Immobility responses are induced by photoactivation of single glomerular species responsive to fox odour TMT

Nat Commun. 2017 Jul 7:8:16011. doi: 10.1038/ncomms16011.

Abstract

Fox odour 2,4,5-trimethyl thiazoline (TMT) is known to activate multiple glomeruli in the mouse olfactory bulb (OB) and elicits strong fear responses. In this study, we screened TMT-reactive odourant receptors and identified Olfr1019 with high ligand reactivity and selectivity, whose glomeruli are located in the posterodorsal OB. In the channelrhodopsin knock-in mice for Olfr1019, TMT-responsive olfactory-cortical regions were activated by photostimulation, leading to the induction of immobility, but not aversive behaviour. Distribution of photoactivation signals was overlapped with that of TMT-induced signals, but restricted to the narrower regions. In the knockout mice, immobility responses were reduced, but not entirely abolished likely due to the compensatory function of other TMT-responsive glomeruli. Our results demonstrate that the activation of a single glomerular species in the posterodorsal OB is sufficient to elicit immobility responses and that TMT-induced fear may be separated into at least two different components of immobility and aversion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aversive Agents / isolation & purification
  • Aversive Agents / pharmacology
  • Behavior, Animal / drug effects
  • Channelrhodopsins / genetics
  • Channelrhodopsins / metabolism
  • Fear / drug effects*
  • Fear / psychology
  • Feces / chemistry
  • Foxes
  • Freezing Reaction, Cataleptic / drug effects*
  • Freezing Reaction, Cataleptic / physiology
  • Gene Expression
  • Gene Knock-In Techniques
  • Male
  • Mice
  • Odorants / analysis
  • Olfactory Bulb / drug effects*
  • Olfactory Bulb / physiology
  • Olfactory Perception / physiology*
  • Photic Stimulation
  • Receptors, Odorant / genetics*
  • Receptors, Odorant / metabolism
  • Smell / physiology*
  • Stereotaxic Techniques
  • Thiazoles / isolation & purification
  • Thiazoles / pharmacology*

Substances

  • 2,4,5 trimethylthiazoline
  • Aversive Agents
  • Channelrhodopsins
  • Receptors, Odorant
  • Thiazoles