When you enjoy food, it’s not just about the taste. The appearance, flavor, and texture also play a role. Some food items are chewy, some are crispy, and others just melt inside your mouth. The impact of texture is rarely mentioned but it plays an important role in our eating habits.

We care about textures so much that our brain has neurons specialized in detecting texture. According to a new study, we’re not the only ones.

Researchers have found that maggots (fly larvae) also have neurons dedicated to textures and that’s why they prefer rotten fruits and vegetables over fresh ones.

How does texture tasting work for maggots?

The study authors conducted experiments on maggots to explore the science of texture sensation in their tiny brains. The first experiment tested their food preference. The researchers placed maggots on a surface with both fresh and rotten fruit, observing whether they gravitated toward softer, decaying fruit compared to the harder, fresh fruit.

The researchers observed that the maggots consistently preferred the rotten fruit over the fresh one. This behavior suggested that maggots are more attracted to the texture of decaying food, which may be linked to easier digestion or availability of certain nutrients.

Next, the researchers investigated whether maggots had specific neurons that responded to food texture. They used advanced imaging techniques to observe the neural activity in maggots when exposed to different textures. 

This allowed them to identify a group of neurons with texture-sensing mechanoreceptors in the maggot’s peripheral taste organs. These receptors were active when the larvae encountered rotten food, suggesting that the maggots’ preference for rotten fruit is linked to these neurons

To further confirm whether these neurons were directly responsible for the maggots’ preference, the researchers used genetic tools to activate or inhibit the texture-sensing neurons. They noticed that when the neurons were activated, the maggots showed a stronger preference for rotten food. However, when these neurons were switched off, the maggots no longer showed the same strong preference, proving that these neurons played a key role in their food selection.

This experiment also revealed that a particular neuron, called C6 in the maggot taste organ can sense both sugar and mechanical stimulation, meaning that “the same neuron can taste food texture and food substance,” the study authors said.

Fly larva is best for studying texture sensation

It’s challenging to study the texture-tasting neurons in humans and other animals because they have a vast and complex nervous system. For instance, while humans have 86 billion neurons, the most popular lab animal, the rat, has 200 million neurons. 

A fruit fly, by comparison, has a much simpler brain with just about 140,000 neurons. So identifying and monitoring particular neurons in their nervous system is easier.

“The larva of the fruit fly Drosophila melanogaster provides a powerful model to uncover mechanisms of sensory perception due to its relative neuronal numerical simplicity, ample genetic tools, and, importantly, traceable processing and stereotypic behavioral responses,” the study authors note.

Given these advantages, the researchers now plan to conduct more experiments on fruit flies to deepen their understanding of texture-sensing neurons.

The study is published in the journal PLOS Biology.