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Ye Z, Shelton AM, Shaker JR, Boussard J, Colonell J, Birman D, Manavi S, Chen S, Windolf C, Hurwitz C, Namima T, Pedraja F, Weiss S, Raducanu B, Ness TV, Jia X, Mastroberardino G, Rossi LF, Carandini M, Häusser M, Einevoll GT, Laurent G, Sawtell NB, Bair W, Pasupathy A, Lopez CM, Dutta B, Paninski L, Siegle JH, Koch C, Olsen SR, Harris TD, Steinmetz NA. Ultra-high density electrodes improve detection, yield, and cell type identification in neuronal recordings. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.23.554527. [PMID: 37662298 PMCID: PMC10473688 DOI: 10.1101/2023.08.23.554527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
To understand the neural basis of behavior, it is essential to sensitively and accurately measure neural activity at single neuron and single spike resolution. Extracellular electrophysiology delivers this, but it has biases in the neurons it detects and it imperfectly resolves their action potentials. To minimize these limitations, we developed a silicon probe with much smaller and denser recording sites than previous designs, called Neuropixels Ultra (NP Ultra). This device samples neuronal activity at ultra-high spatial density (~10 times higher than previous probes) with low noise levels, while trading off recording span. NP Ultra is effectively an implantable voltage-sensing camera that captures a planar image of a neuron's electrical field. We use a spike sorting algorithm optimized for these probes to demonstrate that the yield of visually-responsive neurons in recordings from mouse visual cortex improves up to ~3-fold. We show that NP Ultra can record from small neuronal structures including axons and dendrites. Recordings across multiple brain regions and four species revealed a subset of extracellular action potentials with unexpectedly small spatial spread and axon-like features. We share a large-scale dataset of these brain-wide recordings in mice as a resource for studies of neuronal biophysics. Finally, using ground-truth identification of three major inhibitory cortical cell types, we found that these cell types were discriminable with approximately 75% success, a significant improvement over lower-resolution recordings. NP Ultra improves spike sorting performance, detection of subcellular compartments, and cell type classification to enable more powerful dissection of neural circuit activity during behavior.
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Affiliation(s)
- Zhiwen Ye
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Andrew M. Shelton
- MindScope Program, Allen Institute, Seattle, WA, USA
- Allen Institute for Neural Dynamics, Seattle, WA, USA
| | - Jordan R. Shaker
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Julien Boussard
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | | | - Daniel Birman
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Sahar Manavi
- MindScope Program, Allen Institute, Seattle, WA, USA
| | - Susu Chen
- Janelia Research Campus, Ashburn, VA, USA
| | - Charlie Windolf
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Cole Hurwitz
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Tomoyuki Namima
- Department of Biological Structure, University of Washington, Seattle, WA, USA
- Washington National Primate Research Center, Seattle, WA, USA
| | - Federico Pedraja
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Shahaf Weiss
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | | | | | - Xiaoxuan Jia
- Center for Life Sciences & IDG/McGovern Institute for Brain Research, Tsinghua University, China
| | - Giulia Mastroberardino
- UCL Institute of Ophthalmology, University College London, London, UK
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - L. Federico Rossi
- Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy
| | - Matteo Carandini
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Michael Häusser
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Gaute T. Einevoll
- Norwegian University of Life Sciences, Ås, Norway
- University of Oslo, Oslo, Norway
| | - Gilles Laurent
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Nathaniel B. Sawtell
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Wyeth Bair
- Department of Biological Structure, University of Washington, Seattle, WA, USA
- Washington National Primate Research Center, Seattle, WA, USA
| | - Anitha Pasupathy
- Department of Biological Structure, University of Washington, Seattle, WA, USA
- Washington National Primate Research Center, Seattle, WA, USA
| | | | | | - Liam Paninski
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | | | - Christof Koch
- MindScope Program, Allen Institute, Seattle, WA, USA
| | - Shawn R. Olsen
- MindScope Program, Allen Institute, Seattle, WA, USA
- Allen Institute for Neural Dynamics, Seattle, WA, USA
| | - Timothy D. Harris
- Janelia Research Campus, Ashburn, VA, USA
- Biomedical Engineering Department, Johns Hopkins University, Baltimore, MD, USA
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Müller-Komorowska D, Kuru B, Beck H, Braganza O. Phase information is conserved in sparse, synchronous population-rate-codes via phase-to-rate recoding. Nat Commun 2023; 14:6106. [PMID: 37777512 PMCID: PMC10543394 DOI: 10.1038/s41467-023-41803-8] [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: 08/08/2022] [Accepted: 09/19/2023] [Indexed: 10/02/2023] Open
Abstract
Neural computation is often traced in terms of either rate- or phase-codes. However, most circuit operations will simultaneously affect information across both coding schemes. It remains unclear how phase and rate coded information is transmitted, in the face of continuous modification at consecutive processing stages. Here, we study this question in the entorhinal cortex (EC)- dentate gyrus (DG)- CA3 system using three distinct computational models. We demonstrate that DG feedback inhibition leverages EC phase information to improve rate-coding, a computation we term phase-to-rate recoding. Our results suggest that it i) supports the conservation of phase information within sparse rate-codes and ii) enhances the efficiency of plasticity in downstream CA3 via increased synchrony. Given the ubiquity of both phase-coding and feedback circuits, our results raise the question whether phase-to-rate recoding is a recurring computational motif, which supports the generation of sparse, synchronous population-rate-codes in areas beyond the DG.
