I love real science.
These guys cut up a Drosophila brain into 20 micron thick sections, and photographed each one at high resolution.
Then they fed all the pictures into a computer, and trained a neural network to distinguish the cell types.
Then for each cell type, they mapped all the synapses, and trained another neural network to predict the neurotransmitter types on the basis of genetic markers.
Then, they took representative samples of each cell type and rendered them in Blender, so they could be viewed in 3d from any angle along with all their connections.
All their code is in the public domain, accessible on GitHub.
What's super-interesting about this study is some cell types only have ONE neuron. There are around 50,000 neurons in the fruit fly retina, but only around 5,000 in the central nervous system, and only about 500 in the cortex. The idea that specific genetics could program ONE neuron is reminiscent of the earliest nervous systems like Aplysia.
Fruit flys have the equivalent of human retina, LGN, and V1. Their V1 has a columnar organization, just like humans - and the pyramidal cells are layered with spines just like humans. Also interesting is the observation that directional selectivity has moved from the retina in fruit flies, to the cortex in humans.
This type of study is intensely interdisciplinary. These guys had to be neuroscientists to understand the fruit fly brain, cell biologists to do the electron microscopy, biochemists to do the genetics, and computer scientists to do the AI.
This is the new gold standard for science. The same thing is happening in the area of materials, where you have to be a physicist, a chemist, an electrical engineer, and a computer programmer. Gone are the days of "a degree gets you a job".
www.nature.com
