Current Biology
Volume 15, Issue 17, 6 September 2005, Pages 1535-1547
Journal home page for Current Biology

Article
Molecular, Anatomical, and Functional Organization of the Drosophila Olfactory System

https://doi.org/10.1016/j.cub.2005.07.034Get rights and content
Under an Elsevier user license
open archive

Summary

Background: Olfactory receptor neurons (ORNs) convey chemical information into the brain, producing internal representations of odors detected in the periphery. A comprehensive understanding of the molecular and neural mechanisms of odor detection and processing requires complete maps of odorant receptor (Or) expression and ORN connectivity, preferably at single-cell resolution.

Results: We have constructed near-complete maps of Or expression and ORN targeting in the Drosophila olfactory system. These maps confirm the general validity of the “one neuron—one receptor” and “one glomerulus—one receptor” principles and reveal several additional features of olfactory organization. ORNs in distinct sensilla types project to distinct regions of the antennal lobe, but neighbor relations are not preserved. ORNs grouped in the same sensilla do not express similar receptors, but similar receptors tend to map to closely appositioned glomeruli in the antennal lobe. This organization may serve to ensure that odor representations are dispersed in the periphery but clustered centrally. Integrated with electrophysiological data, these maps also predict glomerular representations of specific odorants. Representations of aliphatic and aromatic compounds are spatially segregated, with those of aliphatic compounds arranged topographically according to carbon chain length.

Conclusions: These Or expression and ORN connectivity maps provide further insight into the molecular, anatomical, and functional organization of the Drosophila olfactory system. Our maps also provide an essential resource for investigating how internal odor representations are generated and how they are further processed and transmitted to higher brain centers.

Cited by (0)

1

These authors contributed equally to this work.