Stars from the darkest night: unlocking the neurogenic potential of astrocytes in different brain regions

Abstract

In a few regions of the adult brain, specialized astrocytes act as neural stem cells capable of sustaining life-long neurogenesis. In other, typically non-neurogenic regions, some astrocytes have an intrinsic capacity to produce neurons when provoked by particular conditions but do not use this ability to replace neurons completely after injury or disease. Why do astrocytes display regional differences and why do they not use their neurogenic capacity for brain repair to a greater extent? In this Review, we discuss the neurogenic potential of astrocytes in different brain regions and ask what stimulates this potential in some regions but not in others. We discuss the transcriptional networks and environmental cues that govern cell identity, and consider how the activation of neurogenic properties in astrocytes can be understood as the de-repression of a latent neurogenic transcriptional program.

Neural stem/progenitor cells are activated during tail regeneration in the leopard gecko (Eublepharis macularius)

“…These include the demonstration of: (a) label‐retaining populations prior to injury; (b) immunoreactivity for various radial glia markers, including the stem maintenance marker SOX2 and the intermediate filaments Vimentin and GFAP; (c) changes in protein expression and proliferation following tail loss; and (d) uniciliated cells in the original tail, and uniciliated and biciliated cells in the regenerate tail. Infrequent cell division or quiescence is commonly associated with dormant stemness potential throughout the lifespan of an organism (Magnusson & Frisén, ; Momma, Johansson, & Frisén, ). Once induced to divide, these dormant cells then mediate repopulation via transiently amplifying precursor cells to participate in tissue repair and replacement (C. G. Becker & Becker, ; Momma et al, ; Richmond, Shah, Carlone, & Breault, ) As expected (given the timeframe of the pulse), only a small percent of original spinal cord ELCs (2.5%) were found to be slow‐cycling at the end of a lengthy (140‐day) chase period.…”

The Role of Astrocytes in Neuroprotection after Brain Stroke: Potential in Cell Therapy

“…The primary precursors in the SVZ, the other germinal region of the adult brain, have been identified as having the characteristics of astrocytes and expressing GFAP (Laywell et al, 2000). The reports are suggested that some of these cells can maintain a neurogenic potential and act as NSCs (Mori et al, 2005; Magnusson and Frisén, 2016). These cells can divide and generate new neurons under normal conditions or after the chemical removal.…”

Neuron-glia interaction through Serotonin-BDNF-NGFR axis enables regenerative neurogenesis in Alzheimer’s model of adult zebrafish brain

“…Yet, neurogenesis in human brains is quite controversial (Arellano et al, 2018;Cipriani et al, 2018;Dennis et al, 2016;Duque and Spector, 2019;Sorrells et al, 2018). Although many reports documented the presence of adult neurogenesis in human brains (Boldrini et al, 2018;Ernst et al, 2014;Kempermann et al, 2018;Magnusson and Frisen, 2016;Moreno-Jimenez et al, 2019;Spalding et al, 2013), and several studies demonstrated that boosting the neurogenesis might be a viable option for alleviating the cognitive decline (Casse et al, 2018;Choi et al, 2018;Martinez-Canabal, 2014;Papadimitriou et al, 2018;Rodriguez and Verkhratsky, 2011), the potential benefits of neurogenic outcome in AD conditions requires further investigation and critical testing. Additionally, in AD conditions, mammalian NSCs reduce the proliferative ability dramatically, and for neurogenesis to become a viable option for treatment of neurological disorders, mammalian NSCs must become plastic first.…”