Floor Plate Roof Plate Neural Tube Release

Roof plate alar plate.

Floor plate roof plate neural tube release.

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. 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 floor plate is a structure integral to the developing nervous system of vertebrate organisms. The neural tube is from its very outset patterned in this axis as there is a roof plate floor plate and differing numbers and types of neuroblasts.

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. The notochord expresses shh. 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 is an embryonic organizing centre that occupies the dorsal midline of the vertebrate neural tube.

The dorsal and ventral midline portions of the neural tube known as the roof and floor plates respectively do not contain neuroblasts. The floor plate responds to shh by producing its own shh and forming a gradient. 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 alar plate.

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. During early cns development the roof plate produces secreted factors which. 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 basal plate forms most of the ventral portion of the nervous system including the motor portion of the spinal cord and brain stem.

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. These neuroblasts develop into different types of neurons which express a different range of marker genes.