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Rabiller G, Ip Z, Zarrabian S, Zhang H, Sato Y, Yazdan-Shahmorad A, Liu J. Type-2 Diabetes Alters Hippocampal Neural Oscillations and Disrupts Synchrony between the Hippocampus and Cortex. Aging Dis 2024; 15:2255-2270. [PMID: 38029397 PMCID: PMC11346393 DOI: 10.14336/ad.2023.1106] [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: 09/06/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) increases the risk of neurological diseases, yet how brain oscillations change as age and T2DM interact is not well characterized. To delineate the age and diabetic effect on neurophysiology, we recorded local field potentials with multichannel electrodes spanning the somatosensory cortex and hippocampus (HPC) under urethane anesthesia in diabetic and normoglycemic control mice, at 200 and 400 days of age. We analyzed the signal power of brain oscillations, brain state, sharp wave associate ripples (SPW-Rs), and functional connectivity between the cortex and HPC. We found that while both age and T2DM were correlated with a breakdown in long-range functional connectivity and reduced neurogenesis in the dentate gyrus and subventricular zone, T2DM further slowed brain oscillations and reduced theta-gamma coupling. Age and T2DM also prolonged the duration of SPW-Rs and increased gamma power during SPW-R phase. Our results have identified potential electrophysiological substrates of hippocampal changes associated with T2DM and age. The perturbed brain oscillation features and diminished neurogenesis may underlie T2DM-accelerated cognitive impairment.
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Affiliation(s)
- Gratianne Rabiller
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- San Francisco VA medical Center, San Francisco, CA, USA
| | - Zachary Ip
- Departments of Bioengineering, University of Washington, Seattle, WA, USA
| | - Shahram Zarrabian
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- San Francisco VA medical Center, San Francisco, CA, USA
| | - Hongxia Zhang
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- San Francisco VA medical Center, San Francisco, CA, USA
| | - Yoshimichi Sato
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- San Francisco VA medical Center, San Francisco, CA, USA
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Azadeh Yazdan-Shahmorad
- Departments of Bioengineering, University of Washington, Seattle, WA, USA
- Electrical and Computer Engineering, University of Washington, Seattle, WA, USA
| | - Jialing Liu
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA, USA
- San Francisco VA medical Center, San Francisco, CA, USA
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2
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Xiang LY, Chen XY, Lu LM, Kong MH, Ji Q, Xiong Y, Xie MM, Jian XL, Zhu ZR. Mechanisms of Neuronal Reactivation in Memory Consolidation: A Perspective from Pathological Conditions. Neuroscience 2024; 551:196-204. [PMID: 38810690 DOI: 10.1016/j.neuroscience.2024.05.030] [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: 01/29/2024] [Revised: 05/19/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024]
Abstract
Memory consolidation refers to a process by which labile newly formed memory traces are progressively strengthened into long term memories and become more resistant to interference. Recent work has revealed that spontaneous hippocampal activity during rest, commonly referred to as "offline" activity, plays a critical role in the process of memory consolidation. Hippocampal reactivation occurs during sharp-wave ripples (SWRs), which are events associated with highly synchronous neural firing in the hippocampus and modulation of neural activity in distributed brain regions. Memory consolidation occurs primarily through a coordinated communication between hippocampus and neocortex. Cortical slow oscillations drive the repeated reactivation of hippocampal memory representations together with SWRs and thalamo-cortical spindles, inducing long-lasting cellular and network modifications responsible for memory stabilization.In this review, we aim to comprehensively cover the field of "reactivation and memory consolidation" research by detailing the physiological mechanisms of neuronal reactivation and firing patterns during SWRs and providing a discussion of more recent key findings. Several mechanistic explanations of neuropsychiatric diseases propose that impaired neural replay may underlie some of the symptoms of the disorders. Abnormalities in neuronal reactivation are a common phenomenon and cause pathological impairment in several diseases, such as Alzheimer's disease (AD), epilepsy and schizophrenia. However, the specific pathological changes and mechanisms of reactivation in each disease are different. Recent work has also enlightened some of the underlying pathological mechanisms of neuronal reactivation in these diseases. In this review, we further describe how SWRs, ripples and slow oscillations are affected in Alzheimer's disease, epilepsy, and schizophrenia. We then compare the differences of neuronal reactivation and discuss how different reactivation abnormalities cause pathological changes in these diseases. Aberrant neural reactivation provides insights into disease pathogenesis and may even serve as biomarkers for early disease progression and treatment response.
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Affiliation(s)
- Lei-Ying Xiang
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Xiao-Yi Chen
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Li-Ming Lu
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Ming-Hui Kong
- School of Educational Sciences, Chongqing Normal University, Chongqing, PR China
| | - Qi Ji
- Department of Medical Psychology, Army Medical University, Chongqing, PR China
| | - Yu Xiong
- Department of Stomatology, Southwest Hospital, Chongqing, PR China
| | - Mei-Ming Xie
- Chinese People's Liberation Army Western Theater General Hospital, Chengdu, PR China
| | - Xin-Ling Jian
- No. 950 Hospital of the Chinese People's Liberation Army, Yecheng, PR China
| | - Zhi-Ru Zhu
- Department of Medical Psychology, Army Medical University, Chongqing, PR China.
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3
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Johnsen KA, Cruzado NA, Menard ZC, Willats AA, Charles AS, Markowitz JE, Rozell CJ. Bridging model and experiment in systems neuroscience with Cleo: the Closed-Loop, Electrophysiology, and Optophysiology simulation testbed. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.01.27.525963. [PMID: 39026717 PMCID: PMC11257437 DOI: 10.1101/2023.01.27.525963] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Systems neuroscience has experienced an explosion of new tools for reading and writing neural activity, enabling exciting new experiments such as all-optical or closed-loop control that effect powerful causal interventions. At the same time, improved computational models are capable of reproducing behavior and neural activity with increasing fidelity. Unfortunately, these advances have drastically increased the complexity of integrating different lines of research, resulting in the missed opportunities and untapped potential of suboptimal experiments. Experiment simulation can help bridge this gap, allowing model and experiment to better inform each other by providing a low-cost testbed for experiment design, model validation, and methods engineering. Specifically, this can be achieved by incorporating the simulation of the experimental interface into our models, but no existing tool integrates optogenetics, two-photon calcium imaging, electrode recording, and flexible closed-loop processing with neural population simulations. To address this need, we have developed Cleo: the Closed-Loop, Electrophysiology, and Optophysiology experiment simulation testbed. Cleo is a Python package enabling injection of recording and stimulation devices as well as closed-loop control with realistic latency into a Brian spiking neural network model. It is the only publicly available tool currently supporting two-photon and multi-opsin/wavelength optogenetics. To facilitate adoption and extension by the community, Cleo is open-source, modular, tested, and documented, and can export results to various data formats. Here we describe the design and features of Cleo, validate output of individual components and integrated experiments, and demonstrate its utility for advancing optogenetic techniques in prospective experiments using previously published systems neuroscience models.
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Affiliation(s)
- Kyle A. Johnsen
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | | | - Zachary C. Menard
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Adam A. Willats
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Adam S. Charles
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
| | - Jeffrey E. Markowitz
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
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Jauch J, Becker M, Tetzlaff C, Fauth MJ. Differences in the consolidation by spontaneous and evoked ripples in the presence of active dendrites. PLoS Comput Biol 2024; 20:e1012218. [PMID: 38917228 PMCID: PMC11230591 DOI: 10.1371/journal.pcbi.1012218] [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: 09/22/2023] [Revised: 07/08/2024] [Accepted: 05/31/2024] [Indexed: 06/27/2024] Open
Abstract
Ripples are a typical form of neural activity in hippocampal neural networks associated with the replay of episodic memories during sleep as well as sleep-related plasticity and memory consolidation. The emergence of ripples has been observed both dependent as well as independent of input from other brain areas and often coincides with dendritic spikes. Yet, it is unclear how input-evoked and spontaneous ripples as well as dendritic excitability affect plasticity and consolidation. Here, we use mathematical modeling to compare these cases. We find that consolidation as well as the emergence of spontaneous ripples depends on a reliable propagation of activity in feed-forward structures which constitute memory representations. This propagation is facilitated by excitable dendrites, which entail that a few strong synapses are sufficient to trigger neuronal firing. In this situation, stimulation-evoked ripples lead to the potentiation of weak synapses within the feed-forward structure and, thus, to a consolidation of a more general sequence memory. However, spontaneous ripples that occur without stimulation, only consolidate a sparse backbone of the existing strong feed-forward structure. Based on this, we test a recently hypothesized scenario in which the excitability of dendrites is transiently enhanced after learning, and show that such a transient increase can strengthen, restructure and consolidate even weak hippocampal memories, which would be forgotten otherwise. Hence, a transient increase in dendritic excitability would indeed provide a mechanism for stabilizing memories.
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Affiliation(s)
- Jannik Jauch
- Third Institute for Physics, Georg-August-University, Göttingen, Germany
| | - Moritz Becker
- Group of Computational Synaptic Physiology, Department for Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Christian Tetzlaff
- Group of Computational Synaptic Physiology, Department for Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Michael Jan Fauth
- Third Institute for Physics, Georg-August-University, Göttingen, Germany
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5
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Okada R, Ikegaya Y, Matsumoto N. Short-Term Preexposure to Novel Enriched Environment Augments Hippocampal Ripples in Urethane-Anesthetized Mice. Biol Pharm Bull 2024; 47:1021-1027. [PMID: 38797694 DOI: 10.1248/bpb.b24-00118] [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] [Indexed: 05/29/2024]
Abstract
Learning and memory are affected by novel enriched environment, a condition where animals play and interact with a variety of toys and conspecifics. Exposure of animals to the novel enriched environments improves memory by altering neural plasticity during natural sleep, a process called memory consolidation. The hippocampus, a pivotal brain region for learning and memory, generates high-frequency oscillations called ripples during sleep, which is required for memory consolidation. Naturally occurring sleep shares characteristics in common with general anesthesia in terms of extracellular oscillations, guaranteeing anesthetized animals suitable to examine neural activity in a sleep-like state. However, it is poorly understood whether the preexposure of animals to the novel enriched environment modulates neural activity in the hippocampus under subsequent anesthesia. To ask this question, we allowed mice to freely explore the novel enriched environment or their standard environment, anesthetized them, and recorded local field potentials in the hippocampal CA1 area. We then compared the characteristics of hippocampal ripples between the two groups and found that the amplitude of ripples and the number of successive ripples were larger in the novel enriched environment group than in the standard environment group, suggesting that the afferent synaptic input from the CA3 area to the CA1 area was higher when the animals underwent the novel enriched environment. These results underscore the importance of prior experience that surpasses subsequent physical states from the neurophysiological point of view.
