Compared to human apes – gorillas and chimpanzees – the human brain is three times larger in proportion and contains a greater number of neurons. Researchers at the University of Cambridge A cell magazine They published their latest study on the evolution of human brain size. This research is due to organelles, a 3D cell culture. Organisms are close to tissue organization within living organisms and reproduce the early stages of brain development.
Brain organoids are tissue cultures that can be used to model a patient’s brain with a small organ created from its cells.
In the early stages of brain development, before neurons appear, the neuroepithelial cells, the layer of cells that line the central cavity of the neural tube, differentiate and proliferate. These cells proliferate in the early stages of embryonic development and develop into radial glial cells (the cells that build the nervous system, and supply neurons with nutrients and oxygen) that make up the neurons in the brain and the majority of glial cells..
In monkeys and humans, neuroepithelial cells take several days to transform and gradually change shape. This long process means that there are transient cells that are no longer neuroepithelial cells but no longer radial glial cells.
These transient cells appear in monkeys on the fifth day of development, while in humans they appear on the eighth day. This late transformation allows for a longer multiplication of cells, so on the 10th day when radial glia develop, their numbers in humans are greater than in monkeys.
What is responsible for this small delay in the development of the human brain?
The researchers identified a transcription factor called ZEB2 (a protein that regulates gene function) that is responsible for the transition between neuroepithelial cell and radial glia.
By modifying ZEB2, the researchers were able to alter the characteristics of a particular organism. Human organelles became similar to those of humans when ZEB2 started working from day 5, and on the contrary, human organelles took on the shape of a human body when ZEB2 started working from day 8. This slight difference is the reason why volume is imposed on the human brain compared to humans.
(Cover Photo: Matthew Horwood/Getty Images Hungary)
