Behaviour 2019
Idiosyncratic neural coding and neuromodulation of olfactory individuality in Drosophila
Matthew/A Smith1,2, Kyle Honegger3, Matthew Churgin1,2, Glenn Turner4, Benjamin de Bivort1,2. 1Harvard OEB, Cambridge, MA, United States; 2Harvard Center for Brain Science, Cambridge, MA, United States; 3Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States; 4Janelia Research Campus, Ashburn, VA, United States

Innate behavioral biases and preferences can vary significantly among individuals of the same
genotype. Though individuality is a fundamental property of behavior, it is not currently understood how individual differences in brain structure and physiology give rise to idiosyncratic behaviors. Here we present evidence for idiosyncrasy in olfactory behavior and neural responses in Drosophila. We show that individual female Drosophila from a highly inbred lab strain exhibit idiosyncratic odor preferences that persist for days. We used in vivo calcium imaging of neural responses to directly compare projection neuron (second order neurons that convey odor information from the sensory periphery to the central brain) responses to the same odors across animals. We found that, while odor responses appear grossly stereotyped, upon closer inspection, many individual differences are apparent across antennal lobe (AL) glomeruli (compact microcircuits corresponding to different odor channels). Moreover, we show that neuromodulation, environmental stress in the form of altered nutrition, and the activity of certain AL local interneurons affect the magnitude of interfly behavioral variability.