Radial glia and radial glia-like cells: Their role in neurogenesis and regeneration

Radial glia cells (RGCs) are traditionally associated with the development of the nervous system, specifically in the formation of cortical layers in the mammalian brain. However, similar cells, known as radial glia-like cells (RGLCs), are found in the adult central nervous system (CNS). These RGLCs act as neurogenic progenitors, contributing to normal maintenance and responding to injuries. Adult RGLCs in vertebrates can proliferate throughout the animal’s life in the hippocampal dentate gyrus (DG) and in the subventricular zone (SVZ) of the lateral ventricle. Those that reside in the SGZ have long processes that reach the granule cell layer and extend into the inner molecular layer. They also share distinctive marker expressions, such as BLBP, Sox2, GFAP, and Nestin In echinoderms, studies have identified RGLCs using cell morphology, Reissner’s substance immunolabeling, and the expression of an antigen recognized by monoclonal antibodies. In H. glaberrima, RGLCs comprise a significant portion of the cells in the RNCs, constituting most, if not all, of the glial cells present.

• 1
  Radial glial cells (RGCs) or radial glia-like cells (RGLCs) have been documented in adults of various species, where functions, additional to their embryological role, have been described.
• 2
  In adult rodents, RGLCs of the SGZ have been shown to produce excitatory neurons that might be involved in memory formation and learning capacity, while RGLCs of the SVZ are associated with the formation of inhibitory neurons that contribute to odor discrimination and odor-reward association.
• 3
  Following RNC reconnection, dedifferentiated cells in the regenerative zone redifferentiate, which is reflected by the growth in the size of the “new” tissue between the stumps. Birth dating experiments have shown that dedifferentiated RGLCs cells play a role in this event by giving rise to both RGLCs and neuronal populations in the regenerated structure