Neurulation is the primary embryological event that defines all vertebrates; the process begins with a flat sheet of epidermis-like cells, called the neural plate, that folds into a tube.  This tube becomes the future brain and spinal cord. The tube is also called the neural tube and it runs from the anterior to posterior end of the embryo. Initially, the tube has two edges, called neural folds, which gradually move towards one another at the midline. There are numerous ways in which the neural folds fuse, depending on which animal you consider, but in the axolotl the fusion occurs first in the middle of the future back, then at the ends of the tube.  The two temporary open ends are called the anterior neuropore and posterior neuropore. 

In this video you will see all of these basic structures of neurulation, from the earliest evidence of neural plate formation to the final closure of the neuropores.  You can even see the early blocks of mesoderm, called somites, coalescing next to the complete neural tube!  It took 15 hours, one image recorded per minute, to create this video.

For more information on how the video was made, click here.