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Affiliation(s)
- Daniel Müller-Komorowska
- Neural Coding and Brain Computing Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan.
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany.
| | - Baris Kuru
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Heinz Beck
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen e.V, Bonn, Germany
| | - Oliver Braganza
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany.
- Institute for Socio-Economics, University of Duisburg-Essen, Duisburg, Germany.
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Wang H, Gong D, Augustinack JC, Magnain C. Quantitative optical coherence microscopy of neuron morphology in human entorhinal cortex. Front Neurosci 2023; 17:1074660. [PMID: 37152599 PMCID: PMC10160389 DOI: 10.3389/fnins.2023.1074660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/06/2023] [Indexed: 05/09/2023] Open
Abstract
Introduction The size and shape of neurons are important features indicating aging and the pathology of neurodegenerative diseases. Despite the significant advances of optical microscopy, quantitative analysis of the neuronal features in the human brain remains largely incomplete. Traditional histology on thin slices bears tremendous distortions in three-dimensional reconstruction, the magnitude of which are often greater than the structure of interest. Recently development of tissue clearing techniques enable the whole brain to be analyzed in small animals; however, the application in the human remains challenging. Methods In this study, we present a label-free quantitative optical coherence microscopy (OCM) technique to obtain the morphological parameters of neurons in human entorhinal cortex (EC). OCM uses the intrinsic back-scattering property of tissue to identify individual neurons in 3D. The area, length, width, and orientation of individual neurons are quantified and compared between layer II and III in EC. Results The high-resolution mapping of neuron size, shape, and orientation shows significant differences between layer II and III neurons in EC. The results are validated by standard Nissl staining of the same samples. Discussion The quantitative OCM technique in our study offers a new solution to analyze variety of neurons and their organizations in the human brain, which opens new insights in advancing our understanding of neurodegenerative diseases.
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Schlesiger MI, Ruff T, MacLaren DAA, Barriuso-Ortega I, Saidov KM, Yen TY, Monyer H. Two septal-entorhinal GABAergic projections differentially control coding properties of spatially tuned neurons in the medial entorhinal cortex. Cell Rep 2021; 34:108801. [PMID: 33657367 DOI: 10.1016/j.celrep.2021.108801] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 12/23/2020] [Accepted: 02/05/2021] [Indexed: 12/20/2022] Open
Abstract
Septal parvalbumin-expressing (PV+) and calbindin-expressing (CB+) projections inhibit low-threshold and fast-spiking interneurons, respectively, in the medial entorhinal cortex (MEC). We investigate how the two inputs control neuronal activity in the MEC in freely moving mice. Stimulation of PV+ and CB+ terminals causes disinhibition of spatially tuned MEC neurons, but exerts differential effects on temporal coding and burst firing. Thus, recruitment of PV+ projections disrupts theta-rhythmic firing of MEC neurons, while stimulation of CB+ projections increases burst firing of grid cells and enhances phase precession in a cell-type-specific manner. Inactivation of septal PV+ or CB+ neurons differentially affects context, reference, and working memory. Together, our results reveal how specific connectivity of septal GABAergic projections with MEC interneurons translates into differential modulation of MEC neuronal coding.
