Fruit flies use an ingenious trick to find rotting fruit: They smell the carbon dioxide (CO₂) that the fruit gives off as it begins to decompose. Scientists have long known that fruit flies have specialized neurons in their antennae that are tuned to detect CO₂, but the exact molecular mechanism by which these neurons work has remained a mystery. Now, a new study published in the journal Nature Neuroscience has finally identified the individual receptors on these neurons that detect CO₂. The study also reveals how to block these receptors, potentially opening the door to new ways to control fruit flies and other pests that are attracted to CO₂.

How Fruit Flies Detect CO₂

The study was led by researchers at the University of California, Berkeley. The researchers used a combination of genetics, electrophysiology, and imaging techniques to identify the CO₂ receptors on fruit fly neurons. They found that these receptors are part of a family of proteins called ionotropic glutamate receptors (iGluRs). These receptors are normally activated by the neurotransmitter glutamate, but in the case of fruit flies, they have evolved to also respond to CO₂.

The researchers also found that the CO₂ receptors are located on the tips of the dendrites of the neurons. This is the part of the neuron that receives signals from other neurons and sensory cells. The CO₂ receptors are able to detect even very low levels of CO₂, which is essential for fruit flies to find rotting fruit.

How to Block CO₂ Receptors

In addition to identifying the CO₂ receptors, the researchers also found a way to block them. They screened a library of compounds and identified a small molecule that binds to the receptors and prevents them from responding to CO₂. This compound could potentially be used to develop new ways to control fruit flies and other pests that are attracted to CO₂.

Potential Applications

The discovery of the CO₂ receptors on fruit fly neurons could have a number of potential applications. For example, it could be used to develop new ways to control fruit flies and other pests that are attracted to CO₂. It could also be used to study the sense of smell in other insects and animals. Finally, it could help scientists to better understand how neurons work and how they process sensory information.

Pest Control

The CO₂ receptors identified in this study could be used to develop new ways to control fruit flies and other pests that are attracted to CO₂. For example, traps could be baited with CO₂ and then used to capture the pests. Alternatively, compounds that block the CO₂ receptors could be sprayed on crops or other areas where pests are a problem. This would make the pests less able to find food and could help to reduce their populations.

Studying the Sense of Smell

The CO₂ receptors identified in this study could also be used to study the sense of smell in other insects and animals. By comparing the CO₂ receptors in different species, scientists could learn more about how the sense of smell has evolved and how it is used for different purposes. This information could help to better understand how animals interact with their environment and how they find food and mates.

Understanding Neuron Function

Finally, the discovery of the CO₂ receptors on fruit fly neurons could help scientists to better understand how neurons work and how they process sensory information. This information could help to advance the field of neuroscience and lead to new insights into how the brain works.