title: Overlapping memory trace indispensable for linking, but not recalling, individual memories.
abstract: Memories are not stored in isolation from other memories but are integrated into associative networks. However, the mechanisms underlying memory association remain elusive. Using two amygdala-dependent behavioral paradigms-conditioned taste aversion (CTA) and auditory-cued fear conditioning (AFC)-in mice, we found that presenting the conditioned stimulus used for the CTA task triggered the conditioned response of the AFC task after natural coreactivation of the memories. This was accompanied through an increase in the overlapping neuronal ensemble in the basolateral amygdala. Silencing of the overlapping ensemble suppressed CTA retrieval-induced freezing. However, retrieval of the original CTA or AFC memory was not affected. A small population of coshared neurons thus mediates the link between memories. They are not necessary for recalling individual memories.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yokose
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Okubo-Suzuki
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Nomoto
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ohkawa
authors.affiliation: Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Division of Animal Experimental Laboratory, Life Science Research Centre, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nishizono
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Division of Animal Experimental Laboratory, Life Science Research Centre, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Matsuo
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Tsujimura
authors.affiliation: Department of Neuroscience, Jikei University School of Medicine, Tokyo 105-8461, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Neuroscience, Jikei University School of Medicine, Tokyo 105-8461, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagase
authors.affiliation: Department of Neuroscience, Jikei University School of Medicine, Tokyo 105-8461, Japan.
authors.forename: Ayako M
authors.initials: AM
authors.lastname: Watabe
authors.affiliation: Department of Pathology, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Masakiyo
authors.initials: M
authors.lastname: Sasahara
authors.affiliation: Department of Neuroscience, Jikei University School of Medicine, Tokyo 105-8461, Japan.
authors.forename: Fusao
authors.initials: F
authors.lastname: Kato
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan. inokuchi@med.u-toyama.ac.jp.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Inokuchi
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D003463:Cues; D005239:Fear; D046352:Freezing Reaction, Cataleptic; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000502:physiology; D012439:Saccharin / Q000494:pharmacology
chemical_list: D012439:Saccharin