How Flies Use Smell to Navigate

Have you ever wondered how tiny fruit flies manage to find their way around? It turns out that their ability to sniff out their surroundings has a lot to do with special cells in their antennae called olfactory receptor neurons (ORNs). These cells help flies detect smells and guide them through their environment. Scientists have been studying how these ORNs work, especially in baby flies called larvae. They found that different smells activate ORNs in different ways, grouping them into four categories based on how the larvae respond. What's even cooler is that these ORNs can detect changes in smell intensity over time. Some ORNs react to increasing smells, while others react to decreasing smells. This helps the larvae instantly figure out if a smell is getting stronger or weaker, which is super important for navigating their world. These abilities make the olfactory system in flies quite complex and efficient. By understanding how ORNs work, we might also learn more about how our own brains process and send smell information to other parts of our nervous system.