To usher in a big advance in brain imaging, scientists simply had to cut the fat. By subbing out light-blocking fatty molecules, a new technique turns mouse brains almost fully transparent while retaining their structure and nearly all their important molecules, researchers report in the April 11 Nature.
The new method could help researchers image the whole brain and its circuitry while also doing detailed molecular and cellular analyses, says Clay Reid, a neurobiologist at Harvard University and the Seattle-based Allen Institute for Brain Science. “It’s a lovely paper, and it’s something that a lot of people will want to be using,” says Reid, who was not involved in the study.
There are tradeoffs in studying the brain. Typically researchers create thin slices of the brain for detailed looks at cellular and molecular anatomy. But that’s at the expense of learning how neurons are wired to far-away brain regions. Moreover, using light-based microscopes to look at the whole brain has its pitfalls. Light struggles to penetrate deep into organs mainly because lipids — the building blocks of fats — can block and scatter it. Lipids help maintain the brain’s structure, and removing them could cause the brain to fall apart.