Radial glial cell and OPCs can be generated from radial glial cells "in vitro", more evidence is yet needed to conclude whether this process also occurs in the developing brain. Recently, radial glia that exclusively generate upper-layer cortical neurons have also been discovered. Since upper cortical layers have expanded greatly in recent evolution, and are associated with higher-level information processing and thinking, radial glia have been implicated as important mediators of brain evolution. The best characterized and first widely accepted function of radial glia is their role as scaffolds for neuronal migration in the cerebral and cerebellar cortexes. This role can be easily
Guidepost cells set of guidepost cells present for TCA guidance. These GABAergic neurons migrate to the medial ganaglionic eminence (MGE) region to form a "corridor" between proliferation zones of the MGE and globus pallidus (GP). Corridor cells provide TCA growth through MGE-derived regions. However, the Neurgulin1 signaling pathway needs to be activated, with the expression of ErbB4 receptors on the surface of TCAs, for the connection to occur between corridor cells and TCAs. There are subpopulations of glial cells that provide guidance cues for axonal growth. The first set of cells, called the "mid-line glial zipper", regulate the midline fusion and guidance