Harvard Team Discovers How the Brain Gets Its Folds

Mechanical Instability Linked with Buckling- Probable Cause of Folds

The human brain is famous for its walnut shape. It was earlier unclear as to how the brain got its distinctive folds but a team at the Harvard John A. Paulson School of Engineering and Applied Sciences have now discovered that a mechanical instability connected with buckling is the probable cause of the folds in the brain.

Published in Nature Physics, the team, in research had created a 3D gel model of a smooth foetal brain constructed on MRI image which was then covered with layer of elastomer gel to duplicate the cortex. It was then immersed in a solvent which led it to swell relative to its deeper regions. Compression within minutes led to the formation of folds identical in size and shape like the real brains.

Lead author of the study, L. Mahadevan had informed that they found that they could imitate cortical folding by utilising simple physical principle and get the results which were similar to what is seen in real foetal brains. This simple evolutionary innovation enabled a larger cortex to be packed into a small volume and is probably the main cause behind the brain folding. He added that when he put the model in the solvent, he was aware that there would be folding but had not expected that kind of close pattern to the human brain.

Brain Folding Abnormalities - Serious

The study of the human cortex could help in solving a longstanding secret regarding the structure of grey matter in brain and understand better the disorder connected to under-folding or over-folding of the brain. Brain folding abnormalities could be serious and infants born with completely smooth brains tend to have very short life expectations. Folding tends to happen as the brain grows with the number, shape, size and position of the neuronal cells which contribute to the expansion of the cortex which is also known as the grey matter comparative to the white matter which is beneath.

The subsequent compression leads to mechanical instability causing the iconic folds. This simple evolutionary invention permits the thin though expansive cortex to be packed in a small volume and is the leading cause behind the folds in the brain which has surprised even the scientists.

Understanding Brain Related Disorders

Researchers suggest that the resemblances between the model and a real brain in the shape of a brain, the geometry of the brain tends to serve in positioning the folds in certain directions. The earlier research in this space observed that a difference in growth between the cortex as well as the soft tissue beneath could enlighten the differences in the folding pattern through the organisms. Comprehending the mechanism, the researcher comment could help in further understanding of brain related disorders.

Mahadevan had stated that `brains are not accurately the same from one human to another, though we should all have the same main folds in order to be healthy. Research portrays that if a part of the brain does not tend to grow properly, or if the global geometry seems to be disrupted, it may not have the main folds in the right place, which could cause dysfunction in the brain’.

Though the researchers have pointed out that the 3D printed gel based model only predicts the behaviour of simple and regular brain structure at the start of the gyrification process, it is an important step in ultimately recreating more complex and dynamic emerging folds.