Lengthening Neurogenic Period During Neocortical Development Causes a Hallmark of Neocortex Expansion

From stem and progenitor cells to neurons in the developing neocortex: key differences among hominids

“…In fact, mathematical modelling has shown that the neurogenic period is a likely candidate to sufficiently explain differences in cortical neuron numbers among hominids [35]. Consistent with this modelling, which has received experimental support recently [36], the increase in size among primate brains and neocortices, from monkeys to humans, occurs in similar correlation with the increase in neuron numbers [6,37]. Differences in the proliferation of NSPCs among hominids found at specific stages of neocortex development may therefore mostly reflect differences in the onset, dynamics and end of the neurogenic period.…”

Metabolic Regulation of Neocortical Expansion in Development and Evolution

“…For example, recent studies have shown that the maternal metabolism affects (i) mitochondrial metabolism in mouse embryonic liver (Bowman et al, 2019) and (ii) mitochondrial mobility in NPCs as well as the thickness of the mouse embryonic neocortex (Rash et al, 2018). In addition, a maternal influence on the development of the mouse embryonic neocortex has very recently been reported (Stepien et al, 2020). Therefore, it appears worthwhile to study the maternalfetal metabolic relationship in the context of neocortical development, its disorders, and neocortical evolution.…”

MicroRNA-eQTLs in the developing human neocortex link miR-4707-3p expression to brain size

“…We have yet to uncover the specific regulatory effects of miR-4707-3p (which genes are targeted or which pathways disrupted), but the effect on cellular behavior is clear. The lengthening of neurogenesis and associated expansion of the brain are hallmarks of the evolutionary differences between humans and other mammals [63][64][65][66] . Comparative genomic studies have revealed that humanspecific gene regulatory differences in developing neocortex are associated with neurogenesis, brain complexity, and disease, and that primate-specific miRNAs have been shown to play a role in post transcriptionally regulating gene expression associated with these developmental processes [67][68][69][70][71] .…”