The nonspecific thalamus: A place in a wedding bed for making memories last?

Neurosci Biobehav Rev. 2015 Jul;54:175-96. doi: 10.1016/j.neubiorev.2014.10.021. Epub 2014 Nov 1.

Abstract

We summarize anatomical, electrophysiological and behavioral evidence that the rostral intralaminar (ILN) and the reuniens and rhomboid (ReRh) nuclei that belong to the nonspecific thalamus, might be part of a hippocampo-cortico-thalamic network underlying consolidation of enduring declarative(-like) memories at systems level. The first part of this review describes the anatomical and functional organization of these thalamic nuclei. The second part presents the theoretical models supporting the active systems-level consolidation, a process that relies upon sleep specific field-potential oscillations occurring during both slow-wave sleep (SWS) and rapid eye movement (REM) sleep. The last part presents data in the rat showing that the lesion of the rostral ILN or of the ReRh specifically hinders the formation of remote spatial memories without affecting task acquisition or retrieval of a recent memory. These results showing a critical role of the ILN and ReRh nuclei in the transformation of a recent memory into a remote one are discussed in the context of their control of cortical arousal (ARAS) and of thalamo-cortico-thalamic synchronization.

Keywords: Ascending reticular activating system (ARAS); Intralaminar nuclei; Memory; Nonspecific thalamus; Rapid eye movement (REM) sleep; Reuniens nucleus; Rhomboid nucleus; Slow-wave sleep (SWS); Systems-level consolidation; Thalamocortical synchrony; Thalamus core and matrix.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Hippocampus / cytology
  • Hippocampus / physiology
  • Humans
  • Intralaminar Thalamic Nuclei / cytology*
  • Intralaminar Thalamic Nuclei / physiology*
  • Memory Consolidation / physiology*
  • Midline Thalamic Nuclei / cytology*
  • Midline Thalamic Nuclei / physiology*
  • Models, Neurological
  • Neural Pathways / cytology
  • Neural Pathways / physiology
  • Neurons / physiology
  • Prefrontal Cortex / cytology
  • Prefrontal Cortex / physiology
  • Sleep Stages
  • Spatial Memory / physiology*