The folds in our grey cells

We all know that deep grooves and folds are characteristic of the human brain. But why are our grey cells in folds like this? And what can the grooves tell us? These are questions Dr. Silvia Budday from the Chair of Applied Mechanics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) is researching. The German Research Foundation (DFG) has accepted her into the Emmy Noether programme, and has provided her with approximately one million euros in the first funding period to lead a junior research group investigating the mechanics of our brains.

Under the influence of external forces, for example a sharp bang on the head, our brain can be damaged or its structure altered. However, the structure of the brain is not only altered by external influences. The human brain starts to develop into folds in the womb. The outer layer of the brain grows quicker than the inner layer which holds it. The tension created as a result causes the cerebral matter to create folds. Dr. Silvia Budday is researching these folds, in other words the mechanics of the human brain.

How does cerebral matter react when it is pulled or pushed? In order to find out how brain tissue reacts from a mechanical point of view, Dr. Silvia Budday is running tests on dead brain tissue, obtained either from brains donated from the Department of Anatomy or pigs’ brains from the slaughterhouse. She investigates the brains systematically, clamping individual pieces and then changing their shape.

Silvia Budday has to be extremely careful, as brain tissue is very soft, complex and acts differently depending on how force is exerted on it. ‘Cerebral matter is softer than jelly. You can’t really imagine what it is like until you actually hold it,’ says Dr. Budday.

Budday’s aim is to create 3D computer models of the brain. These models consist of small cubes representing the various areas of the brain. It is then possible to observe the mechanics of individual cubes, in other words individual areas of the brain. Ideally, these models will be able to be used to simulate operations, for example. ‘We can basically use our PC to look into the future,’ explains Dr. Budday. By pressing cubes, the situation which occurs when the surgeon has to hold the brain during surgery is simulated, allowing the user to predict changes in structure and tension of the tissue as a result. This allows the surgeon to find out beforehand what the cells within the brain will have to cope with during an operation.

Dr. Budday’s models of the brain may also be able to be used to diagnose illnesses. Certain diseases such as epilepsy or schizophrenia change the mechanic properties of the brain. Structural changes can then affect the functioning of the brain. In many instances, however, symptoms only appear once it is already too late. The models could help them to be detected earlier.

Prof. Dr. Ingmar Blümcke, Director of the Institute of Neuropathology at FAU, is a specialist in epilepsy. One form of this disorder is caused, for example, by errors in the folds of the brain. Treatment involves removing the malfunctioning part of the brain. MRI images which surgeons use to localise the areas where misfolding has occurred can often be rather inaccurate. Dr. Budday’s models could help doctors identify the relevant areas more easily and accurately.

However, investigating mechanics alone is not enough. The research is aimed at supporting doctors, who can use the research to develop new cures for diseases. It is therefore crucial that the researchers co-operate with medical experts. ‘I decided on FAU because it offers the entire spectrum of academic disciplines. The Faculty of Engineering, Faculty of Sciences, Faculty of Medicine and Universitätsklinikum – here everything is offered under one umbrella,’ says Silvia Budday.

Dr. Silvia Budday studied Mechanical Engineering at the Karlsruhe Institute of Technology. Most people who think of mechanical engineering think of metal and machines. How did engineer Dr. Silvia Budday come to study the mechanics of the brain? She took a rather roundabout route: She wrote her Bachelor’s thesis at a roller coaster construction company. ‘Roller coasters are based on an exciting mechanical system’, Silvia Budday explains. As part of her thesis, she had to investigate the effects a roller coaster ride has on the human body. Passengers on a roller coaster should be given a good shaking, but they shouldn’t be injured. Therefore, engineers have to calculate exactly what happens during the ride and what effect the bumps have on the human body. This was how Silvia Budday first came into contact with human mechanics. In her Master’s thesis, she then focussed more on biomechanics, in other words mechanics with reference to the human body. This then led her to the mechanics of the brain.

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