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Lee H, Keene PA, Sweigart SC, Hutchinson JB, Kuhl BA. Adding Meaning to Memories: How Parietal Cortex Combines Semantic Content with Episodic Experience. J Neurosci 2023; 43:6525-6537. [PMID: 37596054 PMCID: PMC10513070 DOI: 10.1523/jneurosci.1919-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 07/20/2023] [Accepted: 07/24/2023] [Indexed: 08/20/2023] Open
Abstract
Neuroimaging studies of human memory have consistently found that univariate responses in parietal cortex track episodic experience with stimuli (whether stimuli are 'old' or 'new'). More recently, pattern-based fMRI studies have shown that parietal cortex also carries information about the semantic content of remembered experiences. However, it is not well understood how memory-based and content-based signals are integrated within parietal cortex. Here, in humans (males and females), we used voxel-wise encoding models and a recognition memory task to predict the fMRI activity patterns evoked by complex natural scene images based on (1) the episodic history and (2) the semantic content of each image. Models were generated and compared across distinct subregions of parietal cortex and for occipitotemporal cortex. We show that parietal and occipitotemporal regions each encode memory and content information, but they differ in how they combine this information. Among parietal subregions, angular gyrus was characterized by robust and overlapping effects of memory and content. Moreover, subject-specific semantic tuning functions revealed that successful recognition shifted the amplitude of tuning functions in angular gyrus but did not change the selectivity of tuning. In other words, effects of memory and content were additive in angular gyrus. This pattern of data contrasted with occipitotemporal cortex where memory and content effects were interactive: memory effects were preferentially expressed by voxels tuned to the content of a remembered image. Collectively, these findings provide unique insight into how parietal cortex combines information about episodic memory and semantic content.SIGNIFICANCE STATEMENT Neuroimaging studies of human memory have identified multiple brain regions that not only carry information about "whether" a visual stimulus is successfully recognized but also "what" the content of that stimulus includes. However, a fundamental and open question concerns how the brain integrates these two types of information (memory and content). Here, using a powerful combination of fMRI analysis methods, we show that parietal cortex, particularly the angular gyrus, robustly combines memory- and content-related information, but these two forms of information are represented via additive, independent signals. In contrast, memory effects in high-level visual cortex critically depend on (and interact with) content representations. Together, these findings reveal multiple and distinct ways in which the brain combines memory- and content-related information.
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Affiliation(s)
- Hongmi Lee
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218
| | - Paul A Keene
- Department of Psychology, University of Oregon, Eugene, OR 97403
| | - Sarah C Sweigart
- Department of Psychology, University of California-Davis, Davis, California 95616
| | | | - Brice A Kuhl
- Department of Psychology, University of Oregon, Eugene, OR 97403
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403
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2
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Schultz H, Yoo J, Meshi D, Heekeren HR. Category-specific memory encoding in the medial temporal lobe and beyond: the role of reward. Learn Mem 2022; 29:379-389. [PMID: 36180131 PMCID: PMC9536755 DOI: 10.1101/lm.053558.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 07/28/2022] [Indexed: 12/15/2022]
Abstract
The medial temporal lobe (MTL), including the hippocampus (HC), perirhinal cortex (PRC), and parahippocampal cortex (PHC), is central to memory formation. Reward enhances memory through interplay between the HC and substantia nigra/ventral tegmental area (SNVTA). While the SNVTA also innervates the MTL cortex and amygdala (AMY), their role in reward-enhanced memory is unclear. Prior research suggests category specificity in the MTL cortex, with the PRC and PHC processing object and scene memory, respectively. It is unknown, however, whether reward modulates category-specific memory processes. Furthermore, no study has demonstrated clear category specificity in the MTL for encoding processes contributing to subsequent recognition memory. To address these questions, we had 39 healthy volunteers (27 for all memory-based analyses) undergo functional magnetic resonance imaging while performing an incidental encoding task pairing objects or scenes with high or low reward, followed by a next-day recognition test. Behaviorally, high reward preferably enhanced object memory. Neural activity in the PRC and PHC reflected successful encoding of objects and scenes, respectively. Importantly, AMY encoding effects were selective for high-reward objects, with a similar pattern in the PRC. The SNVTA and HC showed no clear evidence of successful encoding. This behavioral and neural asymmetry may be conveyed through an anterior-temporal memory system, including the AMY and PRC, potentially in interplay with the ventromedial prefrontal cortex.
