Figure 4.

Axon and Dendrite Growth and Guidance

(A) Left: Reconstruction of a typical rat cortical pyramidal neuron. Right: A neuron generated with NETMORPH using appropriately tuned model parameters (reproduced with permission from Koene et al. (2009)).

(B) Example of simulated growth of axons (black) and dendrites (red) across three cortical layers (reproduced from Zubler and Douglas (2009)).

(C) Some key structures and molecules involved in neurite growth and guidance.

(D) Number of growth cone point contacts as a function of time from the model of Padmanabhan and Goodhill (2018), corresponding to stochastic oscillations between growth and paused states.

(E) Model predictions for whether axons are attracted or repelled in response to a molecular gradient as a function of levels of calcium and cAMP (Forbes et al., 2012) (reproduced with permission from Sutherland et al. (2014)).

(F) Measured chemotactic sensitivity as a function of concentration and steepness of dorsal root ganglion explants grown in gradients of nerve growth factor (Mortimer et al., 2009).

(G) Chemotactic sensitivity predicted by the Bayesian model of Mortimer et al. (2009) (different y axis units from F).

(H) Chemotactic sensitivity predicted by the model of Bicknell et al. (2018a), which addresses signaling pathways shared between growth and guidance (same y axis units as F).