Scientists at Harvard University have discovered how the human cortex develops its folds by 3D-printing a fake gel brain.
The study has been published in the journal Nature Physics. The new discovery comes to solve a longstanding mystery about the brain structure and could help to better understand certain disorders linked to overfolding and underfolding of the brain.
Ellen Kuhl of Stanford University wrote in a commentary that this is the first experimental evidence of the theory of differential growth. She added that, rather than just biochemical processes alone, physical forces also play a critical role in neurodevelopment. The new findings could help in preventing, diagnosing and treating a wide variety of neurological disorders.
According to Los Angeles Times, scientists have long known that the brain's folded structure allows for far more connectivity across the cortex than a smooth surface would. However, until now, the process of developing these folds has been poorly understood.
In their need to better understand the functioning of the human brain, scientists cannot use experiments with rats of other small animals because their brains are different, and cannot experiment with human brains because of ethical concerns.
Lakshminarayanan Mahadevan, a physicist and applied mathematician at Harvard University, has developed a mathematical model of the brain behavior in order to study the physics of the structure itself.
For this new research, scientists at Harvard have built a 3D physical model of the brain by using magnetic resonance imagery from a fetal brain at 22 weeks' gestation. The 3D brain model was printed out of gel. The "gray matter" was simulated with a thin coat of rubbery gel.
The brain was submerged in a liquid solvent that caused the rubbery gel layer to start growing and brain-like folds began to emerge. By linking these large-scale structural processes to the molecular level process, the researchers could better understand a variety of different neurological disorders.
