ABSTRACT
In this review article, the traditional viewpoint of how neurulation occurs is evaluated in light of recent advances. This has led to the formulation of the following fundamentals: (1) neurulation, specifically neural plate shaping and bending, is a multifactorial process resulting from forces both intrinsic and extrinsic to the neural plate; (2) neurulation is driven by both changes in neurepithelial cell shape and other form-shaping events; and (3) forces for cell shape changes are generated by both the cytoskeleton and other factors. Several cell behaviors within the neural plate have been elucidated. Future challenges include identifying cell behaviors within non-neurepithelial tissues, determining how intrinsic and extrinsic cell behaviors are orchestrated into coordinated morphogenetic movements and elucidating the molecular mechanisms underlying such behaviors.
Textbooks are principally distillations of tradition. Thus, by the traditional viewpoint we mean the body of accepted facts, the dogma, appearing in most general textbooks of developmental biology.