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Miles JT, Mullins GL, Mizumori SJY. Flexible decision-making is related to strategy learning, vicarious trial and error, and medial prefrontal rhythms during spatial set-shifting. Learn Mem 2024; 31:a053911. [PMID: 39038921 PMCID: PMC11369635 DOI: 10.1101/lm.053911.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/14/2024] [Indexed: 07/24/2024]
Abstract
Flexible decision-making requires a balance between exploring features of an environment and exploiting prior knowledge. Behavioral flexibility is typically measured by how long it takes subjects to consistently make accurate choices after reward contingencies switch or task rules change. This measure, however, only allows for tracking flexibility across multiple trials, and does not assess the degree of flexibility. Plus, although increases in decision-making accuracy are strong indicators of learning, other decision-making behaviors have also been suggested as markers of flexibility, such as the on-the-fly decision reversals known as vicarious trial and error (VTE) or switches to a different, but incorrect, strategy. We sought to relate flexibility, learning, and neural activity by comparing choice history-derived evaluation of strategy use with changes in decision-making accuracy and VTE behavior while recording from the medial prefrontal cortex (mPFC) in rats. Using a set-shifting task that required rats to repeatedly switch between spatial decision-making strategies, we show that a previously developed strategy likelihood estimation procedure could identify putative learning points based on decision history. We confirm the efficacy of learning point estimation by showing increases in decision-making accuracy aligned to the learning point. Additionally, we show increases in the rate of VTE behavior surrounding identified learning points. By calculating changes in strategy likelihoods across trials, we tracked flexibility on a trial-by-trial basis and show that flexibility scores also increased around learning points. Further, we demonstrate that VTE behaviors could be separated into indecisive and deliberative subtypes depending on whether they occurred during periods of high or low flexibility and whether they led to correct or incorrect choice outcomes. Field potential recordings from the mPFC during decisions exhibited increased beta band activity on trials with VTE compared to non-VTE trials, as well as increased gamma during periods when learned strategies could be exploited compared to prelearning, exploratory periods. This study demonstrates that increased behavioral flexibility and VTE rates are often aligned to task learning. These relationships can break down, however, suggesting that VTE is not always an indicator of deliberative decision-making. Additionally, we further implicate the mPFC in decision-making and learning by showing increased beta-based activity on VTE trials and increased gamma after learning.
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Affiliation(s)
- Jesse T Miles
- Neuroscience Graduate Program, University of Washington, Seattle, Washington 98195, USA
- Psychology Department, University of Washington, Seattle, Washington 98195, USA
| | - Ginger L Mullins
- Psychology Department, University of Washington, Seattle, Washington 98195, USA
| | - Sheri J Y Mizumori
- Neuroscience Graduate Program, University of Washington, Seattle, Washington 98195, USA
- Psychology Department, University of Washington, Seattle, Washington 98195, USA
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2
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Wang Y, Wang X, Wang L, Zheng L, Meng S, Zhu N, An X, Wang L, Yang J, Zheng C, Ming D. Dynamic prediction of goal location by coordinated representation of prefrontal-hippocampal theta sequences. Curr Biol 2024; 34:1866-1879.e6. [PMID: 38608677 DOI: 10.1016/j.cub.2024.03.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/20/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024]
Abstract
Prefrontal (PFC) and hippocampal (HPC) sequences of neuronal firing modulated by theta rhythms could represent upcoming choices during spatial memory-guided decision-making. How the PFC-HPC network dynamically coordinates theta sequences to predict specific goal locations and how it is interrupted in memory impairments induced by amyloid beta (Aβ) remain unclear. Here, we detected theta sequences of firing activities of PFC neurons and HPC place cells during goal-directed spatial memory tasks. We found that PFC ensembles exhibited predictive representation of the specific goal location since the starting phase of memory retrieval, earlier than the hippocampus. High predictive accuracy of PFC theta sequences existed during successful memory retrieval and positively correlated with memory performance. Coordinated PFC-HPC sequences showed PFC-dominant prediction of goal locations during successful memory retrieval. Furthermore, we found that theta sequences of both regions still existed under Aβ accumulation, whereas their predictive representation of goal locations was weakened with disrupted spatial representation of HPC place cells and PFC neurons. These findings highlight the essential role of coordinated PFC-HPC sequences in successful memory retrieval of a precise goal location.
