Distinct frequencies balance segregation with interaction between different memory types within a prefrontal circuit

Bracco, M., Mutanen, T. P., Veniero, D., Thut, G. and Robertson, E. M. (2023) Distinct frequencies balance segregation with interaction between different memory types within a prefrontal circuit. Current Biology, 33(12), 2548-2556.e6. (doi: 10.1016/j.cub.2023.05.027) (PMID:37269827)

Abstract

Once formed, the fate of memory is uncertain. Subsequent offline interactions between even different memory types (actions versus words) modify retention.1,2,3,4,5,6 These interactions may occur due to different oscillations functionally linking together different memory types within a circuit.7,8,9,10,11,12,13 With memory processing driving the circuit, it may become less susceptible to external influences.14 We tested this prediction by perturbing the human brain with single pulses of transcranial magnetic stimulation (TMS) and simultaneously measuring the brain activity changes with electroencephalography (EEG15,16,17). Stimulation was applied over brain areas that contribute to memory processing (dorsolateral prefrontal cortex, DLPFC; primary motor cortex, M1) at baseline and offline, after memory formation, when memory interactions are known to occur.1,4,6,10,18 The EEG response decreased offline (compared with baseline) within the alpha/beta frequency bands when stimulation was applied to the DLPFC, but not to M1. This decrease exclusively followed memory tasks that interact, revealing that it was due specifically to the interaction, not task performance. It remained even when the order of the memory tasks was changed and so was present, regardless of how the memory interaction was produced. Finally, the decrease within alpha power (but not beta) was correlated with impairment in motor memory, whereas the decrease in beta power (but not alpha) was correlated with impairment in word-list memory. Thus, different memory types are linked to different frequency bands within a DLPFC circuit, and the power of these bands shapes the balance between interaction and segregation between these memories.

• Item Type: Articles
• Additional Information: The authors are grateful to the Air Force Office of Scientific Research (AFOSR, FA9550-16-1-0191; Virginia, USA; FA9550-21-1-7057; London, UK) for supporting this work, for additional fellowship support (Marie Skłodowska-Curie 897941 to M.B.; Academy of Finland 321631 to T.P.M.).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Robertson, Professor Edwin and Thut, Professor Gregor and Bracco, Dr Martina and Veniero, Dr Domenica and Mutanen, Mr Tuomas
• Authors: Bracco, M., Mutanen, T. P., Veniero, D., Thut, G., and Robertson, E. M.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Current Biology
• Publisher: Elsevier (Cell Press)
• ISSN: 0960-9822
• ISSN (Online): 1879-0445
• Published Online: 02 June 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Current Biology 33(12): 2548-2556.e6
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5281/zenodo.7891964