ELSC Seminar Series

In insects, olfactory information is processed along pathways bifurcating in the Antennal Lobe (AL). Structured AL to Lateral Horn (LH) connections support specific innate odor-guided behaviors, but how this generalizes to processing transient high-dimensional stimuli remains unknown. Random AL to Mushroom Body (MB) connections support learned behaviors, but proposals for the role of randomness rely on unrealistic clustering of AL responses. We show that preprocessing of responses by finely-tuned electrical inhibition between olfactory receptor neurons (ORNs) overcomes these problems. Lateral inhibition between ORNs (i) transiently amplifies valence signals, preparing olfactory information to be read-out in the LH; and (ii) modifies the structure of AL responses, rendering random connections effective for odor classification in the MB. Taken together, a genetically encoded shallow network is shown to be crucial for central olfactory processing.