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Affiliation(s)
- Heidrun Schultz
- Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany
- Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, 14195 Berlin, Germany
- Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
| | - Jungsun Yoo
- Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany
- Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, 14195 Berlin, Germany
- Department of Cognitive Sciences, University of California at Irvine, Irvine, California 92697, USA
| | - Dar Meshi
- Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany
- Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, 14195 Berlin, Germany
- Department of Advertising and Public Relations, Michigan State University, East Lansing, Michigan 48824, USA
| | - Hauke R Heekeren
- Department of Education and Psychology, Freie Universität Berlin, 14195 Berlin, Germany
- Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, 14195 Berlin, Germany
- Executive University Board, Universität Hamburg, 20148 Hamburg, Germany
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3
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Schultz H, Sommer T, Peters J. Category-sensitive incidental reinstatement in medial temporal lobe subregions during word recognition. Learn Mem 2022; 29:126-135. [PMID: 35428729 PMCID: PMC9053111 DOI: 10.1101/lm.053553.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 03/29/2022] [Indexed: 11/25/2022]
Abstract
During associative retrieval, the brain reinstates neural representations that were present during encoding. The human medial temporal lobe (MTL), with its subregions hippocampus (HC), perirhinal cortex (PRC), and parahippocampal cortex (PHC), plays a central role in neural reinstatement. Previous studies have given compelling evidence for reinstatement in the MTL during explicitly instructed associative retrieval. High-confident recognition may be similarly accompanied by recollection of associated information from the encoding context. It is unclear, however, whether high-confident recognition memory elicits reinstatement in the MTL even in the absence of an explicit instruction to retrieve associated information. Here, we addressed this open question using high-resolution fMRI. Twenty-eight male and female human volunteers engaged in a recognition memory task for words that they had previously encoded together with faces and scenes. Using complementary univariate and multivariate approaches, we show that MTL subregions including the PRC, PHC, and HC differentially reinstate category-sensitive representations during high-confident word recognition, even though no explicit instruction to retrieve the associated category was given. This constitutes novel evidence that high-confident recognition memory is accompanied by incidental reinstatement of associated category information in MTL subregions, and supports a functional model of the MTL that emphasizes content-sensitive representations during both encoding and retrieval.
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Affiliation(s)
- Heidrun Schultz
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany
| | - Tobias Sommer
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Jan Peters
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Department of Psychology, Biological Psychology, University of Cologne, 50969 Cologne, Germany
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4
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Vo VA, Sutterer DW, Foster JJ, Sprague TC, Awh E, Serences JT. Shared Representational Formats for Information Maintained in Working Memory and Information Retrieved from Long-Term Memory. Cereb Cortex 2021; 32:1077-1092. [PMID: 34428283 DOI: 10.1093/cercor/bhab267] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/08/2021] [Accepted: 07/13/2021] [Indexed: 11/13/2022] Open
Abstract
Current theories propose that the short-term retention of information in working memory (WM) and the recall of information from long-term memory (LTM) are supported by overlapping neural mechanisms in occipital and parietal cortex. However, the extent of the shared representations between WM and LTM is unclear. We designed a spatial memory task that allowed us to directly compare the representations of remembered spatial information in WM and LTM with carefully matched behavioral response precision between tasks. Using multivariate pattern analyses on functional magnetic resonance imaging data, we show that visual memories were represented in a sensory-like code in both memory tasks across retinotopic regions in occipital and parietal cortex. Regions in lateral parietal cortex also encoded remembered locations in both tasks, but in a format that differed from sensory-evoked activity. These results suggest a striking correspondence in the format of representations maintained in WM and retrieved from LTM across occipital and parietal cortex. On the other hand, we also show that activity patterns in nearly all parietal regions, but not occipital regions, contained information that could discriminate between WM and LTM trials. Our data provide new evidence for theories of memory systems and the representation of mnemonic content.