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Affiliation(s)
- Magdalene Isabell Schlesiger
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Tobias Ruff
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Duncan Archibald Allan MacLaren
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Isabel Barriuso-Ortega
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Khalid Magomedovich Saidov
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ting-Yun Yen
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Hannah Monyer
- Department of Clinical Neurobiology at the Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Katyare N, Sikdar SK. Theta resonance and synaptic modulation scale activity patterns in the medial entorhinal cortex stellate cells. Ann N Y Acad Sci 2020; 1478:92-112. [PMID: 32794193 DOI: 10.1111/nyas.14434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 05/31/2020] [Accepted: 06/19/2020] [Indexed: 11/28/2022]
Abstract
Stellate cells (SCs) of the medial entorhinal cortex (MEC) are rich in hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which are known to effectively shape their activity patterns. The explanatory mechanisms, however, have remained elusive. One important but previously unassessed possibility is that HCN channels control the gain of synaptic inputs to these cells. Here, we test this possibility in rat brain slices, while subjecting SCs to a stochastic synaptic bombardment using the dynamic clamp. We show that in the presence of synaptic noise, HCN channels mainly exert their influence by increasing the relative signal gain in the theta frequency through the theta modulation of stochastic synaptic inputs. This subthreshold synaptic modulation then translates into a spiking resonance, which steepens with excitation in the presence of HCN channels. We present here a systematic assessment of synaptic theta modulation and trace its implications to the suprathreshold control of firing rate motifs. Such analysis was yet lacking in the SC literature. Furthermore, we assess the impact of noise statistics on this gain modulation and indicate possible mechanisms for the emergence of membrane theta oscillations and synaptic ramps, as observed in vivo. We support the data with a computational model that further unveils a competing role of inhibition, suggesting important implications for MEC computations.
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Affiliation(s)
- Nupur Katyare
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sujit Kumar Sikdar
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka, India
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6
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Iwase M, Kitanishi T, Mizuseki K. Cell type, sub-region, and layer-specific speed representation in the hippocampal-entorhinal circuit. Sci Rep 2020; 10:1407. [PMID: 31996750 PMCID: PMC6989659 DOI: 10.1038/s41598-020-58194-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022] Open
Abstract
It has been hypothesised that speed information, encoded by ‘speed cells’, is important for updating spatial representation in the hippocampus and entorhinal cortex to reflect ongoing self-movement during locomotion. However, systematic characterisation of speed representation is still lacking. In this study, we compared the speed representation of distinct cell types across sub-regions/layers in the dorsal hippocampus and medial entorhinal cortex of rats during exploration. Our results indicate that the preferred theta phases of individual neurons are correlated with positive/negative speed modulation and a temporal shift of speed representation in a sub-region/layer and cell type-dependent manner. Most speed cells located in entorhinal cortex layer 2 represented speed prospectively, whereas those in the CA1 and entorhinal cortex layers 3 and 5 represented speed retrospectively. In entorhinal cortex layer 2, putative CA1-projecting pyramidal cells, but not putative dentate gyrus/CA3-projecting stellate cells, represented speed prospectively. Among the hippocampal interneurons, approximately one-third of putative dendrite-targeting (somatostatin-expressing) interneurons, but only a negligible fraction of putative soma-targeting (parvalbumin-expressing) interneurons, showed negative speed modulation. Putative parvalbumin-expressing CA1 interneurons and somatostatin-expressing CA3 interneurons represented speed more retrospectively than parvalbumin-expressing CA3 interneurons. These findings indicate that speed representation in the hippocampal-entorhinal circuit is cell-type, pathway, and theta-phase dependent.
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Affiliation(s)
- Motosada Iwase
- Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan
| | - Takuma Kitanishi
- Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan
| | - Kenji Mizuseki
- Department of Physiology, Osaka City University Graduate School of Medicine, Osaka, 545-8585, Japan. .,Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ, 07102, USA.
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7
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Sheeran WM, Ahmed OJ. The neural circuitry supporting successful spatial navigation despite variable movement speeds. Neurosci Biobehav Rev 2019; 108:821-833. [PMID: 31760048 DOI: 10.1016/j.neubiorev.2019.11.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/30/2019] [Accepted: 11/18/2019] [Indexed: 12/18/2022]
Abstract
Ants who have successfully navigated the long distance between their foraging spot and their nest dozens of times will drastically overshoot their destination if the size of their legs is doubled by the addition of stilts. This observation reflects a navigational strategy called path integration, a strategy also utilized by mammals. Path integration necessitates that animals keep track of their movement speed and use it to precisely and instantly modify where they think they are and where they want to go. Here we review the neural circuitry that has evolved to integrate speed and space. We start with the rate and temporal codes for speed in the hippocampus and work backwards towards the motor and sensory systems. We highlight the need for experiments designed to differentiate the respective contributions of motor efference copy versus sensory inputs. In particular, we discuss the importance of high-resolution tracking of the latency of speed-encoding as a precise way to disentangle the sensory versus motor computations that enable successful spatial navigation at very different speeds.