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Affiliation(s)
- Yimeng Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xueling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Ling Wang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Li Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Shuang Meng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Nan Zhu
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China
| | - Xingwei An
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China
| | - Lei Wang
- School of Statistics and Data Science, Nankai University, Tianjin 300071, China.
| | - Jiajia Yang
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Chenguang Zheng
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Medical College, Tianjin University, Tianjin 300072, China; Tianjin Key Laboratory of Brain Science and Neuroengineering, Tianjin 300072, China; Haihe Laboratory of Brain-Computer Interaction and Human-Machine Integration, Tianjin 300072, China.
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3
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Yadav N, Toader A, Rajasethupathy P. Beyond hippocampus: Thalamic and prefrontal contributions to an evolving memory. Neuron 2024; 112:1045-1059. [PMID: 38272026 DOI: 10.1016/j.neuron.2023.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/07/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024]
Abstract
The hippocampus has long been at the center of memory research, and rightfully so. However, with emerging technological capabilities, we can increasingly appreciate memory as a more dynamic and brain-wide process. In this perspective, our goal is to begin developing models to understand the gradual evolution, reorganization, and stabilization of memories across the brain after their initial formation in the hippocampus. By synthesizing studies across the rodent and human literature, we suggest that as memory representations initially form in hippocampus, parallel traces emerge in frontal cortex that cue memory recall, and as they mature, with sustained support initially from limbic then diencephalic then cortical circuits, they become progressively independent of hippocampus and dependent on a mature cortical representation. A key feature of this model is that, as time progresses, memory representations are passed on to distinct circuits with progressively longer time constants, providing the opportunity to filter, forget, update, or reorganize memories in the process of committing to long-term storage.
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Affiliation(s)
- Nakul Yadav
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA
| | - Andrew Toader
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA
| | - Priya Rajasethupathy
- Laboratory of Neural Dynamics & Cognition, The Rockefeller University, New York, NY, USA.
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Muysers H, Chen HL, Hahn J, Folschweiller S, Sigurdsson T, Sauer JF, Bartos M. A persistent prefrontal reference frame across time and task rules. Nat Commun 2024; 15:2115. [PMID: 38459033 PMCID: PMC10923947 DOI: 10.1038/s41467-024-46350-4] [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: 10/11/2023] [Accepted: 02/22/2024] [Indexed: 03/10/2024] Open
Abstract
Behavior can be remarkably consistent, even over extended time periods, yet whether this is reflected in stable or 'drifting' neuronal responses to task features remains controversial. Here, we find a persistently active ensemble of neurons in the medial prefrontal cortex (mPFC) of mice that reliably maintains trajectory-specific tuning over several weeks while performing an olfaction-guided spatial memory task. This task-specific reference frame is stabilized during learning, upon which repeatedly active neurons show little representational drift and maintain their trajectory-specific tuning across long pauses in task exposure and across repeated changes in cue-target location pairings. These data thus suggest a 'core ensemble' of prefrontal neurons forming a reference frame of task-relevant space for the performance of consistent behavior over extended periods of time.
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Affiliation(s)
- Hannah Muysers
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
| | - Hung-Ling Chen
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
| | - Johannes Hahn
- Institute of Neurophysiology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Shani Folschweiller
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
- Sleep-Wake-Epilepsy Center and Center for Experimental Neurology, Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Torfi Sigurdsson
- Institute of Neurophysiology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jonas-Frederic Sauer
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
| | - Marlene Bartos
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany.
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Zhu JY, Zhang ZH, Liu G, Wan H. Enhanced Hippocampus-Nidopallium Caudolaterale Interaction in Visual-Spatial Associative Learning of Pigeons. Animals (Basel) 2024; 14:456. [PMID: 38338099 PMCID: PMC10854635 DOI: 10.3390/ani14030456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/28/2023] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Learning the spatial location associated with visual cues in the environment is crucial for survival. This ability is supported by a distributed interactive network. However, it is not fully understood how the most important task-related brain areas in birds, the hippocampus (Hp) and the nidopallium caudolaterale (NCL), interact in visual-spatial associative learning. To investigate the mechanisms of such coordination, synchrony and causal analysis were applied to the local field potentials of the Hp and NCL of pigeons while performing a visual-spatial associative learning task. The results showed that, over the course of learning, theta-band (4-12 Hz) oscillations in the Hp and NCL became strongly synchronized before the pigeons entered the critical choice platform for turning, with the information flowing preferentially from the Hp to the NCL. The learning process was primarily associated with the increased Hp-NCL interaction of theta rhythm. Meanwhile, the enhanced theta-band Hp-NCL interaction predicted the correct choice, supporting the pigeons' use of visual cues to guide navigation. These findings provide insight into the dynamics of Hp-NCL interaction during visual-spatial associative learning, serving to reveal the mechanisms of Hp and NCL coordination during the encoding and retrieval of visual-spatial associative memory.
