Fruit flies that learn to associate a scent with a color actually hijack their visual neurons to expand their smell memory.
Memory in the brain was long thought to stay within the specific department related to the sense, like smell staying in the olfactory bulb. Serotonergic DPM neurons bridge different brain regions during multisensory learning to physically recruit neurons that usually only handle vision. These visual cells are forced to join a smell memory engram to create a more stable and combined sensory record. The brain effectively rewrites its own internal map to include new data across different senses. Understanding this cross-talk explains why a specific scent can instantly bring a vivid visual memory to life.
Multisensory learning recruits visual neurons into an olfactory memory engram
arXiv · 2604.28007
Associating multiple sensory cues with a single experience or object is a fundamental process that improves object recognition and memory performance. However, neural mechanisms that bind sensory features during learning and augment memory expression are unknown. Here we demonstrate multisensory appetitive and aversive memory in Drosophila. Combining colours and odours improved memory performance, even when each sensory modality was tested alone. Temporal control of neuronal function revealed vi