The olfactory glomerulus: a cortical module with specific functions

J Neurocytol. 2005 Sep;34(3-5):353-60. doi: 10.1007/s11068-005-8362-0. Epub 2006 Jul 13.


The axons of many olfactory receptor cells converge on an individual glomerulus in the olfactory bulb, where they make contacts with the distal dendrites of mitral and tufted cells. Each glomerulus is targeted by olfactory receptor neurons expressing a single type of olfactory receptor protein. The glomerulus provides a unique model in which the function of a cortical module can be unambiguously established. Here we review the increasing evidence that a key functional operation of the glomerulus is to act as a signal-to-noise enhancing device in the processing of sensory input and that this function is critical across vertebrate and invertebrate species for the ability to detect specific odor stimuli within "noisy" odor environments and to carry out discriminations between odor molecules that are structurally closely related.

Publication types

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

MeSH terms

  • Animals
  • Humans
  • Olfactory Bulb / cytology*
  • Olfactory Bulb / physiology*
  • Olfactory Receptor Neurons / cytology*
  • Signal Transduction / physiology*
  • Smell / physiology*