Floor Plate Roof Plate Neural Tube Release

Just as the floor plate is important in ventral patterning the roof plate serves as an important organizing center for dorsal patterning along with the dorsal epidermis.

Floor plate roof plate neural tube release.

Similarly exposure of neural cells to shh protein in vitro results in floor plate induction suggesting that high levels of shh can act alone to induce the floor plate 10 11. The basal plate forms most of the ventral portion of the nervous system including the motor portion of the spinal cord and brain stem. The floor plate responds to shh by producing its own shh and forming a gradient. The best described roles of the roof plate have emerged from studying it in the spinal cord region where the roof plate patterns the dorsal population of sensory neurons lee et.

They serve primarily as pathways for nerve fibers crossing from one side to the other. The notochord expresses shh. The alar plate. During early cns development the roof plate produces secreted factors which.

Despite the importance of the roof plate for normal patterning and development of the neural tube not much was known about its development or function until recently. Located on the ventral midline of the embryonic neural tube the floor plate is a specialized glial structure that spans the anteroposterior axis from the midbrain to the tail regions it has been shown that the floor plate is conserved among vertebrates such as zebrafish and mice with homologous. The roof plate of the neural tube responds to those signals by expressing more bmp4 and other transforming growth factor beta tgf β signals to form a dorsal ventral gradient among the neural tube. These neuroblasts develop into different types of neurons which express a different range of marker genes.

In the spinal cord one of these axes dorsal ventral d v depends largely on signals produced by two specialized midline structures one at the ventral pole of the neural tube the floor plate yamada et al 1991 and the other at the dorsal pole the roof plate figure 58 2 b. After closure the neural tube forms a basal plate or floor plate and an alar plate or roof plate in response to the combined effects of shh and factors including bmp4 secreted by the roof plate. The roof plate is an embryonic organizing centre that occupies the dorsal midline of the vertebrate neural tube. Roof plate alar plate.

In the embryo the ventral midline of the neural tube may be exposed to high levels of shh due to the close apposition of the notochord 12. The dorsal and ventral midline portions of the neural tube known as the roof and floor plates respectively do not contain neuroblasts.