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Affiliation(s)
- Rio Okada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
- Institute for AI and Beyond, The University of Tokyo
- Center for Information and Neural Networks, National Institute of Information and Communications Technology
| | - Nobuyoshi Matsumoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
- Institute for AI and Beyond, The University of Tokyo
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6
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Shin Y, Hwang S, Lee SB, Son H, Chu K, Jung KY, Lee SK, Park KI, Kim YG. Using spectral and temporal filters with EEG signal to predict the temporal lobe epilepsy outcome after antiseizure medication via machine learning. Sci Rep 2023; 13:22532. [PMID: 38110465 PMCID: PMC10728218 DOI: 10.1038/s41598-023-49255-2] [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: 05/17/2023] [Accepted: 12/06/2023] [Indexed: 12/20/2023] Open
Abstract
Epilepsy is a neurological disorder in which the brain is transiently altered. Predicting outcomes in epilepsy is essential for providing feedback that can foster improved outcomes in the future. This study aimed to investigate whether applying spectral and temporal filters to resting-state electroencephalography (EEG) signals could improve the prediction of outcomes for patients taking antiseizure medication to treat temporal lobe epilepsy (TLE). We collected EEG data from a total of 46 patients (divided into a seizure-free group (SF, n = 22) and a non-seizure-free group (NSF, n = 24)) with TLE and retrospectively reviewed their clinical data. We segmented spectral and temporal ranges with various time-domain features (Hjorth parameters, statistical parameters, energy, zero-crossing rate, inter-channel correlation, inter-channel phase locking value and spectral information derived from Fourier transform, Stockwell transform, and wavelet transform) and compared their performance by applying an optimal frequency strategy, an optimal duration strategy, and a combination strategy. For all time-domain features, the optimal frequency and time combination strategy showed the highest performance in distinguishing SF patients from NSF patients (area under the curve (AUC) = 0.790 ± 0.159). Furthermore, optimal performance was achieved by utilizing a feature vector derived from statistical parameters within the 39- to 41-Hz frequency band with a window length of 210 s, as evidenced by an AUC of 0.748. By identifying the optimal parameters, we improved the performance of the prediction model. These parameters can serve as standard parameters for predicting outcomes based on resting-state EEG signals.
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Affiliation(s)
- Youmin Shin
- Department of Transdisciplinary Medicine, Seoul National University Hospital, Seoul, Republic of Korea
- Interdisciplinary Program in Bio-Engineering, Seoul National University, Seoul, Korea
| | - Sungeun Hwang
- Department of Neurology, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea
| | - Seung-Bo Lee
- Department of Medical Informatics, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Hyoshin Son
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kon Chu
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Neurology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Neurology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sang Kun Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Neurology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyung-Il Park
- Department of Neurology, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Department of Neurology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Republic of Korea.
| | - Young-Gon Kim
- Department of Transdisciplinary Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
- Department of Medicine, Seoul National University College of Medicine, Seoul, Korea.
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Santos-Pata D, Barry C, Ólafsdóttir HF. Theta-band phase locking during encoding leads to coordinated entorhinal-hippocampal replay. Curr Biol 2023; 33:4570-4581.e5. [PMID: 37776862 PMCID: PMC10629661 DOI: 10.1016/j.cub.2023.09.011] [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: 05/17/2023] [Revised: 08/06/2023] [Accepted: 09/05/2023] [Indexed: 10/02/2023]
Abstract
Precisely timed interactions between hippocampal and cortical neurons during replay epochs are thought to support learning. Indeed, research has shown that replay is associated with heightened hippocampal-cortical synchrony. Yet many caveats remain in our understanding. Namely, it remains unclear how this offline synchrony comes about, whether it is specific to particular behavioral states, and how-if at all-it relates to learning. In this study, we sought to address these questions by analyzing coordination between CA1 cells and neurons of the deep layers of the medial entorhinal cortex (dMEC) while rats learned a novel spatial task. During movement, we found a subset of dMEC cells that were particularly locked to hippocampal LFP theta-band oscillations and that were preferentially coordinated with hippocampal replay during offline periods. Further, dMEC synchrony with CA1 replay peaked ∼10 ms after replay initiation in CA1, suggesting that the distributed replay reflects extra-hippocampal information propagation and is specific to "offline" periods. Finally, theta-modulated dMEC cells showed a striking experience-dependent increase in synchronization with hippocampal replay trajectories, mirroring the animals' acquisition of the novel task and coupling to the hippocampal local field. Together, these findings provide strong support for the hypothesis that synergistic hippocampal-cortical replay supports learning and highlights phase locking to hippocampal theta oscillations as a potential mechanism by which such cross-structural synchrony comes about.
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Affiliation(s)
- Diogo Santos-Pata
- Division of Natural and Applied Sciences, Duke Kunshan University, Duke Institute for Brain Sciences, Kunshan 215316, Jiangsu, China
| | - Caswell Barry
- Research Department of Cell and Developmental Biology, University College London, London WC1E 7JE, UK
| | - H Freyja Ólafsdóttir
- Research Department of Cell and Developmental Biology, University College London, London WC1E 7JE, UK; Donders Institute for Brain, Cognition & Behaviour, Radboud Universiteit, 6525 XZ Nijmegen, the Netherlands.
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8
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Agrimi J, Menicucci D, Qu JH, Laurino M, Mackey CD, Hasnain L, Tarasova YS, Tarasov KV, McDevitt RA, Hoover DB, Gemignani A, Paolocci N, Lakatta EG. Enhanced Myocardial Adenylyl Cyclase Activity Alters Heart-Brain Communication. JACC Clin Electrophysiol 2023; 9:2219-2235. [PMID: 37737772 DOI: 10.1016/j.jacep.2023.07.023] [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: 02/20/2023] [Revised: 06/14/2023] [Accepted: 07/17/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND The central nervous system's influence on cardiac function is well described; however, direct evidence for signaling from heart to brain remains sparse. Mice with cardiac-selective overexpression of adenylyl cyclase type 8 (TGAC8) display elevated heart rate/contractility and altered neuroautonomic surveillance. OBJECTIVES In this study the authors tested whether elevated adenylyl cyclase type 8-dependent signaling at the cardiac cell level affects brain activity and behavior. METHODS A telemetry system was used to record electrocardiogram (ECG) and electroencephalogram (EEG) in TGAC8 and wild-type mice simultaneously. The Granger causality statistical approach evaluated variations in the ECG/EEG relationship. Mouse behavior was assessed via elevated plus maze, open field, light-dark box, and fear conditioning tests. Transcriptomic and proteomic analyses were performed on brain tissue lysates. RESULTS Behavioral testing revealed increased locomotor activity in TGAC8 that included a greater total distance traveled (+43%; P < 0.01), a higher average speed (+38%; P < 0.01), and a reduced freezing time (-45%; P < 0.01). Dual-lead telemetry recording confirmed a persistent heart rate elevation with a corresponding reduction in ECG-R-waves interval variability and revealed increased EEG-gamma activity in TGAC8 vs wild-type. Bioinformatic assessment of hippocampal tissue indicated upregulation of dopamine 5, gamma-aminobutyric acid A, and metabotropic glutamate 1/5 receptors, major players in gamma activity generation. Granger causality analyses of ECG and EEG recordings showed a marked increase in informational flow between the TGAC8 heart and brain. CONCLUSIONS Perturbed signals arising from the heart cause changes in brain activity, altering mouse behavior. More specifically, the brain interprets augmented myocardial humoral/functional output as a "sustained exercise-like" situation and responds by activating central nervous system output controlling locomotion.
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Affiliation(s)
- Jacopo Agrimi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA; Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Danilo Menicucci
- Department of Surgical, Medical, Molecular Pathology, and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Jia-Hua Qu
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA
| | - Marco Laurino
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Chelsea D Mackey
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA
| | - Laila Hasnain
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA
| | - Yelena S Tarasova
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA
| | - Kirill V Tarasov
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA
| | - Ross A McDevitt
- Center of Excellence in Inflammation, Infectious Disease, and Immunity, East Tennessee State University, Johnson City, Tennessee, USA
| | - Donald B Hoover
- The Comparative Medicine Section, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA; Department of Biomedical Sciences, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA; Center of Excellence in Inflammation, Infectious Disease, and Immunity, East Tennessee State University, Johnson City, Tennessee, USA
| | - Angelo Gemignani
- Department of Surgical, Medical, Molecular Pathology, and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Nazareno Paolocci
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Biomedical Sciences, University of Padova, Padova, Italy.
| | - Edward G Lakatta
- Laboratory of Cardiovascular Sciences, National Institute on Aging, National Institutes of Health Biomedical Research Center (BRC), Baltimore, Maryland, USA.
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Noguchi A, Matsumoto N, Ikegaya Y. Postnatal Maturation of Membrane Potential Dynamics during in Vivo Hippocampal Ripples. J Neurosci 2023; 43:6126-6140. [PMID: 37400254 PMCID: PMC10476637 DOI: 10.1523/jneurosci.0125-23.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/05/2023] Open
Abstract
Sharp-wave ripples (SWRs) are transient high-frequency oscillations of local field potentials (LFPs) in the hippocampus and play a critical role in memory consolidation. During SWRs, CA1 pyramidal cells exhibit rapid spike sequences that often replay the sequential activity that occurred during behavior. This temporally organized firing activity gradually emerges during 2 weeks after the eye opening; however, it remains unclear how the organized spikes during SWRs mature at the intracellular membrane potential (Vm) level. Here, we recorded Vm of CA1 pyramidal cells simultaneously with hippocampal LFPs from anesthetized immature mice of either sex after the developmental emergence of SWRs. On postnatal days 16 and 17, Vm dynamics around SWRs were premature, characterized by prolonged depolarizations without either pre- or post-SWR hyperpolarizations. The biphasic hyperpolarizations, features typical of adult SWR-relevant Vm, formed by approximately postnatal day 30. This Vm maturation was associated with an increase in SWR-associated inhibitory inputs to pyramidal cells. Thus, the development of SWR-relevant inhibition restricts the temporal windows for spikes of pyramidal cells and allows CA1 pyramidal cells to organize their spike sequences during SWRs.SIGNIFICANCE STATEMENT Sharp-wave ripples (SWRs) are prominent hippocampal oscillations and play a critical role in memory consolidation. During SWRs, hippocampal neurons synchronously emit spikes with organized temporal patterns. This temporal structure of spikes during SWRs develops during the third and fourth postnatal weeks, but the underlying mechanisms are not well understood. Here, we recorded in vivo membrane potentials from hippocampal neurons in premature mice and suggest that the maturation of SWR-associated inhibition enables hippocampal neurons to produce precisely controlled spike times during SWRs.
