1
|
Ouchi A, Fujisawa S. Predictive grid coding in the medial entorhinal cortex. Science 2024; 385:776-784. [PMID: 39146428 DOI: 10.1126/science.ado4166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 07/22/2024] [Indexed: 08/17/2024]
Abstract
The entorhinal cortex represents allocentric spatial geometry and egocentric speed and heading information required for spatial navigation. However, it remains unclear whether it contributes to the prediction of an animal's future location. We discovered grid cells in the medial entorhinal cortex (MEC) that have grid fields representing future locations during goal-directed behavior. These predictive grid cells represented prospective spatial information by shifting their grid fields against the direction of travel. Predictive grid cells discharged at the trough phases of the hippocampal CA1 theta oscillation and, together with other types of grid cells, organized sequences of the trajectory from the current to future positions across each theta cycle. Our results suggest that the MEC provides a predictive map that supports forward planning in spatial navigation.
Collapse
Affiliation(s)
- Ayako Ouchi
- Laboratory for Systems Neurophysiology, RIKEN Center for Brain Science, Wako City, Saitama 351-0198, Japan
| | - Shigeyoshi Fujisawa
- Laboratory for Systems Neurophysiology, RIKEN Center for Brain Science, Wako City, Saitama 351-0198, Japan
- Department of Complexity Science and Engineering, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| |
Collapse
|
2
|
Hermansen E, Klindt DA, Dunn BA. Uncovering 2-D toroidal representations in grid cell ensemble activity during 1-D behavior. Nat Commun 2024; 15:5429. [PMID: 38926360 PMCID: PMC11208534 DOI: 10.1038/s41467-024-49703-1] [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: 01/23/2023] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Minimal experiments, such as head-fixed wheel-running and sleep, offer experimental advantages but restrict the amount of observable behavior, making it difficult to classify functional cell types. Arguably, the grid cell, and its striking periodicity, would not have been discovered without the perspective provided by free behavior in an open environment. Here, we show that by shifting the focus from single neurons to populations, we change the minimal experimental complexity required. We identify grid cell modules and show that the activity covers a similar, stable toroidal state space during wheel running as in open field foraging. Trajectories on grid cell tori correspond to single trial runs in virtual reality and path integration in the dark, and the alignment of the representation rapidly shifts with changes in experimental conditions. Thus, we provide a methodology to discover and study complex internal representations in even the simplest of experiments.
Collapse
Affiliation(s)
- Erik Hermansen
- Department of Mathematical Sciences, NTNU, Trondheim, Norway.
| | - David A Klindt
- Department of Mathematical Sciences, NTNU, Trondheim, Norway
- Cold Spring Harbor Laboratory, Cold Spring Harbor, Laurel Hollow, New York, USA
| | - Benjamin A Dunn
- Department of Mathematical Sciences, NTNU, Trondheim, Norway.
| |
Collapse
|
3
|
Rebecca R, Ascoli GA, Sutton NM, Dannenberg H. Spatial periodicity in grid cell firing is explained by a neural sequence code of 2-D trajectories. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.30.542747. [PMID: 37398455 PMCID: PMC10312530 DOI: 10.1101/2023.05.30.542747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Spatial periodicity in grid cell firing has been interpreted as a neural metric for space providing animals with a coordinate system in navigating physical and mental spaces. However, the specific computational problem being solved by grid cells has remained elusive. Here, we provide mathematical proof that spatial periodicity in grid cell firing is the only possible solution to a neural sequence code of 2-D trajectories and that the hexagonal firing pattern of grid cells is the most parsimonious solution to such a sequence code. We thereby provide a teleological cause for the existence of grid cells and reveal the underlying nature of the global geometric organization in grid maps as a direct consequence of a simple local sequence code. A sequence code by grid cells provides intuitive explanations for many previously puzzling experimental observations and may transform our thinking about grid cells.
