title: Functional diversity among sensory receptors in a Drosophila olfactory circuit.
abstract: The ability of an animal to detect, discriminate, and respond to odors depends on the function of its olfactory receptor neurons (ORNs), which in turn depends ultimately on odorant receptors. To understand the diverse mechanisms used by an animal in olfactory coding and computation, it is essential to understand the functional diversity of its odor receptors. The larval olfactory system of Drosophila melanogaster contains 21 ORNs and a comparable number of odorant receptors whose properties have been examined in only a limited way. We systematically screened them with a panel of ∼500 odorants, yielding >10,000 receptor-odorant combinations. We identify for each of 19 receptors an odorant that excites it strongly. The responses elicited by each of these odorants are analyzed in detail. The odorants elicited little cross-activation of other receptors at the test concentration; thus, low concentrations of many of these odorants in nature may be signaled by a single ORN. The receptors differed dramatically in sensitivity to their cognate odorants. The responses showed diverse temporal dynamics, with some odorants eliciting supersustained responses. An intriguing question in the field concerns the roles of different ORNs and receptors in driving behavior. We found that the cognate odorants elicited behavioral responses that varied across a broad range. Some odorants elicited strong physiological responses but weak behavioral responses or weak physiological responses but strong behavioral responses.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Mathew
authors.forename: Carlotta
authors.initials: C
authors.lastname: Martelli
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kelley-Swift
authors.forename: Christopher
authors.initials: C
authors.lastname: Brusalis
authors.forename: Marc
authors.initials: M
authors.lastname: Gershow
authors.forename: Aravinthan D T
authors.initials: AD
authors.lastname: Samuel
authors.forename: Thierry
authors.initials: T
authors.lastname: Emonet
authors.forename: John R
authors.initials: JR
authors.lastname: Carlson
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D008401:Gas Chromatography-Mass Spectrometry; D007814:Larva / Q000166:cytology; D009068:Movement / Q000502:physiology*; D009812:Odorants / Q000032:analysis*; D009833:Olfactory Pathways / Q000378:metabolism*; D018034:Olfactory Receptor Neurons / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism*; D018035:Receptors, Odorant / Q000378:metabolism*
chemical_list: D009930:Organic Chemicals; D018035:Receptors, Odorant