What’s the difference between the brain of an ape and a human? The answer: two days.
At Cambridge University, researchers grew cerebral organoids – pea-size mini-brains that mimic certain functions of the real things – from human, ape, and chimpanzee neurons.
They compared day-by-day development of the mini-brains among the three, especially the point at which general-purpose stem cells begin to differentiate into brain cells, or neurons, a transition that begins about four weeks after conception.
The scientists found that the transition starts two days later in human brains than in the brains of apes and chimps.
Those extra two days are crucial: they allow more time for stem cells to multiply, laying the foundation for more neurons that result in humans’ bigger brains.
The difference: the human mini-brain grew to twice the size of the ape’s.
A gene called ZEB2 determines when the transition from stem cells to neurons begins. When scientists delayed ZEB2’s on-switch by two days in the ape brainlet, it grew to the same larger size as the human organoid.
TRENDPOST: The finding is more than an interesting bit of research.
By controlling ZEB2, scientists now have a way, in theory, to manually time stem cells’ transition to neurons. By delaying the change longer and longer, more and more stem cells could be laid down, creating not just a bigger brain but one with enough neurons to dramatically boost memory and intelligence.
