Bo Lei, Bilin Kang, Yuejun Hao, Haoyu Yang, Zihan Zhong, Zihan Zhai, Yi Zhong
{"title":"Reconstructing a new hippocampal engram for systems reconsolidation and remote memory updating.","authors":"Bo Lei, Bilin Kang, Yuejun Hao, Haoyu Yang, Zihan Zhong, Zihan Zhai, Yi Zhong","doi":"10.1016/j.neuron.2024.11.010","DOIUrl":null,"url":null,"abstract":"<p><p>Recalling systems-consolidated neocortex-dependent remote memories re-engages the hippocampus in a process called systems reconsolidation. However, underlying mechanisms, particularly for the origin of the reinstated hippocampal memory engram, remain elusive. By developing a triple-event labeling tool and employing two-photon imaging, we trace hippocampal engram ensembles from memory acquisition to systems reconsolidation and find that remote recall recruits a new engram ensemble in the hippocampus for subsequent memory retrieval. Consistently, recruiting new engrams is supported by adult hippocampal neurogenesis-mediated silencing of original engrams. This new engram ensemble receives currently experienced contextual information, incorporates new information into the remote memory, and supports remote memory updating. Such a reconstructed hippocampal memory is then integrated with the valence of remote memory via medial prefrontal cortex projection-mediated activity coordination between the hippocampus and amygdala. Thus, the reconstruction of new memory engrams underlies systems reconsolidation, which explains how remote memories are updated with new information.</p>","PeriodicalId":19313,"journal":{"name":"Neuron","volume":" ","pages":""},"PeriodicalIF":14.7000,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Neuron","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.neuron.2024.11.010","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
Reconstructing a new hippocampal engram for systems reconsolidation and remote memory updating.
Recalling systems-consolidated neocortex-dependent remote memories re-engages the hippocampus in a process called systems reconsolidation. However, underlying mechanisms, particularly for the origin of the reinstated hippocampal memory engram, remain elusive. By developing a triple-event labeling tool and employing two-photon imaging, we trace hippocampal engram ensembles from memory acquisition to systems reconsolidation and find that remote recall recruits a new engram ensemble in the hippocampus for subsequent memory retrieval. Consistently, recruiting new engrams is supported by adult hippocampal neurogenesis-mediated silencing of original engrams. This new engram ensemble receives currently experienced contextual information, incorporates new information into the remote memory, and supports remote memory updating. Such a reconstructed hippocampal memory is then integrated with the valence of remote memory via medial prefrontal cortex projection-mediated activity coordination between the hippocampus and amygdala. Thus, the reconstruction of new memory engrams underlies systems reconsolidation, which explains how remote memories are updated with new information.
期刊介绍:
Established as a highly influential journal in neuroscience, Neuron is widely relied upon in the field. The editors adopt interdisciplinary strategies, integrating biophysical, cellular, developmental, and molecular approaches alongside a systems approach to sensory, motor, and higher-order cognitive functions. Serving as a premier intellectual forum, Neuron holds a prominent position in the entire neuroscience community.