Acquiring new memories in neocortex of hippocampal-lesioned mice

• Published in: Nature communications Vol. 13; no. 1; p. 1601
• Main Authors: Luo, Wenhan, Yun, Di, Hu, Yi, Tian, Miaomiao, Yang, Jiajun, Xu, Yifan, Tang, Yong, Zhan, Yang, Xie, Hong, Guan, Ji-Song
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24-03-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 631/378/1595/1554; 631/378/1595/2618; 631/378/3920; 64/60; 9/10; 9/30; Alzheimer's disease; Animal memory; Animals; c-Fos protein; Cerebral cortex; Cognitive ability; Cortex (entorhinal); Cortex (somatosensory); Entorhinal Cortex - physiology; Food; Gene expression; Hippocampus; Hippocampus - physiology; Humanities and Social Sciences; Learning; Man-machine interfaces; Memory; Memory - physiology; Mental Recall - physiology; Mice; multidisciplinary; Neocortex; Neocortex - physiology; Neurons; Recall; Regions; Science; Science (multidisciplinary); Sensory neurons
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-29208-5

The hippocampus interacts with the neocortical network for memory retrieval and consolidation. Here, we found the lateral entorhinal cortex (LEC) modulates learning-induced cortical long-range gamma synchrony (20–40 Hz) in a hippocampal-dependent manner. The long-range gamma synchrony, which was coupled to the theta (7–10 Hz) rhythm and enhanced upon learning and recall, was mediated by inter-cortical projections from layer 5 neurons of the LEC to layer 2 neurons of the sensory and association cortices. Artificially induced cortical gamma synchrony across cortical areas improved memory encoding in hippocampal lesioned mice for originally hippocampal-dependent tasks. Mechanistically, we found that activities of cortical c-Fos labeled neurons, which showed egocentric map properties, were modulated by LEC-mediated gamma synchrony during memory recall, implicating a role of cortical synchrony to generate an integrative memory representation from disperse features. Our findings reveal the hippocampal mediated organization of cortical memories and suggest brain-machine interface approaches to improve cognitive function.
Hippocampal lesioned mice form new memories. Here, the authors show the lateral entorhinal cortex modulates learning-induced cortical long-range gamma synchrony in a hippocampal-dependent manner and artificially induced cortical gamma synchrony across cortical areas improved memory encoding in hippocampal lesioned mice.