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Affiliation(s)
- Asako Noguchi
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, 113-0033, Japan
| | - Nobuyoshi Matsumoto
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, University of Tokyo, Tokyo, 113-0033, Japan
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, University of Tokyo, Tokyo, 113-0033, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, 565-0871, Japan
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10
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Rabiller G, Ip Z, Zarrabian S, Zhang H, Sato Y, Yazdan-Shahmorad A, Liu J. Type-2 diabetes alters hippocampal neural oscillations and disrupts synchrony between hippocampus and cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542288. [PMID: 37292743 PMCID: PMC10245872 DOI: 10.1101/2023.05.25.542288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Type 2 diabetes mellitus (T2DM) increases the risk of neurological diseases, yet how brain oscillations change as age and T2DM interact is not well characterized. To delineate the age and diabetic effect on neurophysiology, we recorded local field potentials with multichannel electrodes spanning the somatosensory cortex and hippocampus (HPC) under urethane anesthesia in diabetic and normoglycemic control mice, at 200 and 400 days of age. We analyzed the signal power of brain oscillations, brain state, sharp wave associate ripples (SPW-Rs), and functional connectivity between the cortex and HPC. We found that while both age and T2DM were correlated with a breakdown in long-range functional connectivity and reduced neurogenesis in the dentate gyrus and subventricular zone, T2DM further slowed brain oscillations and reduced theta-gamma coupling. Age and T2DM also prolonged the duration of SPW-Rs and increased gamma power during SPW-R phase. Our results have identified potential electrophysiological substrates of hippocampal changes associated with T2DM and age. The perturbed brain oscillation features and diminished neurogenesis may underlie T2DM-accelerated cognitive impairment.
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11
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Soula M, Martín-Ávila A, Zhang Y, Dhingra A, Nitzan N, Sadowski MJ, Gan WB, Buzsáki G. Forty-hertz light stimulation does not entrain native gamma oscillations in Alzheimer's disease model mice. Nat Neurosci 2023; 26:570-578. [PMID: 36879142 PMCID: PMC10839995 DOI: 10.1038/s41593-023-01270-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/31/2023] [Indexed: 03/08/2023]
Abstract
There is a demand for noninvasive methods to ameliorate disease. We investigated whether 40-Hz flickering light entrains gamma oscillations and suppresses amyloid-β in the brains of APP/PS1 and 5xFAD mouse models of Alzheimer's disease. We used multisite silicon probe recording in the visual cortex, entorhinal cortex or the hippocampus and found that 40-Hz flickering simulation did not engage native gamma oscillations in these regions. Additionally, spike responses in the hippocampus were weak, suggesting 40-Hz light does not effectively entrain deep structures. Mice avoided 40-Hz flickering light, associated with elevated cholinergic activity in the hippocampus. We found no reliable changes in plaque count or microglia morphology by either immunohistochemistry or in vivo two-photon imaging following 40-Hz stimulation, nor reduced levels of amyloid-β 40/42. Thus, visual flicker stimulation may not be a viable mechanism for modulating activity in deep structures.
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Affiliation(s)
- Marisol Soula
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, USA
| | - Alejandro Martín-Ávila
- Department of Physiology and Neuroscience, Langone Medical Center, New York University, New York, NY, USA
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, USA
| | - Yiyao Zhang
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, USA
| | - Annika Dhingra
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, USA
| | - Noam Nitzan
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, USA
| | - Martin J Sadowski
- Department of Neurology and Psychiatry, Langone Medical Center, New York University, New York, NY, USA
- Department of Biochemistry and Molecular Pharmacology, Langone Medical Center, New York University, New York, NY, USA
| | - Wen-Biao Gan
- Skirball Institute of Biomolecular Medicine, Langone Medical Center, New York University, New York, NY, USA
| | - György Buzsáki
- Neuroscience Institute, Langone Medical Center, New York University, New York, NY, USA.
- Department of Physiology and Neuroscience, Langone Medical Center, New York University, New York, NY, USA.
- Department of Neurology and Psychiatry, Langone Medical Center, New York University, New York, NY, USA.
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12
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Chen ZS, Wilson MA. How our understanding of memory replay evolves. J Neurophysiol 2023; 129:552-580. [PMID: 36752404 PMCID: PMC9988534 DOI: 10.1152/jn.00454.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 02/09/2023] Open
Abstract
Memory reactivations and replay, widely reported in the hippocampus and cortex across species, have been implicated in memory consolidation, planning, and spatial and skill learning. Technological advances in electrophysiology, calcium imaging, and human neuroimaging techniques have enabled neuroscientists to measure large-scale neural activity with increasing spatiotemporal resolution and have provided opportunities for developing robust analytic methods to identify memory replay. In this article, we first review a large body of historically important and representative memory replay studies from the animal and human literature. We then discuss our current understanding of memory replay functions in learning, planning, and memory consolidation and further discuss the progress in computational modeling that has contributed to these improvements. Next, we review past and present analytic methods for replay analyses and discuss their limitations and challenges. Finally, looking ahead, we discuss some promising analytic methods for detecting nonstereotypical, behaviorally nondecodable structures from large-scale neural recordings. We argue that seamless integration of multisite recordings, real-time replay decoding, and closed-loop manipulation experiments will be essential for delineating the role of memory replay in a wide range of cognitive and motor functions.
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Affiliation(s)
- Zhe Sage Chen
- Department of Psychiatry, New York University Grossman School of Medicine, New York, New York, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, New York, United States
- Neuroscience Institute, New York University Grossman School of Medicine, New York, New York, United States
- Department of Biomedical Engineering, New York University Tandon School of Engineering, Brooklyn, New York, United States
| | - Matthew A Wilson
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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13
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Oliva A, Fernandez-Ruiz A, Karaba LA. CA2 orchestrates hippocampal network dynamics. Hippocampus 2023; 33:241-251. [PMID: 36575880 PMCID: PMC9974898 DOI: 10.1002/hipo.23495] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 11/25/2022] [Accepted: 12/11/2022] [Indexed: 12/29/2022]
Abstract
The hippocampus is composed of various subregions: CA1, CA2, CA3, and the dentate gyrus (DG). Despite the abundant hippocampal research literature, until recently, CA2 received little attention. The development of new genetic and physiological tools allowed recent studies characterizing the unique properties and functional roles of this hippocampal subregion. Despite its small size, the cellular content of CA2 is heterogeneous at the molecular and physiological levels. CA2 has been heavily implicated in social behaviors, including social memory. More generally, the mechanisms by which the hippocampus is involved in memory include the reactivation of neuronal ensembles following experience. This process is coordinated by synchronous network events known as sharp-wave ripples (SWRs). Recent evidence suggests that CA2 plays an important role in the generation of SWRs. The unique connectivity and physiological properties of CA2 pyramidal cells make this region a computational hub at the core of hippocampal information processing. Here, we review recent findings that support the role of CA2 in coordinating hippocampal network dynamics from a systems neuroscience perspective.
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Affiliation(s)
- Azahara Oliva
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, USA
| | | | - Lindsay A Karaba
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, USA
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14
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Qin Y, Sheremet A, Cooper TL, Burke SN, Maurer AP. Nonlinear Theta-Gamma Coupling between the Anterior Thalamus and Hippocampus Increases as a Function of Running Speed. eNeuro 2023; 10:ENEURO.0470-21.2023. [PMID: 36858827 PMCID: PMC10027116 DOI: 10.1523/eneuro.0470-21.2023] [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: 11/08/2021] [Revised: 02/06/2023] [Accepted: 02/17/2023] [Indexed: 03/03/2023] Open
Abstract
The hippocampal theta rhythm strongly correlates to awake behavior leading to theories that it represents a cognitive state of the brain. As theta has been observed in other regions of the Papez circuit, it has been theorized that activity propagates in a reentrant manner. These observations complement the energy cascade hypothesis in which large-amplitude, slow-frequency oscillations reflect activity propagating across a large population of neurons. Higher frequency oscillations, such as gamma, are related to the speed with which inhibitory and excitatory neurons interact and distribute activity on the local level. The energy cascade hypothesis suggests that the larger anatomic loops, maintaining theta, drive the smaller loops. As hippocampal theta increases in power with running speed, so does the power and frequency of the gamma rhythm. If theta is propagated through the circuit, it stands to reason that the local field potential (LFP) recorded in other regions would be coupled to the hippocampal theta, with the coupling increasing with running speed. We explored this hypothesis using open-source simultaneous recorded data from the CA1 region of the hippocampus and the anterior dorsal and anterior ventral thalamus. Cross-regional theta coupling increased with running speed. Although the power of the gamma rhythm was lower in the anterior thalamus, there was an increase in the coupling of hippocampal theta to anterior thalamic gamma. Broadly, the data support models of how activity moves across the nervous system, suggesting that the brain uses large-scale volleys of activity to support higher cognitive processes.
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Affiliation(s)
- Yu Qin
- Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611
| | - Alex Sheremet
- Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611
- McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL 32610
| | - Tara L Cooper
- McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL 32610
| | - Sara N Burke
- McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL 32610
| | - Andrew P Maurer
- Engineering School of Sustainable Infrastructure and Environment, University of Florida, Gainesville, FL 32611
- McKnight Brain Institute, Department of Neuroscience, University of Florida, Gainesville, FL 32610
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611
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15
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He H, Wang Y, McHugh TJ. Behavioral status modulates CA2 influence on hippocampal network dynamics. Hippocampus 2023; 33:252-265. [PMID: 36594707 DOI: 10.1002/hipo.23498] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 12/02/2022] [Accepted: 12/19/2022] [Indexed: 01/04/2023]
Abstract
Dynamic interactions between the subregions of the hippocampus are required for the encoding and consolidation of memory. While the interplay and contributions of the CA1 and CA3 regions are well understood, we continue to learn more about how CA2 differentially contributes to the organization of network function. For example, CA2 place cells have been reported to be less spatially tuned during exploration, but uniquely capable of coding place while an animal stops. Here we applied chemogenetics to transiently silence CA2 pyramidal cells and found that CA2 influences hippocampal dynamics in a state-dependent manner. We find that during rest, CA2 inhibition reduces synchronization across regions (CA1, CA2, CA3) and frequency bands (low-gamma- and ripple-band). Moreover, during new learning CA1 place field formation is slower in the absence of CA2 transmission and during pausing, CA1 pyramidal cells are less excitable without CA2 drive. On the network level, a novel convolutional neural network (SpikeDecoder) was employed to show subregion and state-dependent changes in spatial coding that agree with our observations on the single cell level. Together these data suggest additional novel roles for CA2 in governing and differentiating hippocampal dynamics under discrete behavioral states.
