Two Drosophila Neuropeptide Y-like Neurons Define a Reward Module for Transforming Appetitive Odor Representations to Motivation

Sci Rep. 2018 Aug 3;8(1):11658. doi: 10.1038/s41598-018-30113-5.

Abstract

Neuropeptides, many of which are conserved among vertebrate and invertebrate animals, are implicated in the regulation of motivational states that selectively facilitate goal-directed behaviors. After a brief presentation of appetitive odors, Drosophila larvae display an impulsive-like feeding activity in readily accessible palatable food. This innate appetitive response may require coordinated signaling activities of dopamine (DA) and neuropeptide F (NPF; a fly homolog of neuropeptide Y). Here we provide anatomical and functional evidence, at single-cell resolution, that two NPF neurons define a reward module in the highest-order brain region for cognitive processing of food-related olfactory representations. First, laser lesioning of these NPF neurons abolished odor induction of appetitive arousal, while their genetic activation mimicked the behavioral effect of appetitive odors. Further, a circuit analysis shows that each of the two NPF neurons relays its signals to a subset of target neurons in the larval hindbrain-like region. Finally, the NPF neurons discriminatively responded to appetitive odor stimuli, and their odor responses were blocked by targeted lesioning of a pair of dopaminergic third-order olfactory neurons that appear to be presynaptic to the NPF neurons. Therefore, the two NPF neurons contribute to appetitive odor induction of impulsive-like feeding by selectively decoding DA-encoded ascending olfactory inputs and relaying NPF-encoded descending motivational outputs for behavioral execution.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Appetite / genetics*
  • Appetite / physiology
  • Dopamine / genetics
  • Dopamine / metabolism
  • Dopaminergic Neurons / metabolism
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / physiology
  • Feeding Behavior / physiology*
  • Larva / genetics
  • Larva / physiology
  • Motivation / genetics
  • Neuropeptide Y / genetics
  • Neuropeptides / genetics*
  • Odorants
  • Rhombencephalon / metabolism
  • Rhombencephalon / physiology
  • Smell / genetics
  • Smell / physiology

Substances

  • Drosophila Proteins
  • Neuropeptide Y
  • Neuropeptides
  • neuropeptide F, Drosophila
  • Dopamine