Human memory formation is accompanied by rhinal-hippocampal coupling and decoupling

Nat Neurosci. 2001 Dec;4(12):1259-64. doi: 10.1038/nn759.

Abstract

In humans, distinct processes within the hippocampus and rhinal cortex support declarative memory formation. But do these medial temporal lobe (MTL) substructures directly cooperate in encoding new memories? Phase synchronization of gamma-band electroencephalogram (EEG) oscillations (around 40 Hz) is a general mechanism of transiently connecting neural assemblies. We recorded depth-EEG from within the MTL of epilepsy patients performing a memorization task. Successful as opposed to unsuccessful memory formation was accompanied by an initial elevation of rhinal-hippocampal gamma synchronization followed by a later desynchronization, suggesting that effective declarative memory formation is accompanied by a direct and temporarily limited cooperation between both MTL substructures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Adult
  • Biological Clocks / physiology*
  • Cortical Synchronization*
  • Entorhinal Cortex / anatomy & histology
  • Entorhinal Cortex / physiology*
  • Epilepsy, Temporal Lobe / physiopathology
  • Epilepsy, Temporal Lobe / psychology
  • Female
  • Hippocampus / anatomy & histology
  • Hippocampus / physiology*
  • Humans
  • Magnetic Resonance Angiography
  • Male
  • Memory / physiology*
  • Memory Disorders / etiology
  • Memory Disorders / physiopathology
  • Memory Disorders / psychology
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology*
  • Neurons / physiology*
  • Neuropsychological Tests
  • Synaptic Transmission / physiology
  • Verbal Behavior / physiology