<P> As neurulation proceeds after induction the cells of the neural plate become high - columnar and can be identified through microscopy as different from the surrounding presumptive epithelial ectoderm ( epiblastic endoderm in amniotes ) . The cells move laterally and away from the central axis and change into a truncated pyramid shape . This pyramid shape is achieved through tubulin and actin in the apical portion of the cell which constricts as they move . The variation in cell shapes is partially determined by the location of the nucleus within the cell , causing bulging in areas of the cells forcing the height and shape of the cell to change . This process is known as apical constriction . The result is a flattening of the differentiating neural plate which is particularly obvious in salamanders when the previously round gastrula becomes a rounded ball with a flat top . See Neural plate </P>
<P> As neurulation proceeds after induction the cells of the neural plate become high - columnar and can be identified through microscopy as different from the surrounding presumptive epithelial ectoderm ( epiblastic endoderm in amniotes ) . The cells move laterally and away from the central axis and change into a truncated pyramid shape . This pyramid shape is achieved through tubulin and actin in the apical portion of the cell which constricts as they move . The variation in cell shapes is partially determined by the location of the nucleus within the cell , causing bulging in areas of the cells forcing the height and shape of the cell to change . This process is known as apical constriction . The result is a flattening of the differentiating neural plate which is particularly obvious in salamanders when the previously round gastrula becomes a rounded ball with a flat top . See Neural plate </P>
primary neurulation begins in response to signals released by cells in the
primary neurulation begins in response to signals released by cells in the
neural plate
neural plate