GFP-expressing neurons were classified into the control group or the SDF-1-stimulated group depending on their distance from a SDF-1-expressing COS cell. Quantification for the number of processes emerging from the cell body (A), the length of the axon and the other neurites (B), the number of branch points per 100 µm of axon and other neurites (C), the number of growth cones per process (D) were performed for the two groups. Data are presented as the mean±s.e.m. of two independent experiments. *P<0.05, **P<0.01 (Student's t-test) compared to corresponding measurements in control cells.