How a tiny insect is transforming mental health research
To the untrained eye, the unassuming fruit fly, Drosophila melanogaster, may seem an unlikely model for understanding the inner workings of the human brain. But for Professor Barry Dickson, a neurobiologist at QBI and a pioneer in his field, the fruit fly is a powerful gateway into the intricate world of neural computation and decision-making.
“A neuroscientist today is a little like an engineer who knows how computer chips work and knows a good algorithm for playing chess, but can’t build a chess-playing machine. We’re trying to understand how that machine actually works – how specific circuits give rise to intelligent behaviour.”
Since establishing his lab at QBI in 2015, Professor Dickson has been leading a team of scientists dedicated to uncovering how the fly’s nervous system produces coordinated motor patterns – how it walks, turns, speeds up or slows down.
At the core of his work lies a deceptively simple yet profound question: How do local circuits in the nervous system produce patterned movement and how does the brain exert control over those circuits to adapt and decide?
“In the fly, we know the complete wiring diagram of its brain,” Professor Dickson explained. “We can track the activity of specific neurons and turn them on or off at will. This is exactly what you need to figure out how this particular computer works – how the fly’s brain solves difficult problems like choosing a mate or navigating its environment.”
This level of precision has allowed Professor Dickson and his team to make discoveries that once seemed the stuff of science fiction. In a landmark study, Professor Dickson’s lab was the first to identify specific neurons and circuits in the fly brain that underpin the male and female mating instincts. That finding opened a new window into how neural circuits for instinctive behaviour are wired and activated in the brain.
“This is a cognitively challenging problem. The female has to assess how good each male is – which she does by evaluating his courtship song – and then compare the quality of any suitor against others she might reasonably expect in the future. Those future expectations are based on her prior experience – encounters with other males she has heard but not mated with. It’s just like we often have to choose the best of the options available to us, often foregoing one good choice in anticipation of a better one in the future."
Professor Dickson’s mapping of the 130,000 neurons and 30 million synapses in the fruit fly brain has earned him the respect of his peers. Last year he was elected a Fellow of the Royal Society in London, joining the ranks of past luminaries such as Isaac Newton, Stephen Hawking, Charles Darwin and Albert Einstein.
Now with a $3 million NHMRC grant in hand, he is turning his attention to anxiety and depression – reframing them as disorders of brain connectivity, triggered by chronic stress. Using the fruit fly as his guide, he’s mapping how stress rewires the brain’s circuitry over time.
It’s a bold mission, powered by a tiny insect.
Professor Barry Dickson will be presenting his research during UQ's Research & Innovation Week.
Sex, Sleep & the Subconscious: What flies tell us about the brain will take place on Friday 12 September. Register here.
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