Meeting Abstract
The brain integrates information from different sensory modalities in order to enhance detection and perception of external stimuli and to respond in the most efficient manner. For a Drosophila larva, this means detecting chemosensory cues to locate the most nutritious food source in its environment. How the larva integrates olfactory and gustatory cues, at both the neuronal and behavioral levels, remains largely unknown. To assess the larva’s behavioral strategy for chemosensory integration, we compared its navigation behavior on attractive olfactory or gustatory gradients alone to that on simultaneous presentations of both gradients in parallel or in conflict. Larvae show multisensory enhancement in their navigation efficiency towards the most attractive region of their chemosensory environment when both gradients are in parallel compared to either one alone. Placing the two gradients in conflict reveals that neither sensory system gates the other. Using in vivo calcium imaging to record neural activity, we identified several local and projection neurons within the antennal lobe, the first olfactory processing center in the larval brain, that respond to both odors and tastes or are modulated by odor-taste mixtures. To our knowledge, these results indicate for the first time that neurons in the antennal lobe have multisensory responses. Our findings support the idea that multisensory integration occurs at early stages of sensory processing and begin to address how this convergence enhances perception and shapes foraging behavior.
