Dynamic Theta Networks in the Human Medial Temporal Lobe Support Episodic Memory.
Publication/Presentation Date
4-1-2019
Abstract
The medial temporal lobe (MTL) is a locus of episodic memory in the human brain. It is comprised of cytologically distinct subregions that, in concert, give rise to successful encoding and retrieval of context-dependent memories. However, the functional connections between these subregions are poorly understood. To determine functional connectivity among MTL subregions, we had 131 subjects fitted with indwelling electrodes perform a verbal memory task and asked how encoding or retrieval correlated with inter-regional synchronization. Using phase-based measures of connectivity, we found that synchronous theta (4-8 Hz) activity underlies successful episodic memory. During encoding, we observed a dynamic pattern of connections converging on the left entorhinal cortex, beginning with the perirhinal cortex and shifting through hippocampal subfields. Retrieval-associated networks demonstrated enhanced involvement of the subiculum and CA1, reflecting a substantial reorganization of the encoding network. We posit that coherent theta activity within the MTL marks periods of successful memory, but distinct patterns of connectivity dissociate key stages of memory processing.
Volume
29
Issue
7
First Page
1100
Last Page
1111
ISSN
1879-0445
Published In/Presented At
Solomon, E. A., Stein, J. M., Das, S., Gorniak, R., Sperling, M. R., Worrell, G., Inman, C. S., Tan, R. J., Jobst, B. C., Rizzuto, D. S., & Kahana, M. J. (2019). Dynamic Theta Networks in the Human Medial Temporal Lobe Support Episodic Memory. Current biology : CB, 29(7), 1100–1111.e4. https://doi.org/10.1016/j.cub.2019.02.020
Disciplines
Medicine and Health Sciences
PubMedID
30905609
Department(s)
Department of Medicine
Document Type
Article