Axonal growth on Sema3A, Sema3C, and control substrates
| Substrate | Average growth speed μm/hr (including collapses) | Rate of collapse (collapses/hr) | Average growth speed μm/hr (excluding collapses) |
|---|---|---|---|
| Control (n = 6) | 18.6 ± 3.7 | 0.34 ± 0.2 | 19.5 ± 3.3 |
| Sema3A (n = 21) | 8.6 ± 1.2* | 1.35 ± 0.2* | 17.2 ± 3.1ns |
| Sema3C (n = 11) | 10.1 ± 2.8* | 0.22 ± 0.1ns | 11.6 ± 1.9* |
| Downhill Sema3C (n = 9) | 11.3 ± 1.2* | 0.24 ± 0.1ns | 13.6 ± 2.2* |
| Uphill Sema3C (n = 15) | 23.5 ± 2.3* | nd | nd |
Growth speed and rate of growth cone collapse of cortical axons growing on a uniform membrane substrate prepared from untransfected, Sema3A-transfected, and Sema3C-transfected HEK 293 cells and on towards decreasing concentrations (downhill) of Sema3C membrane gradients. Students t test; *p < 0.05; ns, not significant; n, number of axons examined; nd, not determined.