Year: 2015
Type: preprint
Abstract: Of the neurogenic zones in the adult brain, adult hippocampal neurogenesis attracts the most attention, because it is involved in higher cognitive function, most notably memory processes, and certain affective behaviors.Adult hippocampal neurogenesis is also found in humans at a considerable level and appears to contribute significantly to hippocampal plasticity across the life span, because it is regulated by activity.Adult hippocampal neurogenesis generates new excitatory granule cells in the dentate gyrus, whose axons form the mossy fiber tract that links the dentate gyrus to CA3.It originates from a population of radial glia-like precursor cells (type 1 cells) that have astrocytic properties, express markers of neural stem cells and divide rarely.They give rise to intermediate progenitor cells with first glial (type 2a) and then neuronal (type 2b) phenotype.Through a migratory neuroblast-like stage (type 3), the newborn, lineage-committed cells exit the cell cycle and enter a maturation stage, during which they extend their dendrites into a the molecular layer and their axon to CA3.They go through a period of several weeks, during which they show increased synaptic plasticity, before finally becoming indistinguishable from the older granule cells. Because it has turned out that adult neuro- genesis not only exists in the human hippocampus but even seems to be restricted to it (see Spalding et al. 2013;Bergmann et al. 2015), public and scientific attention to the phenomenon is soaring.In PubMed, search results for "adult neurogenesis" and "hippocampus" outnumber those for "adult neurogenesis" and "olfactory bulb" or "subventricular" by 3:1.This is no reason to neglect research on adult neurogenesis in the olfactory system, which is a necessary part of any holistic view on adult neuro-genesis, but reason enough to ask for the motifs behind this interest.The answer, presumably, is "function."Adult hippocampal neurogenesis adds particular functionality to the mammalian hippocampus and presumably is involved in cognitive functions that we consider to be essential for humans.There is a price to pay for this type of plasticity.Adult neurogenesis is a complex multistep process, not a simple event.This review deals with the description of this process and the restriction points at which regulation occurs.
Authors: Gerd Kempermann, Hongjun Song, Fred H. Gage
Language: English
Subfield: Developmental Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2115290127