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Affiliation(s)
- Hongshen He
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Yi Wang
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
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16
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van den Berg M, Toen D, Verhoye M, Keliris GA. Alterations in theta-gamma coupling and sharp wave-ripple, signs of prodromal hippocampal network impairment in the TgF344-AD rat model. Front Aging Neurosci 2023; 15:1081058. [PMID: 37032829 PMCID: PMC10075364 DOI: 10.3389/fnagi.2023.1081058] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Alzheimer's disease (AD) is a severe neurodegenerative disorder caused by the accumulation of toxic proteins, amyloid-beta (Aβ) and tau, which eventually leads to dementia. Disease-modifying therapies are still lacking, due to incomplete insights into the neuropathological mechanisms of AD. Synaptic dysfunction is known to occur before cognitive symptoms become apparent and recent studies have demonstrated that imbalanced synaptic signaling drives the progression of AD, suggesting that early synaptic dysfunction could be an interesting therapeutic target. Synaptic dysfunction results in altered oscillatory activity, which can be detected with electroencephalography and electrophysiological recordings. However, the majority of these studies have been performed at advanced stages of AD, when extensive damage and cognitive symptoms are already present. The current study aimed to investigate if the hippocampal oscillatory activity is altered at pre-plaque stages of AD. The rats received stereotactic surgery to implant a laminar electrode in the CA1 layer of the right hippocampus. Electrophysiological recordings during two consecutive days in an open field were performed in 4-5-month-old TgF344-AD rats when increased concentrations of soluble Aβ species were observed in the brain, in the absence of Aβ-plaques. We observed a decreased power of high theta oscillations in TgF344-AD rats compared to wild-type littermates. Sharp wave-ripple (SWR) analysis revealed an increased SWR power and a decreased duration of SWR during quiet wake in TgF344-AD rats. The alterations in properties of SWR and the increased power of fast oscillations are suggestive of neuronal hyperexcitability, as has been demonstrated to occur during presymptomatic stages of AD. In addition, decreased strength of theta-gamma coupling, an important neuronal correlate of memory encoding, was observed in the TgF344-AD rats. Theta-gamma phase amplitude coupling has been associated with memory encoding and the execution of cognitive functions. Studies have demonstrated that mild cognitive impairment patients display decreased coupling strength, similar to what is described here. The current study demonstrates altered hippocampal network activity occurring at pre-plaque stages of AD and provides insights into prodromal network dysfunction in AD. The alterations observed could aid in the detection of AD during presymptomatic stages.
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Affiliation(s)
- Monica van den Berg
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
| | - Daniëlle Toen
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Georgios A. Keliris
- Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Institute of Computer Science, Foundation for Research and Technology – Hellas, Heraklion, Crete, Greece
- *Correspondence: Monica van den Berg, ; Georgios A. Keliris,
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17
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Mysin I, Shubina L. Hippocampal non-theta state: The "Janus face" of information processing. Front Neural Circuits 2023; 17:1134705. [PMID: 36960401 PMCID: PMC10027749 DOI: 10.3389/fncir.2023.1134705] [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: 12/30/2022] [Accepted: 02/14/2023] [Indexed: 03/09/2023] Open
Abstract
The vast majority of studies on hippocampal rhythms have been conducted on animals or humans in situations where their attention was focused on external stimuli or solving cognitive tasks. These studies formed the basis for the idea that rhythmical activity coordinates the work of neurons during information processing. However, at rest, when attention is not directed to external stimuli, brain rhythms do not disappear, although the parameters of oscillatory activity change. What is the functional load of rhythmical activity at rest? Hippocampal oscillatory activity during rest is called the non-theta state, as opposed to the theta state, a characteristic activity during active behavior. We dedicate our review to discussing the present state of the art in the research of the non-theta state. The key provisions of the review are as follows: (1) the non-theta state has its own characteristics of oscillatory and neuronal activity; (2) hippocampal non-theta state is possibly caused and maintained by change of rhythmicity of medial septal input under the influence of raphe nuclei; (3) there is no consensus in the literature about cognitive functions of the non-theta-non-ripple state; and (4) the antagonistic relationship between theta and delta rhythms observed in rodents is not always observed in humans. Most attention is paid to the non-theta-non-ripple state, since this aspect of hippocampal activity has not been investigated properly and discussed in reviews.
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18
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Umbach G, Tan R, Jacobs J, Pfeiffer BE, Lega B. Flexibility of functional neuronal assemblies supports human memory. Nat Commun 2022; 13:6162. [PMID: 36257934 PMCID: PMC9579146 DOI: 10.1038/s41467-022-33587-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/22/2022] [Indexed: 12/24/2022] Open
Abstract
Episodic memories, or consciously accessible memories of unique events, represent a key aspect of human cognition. Evidence from rodent models suggests that the neural representation of these complex memories requires cooperative firing of groups of neurons on short time scales, organized by gamma oscillations. These co-firing groups, termed "neuronal assemblies," represent a fundamental neurophysiological unit supporting memory. Using microelectrode data from neurosurgical patients, we identify neuronal assemblies in the human MTL and show that they exhibit consistent organization in their firing pattern based on gamma phase information. We connect these properties to memory performance across recording sessions. Finally, we describe how human neuronal assemblies flexibly adjust over longer time scales. Our findings provide key evidence linking assemblies to human episodic memory for the first time.
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Affiliation(s)
- Gray Umbach
- Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Ryan Tan
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX, 75235, USA
| | - Joshua Jacobs
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Brad E Pfeiffer
- Department of Neuroscience, University of Texas Southwestern, Dallas, TX, 75235, USA
| | - Bradley Lega
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX, 75235, USA.
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19
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Deng X, Chen S, Sosa M, Karlsson MP, Wei XX, Frank LM. A Variable Clock Underlies Internally Generated Hippocampal Sequences. J Neurosci 2022; 42:3797-3810. [PMID: 35351831 PMCID: PMC9087812 DOI: 10.1523/jneurosci.1120-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/23/2021] [Accepted: 01/01/2022] [Indexed: 11/21/2022] Open
Abstract
Humans have the ability to store and retrieve memories with various degrees of specificity, and recent advances in reinforcement learning have identified benefits to learning when past experience is represented at different levels of temporal abstraction. How this flexibility might be implemented in the brain remains unclear. We analyzed the temporal organization of male rat hippocampal population spiking to identify potential substrates for temporally flexible representations. We examined activity both during locomotion and during memory-associated population events known as sharp-wave ripples (SWRs). We found that spiking during SWRs is rhythmically organized with higher event-to-event variability than spiking during locomotion-associated population events. Decoding analyses using clusterless methods further indicate that a similar spatial experience can be replayed in multiple SWRs, each time with a different rhythmic structure whose periodicity is sampled from a log-normal distribution. This variability increases with experience despite the decline in SWR rates that occurs as environments become more familiar. We hypothesize that the variability in temporal organization of hippocampal spiking provides a mechanism for storing experiences with various degrees of specificity.SIGNIFICANCE STATEMENT One of the most remarkable properties of memory is its flexibility: the brain can retrieve stored representations at varying levels of detail where, for example, we can begin with a memory of an entire extended event and then zoom in on a particular episode. The neural mechanisms that support this flexibility are not understood. Here we show that hippocampal sharp-wave ripples, which mark the times of memory replay and are important for memory storage, have a highly variable temporal structure that is well suited to support the storage of memories at different levels of detail.
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Affiliation(s)
- Xinyi Deng
- Department of Data Science, Beijing University of Technology, Beijing 100124, People's Republic of China
| | - Shizhe Chen
- Department of Statistics, University of California, Davis, Davis, California 95616
| | - Marielena Sosa
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
| | - Mattias P Karlsson
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
| | - Xue-Xin Wei
- Department of Neuroscience, University of Texas at Austin, Austin, Texas 78751
| | - Loren M Frank
- Center for Integrative Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, California 94158
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California 94158
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, California 94158
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20
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Ratner MH, Farb DH. Probing the Neural Circuitry Targets of Neurotoxicants In Vivo Through High Density Silicon Probe Brain Implants. FRONTIERS IN TOXICOLOGY 2022; 4:836427. [PMID: 35548683 PMCID: PMC9081674 DOI: 10.3389/ftox.2022.836427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/22/2022] [Indexed: 12/24/2022] Open
Abstract
Adverse effects of drugs on the human nervous system are rarely possible to anticipate based on preclinical neurotoxicity data, thus propagating the centuries long single most important obstacle to drug discovery and development for disorders of the nervous system. An emerging body of evidence indicates that in vivo electrophysiology using chronically implanted high-density electrodes (ciHDE) in freely moving animals is a rigorous method with enhanced potential for use in translational research. In particular, the structure and function of the hippocampal trisynaptic circuit (HTC) is conserved from rodents to primates, including Homo sapiens, suggesting that the effects of therapeutic agents and other potential neurologically active agents, whether beneficial or adverse, are likely to translate across species when interrogated using a conserved neural circuitry platform. This review explores science advances in the rapidly moving field of in vivo ciHDE in animal models of learning and memory. For this reason we focus on the HTC, where substantial research has investigated neural circuitry level responses and specific behaviors that reflect memory permitting a test of the ground truth validity of the findings. Examples of changes in neural network activity induced by endogenous neurotoxicants associated with neurodegenerative diseases, as well as exogenous therapeutics, drugs, and neurotoxicants are presented. Several illustrative examples of relevant findings that involve longer range neural circuitry outside of the HTC are discussed. Lastly, the limitations of in vivo ciHDE as applied to preclinical neurotoxicology are discussed with a view toward leveraging circuitry level actions to enhance our ability to project the specificity of in vitro target engagement with the desired psychopharmacological or neurological outcome. At the same time, the goal of reducing or eliminating significant neurotoxic adverse events in human is the desired endpoint. We believe that this approach will lead to enhanced discovery of high value neuroactive therapeutics that target neural circuitry domains as their primary mechanism of action, thus enhancing their ultimate contribution toward discovery of precision therapeutics.
