Theta-gamma coupling in the entorhinal-hippocampal system

Curr Opin Neurobiol. 2015 Apr;31:45-50. doi: 10.1016/j.conb.2014.08.001. Epub 2014 Aug 27.

Abstract

For decades, theta rhythms (∼5-10Hz) have been thought to play a critical role in memory processing in the entorhinal-hippocampal network. However, recent evidence suggests that successful memory performance also requires coupling of ∼30-100Hz gamma rhythms to particular phases of the theta cycle. Recent insights imply ways in which theta-gamma coupling may facilitate transfer of information throughout the entorhinal-hippocampal network. Activating gamma-modulated cell assemblies at a particular theta phase may allow the network to produce a more powerful output by ensuring that distributed cells fire closely in time. I hypothesize that such a mechanism would serve to facilitate either memory encoding or memory retrieval, depending on which type of gamma rhythms are recruited.

Publication types

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

MeSH terms

  • Animals
  • Electroencephalography
  • Entorhinal Cortex / physiology*
  • Gamma Rhythm / physiology*
  • Hippocampus / physiology*
  • Humans
  • Neural Pathways / physiology*
  • Theta Rhythm / physiology*