Aversive learning under different training conditions: effects of NMDA receptor blockade in area CA1 of the hippocampus.
Adult male Wistar rats were given either a single training trial or one training trial per day during 3 days followed by a retention test trial in an inhibitory avoidance (IA) task. In animals given a single training trial, pretraining, but not pretest bilateral infusion of the NMDA glutamate receptor antagonist d,l-2-amino-5-phosphonopentanoic acid (AP5) (5.0 microg) into the CA1 hippocampal area blocked IA retention. In animals given three training trials, infusions of AP5 given prior to each of the three training trials severely impaired, but did not block retention. The results indicate that NMDA receptors in the hippocampus are involved in the formation, but not in expression, of aversive memory. In addition, rats given repeated training were able to show a mild improvement of performance across training trials, possibly through mechanisms that do not depend on NMDA receptor activation in the dorsal hippocampus.
Roesler
Rafael
R
Department of Pharmacology, Institute for Basic Health Sciences, Universidade Federal do Rio Grande do Sul (Campus Central/UFRGS), Rua Sarmento Leite, 500, 90046-900, Porto Alegre, RS, Brazil. rroesler@terra.com.br
Vianna
Mônica R M
MR
Schröder
Nadja
N
Ferreira
Maria Beatriz Cardoso
MB
Quevedo
João
J
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D006624:Hippocampus / Q000033:anatomy & histology / Q000378:metabolism; D007858:Learning / Q000502:physiology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D014633:Valine / Q000031:analogs & derivatives / Q000378:metabolism
D016194:Receptors, N-Methyl-D-Aspartate; C056639:2-amino-5-phosphopentanoic acid; D014633:Valine