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Affiliation(s)
- Marcia H. Ratner
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- *Correspondence: Marcia H. Ratner,
| | - David H. Farb
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
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21
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Berners-Lee A, Feng T, Silva D, Wu X, Ambrose ER, Pfeiffer BE, Foster DJ. Hippocampal replays appear after a single experience and incorporate greater detail with more experience. Neuron 2022; 110:1829-1842.e5. [PMID: 35381188 DOI: 10.1016/j.neuron.2022.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 11/01/2021] [Accepted: 03/08/2022] [Indexed: 01/20/2023]
Abstract
The hippocampus is implicated in memory formation, and neurons in the hippocampus take part in replay sequences that have been proposed to reflect memory of explored space. By recording from large ensembles of hippocampal neurons as rats explored various tracks, we show that sustained replay appears after a single experience. Further, we found that with repeated experience in a novel environment, replay slows down, taking more time to traverse the same trajectory. This effect was dependent on experience, not passage of time, and was environment specific. By investigating the slow-gamma (25-50 Hz) hover-and-jump dynamics within replays, we show that replay slows by adding more hover locations, increasing the resolution of the behavioral trajectory. We provide evidence that inhibition and cortical engagement both increase as replay slows. Thus, replays can reflect single experiences and evolve with re-exposure, in a manner consistent with the encoding of greater detail into replay memories with experience.
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Affiliation(s)
- Alice Berners-Lee
- Helen Wills Neuroscience Institute and Department of Psychology, University of California Berkeley, CA 94720, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ting Feng
- Philips Research North America, Cambridge, MA 02141, USA
| | | | - Xiaojing Wu
- New York University Comprehensive Epilepsy Center, 223 East 34th Street, New York, NY 10016, USA
| | | | - Brad E Pfeiffer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - David J Foster
- Helen Wills Neuroscience Institute and Department of Psychology, University of California Berkeley, CA 94720, USA.
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22
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Jones EAA, Rao A, Zilberter M, Djukic B, Bant JS, Gillespie AK, Koutsodendris N, Nelson M, Yoon SY, Huang K, Yuan H, Gill TM, Huang Y, Frank LM. Dentate gyrus and CA3 GABAergic interneurons bidirectionally modulate signatures of internal and external drive to CA1. Cell Rep 2021; 37:110159. [PMID: 34965435 PMCID: PMC9069800 DOI: 10.1016/j.celrep.2021.110159] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 10/04/2021] [Accepted: 12/01/2021] [Indexed: 01/19/2023] Open
Abstract
Specific classes of GABAergic neurons play specific roles in regulating information processing in the brain. In the hippocampus, two major classes, parvalbumin-expressing (PV+) and somatostatin-expressing (SST+), differentially regulate endogenous firing patterns and target subcellular compartments of principal cells. How these classes regulate the flow of information throughout the hippocampus is poorly understood. We hypothesize that PV+ and SST+ interneurons in the dentate gyrus (DG) and CA3 differentially modulate CA3 patterns of output, thereby altering the influence of CA3 on CA1. We find that while suppressing either interneuron class increases DG and CA3 output, the effects on CA1 were very different. Suppressing PV+ interneurons increases local field potential signatures of coupling from CA3 to CA1 and decreases signatures of coupling from entorhinal cortex to CA1; suppressing SST+ interneurons has the opposite effect. Thus, DG and CA3 PV+ and SST+ interneurons bidirectionally modulate the flow of information through the hippocampal circuit.
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Affiliation(s)
- Emily A. Aery Jones
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Antara Rao
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Misha Zilberter
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Jason S. Bant
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Anna K. Gillespie
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA
| | - Nicole Koutsodendris
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Maxine Nelson
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA
| | - Seo Yeon Yoon
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Ky Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Heidi Yuan
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Theodore M. Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143, USA,Developmental & Stem Cell Biology Graduate Program, University of California, San Francisco, CA 94143, USA,Departments of Neurology and Pathology, University of California, San Francisco, CA 94143, USA,Gladstone Center for Translational Advancement, San Francisco, CA 94158, USA,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
| | - Loren M. Frank
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, CA 94143, USA,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA,Lead contact,Correspondence should be addressed to: Loren Frank () or Yadong Huang ()
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23
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Mokhothu TM, Tanaka KZ. Characterizing Hippocampal Oscillatory Signatures Underlying Seizures in Temporal Lobe Epilepsy. Front Behav Neurosci 2021; 15:785328. [PMID: 34899205 PMCID: PMC8656355 DOI: 10.3389/fnbeh.2021.785328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
Temporal Lobe Epilepsy (TLE) is a neurological condition characterized by focal brain hyperexcitability, resulting in abnormal neuronal discharge and uncontrollable seizures. The hippocampus, with its inherently highly synchronized firing patterns and relatively high excitability, is prone to epileptic seizures, and it is usually the focus of TLE. Researchers have identified hippocampal high-frequency oscillations (HFOs) as a salient feature in people with TLE and animal models of this disease, arising before or at the onset of the epileptic event. To a certain extent, these pathological HFOs have served as a marker and a potential target for seizure attenuation using electrical or optogenetic interventions. However, many questions remain about whether we can reliably distinguish pathological from non-pathological HFOs and whether they can tell us about the development of the disease. While this would be an arduous task to perform in humans, animal models of TLE provide an excellent opportunity to study the characteristics of HFOs in predicting how epilepsy evolves. This minireview will (1) summarize what we know about the oscillatory disruption in TLE, (2) summarize knowledge about oscillatory changes in the latent period and their role in predicting seizures, and (3) propose future studies essential to uncovering potential treatments based on early detection of pathological HFOs.
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Affiliation(s)
- Thato Mary Mokhothu
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Kazumasa Zen Tanaka
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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24
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Tomar A, McHugh TJ. The impact of stress on the hippocampal spatial code. Trends Neurosci 2021; 45:120-132. [PMID: 34916083 DOI: 10.1016/j.tins.2021.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/10/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022]
Abstract
Hippocampal function is severely compromised by prolonged, uncontrollable stress. However, how stress alters neural representations of our surroundings and events that occur within them remains less clear. We review hippocampal place cell studies that examine how spatial coding is affected by acute and chronic stress, as well as by stress accompanying fear conditioning. Emerging data suggest that chronic stress disrupts the acuity and specificity of CA1 spatial coding, both in familiar and novel contexts, and alters hippocampal oscillations. By contrast, acute stress may have a facilitatory impact on spatial representations. These findings encourage a fresh look at the documented stress-induced changes in hippocampal anatomy and in vitro excitability, and offer a new perspective on the links between stress and memory.
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Affiliation(s)
- Anupratap Tomar
- Center for Synaptic Plasticity, School of Physiology, Pharmacology, and Neuroscience, University of Bristol, University Walk, Bristol BS8 1TD, UK.
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan.
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25
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Cocina F, Vitalis A, Caflisch A. Unsupervised Methods for Detection of Neural States: Case Study of Hippocampal-Amygdala Interactions. eNeuro 2021; 8:ENEURO.0484-20.2021. [PMID: 34544761 PMCID: PMC8577062 DOI: 10.1523/eneuro.0484-20.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 11/24/2022] Open
Abstract
The hippocampus and amygdala are functionally coupled brain regions that play a crucial role in processes involving memory and learning. Because interareal communication has been reported both during specific sleep stages and in awake, behaving animals, these brain regions can serve as an archetype to establish that measuring functional interactions is important for comprehending neural systems. To this end, we analyze here a public dataset of local field potentials (LFPs) recorded in rats simultaneously from the hippocampus and amygdala during different behaviors. Employing a specific, time-lagged embedding technique, named topological causality (TC), we infer directed interactions between the LFP band powers of the two regions across six frequency bands in a time-resolved manner. The combined power and interaction signals are processed with our own unsupervised tools developed originally for the analysis of molecular dynamics simulations to effectively visualize and identify putative, neural states that are visited by the animals repeatedly. Our proposed methodology minimizes impositions onto the data, such as isolating specific epochs, or averaging across externally annotated behavioral stages, and succeeds in separating internal states by external labels such as sleep or stimulus events. We show that this works better for two of the three rats we analyzed, and highlight the need to acknowledge individuality in analyses of this type. Importantly, we demonstrate that the quantification of functional interactions is a significant factor in discriminating these external labels, and we suggest our methodology as a general tool for large, multisite recordings.
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Affiliation(s)
- Francesco Cocina
- Biochemistry department, University of Zurich, Zurich, Switzerland CH-8057
| | - Andreas Vitalis
- Biochemistry department, University of Zurich, Zurich, Switzerland CH-8057
| | - Amedeo Caflisch
- Biochemistry department, University of Zurich, Zurich, Switzerland CH-8057
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26
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Denovellis EL, Gillespie AK, Coulter ME, Sosa M, Chung JE, Eden UT, Frank LM. Hippocampal replay of experience at real-world speeds. eLife 2021; 10:64505. [PMID: 34570699 PMCID: PMC8476125 DOI: 10.7554/elife.64505] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 09/08/2021] [Indexed: 01/12/2023] Open
Abstract
Representations related to past experiences play a critical role in memory and decision-making processes. The rat hippocampus expresses these types of representations during sharp-wave ripple (SWR) events, and previous work identified a minority of SWRs that contain ‘replay’ of spatial trajectories at ∼20x the movement speed of the animal. Efforts to understand replay typically make multiple assumptions about which events to examine and what sorts of representations constitute replay. We therefore lack a clear understanding of both the prevalence and the range of representational dynamics associated with replay. Here, we develop a state space model that uses a combination of movement dynamics of different speeds to capture the spatial content and time evolution of replay during SWRs. Using this model, we find that the large majority of replay events contain spatially coherent, interpretable content. Furthermore, many events progress at real-world, rather than accelerated, movement speeds, consistent with actual experiences.
