‘Tis the season when scientists hope for – but perhaps do not expect – a call from an unknown number via Sweden. With all the Laureates for this year’s Nobel Prize in natural sciences announced, we now know the names of the seven men (yes, all men!) to be honoured for their significant contributions to advancements in research. There is, however, another character that has shaped this year’s awards more than in any previous year: I speak, of course, of artificial intelligence (AI).
Two researchers who were not expecting ‘the call’, but who may have put themselves in good standing for a future award, are Mala Murthy and Sebastien Seung of Princeton University. The pair have just published their opus, a nine-paper package in Nature entitled the FlyWire Connectome including contributions from a global consortium of 127 institutions, which paves the way for a new era of neuroscience. Utilising machine learning, non-expert volunteers and an interdisciplinary approach, they have mapped an adult fruit fly’s “connectome” – the entire wiring of the brain – down to the nearest nanometer.
A quick biology recap: depending on the species, a brain is made of many thousands, millions or billions of neurons. The nervous system is a broader term which additionally refers to the spinal cord (if there is one) and the individual nerves radiating out to every part of the body. Neurons are the specialised cells which nerves are made of, transferring electrical impulses to and from the brain and providing the body with the information required for coordination. The connectome, then, is a detailed description of the entirety of all the neurons in an organism, their synapses (the junctions which connect neurons), and their circuitry.
The suite of papers from FlyWire includes a free-to-access, interactive 3D model of the connectome displaying the complete network of neurons in the brain of the adult fruit fly. Inside their unimaginably tiny brains extends a connectome the length of three Commonwealth Pools, comprising about 140,000 neurons and a whopping 54.5 million synapses. By processing the data from previous electron microscopy of the fly’s brain through a machine-learning algorithm and using non-expert volunteers to manually proofread the results, the researchers have demonstrated a replicable method for mapping the cerebral nervous system.
In addition to the many fields of research that will be accelerated by this work, an obvious next question is “When will we get round to humans?” This is not the first time a whole connectome has been accurately mapped; the nervous system of a nematode – a microscopic animal which resembles a worm whose connectome consists of 302 neurons – was mapped in 1986. This timeline demonstrates that progress is possible, but it might be a while until the 80-90 billion neuron-strong connectome of a Homo sapiens’ brain has been deciphered. Moritz Helmstaedter, a neuroscientist at the Max Planck Institute, predicts we may be less than a decade from seeing a map of the brain connectome of a mammal.
It is difficult to overstate the significance of the findings, and its many implications cannot be adequately described here in detail, but does FlyWire Connectome have Nobel potential? Not only does the research enable a step-change in neuroscience, but the team’s transparency in presenting the data and the creation of free, interactive tools has meant that the connectome has already appeared in over 50 journal publications relating to vision, motor coordination and stimulation. The ability of researchers and the public alike to have complete freedom of access to research tools was highlighted by The Nobel Foundation when granting the 2024 Prize in Chemistry to the team behind AlphaFold2 (an AI-driven software which predicts protein structures), so it is clear the collaborative application of AI is currently seen favourably by the prize-giving committee.
While the creation of the connectome itself has not answered any burning questions, it provides a platform that enables a step-change in neuroscience research. Like with AlphaFold2, questions that used to take years to answer may now only take weeks. So, has the team broken new ground which will revolutionise neuroscience forever? All I’d say to Murthy and Seung is: don’t leave your phone on silent in October.
Photo by Bioscience Image Library by Fayette Reynolds on Unsplash