Glial proliferation:For the last decades,glial cells have been wrongly believed to have a mere passive supporting role for neurons.Nevertheless,this notion has clearly changed and it is now admitted that these cells are essential for the correct development and regulation of the nervous system.Glia cell population are commonly subdivided in astrocytes,oligodendrocytes and microglia.During the development,neural stem cells(NSCs)(called neuroepithelial progenitor cells or NPCs)transform into radial glia,the primary progenitor cells for neurons,astrocytes and oligodendrocytes(Zuchero and Barres,2015).Microglial cells,however,derive from a mesenchymal precursor infiltration,meaning that during brain development,precursors generated in the bone narrow invade the nervous parenchyma and differentiate into microglial cells(Zuchero and Barres,2015).This proliferative capacity is preserved in the adult mammalian brain,and neurogenic NSCs are stored in two restricted regions of the central nervous system(CNS),the forebrain subventricular zone(SVZ)and the hippocampal dentate gyrus(subgranular zone).These cells continue to produce neurons and glial cells during the adulthood,being activated after certain signals and leaving the quiescent state(Urbán et al.,2019).This process,in which glial progenitor cells differentiate into mature glia during development and in the adult brain to maintain and regulate brain function,is called gliogenesis(Ardaya et al.,2020).
展开▼
