Figure 2.

Multi-stage neuron growth phase field result and four single neuron growth results. The phase field variable field $\varphi$, is shown in (A–I). (A) Initial circular cell at the center of the domain of grid size $380\times 380$ (0 iteration). (B) Stage 1 lamellipodia formation (500 iterations) and (C) Stage 2 initial outgrowth of neurites (10,500 iterations) where the neurites grow to similar length with no constraints applied. (D) The longest neurite grows out further than the rest of the neurites using an extracellular cue-based energy activation zone approach, leading to stage 3 axon differentiation (28,500 iterations). (E) Stage 4 dendrite formation (35,000 iterations) is observed by allowing the neurite extension and branching for more iterations. (F–I) shows four phase field model results of single neuron growth using different $\theta$ initializations using grid size of $383\times 383$, $303\times 303$, $363\times 363$, and $343\times 343$ respectively. Each case exhibits growth behavior from stage 1 lamellipodia formation to stage 4 dendrite formation with observable stage 3 axon differentiation. The axon growth exhibits similar angle changes with experimental data-based extracellular cue placement. (J–M) Intracellular tubulin concentration field is shown for the corresponding phase field results.