Self-organised reactivation maintains and reinforces memories despite synaptic turnover

Fauth, Michael J.; van Rossum, Mark C.W.

Abstract

Long-term memories are believed to be stored in the synapses of cortical neuronal networks. However, recent experiments report continuous creation and removal of cortical synapses, which raises the question how memories can survive on such a variable substrate. Here, we study the formation and retention of associative memory in a computational model based on Hebbian cell assemblies in the presence of both synaptic and structural plasticity. During rest periods, such as may occur during sleep, the assemblies reactivate spontaneously, reinforcing memories against ongoing synapse removal and replacement. Brief daily reactivations during rest-periods suffice to not only maintain the assemblies, but even strengthen them, and improve pattern completion, consistent with offline memory gains observed experimentally. While the connectivity inside memory representations is strengthened during rest phases, connections in the rest of the network decay and vanish thus reconciling apparently conflicting hypotheses of the influence of sleep on cortical connectivity.

Citation

Fauth, M. J., & van Rossum, M. C. (2019). Self-organised reactivation maintains and reinforces memories despite synaptic turnover. eLife, 2019(8), Article e43717. https://doi.org/10.7554/eLife.43717

• Journal Article Type: Article
• Acceptance Date: May 1, 2019
• Online Publication Date: May 10, 2019
• Publication Date: May 10, 2019
• Deposit Date: May 9, 2019
• Publicly Available Date: May 9, 2019
• Journal: eLife
• Electronic ISSN: 2050-084X
• Publisher: eLife Sciences Publications
• Peer Reviewed: Peer Reviewed
• Volume: 2019
• Issue: 8
• Article Number: e43717
• DOI: https://doi.org/10.7554/eLife.43717
• Keywords: General Biochemistry, Genetics and Molecular Biology; General Immunology and Microbiology; General Neuroscience; General Medicine
• Public URL: https://nottingham-repository.worktribe.com/output/2033494
• Publisher URL: https://elifesciences.org/articles/43717
• Contract Date: May 9, 2019