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Affiliation(s)
- Eric L Denovellis
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.,Departments of Physiology and Psychiatry, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Anna K Gillespie
- Departments of Physiology and Psychiatry, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Michael E Coulter
- Departments of Physiology and Psychiatry, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
| | - Marielena Sosa
- Department of Neurobiology, Stanford University School of Medicine, Stanford, United States
| | - Jason E Chung
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, United States
| | - Uri T Eden
- Department of Mathematics and Statistics, Boston University, Boston, United States
| | - Loren M Frank
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States.,Departments of Physiology and Psychiatry, University of California, San Francisco, San Francisco, United States.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
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27
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Sinha M, Narayanan R. Active Dendrites and Local Field Potentials: Biophysical Mechanisms and Computational Explorations. Neuroscience 2021; 489:111-142. [PMID: 34506834 PMCID: PMC7612676 DOI: 10.1016/j.neuroscience.2021.08.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 10/27/2022]
Abstract
Neurons and glial cells are endowed with membranes that express a rich repertoire of ion channels, transporters, and receptors. The constant flux of ions across the neuronal and glial membranes results in voltage fluctuations that can be recorded from the extracellular matrix. The high frequency components of this voltage signal contain information about the spiking activity, reflecting the output from the neurons surrounding the recording location. The low frequency components of the signal, referred to as the local field potential (LFP), have been traditionally thought to provide information about the synaptic inputs that impinge on the large dendritic trees of various neurons. In this review, we discuss recent computational and experimental studies pointing to a critical role of several active dendritic mechanisms that can influence the genesis and the location-dependent spectro-temporal dynamics of LFPs, spanning different brain regions. We strongly emphasize the need to account for the several fast and slow dendritic events and associated active mechanisms - including gradients in their expression profiles, inter- and intra-cellular spatio-temporal interactions spanning neurons and glia, heterogeneities and degeneracy across scales, neuromodulatory influences, and activitydependent plasticity - towards gaining important insights about the origins of LFP under different behavioral states in health and disease. We provide simple but essential guidelines on how to model LFPs taking into account these dendritic mechanisms, with detailed methodology on how to account for various heterogeneities and electrophysiological properties of neurons and synapses while studying LFPs.
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Affiliation(s)
- Manisha Sinha
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India.
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28
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Zhen ZH, Guo MR, Li HM, Guo OY, Zhen JL, Fu J, Tan GJ. Normal and Abnormal Sharp Wave Ripples in the Hippocampal-Entorhinal Cortex System: Implications for Memory Consolidation, Alzheimer's Disease, and Temporal Lobe Epilepsy. Front Aging Neurosci 2021; 13:683483. [PMID: 34262446 PMCID: PMC8273653 DOI: 10.3389/fnagi.2021.683483] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 06/01/2021] [Indexed: 12/14/2022] Open
Abstract
The appearance of hippocampal sharp wave ripples (SWRs) is an electrophysiological biomarker for episodic memory encoding and behavioral planning. Disturbed SWRs are considered a sign of neural network dysfunction that may provide insights into the structural connectivity changes associated with cognitive impairment in early-stage Alzheimer's disease (AD) and temporal lobe epilepsy (TLE). SWRs originating from hippocampus have been extensively studied during spatial navigation in rodents, and more recent studies have investigated SWRs in the hippocampal-entorhinal cortex (HPC-EC) system during a variety of other memory-guided behaviors. Understanding how SWR disruption impairs memory function, especially episodic memory, could aid in the development of more efficacious therapeutics for AD and TLE. In this review, we first provide an overview of the reciprocal association between AD and TLE, and then focus on the functions of HPC-EC system SWRs in episodic memory consolidation. It is posited that these waveforms reflect rapid network interactions among excitatory projection neurons and local interneurons and that these waves may contribute to synaptic plasticity underlying memory consolidation. Further, SWRs appear altered or ectopic in AD and TLE. These waveforms may thus provide clues to understanding disease pathogenesis and may even serve as biomarkers for early-stage disease progression and treatment response.
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Affiliation(s)
- Zhi-Hang Zhen
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Mo-Ran Guo
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - He-Ming Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ou-Yang Guo
- Department of Biology, Boston University, Boston, MA, United States
| | - Jun-Li Zhen
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Neurological Laboratory of Hebei Province, Shijiazhuang, China
| | - Jian Fu
- Department of Emergency Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Guo-Jun Tan
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Neurological Laboratory of Hebei Province, Shijiazhuang, China
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29
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Tomar A, Polygalov D, Chattarji S, McHugh TJ. Stress enhances hippocampal neuronal synchrony and alters ripple-spike interaction. Neurobiol Stress 2021; 14:100327. [PMID: 33937446 PMCID: PMC8079661 DOI: 10.1016/j.ynstr.2021.100327] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/01/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022] Open
Abstract
Adverse effects of chronic stress include anxiety, depression, and memory deficits. Some of these stress-induced behavioural deficits are mediated by impaired hippocampal function. Much of our current understanding about how stress affects the hippocampus has been derived from post-mortem analyses of brain slices at fixed time points. Consequently, neural signatures of an ongoing stressful experiences in the intact brain of awake animals and their links to later hippocampal dysfunction remain poorly understood. Further, no information is available on the impact of stress on sharp-wave ripples (SPW-Rs), high frequency oscillation transients crucial for memory consolidation. Here, we used in vivo tetrode recordings to analyze the dynamic impact of 10 days of immobilization stress on neural activity in area CA1 of mice. While there was a net decrease in pyramidal cell activity in stressed animals, a greater fraction of CA1 spikes occurred specifically during sharp-wave ripples, resulting in an increase in neuronal synchrony. After repeated stress some of these alterations were visible during rest even in the absence of stress. These findings offer new insights into stress-induced changes in ripple-spike interactions and mechanisms through which chronic stress may interfere with subsequent information processing.
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Affiliation(s)
- Anupratap Tomar
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0021, Japan
| | - Denis Polygalov
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0021, Japan
| | - Sumantra Chattarji
- National Centre for Biological Sciences, Bellary Road, Bangalore, 560065, India.,Centre for Discovery Brain Sciences, Deanery of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, 15 George Square, Edinburgh, EH89XD, UK
| | - Thomas J McHugh
- Laboratory for Circuit & Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0021, Japan
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30
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Fernández-Ruiz A, Oliva A, Soula M, Rocha-Almeida F, Nagy GA, Martin-Vazquez G, Buzsáki G. Gamma rhythm communication between entorhinal cortex and dentate gyrus neuronal assemblies. Science 2021; 372:eabf3119. [PMID: 33795429 PMCID: PMC8285088 DOI: 10.1126/science.abf3119] [Citation(s) in RCA: 105] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/29/2021] [Indexed: 01/02/2023]
Abstract
Gamma oscillations are thought to coordinate the spike timing of functionally specialized neuronal ensembles across brain regions. To test this hypothesis, we optogenetically perturbed gamma spike timing in the rat medial (MEC) and lateral (LEC) entorhinal cortices and found impairments in spatial and object learning tasks, respectively. MEC and LEC were synchronized with the hippocampal dentate gyrus through high- and low-gamma-frequency rhythms, respectively, and engaged either granule cells or mossy cells and CA3 pyramidal cells in a task-dependent manner. Gamma perturbation disrupted the learning-induced assembly organization of target neurons. Our findings imply that pathway-specific gamma oscillations route task-relevant information between distinct neuronal subpopulations in the entorhinal-hippocampal circuit. We hypothesize that interregional gamma-time-scale spike coordination is a mechanism of neuronal communication.
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Affiliation(s)
- Antonio Fernández-Ruiz
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.
| | - Azahara Oliva
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Marisol Soula
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
| | - Florbela Rocha-Almeida
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Division of Neurosciences, University Pablo de Olavide, 41013 Seville, Spain
| | - Gergo A Nagy
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
- Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Szigony utca 43, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, H-1085 Budapest, Üllői út 26, Hungary
| | - Gonzalo Martin-Vazquez
- Department of Theoretical Physics, Complutense University, 28040 Madrid, Spain
- School of Experimental Sciences, University Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - György Buzsáki
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.
- Center for Neural Science, New York University, New York, NY 10016, USA
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31
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Sharif F, Tayebi B, Buzsáki G, Royer S, Fernandez-Ruiz A. Subcircuits of Deep and Superficial CA1 Place Cells Support Efficient Spatial Coding across Heterogeneous Environments. Neuron 2021; 109:363-376.e6. [PMID: 33217328 PMCID: PMC7856084 DOI: 10.1016/j.neuron.2020.10.034] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/30/2020] [Accepted: 10/30/2020] [Indexed: 12/20/2022]
Abstract
The hippocampus is thought to guide navigation by forming a cognitive map of space. Different environments differ in geometry and the availability of cues that can be used for navigation. Although several spatial coding mechanisms are known to coexist in the hippocampus, how they are influenced by various environmental features is not well understood. To address this issue, we examined the spatial coding characteristics of hippocampal neurons in mice and rats navigating in different environments. We found that CA1 place cells located in the superficial sublayer were more active in cue-poor environments and preferentially used a firing rate code driven by intra-hippocampal inputs. In contrast, place cells located in the deep sublayer were more active in cue-rich environments and used a phase code driven by entorhinal inputs. Switching between these two spatial coding modes was supported by the interaction between excitatory gamma inputs and local inhibition.
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Affiliation(s)
- Farnaz Sharif
- Neuroscience Institute, New York University, Langone Medical Center, New York, NY 10016, USA; Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Behnam Tayebi
- Neuroscience Institute, New York University, Langone Medical Center, New York, NY 10016, USA
| | - György Buzsáki
- Neuroscience Institute, New York University, Langone Medical Center, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA; Department of Neurology, Langone Medical Center, New York University, New York, NY 10016, USA
| | - Sébastien Royer
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea.
| | - Antonio Fernandez-Ruiz
- Neuroscience Institute, New York University, Langone Medical Center, New York, NY 10016, USA.
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32
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Li KT, Liang J, Zhou C. Gamma Oscillations Facilitate Effective Learning in Excitatory-Inhibitory Balanced Neural Circuits. Neural Plast 2021; 2021:6668175. [PMID: 33542728 PMCID: PMC7840255 DOI: 10.1155/2021/6668175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/19/2020] [Accepted: 01/07/2021] [Indexed: 12/26/2022] Open
Abstract
Gamma oscillation in neural circuits is believed to associate with effective learning in the brain, while the underlying mechanism is unclear. This paper aims to study how spike-timing-dependent plasticity (STDP), a typical mechanism of learning, with its interaction with gamma oscillation in neural circuits, shapes the network dynamics properties and the network structure formation. We study an excitatory-inhibitory (E-I) integrate-and-fire neuronal network with triplet STDP, heterosynaptic plasticity, and a transmitter-induced plasticity. Our results show that the performance of plasticity is diverse in different synchronization levels. We find that gamma oscillation is beneficial to synaptic potentiation among stimulated neurons by forming a special network structure where the sum of excitatory input synaptic strength is correlated with the sum of inhibitory input synaptic strength. The circuit can maintain E-I balanced input on average, whereas the balance is temporal broken during the learning-induced oscillations. Our study reveals a potential mechanism about the benefits of gamma oscillation on learning in biological neural circuits.
