For the fruit fly, a sense of taste is critical to whether it thrives or dies. The little winged creature has taste organs in its mouthpiece as well as throughout its body, including its legs, abdomen and wing margins. When a fruit fly lands on a ripe or rotting fruit, it instantly receives information about whether the fruit is bitter or sweet. Sweetness indicates a caloric payday that cues the fly to feed; bitterness prompts the fly to move on from the potentially toxic substance.

Researchers in the lab of Brown University professor Gilad Barnea have identified the pair of neurons that make this critical choice. The insights on how flies navigate this complex decision-making process, a process not previously clear to scientists, are published online in Nature Communications.

“If a fly makes just one mistake about what to eat, it may die,” said Barnea, a professor of neuroscience and director of the Center for the Neurobiology of Cells and Circuits at Brown’s Carney Institute for Brain Science. “So the decision is super important. This newly discovered mechanism illustrates the impressive level of computation that a single neuron can do.”