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Affiliation(s)
- William M Sheeran
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular, Cellular & Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Omar J Ahmed
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA; Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA; Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, MI 48109, USA.
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8
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Kang L, DeWeese MR. Replay as wavefronts and theta sequences as bump oscillations in a grid cell attractor network. eLife 2019; 8:46351. [PMID: 31736462 PMCID: PMC6901334 DOI: 10.7554/elife.46351] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 11/15/2019] [Indexed: 11/17/2022] Open
Abstract
Grid cells fire in sequences that represent rapid trajectories in space. During locomotion, theta sequences encode sweeps in position starting slightly behind the animal and ending ahead of it. During quiescence and slow wave sleep, bouts of synchronized activity represent long trajectories called replays, which are well-established in place cells and have been recently reported in grid cells. Theta sequences and replay are hypothesized to facilitate many cognitive functions, but their underlying mechanisms are unknown. One mechanism proposed for grid cell formation is the continuous attractor network. We demonstrate that this established architecture naturally produces theta sequences and replay as distinct consequences of modulating external input. Driving inhibitory interneurons at the theta frequency causes attractor bumps to oscillate in speed and size, which gives rise to theta sequences and phase precession, respectively. Decreasing input drive to all neurons produces traveling wavefronts of activity that are decoded as replays.
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Affiliation(s)
- Louis Kang
- Redwood Center for Theoretical Neuroscience, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States.,Department of Physics, University of California, Berkeley, Berkeley, United States
| | - Michael R DeWeese
- Redwood Center for Theoretical Neuroscience, Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States.,Department of Physics, University of California, Berkeley, Berkeley, United States
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9
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Drieu C, Zugaro M. Hippocampal Sequences During Exploration: Mechanisms and Functions. Front Cell Neurosci 2019; 13:232. [PMID: 31263399 PMCID: PMC6584963 DOI: 10.3389/fncel.2019.00232] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/08/2019] [Indexed: 12/13/2022] Open
Abstract
Although the hippocampus plays a critical role in spatial and episodic memories, the mechanisms underlying memory formation, stabilization, and recall for adaptive behavior remain relatively unknown. During exploration, within single cycles of the ongoing theta rhythm that dominates hippocampal local field potentials, place cells form precisely ordered sequences of activity. These neural sequences result from the integration of both external inputs conveying sensory-motor information, and intrinsic network dynamics possibly related to memory processes. Their endogenous replay during subsequent sleep is critical for memory consolidation. The present review discusses possible mechanisms and functions of hippocampal theta sequences during exploration. We present several lines of evidence suggesting that these neural sequences play a key role in information processing and support the formation of initial memory traces, and discuss potential functional distinctions between neural sequences emerging during theta vs. awake sharp-wave ripples.
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Affiliation(s)
- Céline Drieu
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, PSL Research University, Paris, France
| | - Michaël Zugaro
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U 1050, PSL Research University, Paris, France
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10
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Recurrent circuits within medial entorhinal cortex superficial layers support grid cell firing. Nat Commun 2018; 9:3701. [PMID: 30209250 PMCID: PMC6135799 DOI: 10.1038/s41467-018-06104-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 08/15/2018] [Indexed: 11/29/2022] Open
Abstract
Specialized cells in the medial entorhinal cortex (mEC), such as speed cells, head direction (HD) cells, and grid cells, are thought to support spatial navigation. To determine whether these computations are dependent on local circuits, we record neuronal activity in mEC layers II and III and optogenetically perturb locally projecting layer II pyramidal cells. We find that sharply tuned HD cells are only weakly responsive while speed, broadly tuned HD cells, and grid cells show pronounced transient excitatory and inhibitory responses. During the brief period of feedback inhibition, there is a reduction in specifically grid accuracy, which is corrected as firing rates return to baseline. These results suggest that sharp HD cells are embedded in a separate mEC sub-network from broad HD cells, speed cells, and grid cells. Furthermore, grid tuning is not only dependent on local processing but also rapidly updated by HD, speed, or other afferent inputs to mEC. Medial entorhinal cortex (mEC) neurons encode various navigation parameters such as speed, head direction, as well as grid cells. Here, the authors demonstrate that brief disruption of the local activity in mEC specifically affects grid cell tuning.
