3D Model How Brain Develops Wrinkles from Weak Points in Cortex

The deep folds that give the adult human brain its wrinkled walnut appearance were nature's solution to fitting a large, powerful processor into a small skull.

Like a piece of flat, square paper crumpled together to fit into a small, round hole, folding allows more neurons to be packed closer together, with shorter, faster connections between them.

While scientists have long understood why there are folds in the brain's outer layer, called the cerebral cortex or grey matter, the how has remained a mystery.
Do the creases develop as a result of genetic, biological or chemical signals? Or are they caused by physical forces?

Now, an international team of scientists has used a 3D printed brain to explore the folds, which can explained by physics.

Folds in the cortex develop through buckling in weak spots which develop as the foetal brain grows, the scientists reported.

The brains of human foetuses are smooth for about the first 20 weeks, when folding begins and continues until the child is about 18 months old.

http://www.abc.net.au/news/2016-02-02/3d-model-teases-out-physics-of-the-wrinkly-brain/7133074