Neocortex expansion in development and evolution-from genes to progenitor cell biology

Area of Science:

• Neuroscience
• Developmental Biology
• Evolutionary Biology

Background:

• The neocortex, responsible for higher cognitive functions, expanded significantly during human evolution.
• This expansion is linked to increased proliferation of neural progenitor cells during development.
• Basal progenitors, especially basal radial glial cells, are crucial for generating the neurons underlying neocortex expansion.

Purpose of the Study:

• To investigate the genetic and cellular mechanisms driving neocortex expansion.
• To understand the role of primate-specific and human-specific genes in neural progenitor proliferation.
• To explore the cell biological basis of increased neuron generation in the developing neocortex.

Main Methods:

• Analysis of primate-specific and human-specific genes and their expression changes.
• Investigation of cell proliferation in cortical progenitor cells.
• Utilizing model systems including mouse, ferret, nonhuman primates, and cerebral organoids.

Main Results:

• Identification of specific genes and expression changes that enhance cortical progenitor proliferation.
• Elucidation of the cell biological mechanisms underlying increased neuron production.
• Demonstration of the relevance of these genetic factors in various model systems.

Conclusions:

• Evolutionary expansion of the human neocortex is driven by enhanced neural progenitor proliferation.
• Specific genetic factors, particularly those unique to primates and humans, play a key role.
• Understanding these mechanisms provides insights into human brain evolution and cognitive abilities.