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11
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Jaramillo J, Kempter R. Phase precession: a neural code underlying episodic memory? Curr Opin Neurobiol 2017; 43:130-138. [PMID: 28390862 DOI: 10.1016/j.conb.2017.02.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/25/2017] [Accepted: 02/08/2017] [Indexed: 11/29/2022]
Abstract
In the hippocampal formation, the sequential activation of place-specific cells represents a conceptual model for the spatio-temporal events that assemble episodic memories. The imprinting of behavioral sequences in hippocampal networks might be achieved via spike-timing-dependent plasticity and phase precession of the spiking activity of neurons. It is unclear, however, whether phase precession plays an active role by enabling sequence learning via synaptic plasticity or whether phase precession passively reflects retrieval dynamics. Here we examine these possibilities in the context of potential mechanisms generating phase precession. Knowledge of these mechanisms would allow to selectively alter phase precession and test its role in episodic memory. We finally review the few successful approaches to degrade phase precession and the resulting impact on behavior.
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Affiliation(s)
- Jorge Jaramillo
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Richard Kempter
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, Philippstr. 13, 10115 Berlin, Germany.
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12
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Justus D, Dalügge D, Bothe S, Fuhrmann F, Hannes C, Kaneko H, Friedrichs D, Sosulina L, Schwarz I, Elliott DA, Schoch S, Bradke F, Schwarz MK, Remy S. Glutamatergic synaptic integration of locomotion speed via septoentorhinal projections. Nat Neurosci 2016; 20:16-19. [PMID: 27893726 DOI: 10.1038/nn.4447] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022]
Abstract
The medial septum and diagonal band of Broca (MSDB) send glutamatergic axons to medial entorhinal cortex (MEC). We found that this pathway provides speed-correlated input to several MEC cell-types in layer 2/3. The speed signal is integrated most effectively by pyramidal cells but also excites stellate cells and interneurons. Thus, the MSDB conveys speed information that can be used by MEC neurons for spatial representation of self-location.
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Affiliation(s)
- Daniel Justus
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Dennis Dalügge
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stefanie Bothe
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Falko Fuhrmann
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Christian Hannes
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Hiroshi Kaneko
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Detlef Friedrichs
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Liudmila Sosulina
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Inna Schwarz
- Functional Neuroconnectomics Group, Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - David Anthony Elliott
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Susanne Schoch
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.,Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Frank Bradke
- Axon Growth and Regeneration Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Martin Karl Schwarz
- Functional Neuroconnectomics Group, Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases, Bonn, Germany.,Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
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13
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Cell Type-Specific Differences in Spike Timing and Spike Shape in the Rat Parasubiculum and Superficial Medial Entorhinal Cortex. Cell Rep 2016; 16:1005-1015. [PMID: 27425616 PMCID: PMC4967475 DOI: 10.1016/j.celrep.2016.06.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/04/2016] [Accepted: 06/12/2016] [Indexed: 01/05/2023] Open
Abstract
The medial entorhinal cortex (MEC) and the adjacent parasubiculum are known for their elaborate spatial discharges (grid cells, border cells, etc.) and the precessing of spikes relative to the local field potential. We know little, however, about how spatio-temporal firing patterns map onto cell types. We find that cell type is a major determinant of spatio-temporal discharge properties. Parasubicular neurons and MEC layer 2 (L2) pyramids have shorter spikes, discharge spikes in bursts, and are theta-modulated (rhythmic, locking, skipping), but spikes phase-precess only weakly. MEC L2 stellates and layer 3 (L3) neurons have longer spikes, do not discharge in bursts, and are weakly theta-modulated (non-rhythmic, weakly locking, rarely skipping), but spikes steeply phase-precess. The similarities between MEC L3 neurons and MEC L2 stellates on one hand and parasubicular neurons and MEC L2 pyramids on the other hand suggest two distinct streams of temporal coding in the parahippocampal cortex. We find cell type-specific differences in spike shape, burstiness, and phase precession In vivo cell type specificity does not match predictions from previous in vitro studies Anatomical identity is a major determinant of spike patterns in the parahippocampal cortex
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