This is the most accurate 3D map of a brain: 20 million synapses connecting 25,000 neurons that you can explore
The brain is one of the most complex parts of an organism, thousands and thousands of neurons connected to each other to send electrical impulses that make the rest of the living thing work. To put the magnitude of this system in context, a team of researchers has created an accurate three-dimensional map showing a brain with more than 25,000 connected neurons. And it is that of a simple fly, not even close to the human brain, but it is still surprising.
The 3D map has been created and published by a team of researchers from the Janelia Research Campus in Virgina. For this they have used the help of Google and its powerful computing computers. The result is a brain map of the fruit fly that shows thousands upon thousands of neurons connected to each other. An achievement that has taken them more than two years of work.
Mapping a brain: step by step
The complexity of mapping a brain is enormous due to various factors, although the main difficulty is being able to determine each and every one of the neurons that are inside it, they are many and they are tiny. The first step, they say, was to cut the fly's brain into sections to make it easier to trace its operation. Each slice was approximately 20 microns thick and the brain of a fruit fly was chosen because it is a relatively simple brain to study.
With each cut "slice" of the brain, it is passed through a scanning electric microscope, which sends currents of electrons through the sample. The received data is subsequently analyzed to process it and convert it into understandable data. They indicate that each sweep resulted in approximately 50 billion pixels in 3D that had to be subsequently processed (task of Google's algorithms).
The work does not end there, once the algorithm has identified and processed the data, a team of humans reviews each part of the map to verify that all the connections between neurons are correct and there is coherence between them. They explain that for this the human team used virtual reality glasses that allowed them to easily see the brain in three dimensions and move around it.
25,000 neurons are actually small change
25,000 neurons comprise this 3D map of the fruit fly's brain. The more than 20 million synapses shown are certainly a huge achievement, although it only shows how much remains to be done in the field of neuroscience. To put things in context: it is only a third of the brain of the fruit fly, its hemicerebro.
The fruit fly has a brain with around 100,000 neurons, which is nothing compared to the 86 billion neurons in the human brain. So far only the brain of the nematode worm has been fully mapped, which has the simplest brain known to science, just 302 neurons.
If you want to explore the 3D map of the brain you can do it. Google and the FlyEM team have made a map demo available to everyone. They have also made the results obtained available to other researchers so that they can work with them.
More information | Howard Huge Medical Institute and bioRxiv