Thalamocortical interactions

Curr Opin Neurobiol. 2012 Aug;22(4):575-9. doi: 10.1016/j.conb.2012.03.005. Epub 2012 Apr 11.


Glutamatergic pathways dominate information processing in the brain, but these are not homogeneous. They include two distinct types: Class 1, which carries the main information for processing, and Class 2, which serves a modulatory role. Identifying the Class 1 inputs in a circuit can lead to a better understanding of its function. Also, identifying Class 1 inputs to a thalamic nucleus tells us its main function (e.g. the lateral geniculate nucleus, or LGN, is the relay of retinal Class 1 input), and such identification leads to a division of thalamic relays into first and higher order: the former receives Class 1 inputs from subcortical sources; the latter, from layer 5 of cortex, which it then relays to another cortical area. When a cortical area directly connects with another, it often has a parallel, transthalamic connection through these higher order relays. This leads to a novel appreciation of cortical functioning and raises many new questions.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cerebral Cortex / anatomy & histology
  • Cerebral Cortex / physiology*
  • Glutamic Acid / metabolism
  • Humans
  • Neural Pathways / physiology*
  • Thalamus / anatomy & histology*
  • Thalamus / physiology*


  • Glutamic Acid