Table 1.

Summary of model parameters (GC: growth cone).

DOI: http://dx.doi.org/10.7554/eLife.12248.003

Symbol	Meaning
$\theta$	GC’s current bearing
$\Phi$	GC’s overall angle
$\Psi$	Gradient direction
$\Delta \theta$	Bearing change
${\psi }_{turn}$	Turning angle after 80 min
$a$	Persistence strength
$b$	Bias strength
$\xi$	Noise in bearing change
$\sigma$	Standard deviation of $\xi$
$s$	Step size every 5 min
$L$	Distance from origin to GC
$S$	Straightness index
$r$	Anchoring rate