Now it is possible to imagine a whole flying brain in just a few days, according to a new study – this may seem a long time, but it is really an incredible accomplishment, if you consider that the process would take weeks.
Brains are not easy to study – the human brain, for example, contains more than 80 billion cells linked through 7,000 connections each, according to the new study published in Science. Even the smallest flying brains are an incredible challenge to fully study. The new research combines two methods of microscopy in the image and examines the brains as never before.
"It's a new tool to try to understand the biological tissue, and not in a simple cell context, but in a complete multicellular context in high resolution," Eric Betzig, physicist and Nobel Prize winner working at The Janelia Research Campus of Howard Hughes Medical Institute told Gizmodo.
The researchers combined two types of microscopy, called microscopy of expansion and reticulated leaf microscopy, to identify the flying brain. The expansion microscope involves first marking interesting features in a sample with fluorescent proteins, and then bind them with a polymer gel. An enzyme digests the tissue, and then the scientists add water, making the polymer grow and retain the form marked by fluorescence proteins. In this case, the sample grew four times.
But the image of the expanded flying brain requires approximately 20 billion voxels, or 3d pixels, which would take a few weeks to obtain an electronic microscope. The team decided to combine expansion microscopy with another image method, called lightweight microscopy. It uses thin sheets and light laser plates and shows the sample in flat sections, allowing a faster process that also reduces background noise.
Even Betzig did not think the method worked at first, he told Gizmodo, but when he saw the results, he was "surprised" by the fidelity of the expansion. In fact, they could combine methods to create high resolution images, up to dozens of nanometers, according to the document.
But research is nowhere to be able to create similar images of human brains, explained Betzig. They extend the method to (and have done successful images of small pieces) of mouse brains, but a brain flying to a mouse brain is equivalent to "passing a mud hut to the Empire State Building" , he said.
The researchers believe that soon they will be able to obtain multiple flying brains quickly and with an incredible resolution. This is exciting, mainly because the brain can vary according to the individual and compare many brains could teach us more about how these incredible biology jobs work.