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 in the neural tube of Drosophilia available for the binding of growing axons. These studies have defined guidepost cells as non-continuous landmarks located on future paths of growing axons by providing high-affinity substrates to bind to for navigation. Guidepost cells are typically immature glial cells and neuron cells, that have yet to grown an axon. They can either be labeled as short range cells or axon dependent cells. To qualify as a guidepost cell, neurons hypothesized to be influenced by a guidance cell are examined during development. To test the guidance cell in question, neural axon growth and migration is