Researchers have identified neurons in the mouth of fly larvae that enable them to perceive the texture of food. The investigation revealed that the fly’s peripheral taste organ contains neurons equipped with mechanoreceptors capable of detecting food texture, a feature linked to the painless gene.
A research project led by Nikita Komarov and Simon Sprecher at the University of Fribourg, Switzerland, has found neurons in the mouth of fly larvae that allow for the perception of food texture. This study was published in the open-access journal PLOS Biology on January 30 and uncovered that the peripheral taste organ of flies possesses neurons with mechanoreceptors specifically for texture detection, which are influenced by the painless gene.
Traditionally, studies on food sensation have concentrated on tastes such as sweetness or saltiness. However, people’s food preferences are often influenced by the texture; for instance, someone might relish the flavor of mushrooms but dislike their chewy consistency. While tasting flavors relies on chemical sensations, sensing texture requires mechanical sensations, and it remains uncertain if taste organs like the tongue have this capability. The recent research focused on fruit fly larvae, known as maggots, due to the simplicity of their nervous systems and the genetic tools available for study.
The researchers determined that maggots refuse to eat food that is either too hard or too soft, but they will consume food that has the right texture, akin to days-old decaying fruit. Suspecting that the ability to detect food texture resides in the peripheral taste organs, the team selectively disabled taste neurons in the larvae’s mouths. Consequently, the maggots lost their texture sensing ability and began trying to eat foods that were softer or harder than their preferred options. Further investigations demonstrated that the painless mechanoreceptor gene is necessary for this sensory capability. Additionally, they found that the C6 neuron in the maggot’s taste organ is capable of sensing both sugar and mechanical stimuli, indicating that this single neuron is responsible for detecting both food texture and substance. This suggests that how taste sensation and signal integration work is notably different from other systems, highlighting the need for further studies beyond fruit flies to grasp taste perception in mammals, including humans.
The authors concluded, “Food texture is often overlooked as an important aspect of overall food acceptance. Our findings using Drosophila genetics reveal that, at the very least, food hardness is a critical component of the overall taste profile. Excitingly, the very neurons that detect chemicals in the taste system are also able to sense texture in certain instances.”
