title: Off-line Arc transcription in active ensembles during fear memory retrieval.
abstract: Neural activity and de novo protein synthesis during a rest period following memory retrieval in the amygdala is necessary for stabilization of reactivated fear memory. Arc/Arg3.1 (Arc) expression is regulated by neural activity and is a critical protein for memory reconsolidation. However, it remains unclear whether memory retrieval alters Arc transcription during subsequent rest. In this study, the populations of mouse lateral amygdala neurons that transcribe Arc during memory retrieval and at rest were detected using Arc cellular compartment analysis of temporal activity by fluorescence in situ hybridization (Arc catFISH). Results demonstrated that memory retrieval alters the composition of neuronal populations, which activate Arc transcription during subsequent rest. Approximately 50% of neurons that transcribe Arc at subsequent rest, transcribed Arc during memory retrieval, whereas only approximately 10% of neurons that transcribed Arc during a rest period prior to memory retrieval transcribe Arc during memory retrieval. In contrast, re-exposure to the chamber induced less preferential Arc transcription in latent inhibited mice that received shocks but recalled less conditioned fear. Taken together, these findings indicate that neuronal subpopulations activated during fear memory retrieval preferentially transcribe Arc during subsequent rest in the lateral amygdala. This preferential Arc transcription may contribute to memory reconsolidation.
authors.affiliation: Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: Koichi
authors.initials: K
authors.lastname: Hashikawa
authors.forename: Norio
authors.initials: N
authors.lastname: Matsuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nomura
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D000818:Animals; D003214:Conditioning, Classical; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D005239:Fear; D005786:Gene Expression Regulation; D008297:Male; D008568:Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000145:classification / Q000378:metabolism / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein