Question

The ____________, which is region closest to the neural tube lumen contains mostly neural stem cells. a. Ventricular zone b. Mantle c. Marginal zone d. All of the above

Answer 1

Ans.

The correct answer is (a) Ventricular Zone

Explanation:

Ventricular zone is an embryonic layer of tissue that contains the neural stem cells,especially the radial glial cells of the CNS.It lines the ventricular system that contains the cerebrospinal fluid and hence named as ventricular zone.Proliferation of the neural stem cells takes place in this zone,which is adjacent to the neural tube.This zone gives rise to the neuroblasts,that is future nerve cells and glioblasts,which is the future supporting cells,both of which migrates into the intermediate zone or the mantle layer and form 2 collections of cells called as as the alar plate and the basal plate,which is separated by a groove known as the sulcus limitans.Basal plate cells become motor neurons and forms the anterior or the ventral horn of the spinal cord.

Let us also understand what is mantle layer and marginal layer:

• Mantle Layer - This is the gray matter that is formed by the differentiation of neuroepithelial cells,found in the walls of the neural tube, into neuroblasts.
• Marginal Layer - The neuroblasts formed from neuroepithelial cells,give rise to nerve fibers that form the marginal layer or the white matter.