Trigeminally innervated iron-containing structures in the beak of homing pigeons, and other birds

Brain Res. 2001 Jan 19;889(1-2):243-6. doi: 10.1016/s0006-8993(00)03114-0.


The ophthalmic nerve in the upper beak was labelled with cholera toxin B-chain, and iron was identified using the Prussian Blue reaction. Iron deposits were found in the caudal part of the beak, and some were concentrated in cells that clustered in encapsulated structures densely innervated by ophthalmic nerve fibres. Such structures could form the anatomical basis of a type of mechanoreceptor that transmits magnetic sense information to the brain.

MeSH terms

  • Animals
  • Beak / innervation*
  • Beak / metabolism
  • Birds / physiology*
  • Coloring Agents
  • Columbidae / physiology*
  • Iron / metabolism*
  • Ophthalmic Nerve / anatomy & histology
  • Ophthalmic Nerve / metabolism
  • Ophthalmic Nerve / physiology*


  • Coloring Agents
  • Iron