Why does the brain have wrinkles and convolutions?
Virtually everyone knows what the brain looks like, but only a few think about how much this important organ is covered with numerous folds, which makes it look like a huge walnut.
Gyrations and folds are formed on the surface of the brain in the process of embryonic development. They are formed by gray matter or the cortex of the brain. “Wrinkles,” scientists believe, was the answer to the limited space inside the skull. The number of neurons and connections between them in the course of evolution increased and more effort was required to pack all the nerve cells.
The optimal way of packing, perhaps, was a folded structure – so could the connections between neurons located on the surface of areas far from each other were formed.
The brain of mice and rats is not as folded as the human – most likely this is due to the fact that the volume of the cortex (cerebral cortex) is rather weak and the formation of gyri is simply not necessary.
It is also important that the gyruses are not formed at all in a random way – the cavities and bends are similar for representatives of one species – this constancy indicates that this “folding” of the brain is important for its functioning.
However, it is impossible to judge intellect and other cognitive abilities solely by the volume of the brain and the number of folds on it – they depend on other factors, including environmental factors and genetic factors.