Scientists map fruit fly brain in neurobiological milestone

3/10/2024 6:05

        Scientists announced on
        Thursday a milestone in neurobiological research with the
        mapping of the entire brain of an adult fruit fly, a feat that
        may provide insight into brains across the animal kingdom,
        including people.
        
        The research detailed more than 50 million connections
        between more than 139,000 neurons - brain nerve cells - in the
        insect, a species whose scientific name is Drosophila
        melanogaster and is often used in neurobiological studies. The
        research sought to decipher how brains are wired and the signals
        underlying healthy brain functions. It also could pave the way
        for mapping the brains of other species.
        
        "You might be asking why we should care about the brain of a
        fruit fly. My simple answer is that if we can truly understand
        how any brain functions, it's bound to tell us something about
        all brains," said Princeton University professor of neuroscience
        and computer science Sebastian Seung, one of the co-leaders of
        the work published in a series of studies in the journal Nature.
        
        While some people may be more interested in swatting flies
        than studying them, some of the researchers found aesthetic
        satisfaction peering at the fruit fly brain, less than 0.04
        inches (1 mm) wide.
        
        "It's beautiful," said University of Cambridge
        neuroscientist and research co-leader Gregory Jefferis.
        
        The map devised by the researchers provided a wiring
        diagram, known as a connectome, for the brain of an adult fruit
        fly. Similar research previously was conducted with simpler
        organisms, such as the worm Caenorhabditis elegans and the fruit
        fly's larval stage. The adult fruit fly presented more
        complicated behaviors to study through its brain wiring.
        
        "One of the major questions we're addressing is how the
        wiring in the brain, its neurons and connections, can give rise
        to animal behavior," said Princeton neuroscientist Mala Murthy,
        another of the co-leaders of the research.
        
        "And flies are an important model system for neurosciences.
        Their brains solve many of the same problems we do... They're
        capable of sophisticated behaviors like the execution of walking
        and flying, learning and memory behaviors, navigation, feeding
        and even social interactions, which is a behavior that we
        studied in my lab at Princeton," Murthy added.
        
        One of the studies analyzed brain circuits underlying
        walking and discovered how flies halt. Another analyzed the
        fly's taste network and grooming circuits behind behavior such
        as when it uses a leg to remove dirt from its antennae. Another
        looked at the visual system including how the fly's eyes process
        motion and color information. Still another one analyzed
        connectivity through the brain, discovering a large assemblage
        of "hub neurons" that may speed up information flow.
        
        The researchers fashioned a map tracking the organization of
        the hemispheres and behavioral circuits inside the fly's brain.
        They also identified the full set of cell classes in its brain,
        pinpointing different varieties of neurons and chemical
        connections - synapses - between these nerve cells, and looked
        at the types of chemicals secreted by the neurons.
        
        The work was conducted by a large international
        collaboration of scientists known as the FlyWire Consortium.