eLife (Dec 2016)

Immediate perception of a reward is distinct from the reward’s long-term salience

  • John P McGinnis,
  • Huoqing Jiang,
  • Moutaz Ali Agha,
  • Consuelo Perez Sanchez,
  • Jeff Lange,
  • Zulin Yu,
  • Frederic Marion-Poll,
  • Kausik Si

DOI
https://doi.org/10.7554/eLife.22283
Journal volume & issue
Vol. 5

Abstract

Read online

Reward perception guides all aspects of animal behavior. However, the relationship between the perceived value of a reward, the latent value of a reward, and the behavioral response remains unclear. Here we report that, given a choice between two sweet and chemically similar sugars—L- and D-arabinose—Drosophila melanogaster prefers D- over L- arabinose, but forms long-term memories of L-arabinose more reliably. Behavioral assays indicate that L-arabinose-generated memories require sugar receptor Gr43a, and calcium imaging and electrophysiological recordings indicate that L- and D-arabinose differentially activate Gr43a-expressing neurons. We posit that the immediate valence of a reward is not always predictive of the long-term reinforcement value of that reward, and that a subset of sugar-sensing neurons may generate distinct representations of similar sugars, allowing for rapid assessment of the salient features of various sugar rewards and generation of reward-specific behaviors. However, how sensory neurons communicate information about L-arabinose quality and concentration—features relevant for long-term memory—remains unknown.

Keywords