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Affiliation(s)
- Jun-Yao Zhu
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China; (J.-Y.Z.); (Z.-H.Z.)
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Zhi-Heng Zhang
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China; (J.-Y.Z.); (Z.-H.Z.)
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Gang Liu
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China; (J.-Y.Z.); (Z.-H.Z.)
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
- Shanghai Key Laboratory of Brain-Machine Intelligence for Information Behavior, Shanghai International Studies University, Shanghai 201613, China
| | - Hong Wan
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China; (J.-Y.Z.); (Z.-H.Z.)
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
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Jayachandran M, Viena TD, Garcia A, Veliz AV, Leyva S, Roldan V, Vertes RP, Allen TA. Nucleus reuniens transiently synchronizes memory networks at beta frequencies. Nat Commun 2023; 14:4326. [PMID: 37468487 PMCID: PMC10356781 DOI: 10.1038/s41467-023-40044-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 07/10/2023] [Indexed: 07/21/2023] Open
Abstract
Episodic memory-based decision-making requires top-down medial prefrontal cortex and hippocampal interactions. This integrated prefrontal-hippocampal memory state is thought to be organized by synchronized network oscillations and mediated by connectivity with the thalamic nucleus reuniens (RE). Whether and how the RE synchronizes prefrontal-hippocampal networks in memory, however, remains unknown. Here, we recorded local field potentials from the prefrontal-RE-hippocampal network while rats engaged in a nonspatial sequence memory task, thereby isolating memory-related activity from running-related oscillations. We found that synchronous prefrontal-hippocampal beta bursts (15-30 Hz) dominated during memory trials, whereas synchronous theta activity (6-12 Hz) dominated during non-memory-related running. Moreover, RE beta activity appeared first, followed by prefrontal and hippocampal synchronized beta, suggesting that prefrontal-hippocampal beta could be driven by the RE. To test whether the RE is capable of driving prefrontal-hippocampal beta synchrony, we used an optogenetic approach (retroAAV-ChR2). RE activation induced prefrontal-hippocampal beta coherence and reduced theta coherence, matching the observed memory-driven network state in the sequence task. These findings are the first to demonstrate that the RE contributes to memory by driving transient synchronized beta in the prefrontal-hippocampal system, thereby facilitating interactions that underlie memory-based decision-making.
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Affiliation(s)
- Maanasa Jayachandran
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Tatiana D Viena
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Andy Garcia
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Abdiel Vasallo Veliz
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Sofia Leyva
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Valentina Roldan
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA
| | - Robert P Vertes
- Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Timothy A Allen
- Cognitive Neuroscience Program, Department of Psychology, Florida International University, Miami, FL, 33199, USA.
- Department of Environmental & Occupational Health, Robert Stempel College of Public Health, Florida International University, Miami, FL, 33199, USA.
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7
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Zhu JY, Li MM, Zhang ZH, Liu G, Wan H. Performance Baseline of Phase Transfer Entropy Methods for Detecting Animal Brain Area Interactions. ENTROPY (BASEL, SWITZERLAND) 2023; 25:994. [PMID: 37509941 PMCID: PMC10378602 DOI: 10.3390/e25070994] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023]
Abstract
Objective: Phase transfer entropy (TEθ) methods perform well in animal sensory-spatial associative learning. However, their advantages and disadvantages remain unclear, constraining their usage. Method: This paper proposes the performance baseline of the TEθ methods. Specifically, four TEθ methods are applied to the simulated signals generated by a neural mass model and the actual neural data from ferrets with known interaction properties to investigate the accuracy, stability, and computational complexity of the TEθ methods in identifying the directional coupling. Then, the most suitable method is selected based on the performance baseline and used on the local field potential recorded from pigeons to detect the interaction between the hippocampus (Hp) and nidopallium caudolaterale (NCL) in visual-spatial associative learning. Results: (1) This paper obtains a performance baseline table that contains the most suitable method for different scenarios. (2) The TEθ method identifies an information flow preferentially from Hp to NCL of pigeons at the θ band (4-12 Hz) in visual-spatial associative learning. Significance: These outcomes provide a reference for the TEθ methods in detecting the interactions between brain areas.
