Abstract
Animals use olfactory receptors to navigate mates, food, and danger. However, for complex olfactory systems, it is unknown what proportion of primary olfactory sensory neurons can individually drive avoidance or attraction. Similarly, the rules that govern behavioral responses to receptor combinations are unclear. We used optogenetic analysis in Drosophila to map the behavior elicited by olfactory-receptor neuron (ORN) classes: just one-fifth of ORN-types drove either avoidance or attraction. Although wind and hunger are closely linked to olfaction, neither had much effect on single-class responses. Several pooling rules have been invoked to explain how ORN types combine their behavioral influences; we activated two-way combinations and compared patterns of single- and double-ORN responses: these comparisons were inconsistent with simple pooling. We infer that the majority of primary olfactory sensory neurons have neutral behavioral effects individually, but participate in broad, odor-elicited ensembles with potent behavioral effects arising from complex interactions.
Highlights
Animals interact with their environment using motor functions that are guided by information that enters the brain from multiple sensory systems
olfactory-receptor neuron (ORN) sharing the same receptor type converge on a glomerulus in the antennal lobe, where they synapse with local interneurons (LNs) and projection neurons (PNs) (Couto et al, 2005; Gao et al, 2000)
Olfaction typically occurs in windy environments, and is influenced by hunger state, so we explored whether single-type-ORN valence is contingent on these factors (Bell and Wilson, 2016; Sengupta, 2013)
Summary
Animals interact with their environment using motor functions that are guided by information that enters the brain from multiple sensory systems. Innervating throughout the antennal lobe and connecting multiple glomeruli, the LNs facilitate both excitatory and inhibitory interactions between glomeruli (Groschner and Miesenböck, 2019). This modified information is relayed by the PNs to higher brain centers, namely mushroom bodies and the lateral horn (Lai et al, 2008; Wang et al, 2014; Wong et al, 2002). Mapping how ORNs steer behavior would inform a broader understanding of how sensory circuits influence behavioral output
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have