Neuronal basis of innate olfactory attraction to ethanol in Drosophila

PLoS One. 2012;7(12):e52007. doi: 10.1371/journal.pone.0052007. Epub 2012 Dec 20.

Abstract

The decision to move towards a mating partner or a food source is essential for life. The mechanisms underlying these behaviors are not well understood. Here, we investigated the role of octopamine - the invertebrate analogue of noradrenaline - in innate olfactory attraction to ethanol. We confirmed that preference is caused via an olfactory stimulus by dissecting the function of the olfactory co-receptor Orco (formally known as OR83b). Orco function is not required for ethanol recognition per se, however it plays a role in context dependent recognition of ethanol. Odor-evoked ethanol preference requires the function of Tbh (Tyramine β hydroxalyse), the rate-limiting enzyme of octopamine synthesis. In addition, neuronal activity in a subset of octopaminergic neurons is necessary for olfactory ethanol preference. Notably, a specific neuronal activation pattern of tyraminergic/octopaminergic neurons elicit preference and is therefore sufficient to induce preference. In contrast, dopamine dependent increase in locomotor activity is not sufficient for olfactory ethanol preference. Consistent with the role of noradrenaline in mammalian drug induced rewards, we provide evidence that in adult Drosophila the octopaminergic neurotransmitter functions as a reinforcer and that the molecular dissection of the innate attraction to ethanol uncovers the basic properties of a response selection system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Drosophila / physiology*
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / metabolism
  • Ethanol*
  • Male
  • Octopamine / metabolism
  • Odorants
  • Olfactory Perception / physiology*
  • Olfactory Receptor Neurons / physiology*
  • Transcription Factors / metabolism
  • Transgenes
  • Tyrosine Decarboxylase / chemistry
  • Tyrosine Decarboxylase / metabolism

Substances

  • Drosophila Proteins
  • GAL4 protein, Drosophila
  • Transcription Factors
  • Octopamine
  • Ethanol
  • Tdc2 protein, Drosophila
  • Tyrosine Decarboxylase

Grants and funding

This work was supported by the DFG 656/4-1 and DFG656/7-1 to H.S. (http://www.dfg.de). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.