title: Starvation-Induced Depotentiation of Bitter Taste in Drosophila.
abstract: Nutrient deprivation can lead to dramatic changes in feeding behavior, including acceptance of foods that are normally rejected. In flies, this behavioral shift depends in part on reciprocal sensitization and desensitization of sweet and bitter taste, respectively. However, the mechanisms for bitter taste modulation remain unclear. Here, we identify a set of octopaminergic/tyraminergic neurons, named OA-VLs, that directly modulate bitter sensory neuron output in response to starvation. OA-VLs are in close proximity to bitter sensory neuron axon terminals and show reduced tonic firing following starvation. We find that octopamine and tyramine potentiate bitter sensory neuron responses, suggesting that starvation-induced reduction in OA-VL activity depotentiates bitter taste. Consistent with this model, artificial silencing of OA-VL activity induces a starvation-like reduction in bitter sensory neuron output. These results demonstrate that OA-VLs mediate a critical step in starvation-dependent bitter taste modulation, allowing flies to dynamically balance the risks associated with bitter food consumption against the threat of severe starvation.
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Emily E
authors.initials: EE
authors.lastname: LeDue
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Mann
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Ellen
authors.initials: E
authors.lastname: Koch
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Chu
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Roslyn
authors.initials: R
authors.lastname: Dakin
authors.affiliation: Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Electronic address: gordon@zoology.ubc.ca.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Gordon
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000502:physiology*; D005260:Female; D005508:Food Deprivation; D036881:Long-Term Synaptic Depression; D011984:Sensory Receptor Cells / Q000502:physiology; D055697:Taste Perception
keywords: Drosophila; bitter taste; feeding; gustatory; modulation; octopamine; starvation; taste; tyramine