Fig. 5. SDF-1 regulates axonal patterning without influencing the other neurites. Hippocampal neurons were treated at day 1 for 16 hours with (B) or without (A) 50 nM SDF-1 and were fixed at day 2 for analysis by phase-contrast microscopy. Quantification of the length of the axon and the other neurites in the presence and absence of the glial feeder layer (C), the growth cone area (D), the soma area (E), the number of processes emerging from the cell body (F), the number of primary branch points per 100 µm of axon and other neurites (G) and the number of growth cones per process (H) was carried out. The analysis was performed on control cells, cells treated with 50 nM SDF-1, cells treated with 50 nM SDF-1 in the presence of 1 µM bicyclam, a CXCR4 antagonist, and cells treated with bicyclam alone. Data are presented as the mean±s.e.m. of two to three independent experiments. **P<0.01, ***P<0.001 (Student's t-test) compared to corresponding measurements in control cells. Bar, 12 µm.