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Affiliation(s)
- Jun-Yao Zhu
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Meng-Meng Li
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Zhi-Heng Zhang
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Gang Liu
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
| | - Hong Wan
- School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
- Henan Key Laboratory of Brain Science and Brain-Computer Interface Technology, Zhengzhou 450001, China
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Miles JT, Kidder KS, Mizumori SJY. Hippocampal beta rhythms as a bridge between sensory learning and memory-guided decision-making. Front Syst Neurosci 2023; 17:1187272. [PMID: 37215359 PMCID: PMC10196064 DOI: 10.3389/fnsys.2023.1187272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
A pillar of systems neuroscience has been the study of neural oscillations. Research into these oscillations spans brain areas, species, and disciplines, giving us common ground for discussing typically disparate fields of neuroscience. In this review, we aim to strengthen the dialog between sensory systems research and learning and memory systems research by examining a 15-40 Hz oscillation known as the beta rhythm. Starting with foundational observations based largely in olfactory systems neuroscience, we review evidence suggesting beta-based activity may extend across sensory systems generally, as well as into the hippocampus and areas well known for coordinating decisions and memory-guided behaviors. After evaluating this work, we propose a framework wherein the hippocampal beta oscillation and its diverse coupling with other brain areas can support both sensory learning and memory-guided decision-making. Using this framework, we also propose circuitries that may support these processes, and experiments to test our hypothesis.
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Affiliation(s)
- Jesse Thomas Miles
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Kevan Scott Kidder
- Department of Psychology, College of Arts and Sciences, University of Washington, Seattle, WA, United States
| | - Sheri J. Y. Mizumori
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
- Department of Psychology, College of Arts and Sciences, University of Washington, Seattle, WA, United States
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Das A, Menon V. Concurrent- and After-Effects of Medial Temporal Lobe Stimulation on Directed Information Flow to and from Prefrontal and Parietal Cortices during Memory Formation. J Neurosci 2023; 43:3159-3175. [PMID: 36963847 PMCID: PMC10146497 DOI: 10.1523/jneurosci.1728-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 03/06/2023] [Accepted: 03/13/2023] [Indexed: 03/26/2023] Open
Abstract
Electrical stimulation of the medial temporal lobe (MTL) has the potential to uncover causal circuit mechanisms underlying memory function. However, little is known about how MTL stimulation alters information flow with frontoparietal cortical regions implicated in episodic memory. We used intracranial EEG recordings from humans (14 participants, 10 females) to investigate how MTL stimulation alters directed information flow between MTL and PFC and between MTL and posterior parietal cortex (PPC). Participants performed a verbal episodic memory task during which they were presented with words and asked to recall them after a delay of ∼20 s; 50 Hz stimulation was applied to MTL electrodes on selected trials during memory encoding. Directed information flow was examined using phase transfer entropy. Behaviorally, we observed that MTL stimulation reduced memory recall. MTL stimulation decreased top-down PFC→MTL directed information flow during both memory encoding and subsequent memory recall, revealing aftereffects more than 20 s after end of stimulation. Stimulation suppressed top-down PFC→MTL influences to a greater extent than PPC→MTL. Finally, MTL→PFC information flow on stimulation trials was significantly lower for successful, compared with unsuccessful, memory recall; in contrast, MTL→ventral PPC information flow was higher for successful, compared with unsuccessful, memory recall. Together, these results demonstrate that the effects of MTL stimulation are behaviorally, regionally, and directionally specific, that MTL stimulation selectively impairs directional signaling with PFC, and that causal MTL-ventral PPC circuits support successful memory recall. Findings provide new insights into dynamic casual circuits underling episodic memory and their modulation by MTL stimulation.SIGNIFICANCE STATEMENT The medial temporal lobe (MTL) and its interactions with prefrontal and parietal cortices (PFC and PPC) play a critical role in human memory. Dysfunctional MTL-PFC and MTL-PPC circuits are prominent in psychiatric and neurologic disorders, including Alzheimer's disease and schizophrenia. Brain stimulation has emerged as a potential mechanism for enhancing memory and cognitive functions, but the underlying neurophysiological mechanisms and dynamic causal circuitry underlying bottom-up and top-down signaling involving the MTL are unknown. Here, we use intracranial EEG recordings to investigate the effects of MTL stimulation on causal signaling in key episodic memory circuits linking the MTL with PFC and PPC. Our findings have implications for translational applications aimed at realizing the promise of brain stimulation-based treatment of memory disorders.
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Affiliation(s)
- Anup Das
- Department of Psychiatry & Behavioral Sciences
| | - Vinod Menon
- Department of Psychiatry & Behavioral Sciences
- Department of Neurology & Neurological Sciences
- Stanford Neurosciences Institute, Stanford University School of Medicine, Stanford, California 94305
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