How smell develops

Nat Neurosci. 2001 Nov;4 Suppl:1192-8. doi: 10.1038/nn751.


The mouse's sense of smell is built of approximately 1000 input channels. Each of these consists of a population of olfactory sensory neurons that express the same odorant receptor gene and project their axons to the same targets (glomeruli) in the olfactory bulb. A neuron must choose to express a singular receptor gene from a repertoire of approximately 1000 genes, and its axon must be wired to the corresponding glomerulus, from an array of approximately 1800 glomeruli. Genetic experiments have shown that the expressed odorant receptor specifies axonal choice of the innervated glomerulus, but it is not the only determinant. The mechanisms of odorant receptor gene choice and axonal wiring are central to the functional organization of the mammalian olfactory system. Although principles have emerged, our understanding of these processes is still limited.

Publication types

  • Review

MeSH terms

  • Animals
  • Body Patterning / genetics
  • Cell Communication / genetics*
  • Gene Expression Regulation, Developmental / genetics*
  • Growth Cones / metabolism*
  • Growth Cones / ultrastructure
  • Humans
  • Olfactory Pathways / cytology
  • Olfactory Pathways / embryology*
  • Olfactory Pathways / metabolism
  • Olfactory Receptor Neurons / cytology
  • Olfactory Receptor Neurons / embryology*
  • Olfactory Receptor Neurons / metabolism
  • Receptors, Odorant / genetics*
  • Receptors, Odorant / metabolism
  • Smell / genetics


  • Receptors, Odorant