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Affiliation(s)
- Kwan Tung Li
- Department of Physics, Centre for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Junhao Liang
- Department of Physics, Centre for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Changsong Zhou
- Department of Physics, Centre for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Hong Kong
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33
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Hippocampal CA2 sharp-wave ripples reactivate and promote social memory. Nature 2020; 587:264-269. [PMID: 32968277 DOI: 10.1038/s41586-020-2758-y] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 06/25/2020] [Indexed: 02/08/2023]
Abstract
The consolidation of spatial memory depends on the reactivation ('replay') of hippocampal place cells that were active during recent behaviour. Such reactivation is observed during sharp-wave ripples (SWRs)-synchronous oscillatory electrical events that occur during non-rapid-eye-movement (non-REM) sleep1-8 and whose disruption impairs spatial memory3,5,6,8. Although the hippocampus also encodes a wide range of non-spatial forms of declarative memory, it is not yet known whether SWRs are necessary for such memories. Moreover, although SWRs can arise from either the CA3 or the CA2 region of the hippocampus7,9, the relative importance of SWRs from these regions for memory consolidation is unknown. Here we examine the role of SWRs during the consolidation of social memory-the ability of an animal to recognize and remember a member of the same species-focusing on CA2 because of its essential role in social memory10-12. We find that ensembles of CA2 pyramidal neurons that are active during social exploration of previously unknown conspecifics are reactivated during SWRs. Notably, disruption or enhancement of CA2 SWRs suppresses or prolongs social memory, respectively. Thus, SWR-mediated reactivation of hippocampal firing related to recent experience appears to be a general mechanism for binding spatial, temporal and sensory information into high-order memory representations, including social memory.
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34
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Jones EA, Gillespie AK, Yoon SY, Frank LM, Huang Y. Early Hippocampal Sharp-Wave Ripple Deficits Predict Later Learning and Memory Impairments in an Alzheimer's Disease Mouse Model. Cell Rep 2020; 29:2123-2133.e4. [PMID: 31747587 PMCID: PMC7437815 DOI: 10.1016/j.celrep.2019.10.056] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 07/30/2019] [Accepted: 10/11/2019] [Indexed: 12/04/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by progressive memory loss, and there is a pressing need to identify early pathophysiological alterations that predict subsequent memory impairment. Hippocampal sharp-wave ripples (SWRs)—electrophysiological signatures of memory reactivation in the hippocampus—are a compelling candidate for this purpose. Mouse models of AD show reductions in both SWR abundance and associated slow gamma (SG) power during aging, but these alterations have yet to be directly linked to memory impairments. In aged apolipoprotein E4 knockin (apoE4-KI) mice—a model of the major genetic risk factor for AD—we find that reduced SWR abundance and associated CA3 SG power predicted spatial memory impairments measured 1–2 months later. Importantly, SWR-associated CA3 SG power reduction in young apoE4-KI mice also predicted spatial memory deficits measured 10 months later. These results establish features of SWRs as potential functional biomarkers of memory impairment in AD. Currently, there are no functional biomarkers that can predict progression to Alzheimer’s disease before cognitive decline begins. Jones et al. demonstrate that sharp-wave ripple and associated slow gamma deficits predict memory impairments in aged apoE4 mice. Slow gamma deficits in young apoE4 mice predict memory impairment onset 10+ months later.
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Affiliation(s)
- Emily A Jones
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anna K Gillespie
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Seo Yeon Yoon
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Loren M Frank
- Kavli Institute for Fundamental Neuroscience and Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Neurology and Pathology, University of California, San Francisco, San Francisco, CA 94143, USA.
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35
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Ngo HV, Fell J, Staresina B. Sleep spindles mediate hippocampal-neocortical coupling during long-duration ripples. eLife 2020; 9:57011. [PMID: 32657268 PMCID: PMC7363445 DOI: 10.7554/elife.57011] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/06/2020] [Indexed: 01/07/2023] Open
Abstract
Sleep is pivotal for memory consolidation. According to two-stage accounts, memory traces are gradually translocated from hippocampus to neocortex during non-rapid-eye-movement (NREM) sleep. Mechanistically, this information transfer is thought to rely on interactions between thalamocortical spindles and hippocampal ripples. To test this hypothesis, we analyzed intracranial and scalp Electroencephalography sleep recordings from pre-surgical epilepsy patients. We first observed a concurrent spindle power increase in hippocampus (HIPP) and neocortex (NC) time-locked to individual hippocampal ripple events. Coherence analysis confirmed elevated levels of hippocampal-neocortical spindle coupling around ripples, with directionality analyses indicating an influence from NC to HIPP. Importantly, these hippocampal-neocortical dynamics were particularly pronounced during long-duration compared to short-duration ripples. Together, our findings reveal a potential mechanism underlying active consolidation, comprising a neocortical-hippocampal-neocortical reactivation loop initiated by the neocortex. This hippocampal-cortical dialogue is mediated by sleep spindles and is enhanced during long-duration hippocampal ripples.
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Affiliation(s)
- Hong-Viet Ngo
- School of Psychology and Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Juergen Fell
- Department of Epileptology, University of Bonn, Bonn, Germany
| | - Bernhard Staresina
- School of Psychology and Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
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36
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McKenzie S, Nitzan N, English DF. Mechanisms of neural organization and rhythmogenesis during hippocampal and cortical ripples. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190237. [PMID: 32248777 PMCID: PMC7209923 DOI: 10.1098/rstb.2019.0237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2019] [Indexed: 12/19/2022] Open
Abstract
Neural activity during ripples has attracted great theoretical and experimental attention over the last three decades. Perhaps one reason for such interest is that ripples occur during quiet waking moments and during sleep, times when we reflect and dream about what has just occurred and what we expect to happen next. The hope is that understanding such 'offline' activity may yield insights into reflection, planning, and the purposes of sleep. This review focuses on the mechanisms by which neurons organize during these high-frequency events. In studying ripples, broader principles have emerged that relate intrinsic neural properties, network topology and synaptic plasticity in controlling neural activity. Ripples, therefore, serve as an excellent model for studying how properties of a neural network relate to neural dynamics. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.
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Affiliation(s)
- Sam McKenzie
- NYULMC Neuroscience Institute, New York, NY, USA
| | - Noam Nitzan
- Neuroscience Research Center NWFZ, Berlin, Germany
| | - Daniel F. English
- Virginia Tech School of Neuroscience Blacksburg, Blacksburg, VA, USA
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37
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Kumar M, Deshmukh SS. Differential propagation of ripples along the proximodistal and septotemporal axes of dorsal CA1 of rats. Hippocampus 2020; 30:970-986. [PMID: 32386276 DOI: 10.1002/hipo.23211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 03/15/2020] [Accepted: 04/09/2020] [Indexed: 11/10/2022]
Abstract
The functional connectivity of the hippocampus with its primary cortical input, the entorhinal cortex, is organized topographically. In area CA1 of the hippocampus, this leads to different functional gradients along the proximodistal and septotemporal axes of spatial/sensory responsivity and spatial resolution respectively. CA1 ripples, a network phenomenon, allow us to test whether the hippocampal neural network shows corresponding gradients in functional connectivity along the two axes. We studied the occurrence and propagation of ripples across the entire proximodistal axis along with a comparable spatial range of the septotemporal axis of dorsal CA1. We observed that ripples could occur at any location, and their amplitudes were independent of the tetrode location along the proximodistal and septotemporal axes. When a ripple was detected on a particular tetrode ("reference tetrode"), however, the probability of cooccurrence of ripples and ripple amplitude observed on the other tetrodes decreased as a function of distance from the reference tetrode. This reduction was greater along the proximodistal axis than the septotemporal axis. Furthermore, we found that ripples propagate primarily along the proximodistal axis. Thus, over a spatial scale of ∼1.5 mm, the network is anisotropic along the two axes, complementing the topographically organized cortico-hippocampal connections.
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Affiliation(s)
- Mekhala Kumar
- Centre for Neuroscience, Indian Institute of Science, Bangalore, Karnataka, India
| | - Sachin S Deshmukh
- Centre for Neuroscience, Indian Institute of Science, Bangalore, Karnataka, India
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38
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Phase-based coordination of hippocampal and neocortical oscillations during human sleep. Commun Biol 2020; 3:176. [PMID: 32313064 PMCID: PMC7170909 DOI: 10.1038/s42003-020-0913-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 03/25/2020] [Indexed: 01/09/2023] Open
Abstract
During sleep, new memories undergo a gradual transfer from hippocampal (HPC) to neocortical (NC) sites. Precisely timed neural oscillations are thought to mediate this sleep-dependent memory consolidation, but exactly how sleep oscillations instantiate the HPC-NC dialog remains elusive. Employing overnight invasive electroencephalography in ten neurosurgical patients, we identified three broad classes of phase-based communication between HPC and lateral temporal NC. First, we observed interregional phase synchrony for non-rapid eye movement (NREM) spindles, and N2 and rapid eye movement (REM) theta activity. Second, we found asymmetrical N3 cross-frequency phase-amplitude coupling between HPC slow oscillations (SOs) and NC activity spanning the delta to high-gamma/ripple bands, but not in the opposite direction. Lastly, N2 theta and NREM spindle synchrony were themselves modulated by HPC SOs. These forms of interregional communication emphasize the role of HPC SOs in the HPC-NC dialog, and may offer a physiological basis for the sleep-dependent reorganization of mnemonic content.
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39
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de la Prida LM. Potential factors influencing replay across CA1 during sharp-wave ripples. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190236. [PMID: 32248778 DOI: 10.1098/rstb.2019.0236] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sharp-wave ripples are complex neurophysiological events recorded along the trisynaptic hippocampal circuit (i.e. from CA3 to CA1 and the subiculum) during slow-wave sleep and awake states. They arise locally but scale brain-wide to the hippocampal target regions at cortical and subcortical structures. During these events, neuronal firing sequences are replayed retrospectively or prospectively and in the forward or reverse order as defined by experience. They could reflect either pre-configured firing sequences, learned sequences or an option space to inform subsequent decisions. How can different sequences arise during sharp-wave ripples? Emerging data suggest the hippocampal circuit is organized in different loops across the proximal (close to dentate gyrus) and distal (close to entorhinal cortex) axis. These data also disclose a so-far neglected laminar organization of the hippocampal output during sharp-wave events. Here, I discuss whether by incorporating cell-type-specific mechanisms converging on deep and superficial CA1 sublayers along the proximodistal axis, some novel factors influencing the organization of hippocampal sequences could be unveiled. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.
