A field guide to the anterior olfactory nucleus (cortex)

Brain Res Brain Res Rev. 2005 Dec 15;50(2):305-35. doi: 10.1016/j.brainresrev.2005.08.005. Epub 2005 Oct 17.


While portions of the mammalian olfactory system have been studied extensively, the anterior olfactory nucleus (AON) has been relatively ignored. Furthermore, the existing research is dispersed and obscured by many different nomenclatures and approaches. The present review collects and assembles the relatively sparse literature regarding the portion of the brain situated between the olfactory bulb and primary olfactory (piriform) cortex. Included is an overview of the area's organization, the functional, morphological and neurochemical characteristics of its cells and a comprehensive appraisal of its efferent and afferent fiber systems. Available evidence suggests the existence of subdivisions within the AON and demonstrates that the structure influences ongoing activity in many other olfactory areas. We conclude with a discussion of the AON's mysterious but complex role in olfactory information processing.

Publication types

  • Review

MeSH terms

  • Animals
  • Brain Chemistry
  • Brain Mapping*
  • Cell Size
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Humans
  • Neural Networks, Computer
  • Neurons / classification
  • Neurons / physiology
  • Olfactory Bulb / physiology*
  • Olfactory Pathways / physiology*