title: Behavioral tagging of extinction learning.
abstract: Extinction of contextual fear in rats is enhanced by exposure to a novel environment at 1-2 h before or 1 h after extinction training. This effect is antagonized by administration of protein synthesis inhibitors anisomycin and rapamycin into the hippocampus, but not into the amygdala, immediately after either novelty or extinction training, as well as by the gene expression blocker 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole administered after novelty training, but not after extinction training. Thus, this effect can be attributed to a mechanism similar to synaptic tagging, through which long-term potentiation can be enhanced by other long-term potentiations or by exposure to a novel environment in a protein synthesis-dependent fashion. Extinction learning produces a tag at the appropriate synapses, whereas novelty learning causes the synthesis of plasticity-related proteins that are captured by the tag, strengthening the synapses that generated this tag.
authors.affiliation: National institute of Translational Neuroscience, National Research Council of Brazil, and Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul, 90610-000 Porto Alegre, RS, Brazil. jociane_carvalho@hotmail.com
authors.forename: Jociane
authors.initials: J
authors.lastname: de Carvalho Myskiw
authors.forename: Fernando
authors.initials: F
authors.lastname: Benetti
authors.forename: Iván
authors.initials: I
authors.lastname: Izquierdo
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000841:Anisomycin / Q000008:administration & dosage; D004004:Dichlororibofuranosylbenzimidazole / Q000494:pharmacology; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology*; D005239:Fear / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008297:Male; D011500:Protein Synthesis Inhibitors / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D020123:Sirolimus / Q000008:administration & dosage; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D011500:Protein Synthesis Inhibitors; D004004:Dichlororibofuranosylbenzimidazole; D000841:Anisomycin; D020123:Sirolimus