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40
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Fernández-Ruiz A, Oliva A, Fermino de Oliveira E, Rocha-Almeida F, Tingley D, Buzsáki G. Long-duration hippocampal sharp wave ripples improve memory. Science 2020; 364:1082-1086. [PMID: 31197012 DOI: 10.1126/science.aax0758] [Citation(s) in RCA: 236] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 05/01/2019] [Indexed: 01/22/2023]
Abstract
Hippocampal sharp wave ripples (SPW-Rs) have been hypothesized as a mechanism for memory consolidation and action planning. The duration of ripples shows a skewed distribution with a minority of long-duration events. We discovered that long-duration ripples are increased in situations demanding memory in rats. Prolongation of spontaneously occurring ripples by optogenetic stimulation, but not randomly induced ripples, increased memory during maze learning. The neuronal content of randomly induced ripples was similar to short-duration spontaneous ripples and contained little spatial information. The spike content of the optogenetically prolonged ripples was biased by the ongoing, naturally initiated neuronal sequences. Prolonged ripples recruited new neurons that represented either arm of the maze. Long-duration hippocampal SPW-Rs replaying large parts of planned routes are critical for memory.
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Affiliation(s)
- Antonio Fernández-Ruiz
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
| | - Azahara Oliva
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.,Department of Neuroscience and Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Eliezyer Fermino de Oliveira
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.,Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, São Paulo, Brazil
| | - Florbela Rocha-Almeida
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA.,Division of Neurosciences, University Pablo de Olavide, 41013 Seville, Spain
| | - David Tingley
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA
| | - György Buzsáki
- New York University Neuroscience Institute, New York University, New York, NY 10016, USA. .,Center for Neural Science, New York University, New York, NY 10016, USA
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Nokia MS, Waselius T, Sahramäki J, Penttonen M. Most hippocampal CA1 pyramidal cells in rabbits increase firing during awake sharp-wave ripples and some do so in response to external stimulation and theta. J Neurophysiol 2020; 123:1671-1681. [PMID: 32208887 DOI: 10.1152/jn.00056.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hippocampus forms neural representations of real-life events including multimodal information of spatial and temporal context. These representations, i.e., organized sequences of neuronal firing, are repeated during following rest and sleep, especially when so-called sharp-wave ripples (SPW-Rs) characterize hippocampal local field potentials. This SPW-R -related replay is thought to underlie memory consolidation. Here, we set out to explore how hippocampal CA1 pyramidal cells respond to the conditioned stimulus during trace eyeblink conditioning and how these responses manifest during SPW-Rs in awake adult female New Zealand White rabbits. Based on reports in rodents, we expected SPW-Rs to take place in bursts, possibly according to a slow endogenous rhythm. In awake rabbits, half of all SPW-Rs took place in bursts, but no endogenous slow rhythm appeared. Conditioning trials suppressed SPW-Rs while increasing theta for a period of several seconds. As expected based on previous findings, only a quarter of the putative CA1 pyramidal cells increased firing in response to the conditioned stimulus. Compared with other cells, rate-increasing cells were more active during spontaneous epochs of hippocampal theta while response profile during conditioning did not affect firing during SPW-Rs. Taken together, CA1 pyramidal cell firing during SPW-Rs is not limited to cells that fired during the preceding experience. Furthermore, the importance of possible reactivations taking place during theta epochs on memory consolidation warrants further investigation.NEW & NOTEWORTHY We studied hippocampal sharp-wave ripples and theta and CA1 pyramidal cell activity during trace eyeblink conditioning in rabbits. Conditioning trials suppressed ripples while increasing theta for a period of several seconds. A quarter of the cells increased firing in response to the conditioned stimulus and fired extensively during endogenous theta as well as ripples. The role of endogenous theta epochs in off-line memory consolidation should be studied further.
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Affiliation(s)
- Miriam S Nokia
- Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Tomi Waselius
- Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Joonas Sahramäki
- Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Markku Penttonen
- Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
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Harvey RE, Berkowitz LE, Hamilton DA, Clark BJ. The effects of developmental alcohol exposure on the neurobiology of spatial processing. Neurosci Biobehav Rev 2019; 107:775-794. [PMID: 31526818 PMCID: PMC6876993 DOI: 10.1016/j.neubiorev.2019.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/02/2019] [Accepted: 09/11/2019] [Indexed: 01/20/2023]
Abstract
The consumption of alcohol during gestation is detrimental to the developing central nervous system. One functional outcome of this exposure is impaired spatial processing, defined as sensing and integrating information pertaining to spatial navigation and spatial memory. The hippocampus, entorhinal cortex, and anterior thalamus are brain regions implicated in spatial processing and are highly susceptible to the effects of developmental alcohol exposure. Some of the observed effects of alcohol on spatial processing may be attributed to changes at the synaptic to circuit level. In this review, we first describe the impact of developmental alcohol exposure on spatial behavior followed by a summary of the development of brain areas involved in spatial processing. We then provide an examination of the consequences of prenatal and early postnatal alcohol exposure in rodents on hippocampal, anterior thalamus, and entorhinal cortex-dependent spatial processing from the cellular to behavioral level. We conclude by highlighting several unanswered questions which may provide a framework for future investigation.
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Affiliation(s)
- Ryan E Harvey
- Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Laura E Berkowitz
- Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Derek A Hamilton
- Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Benjamin J Clark
- Department of Psychology, University of New Mexico, Albuquerque, NM, United States.
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43
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Ahrens-Nicklas RC, Tecedor L, Hall AF, Lysenko E, Cohen AS, Davidson BL, Marsh ED. Neuronal network dysfunction precedes storage and neurodegeneration in a lysosomal storage disorder. JCI Insight 2019; 4:131961. [PMID: 31573978 PMCID: PMC6948765 DOI: 10.1172/jci.insight.131961] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022] Open
Abstract
Accumulation of lysosomal storage material and late-stage neurodegeneration are hallmarks of lysosomal storage disorders (LSDs) affecting the brain. Yet, for most LSDs, including CLN3 disease, the most common form of childhood dementia, it is unclear what mechanisms drive neurologic symptoms. Do deficits arise from loss of function of the mutated protein or toxicity from storage accumulation? Here, using in vitro voltage-sensitive dye imaging and in vivo electrophysiology, we find progressive hippocampal dysfunction occurs before notable lysosomal storage and neuronal loss in 2 CLN3 disease mouse models. Pharmacologic reversal of lysosomal storage deposition in young mice does not rescue this circuit dysfunction. Additionally, we find that CLN3 disease mice lose an electrophysiologic marker of new memory encoding - hippocampal sharp-wave ripples. This discovery, which is also seen in Alzheimer's disease, suggests the possibility of a shared electrophysiologic signature of dementia. Overall, our data describe new insights into previously unknown network-level changes occurring in LSDs affecting the central nervous system and highlight the need for new therapeutic interventions targeting early circuit defects.
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Affiliation(s)
| | | | - Arron F. Hall
- Division of Human Genetics, Department of Pediatrics
| | | | | | | | - Eric D. Marsh
- Division of Child Neurology, Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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44
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Altered Dynamics of Canonical Feedback Inhibition Predicts Increased Burst Transmission in Chronic Epilepsy. J Neurosci 2019; 39:8998-9012. [PMID: 31519822 DOI: 10.1523/jneurosci.2594-18.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 08/28/2019] [Accepted: 09/04/2019] [Indexed: 11/21/2022] Open
Abstract
Inhibitory interneurons, organized into canonical feedforward and feedback motifs, play a key role in controlling normal and pathological neuronal activity. We demonstrate prominent quantitative changes in the dynamics of feedback inhibition in a rat model of chronic epilepsy (male Wistar rats). Systematic interneuron recordings revealed a large decrease in intrinsic excitability of basket cells and oriens-lacunosum moleculare interneurons in epileptic animals. Additionally, the temporal dynamics of interneuron recruitment by recurrent feedback excitation were strongly altered, resulting in a profound loss of initial feedback inhibition during synchronous CA1 pyramidal activity. Biophysically constrained models of the complete feedback circuit motifs of normal and epileptic animals revealed that, as a consequence of altered feedback inhibition, burst activity arising in CA3 is more strongly converted to a CA1 output. This suggests that altered dynamics of feedback inhibition promote the transmission of epileptiform bursts to hippocampal projection areas.SIGNIFICANCE STATEMENT We quantitatively characterized changes of the CA1 feedback inhibitory circuit in a model of chronic temporal lobe epilepsy. This study shows, for the first time, that dynamic recruitment of inhibition in feedback circuits is altered and establishes the cellular mechanisms for this change. Computational modeling revealed that the observed changes are likely to systematically alter CA1 input-output properties leading to (1) increased seizure propagation through CA1 and (2) altered computation of synchronous CA3 input.
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45
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Cox R, Rüber T, Staresina BP, Fell J. Heterogeneous profiles of coupled sleep oscillations in human hippocampus. Neuroimage 2019; 202:116178. [PMID: 31505272 PMCID: PMC6853182 DOI: 10.1016/j.neuroimage.2019.116178] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 11/24/2022] Open
Abstract
Cross-frequency coupling of sleep oscillations is thought to mediate memory consolidation. While the hippocampus is deemed central to this process, detailed knowledge of which oscillatory rhythms interact in the sleeping human hippocampus is lacking. Combining intracranial hippocampal and non-invasive electroencephalography from twelve neurosurgical patients, we characterized spectral power and coupling during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Hippocampal coupling was extensive, with the majority of channels expressing spectral interactions. NREM consistently showed delta–ripple coupling, but ripples were also modulated by slow oscillations (SOs) and sleep spindles. SO–delta and SO–theta coupling, as well as interactions between delta/theta and spindle/beta frequencies also occurred. During REM, limited interactions between delta/theta and beta frequencies emerged. Moreover, oscillatory organization differed substantially between i) hippocampus and scalp, ii) sites along the anterior-posterior hippocampal axis, and iii) individuals. Overall, these results extend and refine our understanding of hippocampal sleep oscillations. Sleep oscillations in human hippocampus exhibit cross-frequency coupling during non-rapid eye movement sleep Coupling occurs between various frequency pairs, including slow oscillation, delta, theta, spindle, beta, and ripple bands Oscillatory organization varies between hippocampus and scalp, sites along the hippocampal axis, and individuals
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Affiliation(s)
- Roy Cox
- Department of Epileptology, University of Bonn, Bonn, Germany.
| | - Theodor Rüber
- Department of Epileptology, University of Bonn, Bonn, Germany; Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe University Frankfurt, Frankfurt am Main, Germany; Center for Personalized Translational Epilepsy Research (CePTER), Goethe University Frankfurt, Frankfurt am Main, Germany
| | | | - Juergen Fell
- Department of Epileptology, University of Bonn, Bonn, Germany
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