The entorhinal-DG/CA3 pathway in the medial temporal lobe retains visual working memory of a simple surface feature
- National Institute of Neurological Disorders and Stroke, United States
- University of California, Riverside, United States
- University of California, Irvine, United States
- University of Nevada Reno, United States
- University of California Riverside, United States
Abstract
Classic models consider working memory (WM) and long-term memory as distinct mental faculties that are supported by different neural mechanisms. Yet, there are significant parallels in the computation that both types of memory require. For instance, the representation of precise item-specific memory requires the separation of overlapping neural representations of similar information. This computation has been referred to as pattern separation, which can be mediated by the entorhinal-DG/CA3 pathway of the medial temporal lobe (MTL) in service of long-term episodic memory. However, although recent evidence has suggested that the MTL is involved in WM, the extent to which the entorhinal-DG/CA3 pathway supports precise item-specific WM has remained elusive. Here, we combine an established orientation WM task with high-resolution fMRI to test the hypothesis that the entorhinal-DG/CA3 pathway retains visual WM of a simple surface feature. Participants were retrospectively cued to retain one of the two studied orientation gratings during a brief delay period and then tried to reproduce the cued orientation as precisely as possible. By modeling the delay-period activity to reconstruct the retained WM content, we found that the anterior-lateral entorhinal cortex (aLEC) and the hippocampal DG/CA3 subfield both contain item-specific WM information that is associated with subsequent recall fidelity. Together, these results highlight the contribution of MTL circuitry to item-specific WM representation.
Data availability
Non-identified data (e.g., MTL activities across ROIs and trial-by-trial behavior responses) and custom codes are available via the Open Science Framework repository (https://osf.io/zvdnr/).
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Author details
Funding
National Institute of Mental Health (R01MH117132)
- Weiwei Zhang
National Institute of Neurological Disorders and Stroke (ZIA-NS003144)
- Kareem A Zaghloul
National Institute of Neurological Disorders and Stroke (NCFA)
- Weizhen Xie
National Institute of Neurological Disorders and Stroke (K99NS126492)
- Weizhen Xie
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Participants provided written informed consent before the study, following the protocol approved by the Internal Review Broad of the University of California, Riverside.
Copyright
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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The entorhinal-DG/CA3 pathway in the medial temporal lobe retains visual working memory of a simple surface feature
eLife 12:e83365.
https://doi.org/10.7554/eLife.83365
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