title: Retrieval-mediated learning involving episodes requires synaptic plasticity in the hippocampus.
abstract: A novel association can form between two memories even when the events to which they correspond are not physically present. For example, once an integrated memory has formed that binds the (when, where, and what) components of an event together, this memory can be triggered by one of its components, and updated with coincident information in the environment. The neural basis of this form of retrieval-mediated learning is unknown. Here, we show, for the first time, that NMDA receptors in the rat hippocampus are required for retrieval-mediated learning involving episodes, but not for the expression of such learning or for retrieval-mediated learning involving simple associations between the components of episodes. These findings provide a novel insight into learning processes that serve the desirable function of integrating stored information with new information, but whose operation might also provide a substrate for some of the cognitive symptoms of schizophrenia and Alzheimer's disease.
authors.affiliation: School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom.
authors.forename: Mihaela D
authors.initials: MD
authors.lastname: Iordanova
authors.forename: Mark
authors.initials: M
authors.lastname: Good
authors.forename: Robert C
authors.initials: RC
authors.lastname: Honey
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000161:Acoustic Stimulation; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D018691:Excitatory Amino Acid Antagonists; D058785:GABA-A Receptor Agonists; D016194:Receptors, N-Methyl-D-Aspartate; D009118:Muscimol; D015763:2-Amino-5-phosphonovalerate