What’s all the buzz about? Fly brain map could be the first step to understanding how humans think

This post was written by Meghan Lumsden and Sinead Rhodes

Scientists mapped the first complete brain of an adult animal, and it’s smaller than a poppy seed! Led by Princeton University, the FlyWire project involved collaboration from an international team of scientists at over 100 institutions. After five years, they successfully assembled the full picture of a fruit fly’s brain, gaining headline-worthy traction as the most detailed analysis of its kind. Media articles were quick to highlight the significance for our understanding of the human brain — where the applications reach a much larger scale and scope.

FlyWire’s results were published in Nature, sharing a detailed diagram known as the fly ‘connectome’. This provides a visual map of the 50 million wiring connections within the tiny insect’s brain. By studying the networks of neurons and synapses, the researchers started to reveal linkages to complex behaviors from memory to mating. In addition to understanding how the brain processes and acts on information, they’re also interested in understanding how and when things go wrong. Identifying ‘miswiring’ in the brain could potentially help explain neurological diseases, such as Parkinson’s and Alzheimer’s.

However, the human brain has over 600,000 times more neurons than a fly (86 billion vs. 140,000). While the connectome is an excellent model for how a brain works, it’s not indicative of how all brains work. The research has also yet to validate how connectomes may differ between individual flies. The FlyWire project required intense computational assistance from artificial intelligence, and still resulted in nearly 3 million errors that were manually corrected by the research team. AI technology in its current state does not have the capacity to manage the size of the human brain.

Let’s take a look at how this was reported in the news. The BCC said “Fly brain breakthrough ‘huge leap’ to unlock human mind”, immediately jumping to the human connection. ‘Huge leap’ comes from the words of an independent expert in the article, but direct members of the project were also quoted on the transformative potential for understanding the brain. The Guardian leans into this latter angle with “Tiny brain, big deal: fruit fly diagram could transform neuroscience”. The subheader of this article focuses on the connection between wiring and behavior, something that’s not as explicitly mentioned by the BBC. Lastly, we have “The most detailed map of the brain EVER seen: Stunning images reveal all 139,255 neurons – and the 50 million connections between them” from the DailyMail. Here there is an interesting focus on the factual numbers, but the capitalisation of “EVER” seems sensationalist.

Most media articles acknowledge the continued work to be done, with efforts already underway to map the mouse connectome. Overall, these headlines shine a positive and hopeful light on a new scientific development. While this paves the way for future research, it is important to remain grounded in the context that we are still far off from reaching this level of detail and understanding on the human brain. For more advice on analysing coverage of new scientific developments, check out the Research the Headlines list of “How To” tips here.