Drosophila, or fruit flies, are excellent research material. Just because they breed very quickly, giving offspring, and evolutionary changes can be tracked for weeks, not months or years.
These flies were useful to scientists, who study the brain. Since the ganglion of these insects is small, then you can scan it without any problems. The other day, scientists from Janelia Research Campus published the result of their 12-year work – a Drosophila brain map, the most detailed at the moment.
Janelia Research Campus is part of the Howard Hughes Medical Institute. The university team spent 12 years and $ 40 million to map the brain of a tiny fly. These are 25 thousand neurons and about 20 million connections between them. And even this is not the whole brain, but only a third of it, although the most important one. It houses the various organoids responsible for memory, navigation, and learning.
According to the researchers, a brain connection (this is a map of an organ with all the connections between them) will become one of the basic resources for neurosurgeons and scientists who study the nervous system of insects and other living things. Deciphering the brain of a small fly allows you to judge the work of individual organoids, how connections are made and how the brain works in general.
From simple to complex – this is how scientists are acting now. Modern technologies still do not allow creating any kind of detailed connection of the human brain, therefore, the brain of much simpler creatures is being studied. By the way, the first living organism whose brain was “deciphered” was a nematode. Her nerve node consists of only 302 neurons with 7 thousand connections between them. Even this was an extremely difficult job for 1986.
Gradually, experts receive more and more information about the work of the brain of animals and humans. But one of the most important tasks is to make a connection. This is just as important as decoding DNA. Drawing up a connection makes it possible to track the interaction of individual organelles and cells.
In 2004, a technique was developed for analyzing images of neurons obtained by an electron microscope. This was a major achievement, which at times accelerated the “decryption” of the brain. But even in this case, the brain of Drosophila demanded the strength of 250 people – just as many scientists worked on this project for 12 years.
All this time the technique was improved and finalized. As a result, it turned out that the images obtained by the electron microscope were converted into a three-dimensional map of the brain. Drosophila’s brain had to be cut into thin plates 20 nm thick to obtain images of neurons. It was them who were photographed.
After the emergence of neural networks, scientists used them to compile three-dimensional maps of brain areas with tracking connections between individual cells. But the computer cannot do all the necessary work — scientists need to be involved here, both to check the operation of the machine and to perform “manual” tasks, which the computer is not yet able to handle.
Scientists were helped by developers from Google, who created the analysis systems necessary for specialists. The final result was extremely voluminous – the data array “weighs” about 100 gigabytes.
Other scholars connecting with Google are collaborating with Google. For example, as part of a songbird brain study project. The brains of birds themselves are very complex, so in the near foreseeable future, the connectionomes are unlikely to appear. Scientists study certain aspects of work and brain areas – for example, those that are responsible for memorizing songs. In addition, a cubic millimeter section of the mouse brain was previously analyzed.
As for the specialists who make up the Drosophila brain connectomy, they continue to work. Their goal is to compile a complete brain connection of the fruit fly – both male and female. A budget of $ 5 million has been allocated for this.
If you decipher the mouse brain, then, according to scientists, it will take more than half a billion US dollars and even more time.