Fig. 6. Summary of the turning responses of retinal growth cones caused by different axon guidance molecules. Growth cones are repelled by netrin 1 (5 µg/ml) and BDNF (50 µg/ml). Ephrin-A5-Fc at 20 µg/ml induces a substratum-dependent turning on laminin leading to attraction, whereas on fibronectin it leads to repulsion. Shown are mean turning angles (see also Fig. 5). Error bars represent s.e.m.