Chinese scientists identify gene linked to brain evolution

Chinese researchers have found experimental evidence that the gene CCNB1IP1 plays a key role in brain development and may have contributed to the evolution of human intelligence.

Experiments in mice showed that increasing the gene’s expression to human levels promoted cortical folding and improved learning and memory, offering new insights into the genetic mechanisms underlying brain evolution.

The study was led by researchers at the Kunming Institute of Zoology under the Chinese Academy of Sciences. By comparing brain development across species, the team investigated the role of CCNB1IP1 in the evolution of the brain.

One distinctive feature of the human brain is its highly folded cerebral cortex, the outer layer involved in many higher cognitive functions. These folds, known as gyri and sulci, increase the cortex’s surface area while allowing it to fit within the limited space of the skull.

Although cortical folding is associated with brain expansion and cognitive evolution, the degree of folding alone does not determine intelligence.

The researchers found that CCNB1IP1 expression was associated with the expansion and folding of the cerebral cortex during primate evolution. When they increased the gene’s expression in mice to human levels, the animals developed folds in their otherwise smooth cerebral cortex and performed better in learning and memory tests.

The findings provide further evidence of a link between CCNB1IP1, cortical development and cognitive function, offering new clues to the genetic mechanisms that may have shaped the evolution of the human brain.