08 Oct 2020 - 12:00

Benjamin de Bivort

Functional and structural loci of individuality in the Drosophila olfactory circuit
Location: Online (webinar)
Host: Clara Ferreira

Benjamin de Bivort

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Title: Functional and structural loci of individuality in the Drosophila olfactory circuit

Affiliation: Harvard University

Abstract:

Behavior varies even among genetically identical animals raised in the same environment. However, little is known about the circuit or anatomical underpinnings of this individuality, though previous work implicates sensory periphery. Drosophila olfaction presents an ideal model to study the biological basis of behavioral individuality, because while the neural circuit underlying olfactory behavior is well-described and highly stereotyped, persistent idiosyncrasy in behavior, neural coding, and neural wiring have also been described. Projection neurons (PNs), which relay odor signals sensed by olfactory receptor neurons (ORNs) to deeper brain structures, exhibit variable calcium responses to identical odor stimuli across individuals, but how these idiosyncrasies relate to individual behavioral responses remains unknown. Here, using paired behavior and two-photon imaging measurements, we show that idiosyncratic calcium dynamics in both ORNs and PNs predict individual preferences for an aversive monomolecular odorant versus air, suggesting that variation at the periphery of the olfactory system determines individual preference for an odor’s presence. In contrast, PN, but not ORN, calcium responses predict individual preferences in a two-odor choice assay. Furthermore, paired behavior and immunohistochemistry measurements reveal that variation in ORN presynaptic density also predicts two-odor preference, suggesting this site is a locus of individuality where microscale circuit variation gives rise to idiosyncrasy in behavior. Our results demonstrate how a neural circuit may vary functionally and structurally to produce variable behavior among individuals.

Benjamin de Bivort

Bio: Ben studied math and biology at Duke before a PhD in neurobiology at Harvard. The de Bivort lab uses custom instruments to collect quantitative measures of behavior in bumblebees and fruit flies, and is particularly interested in the basis of behavioral variation when genetics and environment are held constant. Studies approach this question at the evolutionary, genetic and neural circuit levels.

Lab webpage