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Affiliation(s)
- Vy A Vo
- Brain-Inspired Computing, Emerging Technologies Research, Intel Labs, Hillsboro, OR 97124, USA.,Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA.,Department of Psychology, University of California San Diego, La Jolla, CA 92093, USA
| | - David W Sutterer
- Department of Psychological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Joshua J Foster
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA.,Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Thomas C Sprague
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106, USA
| | - Edward Awh
- Department of Psychology, The University of Chicago, Chicago, IL 60637, USA.,Institute for Mind and Biology, The University of Chicago, Chicago, IL 60637, USA
| | - John T Serences
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA.,Department of Psychology, University of California San Diego, La Jolla, CA 92093, USA.,Kavli Foundation for the Brain and Mind, University of California San Diego, La Jolla, CA 92093, USA
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5
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Neural correlates of the production effect: An fMRI study. Brain Cogn 2021; 152:105757. [PMID: 34130081 DOI: 10.1016/j.bandc.2021.105757] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/16/2021] [Accepted: 05/18/2021] [Indexed: 11/20/2022]
Abstract
Recognition memory is improved for items produced at study (e.g., by reading them aloud) relative to a non-produced control condition (e.g., silent reading). This production effect is typically attributed to the extra elements in the production task (e.g., motor activation, auditory perception) enhancing item distinctiveness. To evaluate this claim, the present study examined the neural mechanisms underlying the production effect. Prior to a recognition memory test, different words within a study list were read either aloud, silently, or while saying "check" (as a sensorimotor control condition). Production improved recognition, and aloud words yielded higher rates of both recollection and familiarity judgments than either silent or control words. During encoding, fMRI revealed stronger activation in regions associated with motor, somatosensory, and auditory processing for aloud items than for either silent or control items. These activations were predictive of recollective success for aloud items at test. Together, our findings are compatible with a distinctiveness-based account of the production effect, while also pointing to the possible role of other processing differences during the aloud trials as compared to silent and control.
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6
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Steel A, Billings MM, Silson EH, Robertson CE. A network linking scene perception and spatial memory systems in posterior cerebral cortex. Nat Commun 2021; 12:2632. [PMID: 33976141 PMCID: PMC8113503 DOI: 10.1038/s41467-021-22848-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 04/05/2021] [Indexed: 02/03/2023] Open
Abstract
The neural systems supporting scene-perception and spatial-memory systems of the human brain are well-described. But how do these neural systems interact? Here, using fine-grained individual-subject fMRI, we report three cortical areas of the human brain, each lying immediately anterior to a region of the scene perception network in posterior cerebral cortex, that selectively activate when recalling familiar real-world locations. Despite their close proximity to the scene-perception areas, network analyses show that these regions constitute a distinct functional network that interfaces with spatial memory systems during naturalistic scene understanding. These "place-memory areas" offer a new framework for understanding how the brain implements memory-guided visual behaviors, including navigation.
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Affiliation(s)
- Adam Steel
- grid.254880.30000 0001 2179 2404Department of Psychology and Brain Sciences, Dartmouth College, Hanover, NH USA
| | - Madeleine M. Billings
- grid.254880.30000 0001 2179 2404Department of Psychology and Brain Sciences, Dartmouth College, Hanover, NH USA
| | - Edward H. Silson
- grid.4305.20000 0004 1936 7988Psychology, School of Philosophy, Psychology, and Language Sciences, University of Edinburgh, Edinburgh, EH8 9JZ UK
| | - Caroline E. Robertson
- grid.254880.30000 0001 2179 2404Department of Psychology and Brain Sciences, Dartmouth College, Hanover, NH USA
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7
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Yoo J, Min S, Lee SK, Han S. Neural correlates of episodic memory modulated by temporally delayed rewards. PLoS One 2021; 16:e0249290. [PMID: 33826665 PMCID: PMC8026031 DOI: 10.1371/journal.pone.0249290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 03/16/2021] [Indexed: 11/18/2022] Open
Abstract
When a stimulus is associated with an external reward, its chance of being consolidated into long-term memory is boosted via dopaminergic facilitation of long-term potentiation in the hippocampus. Given that higher temporal distance (TD) has been found to discount the subjective value of a reward, we hypothesized that memory performance associated with a more immediate reward will result in better memory performance. We tested this hypothesis by measuring both behavioral memory performance and brain activation using functional magnetic resonance imaging (fMRI) during memory encoding and retrieval tasks. Contrary to our hypothesis, both behavioral and fMRI results suggest that the TD of rewards might enhance the chance of the associated stimulus being remembered. The fMRI data demonstrate that the lateral prefrontal cortex, which shows encoding-related activation proportional to the TD, is reactivated when searching for regions that show activation proportional to the TD during retrieval. This is not surprising given that this region is not only activated to discriminate between future vs. immediate rewards, it is also a part of the retrieval-success network. These results provide support for the conclusion that the encoding-retrieval overlap provoked as the rewards are more delayed may lead to better memory performance of the items associated with the rewards.
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Affiliation(s)
- Jungsun Yoo
- Department of Psychology, Yonsei University, Seoul, Republic of Korea
| | - Seokyoung Min
- Department of Psychology, Yonsei University, Seoul, Republic of Korea
| | - Seung-Koo Lee
- Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea
- Integrated Neurocognitive Functional Imaging Center, Yonsei University, Seoul, Republic of Korea
| | - Sanghoon Han
- Department of Psychology, Yonsei University, Seoul, Republic of Korea
- * E-mail:
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8
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Bainbridge WA, Pounder Z, Eardley AF, Baker CI. Quantifying aphantasia through drawing: Those without visual imagery show deficits in object but not spatial memory. Cortex 2021; 135:159-172. [PMID: 33383478 PMCID: PMC7856239 DOI: 10.1016/j.cortex.2020.11.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/31/2020] [Accepted: 11/10/2020] [Indexed: 01/19/2023]
Abstract
Congenital aphantasia is a recently characterized variation of experience defined by the inability to form voluntary visual imagery, in individuals who are otherwise high performing. Because of this specific deficit to visual imagery, individuals with aphantasia serve as an ideal group for probing the nature of representations in visual memory, particularly the interplay of object, spatial, and symbolic information. Here, we conducted a large-scale online study of aphantasia and revealed a dissociation in object and spatial content in their memory representations. Sixty-one individuals with aphantasia and matched controls with typical imagery studied real-world scene images, and were asked to draw them from memory, and then later copy them during a matched perceptual condition. Drawings were objectively quantified by 2,795 online scorers for object and spatial details. Aphantasic participants recalled significantly fewer objects than controls, with less color in their drawings, and an increased reliance on verbal scaffolding. However, aphantasic participants showed high spatial accuracy equivalent to controls, and made significantly fewer memory errors. These differences between groups only manifested during recall, with no differences between groups during the matched perceptual condition. This object-specific memory impairment in individuals with aphantasia provides evidence for separate systems in memory that support object versus spatial information. The study also provides an important experimental validation for the existence of aphantasia as a variation in human imagery experience.
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Affiliation(s)
- Wilma A Bainbridge
- Department of Psychology, University of Chicago, Chicago, IL, USA; Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD, USA.
| | - Zoë Pounder
- Department of Psychology, University of Westminster, London, UK.
| | - Alison F Eardley
- Department of Psychology, University of Westminster, London, UK.
| | - Chris I Baker
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD, USA.
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9
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Bainbridge WA, Hall EH, Baker CI. Distinct Representational Structure and Localization for Visual Encoding and Recall during Visual Imagery. Cereb Cortex 2020; 31:1898-1913. [PMID: 33285563 DOI: 10.1093/cercor/bhaa329] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/12/2020] [Accepted: 10/12/2020] [Indexed: 01/03/2023] Open
Abstract
During memory recall and visual imagery, reinstatement is thought to occur as an echoing of the neural patterns during encoding. However, the precise information in these recall traces is relatively unknown, with previous work primarily investigating either broad distinctions or specific images, rarely bridging these levels of information. Using ultra-high-field (7T) functional magnetic resonance imaging with an item-based visual recall task, we conducted an in-depth comparison of encoding and recall along a spectrum of granularity, from coarse (scenes, objects) to mid (e.g., natural, manmade scenes) to fine (e.g., living room, cupcake) levels. In the scanner, participants viewed a trial-unique item, and after a distractor task, visually imagined the initial item. During encoding, we observed decodable information at all levels of granularity in category-selective visual cortex. In contrast, information during recall was primarily at the coarse level with fine-level information in some areas; there was no evidence of mid-level information. A closer look revealed segregation between voxels showing the strongest effects during encoding and those during recall, and peaks of encoding-recall similarity extended anterior to category-selective cortex. Collectively, these results suggest visual recall is not merely a reactivation of encoding patterns, displaying a different representational structure and localization from encoding, despite some overlap.
