Scientists at Princeton University, in collaboration with other scientists and citizen scientists, have built a neuron-by-neuron and synapse-by-synapse map (connectome) of the entire brain of an adult fruit fly.
“Any brain that we truly understand tells us something about all brains,” said research co-leader Sebastian Seung. “With the fly wiring diagram, we have the potential for an unprecedented, detailed and deep understanding.”
With almost 140,000 neurons and tens of millions of synapses connecting them, this is by far the most complex brain that has been mapped so far.
The map was built from 21 million images. Using an Artificial Intelligence (AI) AI model built Seung's team, the images were turned into a three-dimensional map by the FlyWire Consortium.
“This is a major achievement,” says research co-leader Mala Murthy. “There is no other full brain connectome for an adult animal of this complexity.”
FlyWire is a collaboration between professional scientists from several institutions and citizen scientists including gamers. The cloud computational infrastructure used by FlyWire has been developed by teams led by Seung and Murthy, in collaboration with the Allen Institute for Brain Science.
Much of this research work has been done by AI systems. Humans have checked, assembled, and annotated the AI-generated products, adding cell type labels to each neuron.
This momentous achievement is described and discussed in a special issue of Nature. The main paper is titled "Neuronal wiring diagram of an adult brain."
It seems plausible that future developments could permit mapping an entire human brain and better understanding human brain diseases.
A step toward mind uploading?
But other, wilder ideas come immediately to mind.
"Minds differ because connectomes differ," said Seung in "Connectome: How the Brain's Wiring Makes Us Who We Are" (2012). "Perhaps even your memories, the most idiosyncratic aspect of your personal identity, could be encoded in your connectome."
In other words, all that matters to personal identity and distinguishes one living being from another is encoded in the connectome. This view, shared by many (but not all) scientists, seems to open the door to the possibility of mind uploading. Humans, Seung said, could one day "discard their bodies completely and transfer their minds to computers." Mind uploading seems a science fictional idea, but "perhaps all we have to do is wait for computers to get more powerful."