Collapse
Affiliation(s)
- R.G. Rebecca
- Department of Mathematical Sciences, George Mason University, 4400 University Dr., Fairfax, VA 22030
| | - Giorgio A. Ascoli
- Department of Bioengineering, George Mason University, 4400 University Dr., Fairfax, VA 22030
| | - Nate M. Sutton
- Department of Bioengineering, George Mason University, 4400 University Dr., Fairfax, VA 22030
| | - Holger Dannenberg
- Department of Bioengineering, George Mason University, 4400 University Dr., Fairfax, VA 22030
| |
Collapse
|
4
|
Cholvin T, Hainmueller T, Bartos M. The hippocampus converts dynamic entorhinal inputs into stable spatial maps. Neuron 2021; 109:3135-3148.e7. [PMID: 34619088 PMCID: PMC8516433 DOI: 10.1016/j.neuron.2021.09.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/31/2021] [Accepted: 09/09/2021] [Indexed: 11/29/2022]
Abstract
The medial entorhinal cortex (MEC)-hippocampal network plays a key role in the processing, storage, and recall of spatial information. However, how the spatial code provided by MEC inputs relates to spatial representations generated by principal cell assemblies within hippocampal subfields remains enigmatic. To investigate this coding relationship, we employed two-photon calcium imaging in mice navigating through dissimilar virtual environments. Imaging large MEC bouton populations revealed spatially tuned activity patterns. MEC inputs drastically changed their preferred spatial field locations between environments, whereas hippocampal cells showed lower levels of place field reconfiguration. Decoding analysis indicated that higher place field reliability and larger context-dependent activity-rate differences allow low numbers of principal cells, particularly in the DG and CA1, to provide information about location and context more accurately and rapidly than MEC inputs. Thus, conversion of dynamic MEC inputs into stable spatial hippocampal maps may enable fast encoding and efficient recall of spatio-contextual information. MEC inputs to the DG, CA3, and CA1 show different spatial coding properties MEC inputs remap even more strongly than hippocampal principal cells Hippocampal principal cell activity is more reliable and stable than their MEC inputs Hippocampal principal cells allow improved spatial and contextual readout
Collapse
Affiliation(s)
- Thibault Cholvin
- Institute for Physiology I, University of Freiburg, Medical Faculty, Freiburg 79104, Germany
| | - Thomas Hainmueller
- NYU Neuroscience Institute, 435 East 30th Street, New York, NY 10016, USA
| | - Marlene Bartos
- Institute for Physiology I, University of Freiburg, Medical Faculty, Freiburg 79104, Germany.
| |
Collapse
|
5
|
Rueckemann JW, Sosa M, Giocomo LM, Buffalo EA. The grid code for ordered experience. Nat Rev Neurosci 2021; 22:637-649. [PMID: 34453151 PMCID: PMC9371942 DOI: 10.1038/s41583-021-00499-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2021] [Indexed: 02/07/2023]
Abstract
Entorhinal cortical grid cells fire in a periodic pattern that tiles space, which is suggestive of a spatial coordinate system. However, irregularities in the grid pattern as well as responses of grid cells in contexts other than spatial navigation have presented a challenge to existing models of entorhinal function. In this Perspective, we propose that hippocampal input provides a key informative drive to the grid network in both spatial and non-spatial circumstances, particularly around salient events. We build on previous models in which neural activity propagates through the entorhinal-hippocampal network in time. This temporal contiguity in network activity points to temporal order as a necessary characteristic of representations generated by the hippocampal formation. We advocate that interactions in the entorhinal-hippocampal loop build a topological representation that is rooted in the temporal order of experience. In this way, the structure of grid cell firing supports a learned topology rather than a rigid coordinate frame that is bound to measurements of the physical world.
Collapse
Affiliation(s)
- Jon W Rueckemann
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, USA
- Washington National Primate Research Center, Seattle, WA, USA
| | - Marielena Sosa
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa M Giocomo
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Elizabeth A Buffalo
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, USA.
- Washington National Primate Research Center, Seattle, WA, USA.
| |
Collapse
|
6
|
Place cells and geometry lead to a flexible grid pattern. J Comput Neurosci 2021; 49:441-452. [PMID: 34125337 DOI: 10.1007/s10827-021-00794-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 05/04/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
Place cells and grid cells are important neurons involved in spatial navigation in the mammalian brain. Grid cells are believed to play an important role in forming a cognitive map of the environment. Experimental observations in recent years showed that the grid pattern is not invariant but is influenced by the shape of the spatial environment. However, the cause of this deformation remains elusive. Here, we focused on the functional interactions between place cells and grid cells, utilizing the information of location relationships between the firing fields of place cells to optimize the previous grid cell feedforward generation model and expand its application to more complex environmental scenarios. Not only was the regular equilateral triangle periodic firing field structure of the grid cells reproduced, but the expected results were consistent with the experiment for the environment with various complex boundary shapes and environmental deformation. Even in the field of three-dimensional spatial grid patterns, forward-looking predictions have been made. This provides a possible model explanation for how the coupling of grid cells and place cells adapt to the diversity of the external environment to deepen our understanding of the neural basis for constructing cognitive maps.
