Plasticity of Sniffing Pattern and Neural Activity in the Olfactory Bulb of Behaving Mice During Odor Sampling, Anticipation, and Reward

Neurosci Bull. 2020 Jun;36(6):598-610. doi: 10.1007/s12264-019-00463-9. Epub 2020 Jan 27.

Abstract

The olfactory bulb (OB) is the first relay station in the olfactory system. In the OB, mitral/tufted cells (M/Ts), which are the main output neurons, play important roles in the processing and representation of odor information. Recent studies focusing on the function of M/Ts at the single-cell level in awake behaving mice have demonstrated that odor-evoked firing of single M/Ts displays transient/long-term plasticity during learning. Here, we tested whether the neural activity of M/Ts and sniffing patterns are dependent on anticipation and reward in awake behaving mice. We used an odor discrimination task combined with in vivo electrophysiological recordings in awake, head-fixed mice, and found that, while learning induced plasticity of spikes and beta oscillations during odor sampling, we also found plasticity of spikes, beta oscillation, sniffing pattern, and coherence between sniffing and theta oscillations during the periods of anticipation and/or reward. These results indicate that the activity of M/Ts plays important roles not only in odor representation but also in salience-related events such as anticipation and reward.

Keywords: Go/no-go; In vivo electrophysiological recording; Odor representation; Olfactory bulb.

MeSH terms

  • Animals
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neuronal Plasticity*
  • Odorants*
  • Olfactory Bulb* / physiology
  • Olfactory Pathways
  • Reward
  • Smell*