Figure 2. Model results with noise.

(A) Long-term behavior of growth cones: Simulation of 9 axons with fixed growth rate and noise in bearing changes (ξ ∼ N(0, π/4) radians) starting at ϕ(0) = 90° subject to the gradient direction Ψ = 0 with persistence $a$ = 1 and bias $b$ = 0.1 (blue), $b$ = 0.2 (red) and $b$ = 0.3 (black) after 150 steps (12.5 hr of real time). (B) The trajectories with the same parameters without noise. (C) The turning angles over time (mean ± SEM) of 1000 axons for different values of $b$ (0.1,0.2, 0.3) and $a$ = 1. (D) Straightness (mean ± std) decreases as the noise variance increases.

DOI: http://dx.doi.org/10.7554/eLife.12248.006