This flexibility allows for the pivoting and hinging that allows the buckling and lifting of the neural plate when formatting the neural tube. The neural plate has to be rigid enough for morphogenic movements to occur while being flexible enough to undergo shape and position changes for the transformation to the neural tube. Other animals The neural tube closes differently in various species, the distinctions between humans and chickens being some of the most studied. In humans, the neural tube fuses together from a central region of the embryo and moves outwards. In chickens, neural tubec closure begins at the future midbrain region and it closes in both directions. In birds and mammals, the closure does not occur at the same time. In newt and general amphibian embryos, cell division is not a driving role in morphogenesis. Newt embryo cells are much larger and exhibit egg pigmentation to distinguish cells from each other. The newt neural plate doubles in length, decreases in apical width, and increases in thickness. The plate edges rise dorsally and fold toward the midline to form the neural tube. The apical surface area decreases. In chicken embryos, while the neural plate increases in length and decreases in apical width, the thickness of the plate does not change drastically. As the neural plate progresses through the Hamburger-Hamilton stages, the plate thickens until about HH6-7, when the neural plate begins to fold into tube form. The apical surface area increases during neurulation, unlike amphibian embryos. In mouse embryos, there is a large convex-shaped curve to each side of the middle of the plate. This curve has to be reversed as the plate rolls together to form the neural tube. Research Research on the neural plate began in earnest by looking into the determination of the ectoderm and its commitment to the neuronal path. With the development of research and laboratory techniques there have been major advances in the study of neurulation and the development and role of the neural plate in a growing embryo. The use of such techniques vary with the stage of development and overall research goals, but include such methods as cell labeling and grafting. Cell labelling The process of in situ hybridization (ISH) follows the labeling of a DNA or RNA sequence to serve as an antisense mRNA probe, complementary to a sequence of mRNA within the embryo. Labeling with a fluorescent dye or