Cytoskeletal mechanics of neurulation: insights obtained from computer simulations

The morphogenetic movements associated with the process of neurulation have been the subject of much investigation during the last one hundred years. A plethora of experimental evidence has been generated regarding the forces that drive this seemingly simple process, and many theories about the mechanics of the process have been proposed. Recent computer simulations have proved useful for evaluating these theories from a mechanical perspective. In this work, computer simulations are used to investigate several theories about the forces that drive neurulation. A simplified version of a formulation previously presented by the authors provides the mathematical foundation for these simulations. The simulations confirm that forces generated by circumferential microfilament bundles (CMB's) in conjunction with notochord forces can produce the rolling motions characteristic of amphibian neurulation. They also support the notion that redundancies exist in the systems of forces available to drive neurulation shape changes. The shape changes that occur following a variety of surgical and teratogenic interventions are also simulated. These simulations corroborate the role of circumferential microfilament bundles as a primary force generator.