New research by scientists from Janelia and the University of North Carolina at Chapel Hill has shed light on how the fruit fly brain converts memories of past rewards into actions, helping the fly find food. The study identified a cluster of neurons, known as Upwind Neurons or UpWiNs, which play a crucial role in transforming these memories into upwind movements.
Fruit flies, like other insects, turn upwind to trace odors and navigate to their source. The fly’s olfactory system detects and senses odors carried by the wind, guiding the fly to the reward. However, the link between the processing of odors in the brain and motor actions remained unclear.
The researchers focused on a brain region called the mushroom body, which processes and integrates olfactory information. Multiple compartments within the mushroom body assign positive or negative values to an odor stimulus. The study revealed that reward memories formed in different compartments elicited distinct behaviors, with only some driving the fly’s upwind movement.
The UpWiNs were found to integrate inhibitory and excitatory inputs from these compartments, causing the fly to turn and move into the wind. Additionally, the UpWiNs send excitatory signals to dopaminergic neurons for higher-order learning.
These findings offer valuable insights into how learned positive and negative values are transformed into concrete memory-driven actions. They also help explain how parallel dopaminergic neurons and memory subsystems interact to guide memory-based actions and learning at the level of individual neural circuits.
The research was published in the journal eLife and provides a deeper understanding of the intricate neural circuits involved in how memories influence behavior. By uncovering the role of UpWiNs in converting odor memories into upwind movements, the study contributes to our knowledge of how the brain processes sensory information and translates it into actions.
Further exploration of these neural circuits could have implications for understanding how memories and past experiences shape behavior in other organisms, including humans. By unraveling these complex processes, scientists can gain a better understanding of the fundamental workings of the brain.