Revolution in Brain Research from Austria: How Inspiration from a Diaper Captured the Attention of Nature Magazine

For the first time, the trade journal Nature has recognized an Austrian invention as a technology of the future, as listed by Nature. What sounds like science fiction owes its existence to a surprising inspiration from everyday life: the absorbency of baby diapers. Our brain is a monumental labyrinth. Around 86 billion nerve cells are interwoven via trillions of synapses. Until now, it has been an almost impossible task to map this “connectome” – the complete circuit diagram of the brain – in detail. Conventional light microscopes reached their physical limits here. In order to detect the fine extensions of neurons, which often measure only a few nanometers (one ten-thousandth of the width of a hair), expensive and extremely complex electron microscopes were previously necessary.

This is where LICONN (Light Microscopy-Based Connectomics) comes in. The team led by research group leader Johann Danzl solved the problem of insufficient resolution not with better lenses, but with an ingenious chemical trick: they enlarge not the image, but the sample itself.

The Nature jury sees LICONN as a technology of the future because it democratizes brain research, as reported by ORF. Since no special equipment costing millions of euros is required, laboratories around the world can now study the neural “wiring diagram” of mammals. This could make a decisive contribution to a better understanding of diseases such as Alzheimer's or autism, in which communication between cells is disrupted. “We are now a big step closer to putting together the puzzle pieces of the mammalian brain,” summarizes Danzl.

The “gummy bear principle” from the diaper bag

The method uses the physical properties of hydrogels, such as those found in baby diapers. “The principle is similar to a gummy bear that you put in water,” explains Danzl. “It swells up but retains its structure.”

The brain tissue is embedded in a special polymer network. When water is added, the gel expands evenly in all directions. The biological structures are enlarged 16-fold. As a result, the cell structures, which were previously too dense, are now far enough apart to be imaged with a conventional, off-the-shelf light microscope with an effective resolution of less than 20 nanometers. “The process makes the samples perfectly transparent, which allows us to capture the entire volume in 3D,” says Danzl.

Google Research and the power of AI

A brain magnified in this way provides enormous amounts of data. To create a coherent map from the billions of pixels, the ISTA team enlisted the help of Google Research. The deep learning experts developed algorithms that are able to automatically recognize and segment individual nerve cells and their connections.

Particularly groundbreaking: LICONN can simultaneously visualize specific molecules. This means that researchers can not only see where a nerve strand leads, but also what chemical signals are currently being transmitted there.

ISTA

Nature