Researchers at the Montreal Clinical Research Institute have uncovered a key mechanism that sheds light on how the human brain achieves its optimal size and why mice have smaller eyes compared to humans. This breakthrough not only enhances our understanding of nervous system evolution but also holds promise for advancing knowledge in human developmental disorders and potentially developing new strategies to combat cancer.
Dr. Michel Cayouette and his team at the IRCM have identified two crucial genes that dictate the direction of cell division in neural stem cells, influencing the production of cells in the brain and retina. By manipulating this orientation, they were able to expand brain and retinal tissues by up to 30%, demonstrating the significant impact of cell division orientation on tissue size.
In normal circumstances, mice undergo cell division along a horizontal axis, limiting tissue expansion and determining their final size. However, by deactivating the GPSM2 and SAPCD2 genes, the researchers redirected cell division along a vertical axis in mice, resulting in the generation of larger tissues.
In contrast, humans and macaques naturally exhibit more vertical divisions of stem cells in the retina, hinting at the potential for increased stem cell “pool” and enhanced tissue size control.
Dr. Cayouette emphasized the remarkable impact of altering cell division orientation on tissue size regulation, highlighting the importance of this mechanism in shaping the development of the brain and retina.
This groundbreaking research not only offers insights into the fundamental mechanisms governing tissue size but also opens up new possibilities for understanding and potentially treating conditions related to abnormal brain development.
Keyphrase: brain size evolution
