Hinge point emergence in mammalian spinal neurulation

Abstract

Significance Spinal neural tube folding shows a transition from medial to dorsolateral neural plate bending sites (hinge points) along the embryo’s body axis. While hinge points are considered an important driving force in neural tube closure, their biomechanical origin is poorly understood. Here we use a computational model based on mouse and human embryo imaging data to show that the median hinge point emerges in simulations combining mesoderm expansion, nonneural ectoderm expansion, and neural plate adhesion to the notochord. Furthermore, dorsolateral hinge points emerge through a medial pulling force exerted by dorsal nonneural ectoderm (zippering). This indicates that spinal neural tube folding could be primarily driven by mesoderm expansion and zippering, with hinge points passively emerging in response to extrinsic forces.