Editing Neuroblast (section)

==Formation==
Neuroblasts are formed by the [[asymmetric cell division|asymmetric division]] of radial glial cells. They start to migrate as soon as they are born. [[Neurogenesis]] can only take place when neural stem cells have transitioned into radial glial cells.<ref name="Johnson"/>

===Differentiation===
Neuroblasts are mainly present as precursors of neurons during embryonic development; however, they also constitute one of the cell types involved in [[adult neurogenesis]]. Adult neurogenesis is characterized by neural stem cell differentiation and integration in the mature adult mammalian brain. This process occurs in the [[dentate gyrus]] of the hippocampus and in the [[subventricular zone]]s of the adult mammalian brain. Neuroblasts are formed when a [[neural stem cell]], which can differentiate into any type of mature neural cell (i.e. neurons, [[oligodendrocyte]]s, [[astrocyte]]s, etc.), divides and becomes a '''transit amplifying cell'''. Transit amplifying cells are slightly more differentiated than neural stem cells and can divide asymmetrically to produce postmitotic neuroblasts and glioblasts, as well as other transit amplifying cells. A neuroblast, a daughter cell of a transit amplifying cell, is initially a neural stem cell that has reached the "point of no return." A neuroblast has differentiated such that it will mature into a neuron and not any other neural cell type.<ref>{{cite book|last=Purves|first=D|title=Neuroscience |year=2007|publisher=W. H. Freeman|location=New York|isbn=978-0-87893-697-7|edition=4th|display-authors=etal}}{{page needed|date=April 2018}}</ref> Neuroblasts are being studied extensively as they have the potential to be used therapeutically to combat cell loss due to injury or disease in the brain, although their potential effectiveness is debated.

===Migration===
In the [[embryo]] neuroblasts form the middle '''mantle layer''' of the [[neural tube]] wall which goes on to form the [[grey matter]] of the [[spinal cord]]. The outer layer to the mantle layer is the '''marginal layer''' and this contains the myelinated axons from the neuroblasts forming the [[white matter]] of the spinal cord.<ref name="Sadler"/> The inner layer is the [[ependyma|ependymal layer]] that will form the lining of the [[ventricular system|ventricles]] and [[central canal]] of the spinal cord.<ref name="Tortora">{{cite book |last1=Tortora |first1=G |last2=Derrickson |first2=B |title=Principles of anatomy & physiology. |date=2011 |publisher=Wiley |isbn=9780470646083 |page=571 |edition=13th.}}</ref>

In humans, neuroblasts produced by stem cells in the adult [[subventricular zone]] [[cell migration|migrate]] into damaged areas after brain injuries. However, they are restricted to the subtype of small interneuron-like cells, and it is unlikely that they contribute to functional recovery of [[Striatum|striatal]] circuits.<ref name="Liu">{{cite journal | last1=Liu | first1=F | title=Brain Injury Does Not Alter the Intrinsic Differentiation Potential of Adult Neuroblasts | journal=The Journal of Neuroscience | volume=29 | issue=16 | pages=5075–5087 |date=April 2009 | doi=10.1523/JNEUROSCI.0201-09.2009 | pmid=19386903 | last2=You | first2=Y | last3=Li | first3=X | last4=Ma | first4=T | last5=Nie | first5=Y | last6=Wei | first6=B | last7=Li | first7=T | last8=Lin | first8=H | last9=Yang | first9=Z | pmc=6665479 | doi-access=free }}</ref>