Scientists have discovered that fruit fly larvae can actually "taste" the texture of food, thanks to special neurons in their mouthparts. By disabling these neurons, the researchers found that the larvae lost the ability to judge the hardness of food and tried to eat things they wouldn't normally eat.
Surprisingly, neurons that detect sugar can also sense mechanical properties such as food texture. The discovery shows that our understanding of taste is more complex than previously thought, opening the door to further research on humans.
Scientists at the University of Friborg in Switzerland, led by Nikita Komarov and Simon Sprecher, have discovered that fruit fly larvae can use special neurons in their mouths to detect the texture of food. Their study, published January 30 in PLOS Biology, reveals that these neurons, located in the larval peripheral taste organs, contain mechanoreceptors that sense texture. This ability is linked to the pain-free gene, which plays a key role in its function.
While most research on taste has focused on flavors such as sweet or salty, food texture can also influence dietary preferences. For example, someone might like the flavor of mushrooms but not their tough texture. While taste perception relies on chemical signals, texture detection requires mechanical senses, and it is unclear whether taste organs such as the tongue have this ability. To explore this, researchers studied fruit fly larvae, commonly known as maggots, because of their simple nervous systems and powerful genetic tools.
Researchers determined that maggots won't eat food that's too hard or too soft, but they will eat it if the texture is just right - the equivalent of days-old rotten fruit.
The researchers hypothesized that this ability to sense food texture occurs in peripheral taste organs, thus selectively disabling taste neurons in the larval mouth. As a result, maggots lose their sense of taste texture and try to eat softer or harder foods than they normally prefer. Further experiments showed that the painless mechanoreceptor gene is required for this sensation.
Finally, they found that C6 neurons in the maggot's taste organ can sense both sugar and mechanical stimuli, meaning that the same neuron can taste both food texture and food substances. Thus, taste and signal integration are distinct from other systems, and studies in animals other than Drosophila are needed to fully understand taste perception in mammals, including humans.
The authors add: "Food texture remains an overlooked attribute in overall food fitness. We found - through the power of Drosophila genetics - that at least the hardness of food is a key aspect of the overall taste profile. Excitingly, neurons that sense chemicals in the taste system can also sense texture in some cases."
Compiled from /ScitechDaily