Collapse
|
7
|
Zhang X, Schlögl A, Jonas P. Selective Routing of Spatial Information Flow from Input to Output in Hippocampal Granule Cells. Neuron 2020; 107:1212-1225.e7. [PMID: 32763145 PMCID: PMC7523402 DOI: 10.1016/j.neuron.2020.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/22/2020] [Accepted: 07/10/2020] [Indexed: 11/18/2022]
Abstract
Dentate gyrus granule cells (GCs) connect the entorhinal cortex to the hippocampal CA3 region, but how they process spatial information remains enigmatic. To examine the role of GCs in spatial coding, we measured excitatory postsynaptic potentials (EPSPs) and action potentials (APs) in head-fixed mice running on a linear belt. Intracellular recording from morphologically identified GCs revealed that most cells were active, but activity level varied over a wide range. Whereas only ∼5% of GCs showed spatially tuned spiking, ∼50% received spatially tuned input. Thus, the GC population broadly encodes spatial information, but only a subset relays this information to the CA3 network. Fourier analysis indicated that GCs received conjunctive place-grid-like synaptic input, suggesting code conversion in single neurons. GC firing was correlated with dendritic complexity and intrinsic excitability, but not extrinsic excitatory input or dendritic cable properties. Thus, functional maturation may control input-output transformation and spatial code conversion.
Collapse
Affiliation(s)
- Xiaomin Zhang
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Alois Schlögl
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Peter Jonas
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria.
| |
Collapse
|
8
|
Nagele J, Herz AVM, Stemmler MB. Untethered firing fields and intermittent silences: Why grid-cell discharge is so variable. Hippocampus 2020; 30:367-383. [PMID: 32045073 DOI: 10.1002/hipo.23191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/20/2019] [Accepted: 12/31/2019] [Indexed: 11/07/2022]
Abstract
Grid cells in medial entorhinal cortex are notoriously variable in their responses, despite the striking hexagonal arrangement of their spatial firing fields. Indeed, when the animal moves through a firing field, grid cells often fire much more vigorously than predicted or do not fire at all. The source of this trial-to-trial variability is not completely understood. By analyzing grid-cell spike trains from mice running in open arenas and on linear tracks, we characterize the phenomenon of "missed" firing fields using the statistical theory of zero inflation. We find that one major cause of grid-cell variability lies in the spatial representation itself: firing fields are not as strongly anchored to spatial location as the averaged grid suggests. In addition, grid fields from different cells drift together from trial to trial, regardless of whether the environment is real or virtual, or whether the animal moves in light or darkness. Spatial realignment across trials sharpens the grid representation, yielding firing fields that are more pronounced and significantly narrower. These findings indicate that ensembles of grid cells encode relative position more reliably than absolute position.
Collapse
Affiliation(s)
- Johannes Nagele
- Bernstein Center for Computational Neuroscience Munich and Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Andreas V M Herz
- Bernstein Center for Computational Neuroscience Munich and Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin B Stemmler
- Bernstein Center for Computational Neuroscience Munich and Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| |
Collapse
|
9
|
Jacob PY, Capitano F, Poucet B, Save E, Sargolini F. Path integration maintains spatial periodicity of grid cell firing in a 1D circular track. Nat Commun 2019; 10:840. [PMID: 30783085 PMCID: PMC6381105 DOI: 10.1038/s41467-019-08795-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 01/29/2019] [Indexed: 12/11/2022] Open
Abstract
Entorhinal grid cells are thought to provide a 2D spatial metric of the environment. In this study we demonstrate that in a familiar 1D circular track (i.e., a continuous space) grid cells display a novel 1D equidistant firing pattern based on integrated distance rather than travelled distance or time. In addition, field spacing is increased compared to a 2D open field, probably due to a reduced access to the visual cue in the track. This metrical modification is accompanied by a change in LFP theta oscillations, but no change in intrinsic grid cell rhythmicity, or firing activity of entorhinal speed and head-direction cells. These results suggest that in a 1D circular space grid cell spatial selectivity is shaped by path integration processes, while grid scale relies on external information. In an open field, the preferential firing of grid cells on a hexagonal lattice is formed by integrating external as well as self-motion cues. Here, the authors show that on a 1D circular track, path integration cues shape the spatial selectivity of grid cells while external cues determine the scale of the grid.
Collapse
Affiliation(s)
- Pierre-Yves Jacob
- Aix Marseille Université, CNRS, LNC UMR 7291, 13331, Marseille, France.
| | - Fabrizio Capitano
- Aix Marseille Université, CNRS, LNC UMR 7291, 13331, Marseille, France
| | - Bruno Poucet
- Aix Marseille Université, CNRS, LNC UMR 7291, 13331, Marseille, France
| | - Etienne Save
- Aix Marseille Université, CNRS, LNC UMR 7291, 13331, Marseille, France
| | | |
Collapse
|