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The notochord plays an integral role in the development of the neural tube. Prior to neurulation, during the migration of epiblastic endoderm cells towards the hypoblastic endoderm, the notochordal process opens into an arch termed the notochordal plate and attaches overlying neuroepithelium of the neural plate.
The progenitor notochord is derived from cells migrating from the primitive node and pit. [9] The notochord forms during gastrulation and soon after induces the formation of the neural plate (neurulation), synchronizing the development of the neural tube. On the ventral aspect of the neural groove, an axial thickening of the endoderm takes place.
For a short time, the neural tube is open both cranially and caudally. These openings, called neuropores, close during the fourth week in humans. Improper closure of the neuropores can result in neural tube defects such as anencephaly or spina bifida. The dorsal part of the neural tube contains the alar plate, which is associated primarily with ...
An elevated MSAFP measured at 16–18 weeks gestation is a good predictor of open neural tube defects, however the test has a very high false positive rate, (2% of all women tested in Ontario, Canada between 1993 and 2000 tested positive without having an open neural tube defect, although 5% is the commonly quoted result worldwide) and only a ...
[5] [6] The neural plate is the source of the majority of neurons and glial cells of the CNS. The neural groove forms along the long axis of the neural plate, and the neural plate folds to give rise to the neural tube. [7] This process is known as neurulation. [8] When the tube is closed at both ends it is filled with embryonic cerebrospinal ...
Axial mesoderm, or chordamesoderm, is the mesoderm in the embryo that lies along the central axis under the neural tube.. will give rise to notochord; starts as the notochordal process, whose formation finishes at day 20 in humans.
The neural fold is a structure that arises during neurulation in the embryonic development of both birds and mammals among other organisms. [1] [2] This structure is associated with primary neurulation, meaning that it forms by the coming together of tissue layers, rather than a clustering, and subsequent hollowing out, of individual cells (known as secondary neurulation).
It is released from the notochord and regulates bone morphogenic protein 4 (BMP4) during development. [9] The absence of BMP4 will cause the patterning of the neural tube and somites from the neural plate in the developing embryo. It also causes formation of the head and other dorsal structures. [9]