NMDA receptors mediate consolidation of contextual memory in the hippocampus after context preexposure.
Male Wistar rats received bilateral infusions of vehicle (VEH) or aminophosphonopentanoic acid (AP5), an N-metil-D-aspartate (NMDA) receptor antagonist, into the dorsal hippocampus immediately after inhibitory avoidance (IA) training. Intrahippocampal infusion of AP5 blocked 24 h IA retention. In the second experiment, animals were preexposed to the IA training context 24 h prior to training and received an infusion of either VEH or AP5 immediately after the preexposure trial and a second infusion of VEH or AP5 immediately after IA training. AP5 did not affect retention in animals preexposed to the IA box and given VEH after preexposure, but blocked retention when given after both preexposure and training. AP5 impaired retention in rats preexposed to an environment distinct from the IA box. These results suggest that NMDA receptors in the dorsal hippocampus mediate the formation of a contextual representation of the task environment.
Roesler
Rafael
R
Preclinical Neuropharmacology Research Group, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 90046-900, Porto Alegre, RS, Brazil. rroesler@terra.com.br
Reolon
Gustavo K
GK
Luft
Tatiana
T
Martins
Márcio R
MR
Schröder
Nadja
N
Vianna
Mônica R M
MR
Quevedo
João
J
D015763:2-Amino-5-phosphonovalerate / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D015763:2-Amino-5-phosphonovalerate