Developmental Biology Primary neurulation的过程 (A)Formation of neural folds (B)Elevation of neural folds Presumptive 沙 Notochord DLHP DLHP Presumptive neural plate r Furrowing Transition zone MHP Wedging Neural plate Epidermis Anchoring Notochord Figure 7.4 anchored to the notochord the neural Schematic representation of the epithe- folds are elevated. These movements lial bending during chick neurulation. appear to be continued as the medially (A)Formation of neural folds occurs moving epidermis drags the neural when presumptive epidermal cells plate with it, resulting in the apposition move medially toward the center of the of the neural folds. (C)In the three embryo. This presumptive epidermis hinge regions(the medial hinge point, pushes the neural plate under it as it MHP and the two dorsolateral hing moves.(B)As the midline cells of the neural plate( the floor plate cells)are positions, the DLHP), the neural plate lls change their length and constrict at their apiceDevelopmental Biology Primary neurulation的过程