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Affiliation(s)
- Wilma A Bainbridge
- Department of Psychology, University of Chicago, Chicago, IL 60637, USA.,Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD 20814, USA
| | - Elizabeth H Hall
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD 20814, USA.,Department of Psychology, University of California Davis, Davis, CA 95616, USA.,Center for Mind and Brain, University of California Davis, Davis, CA 95618, USA
| | - Chris I Baker
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD 20814, USA
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10
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Cong S, Yao X, Huang Z, Risacher SL, Nho K, Saykin AJ, Shen L. Volumetric GWAS of medial temporal lobe structures identifies an ERC1 locus using ADNI high-resolution T2-weighted MRI data. Neurobiol Aging 2020; 95:81-93. [PMID: 32768867 PMCID: PMC7609616 DOI: 10.1016/j.neurobiolaging.2020.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/09/2020] [Accepted: 07/04/2020] [Indexed: 12/18/2022]
Abstract
Medial temporal lobe (MTL) consists of hippocampal subfields and neighboring cortices. These heterogeneous structures are differentially involved in memory, cognitive and emotional functions, and present nonuniformly distributed atrophy contributing to cognitive disorders. This study aims to examine how genetics influences Alzheimer's disease (AD) pathogenesis via MTL substructures by analyzing high-resolution magnetic resonance imaging (MRI) data. We performed genome-wide association study to examine the associations between 565,373 single nucleotide polymorphisms (SNPs) and 14 MTL substructure volumes. A novel association with right Brodmann area 36 volume was discovered in an ERC1 SNP (i.e., rs2968869). Further analyses on larger samples found rs2968869 to be associated with gray matter density and glucose metabolism measures in the right hippocampus, and disease status. Tissue-specific transcriptomic analysis identified the minor allele of rs2968869 (rs2968869-C) to be associated with reduced ERC1 expression in the hippocampus. All the findings indicated a protective role of rs2968869-C in AD. We demonstrated the power of high-resolution MRI and the promise of fine-grained MTL substructures for revealing the genetic basis of AD biomarkers.
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Affiliation(s)
- Shan Cong
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Xiaohui Yao
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Zhi Huang
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Shannon L Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kwangsik Nho
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Li Shen
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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11
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Goode TD, Tanaka KZ, Sahay A, McHugh TJ. An Integrated Index: Engrams, Place Cells, and Hippocampal Memory. Neuron 2020; 107:805-820. [PMID: 32763146 PMCID: PMC7486247 DOI: 10.1016/j.neuron.2020.07.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/17/2020] [Accepted: 07/13/2020] [Indexed: 01/10/2023]
Abstract
The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral studies, we propose that hippocampal engrams function as indices to mediate memory recall. We broaden this idea to discuss potential relationships between engrams and hippocampal place cells, as well as the molecular, cellular, physiological, and circuit determinants of engrams that permit flexible routing of information to intra- and extrahippocampal circuits for reinstatement, a feature critical to memory indexing. Incorporating indexing into frameworks of memory function opens new avenues of study and even therapies for hippocampal dysfunction.
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Affiliation(s)
- Travis D Goode
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Kazumasa Z Tanaka
- Memory Research Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Kunigami-gun, Okinawa, Japan
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wakoshi, Saitama, Japan.
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12
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Xie W, Park HB, Zaghloul KA, Zhang W. Correlated Individual Differences in the Estimated Precision of Working Memory and Long-Term Memory: Commentary on the Study by Biderman, Luria, Teodorescu, Hajaj, and Goshen-Gottstein (2019). Psychol Sci 2020; 31:345-348. [PMID: 32049590 DOI: 10.1177/0956797620903718] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Weizhen Xie
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Hyung-Bum Park
- Department of Psychology, University of California, Riverside
| | - Kareem A Zaghloul
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Weiwei Zhang
- Department of Psychology, University of California, Riverside
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