Loss-of-function mutations in sodium channel Nav1.7 cause anosmia

Nature. 2011 Apr 14;472(7342):186-90. doi: 10.1038/nature09975. Epub 2011 Mar 23.

Abstract

Loss of function of the gene SCN9A, encoding the voltage-gated sodium channel Na(v)1.7, causes a congenital inability to experience pain in humans. Here we show that Na(v)1.7 is not only necessary for pain sensation but is also an essential requirement for odour perception in both mice and humans. We examined human patients with loss-of-function mutations in SCN9A and show that they are unable to sense odours. To establish the essential role of Na(v)1.7 in odour perception, we generated conditional null mice in which Na(v)1.7 was removed from all olfactory sensory neurons. In the absence of Na(v)1.7, these neurons still produce odour-evoked action potentials but fail to initiate synaptic signalling from their axon terminals at the first synapse in the olfactory system. The mutant mice no longer display vital, odour-guided behaviours such as innate odour recognition and avoidance, short-term odour learning, and maternal pup retrieval. Our study creates a mouse model of congenital general anosmia and provides new strategies to explore the genetic basis of the human sense of smell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Animals
  • Behavior, Animal
  • Disease Models, Animal
  • Female
  • Gene Expression Profiling
  • Humans
  • Male
  • Mice
  • Mutant Proteins / genetics*
  • Mutant Proteins / metabolism*
  • Mutation / genetics*
  • NAV1.7 Voltage-Gated Sodium Channel
  • Odorants / analysis
  • Olfaction Disorders / congenital
  • Olfaction Disorders / genetics*
  • Olfaction Disorders / pathology
  • Olfaction Disorders / physiopathology*
  • Olfactory Mucosa / cytology
  • Olfactory Mucosa / pathology
  • Olfactory Pathways / metabolism
  • Olfactory Pathways / pathology
  • Olfactory Pathways / physiopathology
  • Olfactory Perception / genetics
  • Olfactory Perception / physiology
  • Olfactory Receptor Neurons / metabolism
  • Olfactory Receptor Neurons / pathology
  • Pain / genetics
  • Pain / physiopathology
  • Phenotype
  • Smell / genetics
  • Smell / physiology
  • Sodium Channels / deficiency
  • Sodium Channels / genetics*
  • Sodium Channels / metabolism
  • Synapses / metabolism
  • Synapses / pathology
  • Urine / chemistry

Substances

  • Mutant Proteins
  • NAV1.7 Voltage-Gated Sodium Channel
  • SCN9A protein, human
  • Scn9a protein, mouse
  • Sodium Channels