Impaired sequential egocentric and allocentric memories in forebrain-specific-NMDA receptor knock-out mice during a new task dissociating strategies of navigation.
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.
Rondi-Reig
Laure
L
Collège de France, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7152, Laboratoire de Physiologie de la Perception et de l'Action, F-75005 Paris, France. laure.rondi-reig@college-de-france.fr
Petit
Géraldine H
GH
Tobin
Christine
C
Tonegawa
Susumu
S
Mariani
Jean
J
Berthoz
Alain
A
D000818:Animals; D005838:Genotype; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012016:Reference Values
C409466:NR1 NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate