Oscillations support short latency co-firing of neurons during human episodic memory formation
- University of Birmingham, United Kingdom
- Queen Elizabeth Hospital Birmingham, United Kingdom
- University Hospital Erlangen, Germany
- University of Glasgow, United Kingdom
- Netherlands Institute for Neuroscience, Netherlands
Abstract
Theta and gamma oscillations in the medial temporal lobe are suggested to play a critical role for human memory formation via establishing synchrony in neural assemblies. Arguably, such synchrony facilitates efficient information transfer between neurons and enhances synaptic plasticity, both of which benefit episodic memory formation. However, to date little evidence exists from humans that would provide direct evidence for such a specific role of theta and gamma oscillations for episodic memory formation. Here we investigate how oscillations shape the temporal structure of neural firing during memory formation in the medial temporal lobe. We measured neural firing and local field potentials in human epilepsy patients via micro-wire electrode recordings to analyze whether brain oscillations are related to co-incidences of firing between neurons during successful and unsuccessful encoding of episodic memories. The results show that phase-coupling of neurons to faster theta and gamma oscillations correlates with co-firing at short latencies (~20-30 ms) and occurs during successful memory formation. Phase-coupling at slower oscillations in these same frequency bands, in contrast, correlates with longer co-firing latencies and occurs during memory failure. Thus, our findings suggest that neural oscillations play a role for the synchronization of neural firing in the medial temporal lobe during the encoding of episodic memories.
Data availability
All code used for data analysis and visualization of results is deposited here: https://osf.io/fngz8/
Article and author information
Author details
Bernhard P Staresina
Funding
European Research Council (647954)
- Simon Hanslmayr
Economic and Social Research Council (ES/R010072/1)
- Simon Hanslmayr
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Informed consent to participate in the experiments and consent to publish the results was obtained from the patients prior to data collection. Ethical approvals were given by National Research Ethics Service (NRES), Research Ethics Committee (Nr. 15/WM/0219), the ethical review board of the Friedrich-Alexander Universität Erlangen-Nürnberg (Nr. 124_12 B), and the Medical Ethical Review board of the Vrije Universiteit Medisch Centrum (Nr. NL55554.029.15), for Birmingham, Erlangen and Amsterdam respectively.
Copyright
© 2022, Roux et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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