Dynamic sensory representations in the olfactory bulb: modulation by wakefulness and experience

Neuron. 2012 Dec 6;76(5):962-75. doi: 10.1016/j.neuron.2012.09.037.

Abstract

How are sensory representations in the brain influenced by the state of an animal? Here we use chronic two-photon calcium imaging to explore how wakefulness and experience shape odor representations in the mouse olfactory bulb. Comparing the awake and anesthetized state, we show that wakefulness greatly enhances the activity of inhibitory granule cells and makes principal mitral cell odor responses more sparse and temporally dynamic. In awake mice, brief repeated odor experience leads to a gradual and long-lasting (months) weakening of mitral cell odor representations. This mitral cell plasticity is odor specific, recovers gradually over months, and can be repeated with different odors. Furthermore, the expression of this experience-dependent plasticity is prevented by anesthesia. Together, our results demonstrate the dynamic nature of mitral cell odor representations in awake animals, which is constantly shaped by recent odor experience.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / genetics
  • Animals
  • Animals, Newborn
  • Cadherins / genetics
  • Calmodulin / genetics
  • Calmodulin / metabolism
  • Glutamate Decarboxylase / genetics
  • Green Fluorescent Proteins / genetics
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Models, Biological
  • Nerve Tissue Proteins / genetics
  • Neuronal Plasticity / genetics
  • Neuronal Plasticity / physiology
  • Neurons / physiology
  • Nonlinear Dynamics*
  • Odorants*
  • Olfactory Bulb / cytology
  • Olfactory Bulb / physiology*
  • Olfactory Marker Protein / genetics
  • Olfactory Pathways / physiology
  • Smell / physiology*
  • Time Factors
  • Wakefulness / physiology*

Substances

  • CDHR1 protein, human
  • Cadherins
  • Calmodulin
  • Nerve Tissue Proteins
  • Olfactory Marker Protein
  • Omp protein, mouse
  • synapto-pHluorin protein, mouse
  • Green Fluorescent Proteins
  • Glutamate Decarboxylase
  • glutamate decarboxylase 2