A gene unique to humans creates smarter mice, according to a new study conducted at the Max Planck Institute for Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, Germany. The ARHGAP11B gene stimulates the production of more neurons and causes the development of larger brains in rodents that express it. At the same time, it optimizes memory and reduces anxiety.
Most specialists agree that the neocortex development it was one of the key points of human evolution. The “newer” region of the cerebral cortex expanded considerably, resulting in an increase in the size of the human brain, which in turn led to more complex and advanced brain functions.
Is it possible to “transfer” this type of development to other species through genetic information? What would the consequences be? German scientists seem to confirm this possibility in the new research, although it is still difficult to pin down the scope that these kinds of innovations could have. Beyond this, they can shed light on phenomena peculiar to the human brain and how it managed to develop.
According to the conclusions of the research, published in Embo Journal, the experiments with transgenic mice confirm the crucial role of the mentioned gene in the expansion of the neocortex, which at the same time motivated a growth in the size of the human brain.
But they would also indicate that the increase in brain volume is directly related to the development of greater cognitive skills, or that at least it would be a transcendent factor in that sense.
According to a Press release, the researchers verified that mouse embryos that express the ARHGAP11B gene show an increase in the production of neural stem cells, responsible for developing new neurons.
This results in an increase in the number of cortical neurons, as well as in the size of the neocortex and the brain structure in general.
An important point is that the modification is not momentary, but is maintained until adulthood. Rodent behaviors also change: the scientists ran four different tests, targeting different types of learning and memory.
More flexible memory, better learning and less anxiety
The researchers placed bottles of water in the mice’s cages, the location of which was changed daily. In this way, the rodents needed to learn the patterns that indicated the position of the containers. Otherwise, it was impossible for them to access the water.
Over the course of the experiments, the researchers found that the mice that had expressed the ARHGAP11B gene made less mistakes when looking for water than those without the indicated genetic modification.
In this way, they concluded that rodents acquire greater memory flexibility thanks to the incorporation of the human gene and, as a consequence, can process new learnings faster.
At the same time, they observed that mice with the genetic addition they remained still in the center of their cage for a longer time, while the specimens with normal brain size appeared more restless and erratic. In this way, they verified that the expression of the gene also leads to a reduced anxiety levels.
In conclusion, the specialists suggest that the expansion of the neocortex induced by the ARHGAP11B gene produces better cognitive performance. Beyond the impact on rodents, this confirms the role that this gene has had in the evolution of the human brain, and the potential that its study would have to fully understand this evolution and its implications.
Expression of human-specific ARHGAP11B in mice leads to neocortex expansion and increased memory flexibility. Lei Xing et al. Embo Journal (2021) .DOI: https://doi.org/10.15252/embj.2020107093
Photo: Wolfgang Hasselmann and Unsplash.
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.