Differential Timing and Coordination of Neurogenesis and Astrogenesis in Developing Mouse Hippocampal Subregions

Abstract

Neocortical development has been extensively studied and therefore is the basis of our understanding of mammalian brain development. One fundamental principle of neocortical development is that neurogenesis and gliogenesis are temporally segregated processes. However, it is unclear how neurogenesis and gliogenesis are coordinated in non-neocortical regions of the cerebral cortex, such as the hippocampus, also known as the archicortex. Here, we show that the timing of neurogenesis and astrogenesis in the Cornu Ammonis (CA) 1 and CA3 regions of mouse hippocampus mirrors that of the neocortex; neurogenesis occurs embryonically, followed by astrogenesis during early postnatal development. In contrast, we find that neurogenesis in the dentate gyrus begins embryonically but is a protracted process which peaks neonatally and continues at low levels postnatally. As a result, astrogenesis, which occurs during early postnatal development, overlaps with the process of neurogenesis in the dentate gyrus. During all stages, neurogenesis overwhelms astrogenesis in the dentate gyrus. In addition, we find that the timing of peak astrogenesis varies by hippocampal subregion. Together, our results show differential timing and coordination of neurogenesis and astrogenesis in developing mouse hippocampal subregions and suggest that neurogenesis and gliogenesis occur simultaneously during dentate gyrus development, challenging the conventional principle that neurogenesis and gliogenesis are temporally separated processes.

Antisense oligonucleotide treatment rescues UBE3A expression and multiple phenotypes of an Angelman syndrome mouse model

“…ICV injection of ASO in Ube3a m–/p+ mice at P1 or P21 resulted in a wide distribution of UBE3A throughout the brain. However, in the hippocampus of both P1 and P21 ASO-treated AS mice, lower UBE3A reinstatement was observed in the dentate gyrus, possibly due to neurogenesis, which occurs from embryonic development until adulthood, leading to dilution of the ASO ( Figure 2A and Figure 4B ) ( 20 , 21 , 26 ).…”

Neural Stem Cells: What Happens When They Go Viral?

“…During brain development, NSCs differentiate in a temporal sequence with neurogenesis occurring first followed by gliogenesis [ 8 , 14 , 61 , 62 , 63 , 64 ]. In rodents, neurogenesis begins during early embryonic stages 10–11 (E10–E11) and continues till birth, although dendritic and axonal maturation continues postnatally [ 61 , 65 ]. Gliogenesis begins during late embryonic stages and peaks at birth [ 61 , 63 , 64 ].…”

“…In rodents, neurogenesis begins during early embryonic stages 10–11 (E10–E11) and continues till birth, although dendritic and axonal maturation continues postnatally [ 61 , 65 ]. Gliogenesis begins during late embryonic stages and peaks at birth [ 61 , 63 , 64 ]. In humans, both neurogenesis and gliogenesis occur majorly during gestation, but development continues even after birth [ 65 ].…”

Mercury Toxicity and Neurogenesis in the Mammalian Brain

“…In the developing embryonic mammalian brain, neurogenesis occurs before gliogenesis [ 25 ]. Interestingly, the process of astrogenesis overlaps neurogenesis in the developing hippocampal dentate gyrus, which makes the process of neurogenesis and astrogenesis more complex in that brain region.…”

“…Interestingly, the process of astrogenesis overlaps neurogenesis in the developing hippocampal dentate gyrus, which makes the process of neurogenesis and astrogenesis more complex in that brain region. [ 25 ] On the other hand, the effects of mercury toxicity are not influenced by astrocytes and oligodendrocytes during neural tube formation and early brain development.…”