Efferent connections of the parabigeminal nucleus to the amygdala and the superior colliculus in the rat: a double-labeling fluorescent retrograde tracing study

Brain Res. 2007 Feb 16;1133(1):87-91. doi: 10.1016/j.brainres.2006.11.073. Epub 2006 Dec 29.


The parabigeminal nucleus (Pbg) is a subcortical visual center that besides reciprocal connections with the superior colliculus (SC), also projects to the amygdala (Am). The Pbg-Am connection is part of a multineuronal pathway that conveys extrageniculostriate inputs of the retina to the Am, and it rapidly responds to the sources of threat before conscious detection. The present study demonstrates that Pbg projects bilaterally to Am and SC. The ipsilateral projections arise from separate cell populations, whilst the contralaterally projecting Pbg neurons emit branching axons that simultaneously innervate Am and SC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / anatomy & histology*
  • Amygdala / physiology
  • Animals
  • Axons / physiology
  • Axons / ultrastructure*
  • Brain Mapping
  • Fluorescent Dyes
  • Male
  • Motion Perception / physiology
  • Rats
  • Rats, Wistar
  • Superior Colliculi / anatomy & histology*
  • Superior Colliculi / physiology
  • Tectum Mesencephali / anatomy & histology*
  • Tectum Mesencephali / physiology
  • Visual Pathways / anatomy & histology*
  • Visual Pathways / physiology


  • Fluorescent Dyes