“To do this, we needed to understand which neurons were involved in the flow of this information and how it was triggered,” he said.
What connects people to flies?
Biologists from the University of Bonn and the University of Cambridge used fly larvae for this study because they have a network of approximately 15,000 nerve cells — much easier to manage than the network of 100 billion cells in the human brain.
However, neuronal wiring in flies is still complex enough that mapping it in its entirety could yield measurable research results.
The researchers cut the fly larva into thousands of thin slices and photographed them under a microscope. “We used a high-performance computer to create three-dimensional images from these photos,” Pankratz said.
Lead author Andreas Schoofs and co-author Anton Miroschnikow used these images to investigate how nerve cells are connected in the digestive system and the brain.
The team identified a receptor in the throat, connected by the vagus nerve (sometimes called the gut-brain axis) to a group of six neurons in the larval brain that can produce serotonin.
They concluded that the swallowing process, combined with sensory information about the value of the food, can trigger the release of serotonin in the brain, which encourages people to continue eating.
“[Zwierzęta] they can detect whether something is edible or not and also assess its quality,” Schoof said. “The serotonin production process only occurs when good quality food is detected, which in turn influences the larva to continue eating.”
Scientists also speculated about the study’s potential use in relation to human health.
They suggested that a faulty swallowing mechanism – in which too much or too little serotonin is released in the brain in response to eating – could cause eating disorders, including anorexia or binge eating. Therefore, the scientists suggest that further research into the topic could have an impact on the treatment of eating disorders.
“At this stage, we don’t know enough about how the functional system actually works in humans in this context,” Pankratz said. “Years of research in this area are still needed.”
Text published in the American magazine “Newsweek”. Title, lead and subtitles by the editors of “Newsweek Polska”
