Impaired sequential egocentric and allocentric memories in forebrain-specific-NMDA receptor knock-out mice during a new task dissociating strategies of navigation

J Neurosci. 2006 Apr 12;26(15):4071-81. doi: 10.1523/JNEUROSCI.3408-05.2006.

Abstract

The hippocampus is considered to play a role in allocentric but not in egocentric spatial learning. How does this view fit with the emerging evidence that the hippocampus and possibly related cortical areas are necessary for episodic-like memory, i.e., in all situations in which events need to be spatially or sequentially organized? Are NMDA receptor-dependent mechanisms crucial for the acquisition of spatiotemporal relationships? To address this issue, we used knock-out (KO) mice lacking hippocampal CA1 NMDA receptors and presenting a reduction of these receptors in the deep cortical layers (NR1-KO mice). A new task (the starmaze) was designed, allowing us to distinguish allocentric and sequential-egocentric memories. NR1-KO mice were impaired in acquiring both types of memory. Our findings suggest that memories composed of multiple spatiotemporal events require intact NMDA receptors-dependent mechanisms in CA1 and possibly in the deep cortical layers.

Publication types

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

MeSH terms

  • Animals
  • Genotype
  • Hippocampus / physiology*
  • Learning / physiology*
  • Maze Learning / physiology*
  • Memory / physiology*
  • Mice
  • Mice, Knockout
  • Motor Activity / physiology*
  • Receptors, N-Methyl-D-Aspartate / deficiency
  • Receptors, N-Methyl-D-Aspartate / genetics
  • Receptors, N-Methyl-D-Aspartate / physiology*
  • Reference Values

Substances

  • NR1 NMDA receptor
  • Receptors, N-Methyl-D-Aspartate