A tiny brain for immense discoveries. The fruit fly, this simple vinegar fly, holds within it the secrets of neural connections. Could understanding its brain pave the way for insights into human diseases?
With 140,000 neurons mapped, the scientific community is now equipped with a complete brain map, the fruit of a decade of research. The goal? Decoding neural circuits.
A 3D interface allows for selecting and navigating through the brain's structure
The Flywire project, led by researchers at Princeton, used the fruit fly to create an unprecedented "connectome." Why a fly? Its modest size makes analyses easier while still offering complex behaviors, similar to those of humans.
One of the main challenges in neuroscience remains understanding neural circuits and their role in diseases such as Alzheimer's or Parkinson's. The limited knowledge of brain connections hinders the development of effective treatments.
With this new map, researchers have identified 139,255 neurons and more than 50 million synaptic connections. Ultra-thin sections of this brain were assembled in 3D using artificial intelligence tools.
The team overcame considerable challenges: the AI models used to reconstruct the neurons required human validation, which prolonged the process of creating the connectome. Without AI, more than 4,000 years of human labor would have been required.
The results, shared on the
FlyWire Codex, are a valuable resource for researchers. This neural map reveals not only the structure, but also the functional connections, including "distributor" neurons that coordinate the circuits.
The importance of vision in the fruit fly is reflected in the predominance of optic neurons. The role of neurotransmitters has also been better understood, opening pathways to understanding their influence in neurodegenerative diseases.
With more ambitious goals, the Flywire consortium is now focusing on the mouse, whose connectome could provide even further revelations about the human brain. This project is expected to be completed in 5 to 10 years. A technological and scientific adventure that is just beginning.
What is a connectome?
A connectome is a complete map of the neural connections in a brain. It allows for the visualization of the organization of neurons and their synapses, which are the communication points between them. These connections are essential to understanding how the brain processes information and generates actions.
Establishing a connectome involves the detailed analysis of neural circuits. It allows us to track the transmission of nerve signals throughout the brain. Thanks to artificial intelligence, the mapping of these millions of connections, once unattainable, can now be accelerated.
Why is the fruit fly used to study the human brain?
The fruit fly, a tiny vinegar fly, is a highly prized model organism in neuroscience. Despite its brain's small size, it shares about 60% of its genes with humans, including those linked to neurological diseases. This makes it possible to study its cognitive processes to better understand our own.
The relative simplicity of its brain makes it possible to establish a complete connectome, a task currently impossible with the human brain. The results obtained from the fruit fly provide clues about the functioning of more complex brains.
Author of the article: Cédric DEPOND