OMgp-induced growth cone repulsion does not require β1-integrin function. A. Growth cone turning of rat hippocampal neurons in a gradient of OMgp. Sample images show an axon of a P5 hippocampal neuron in an OMgp gradient (5 μg/ml in the pipette) at the onset (0') and at the end (30') of the turning assay. Scale bar: 20 μm. Right traces show sample trajectories of axons during the turning assay from 15 randomly selected neurons. Scale bar: 5 μm. B. Growth cone turning in a gradient of OMgp in the presence of a blocking antibody to β1-integrin. Similar as in (A), except for the presence of Ha2/5 (1.0 μg/ml). C. Summary of growth cone turning angles under different conditions. Echistatin (100 nM) or Ha2/5 (1 μg/ml) was preincubated for 30 min and present throughout the turning assay. Values represent mean ± s.e.m. Numbers associated with the bar graph indicate the number of growth cones analyzed. "*" indicates significant difference from the heat-inactivated (HI) OMgp (p < 0.01, ANOVA).