Edvard Moser

Edvard Moser
Norwegian University of Science and Technology | NTNU · Kavli Institute for Systems Neuroscience and Centre for Neural Computation

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188
Publications
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Introduction

Publications

Publications (188)
Article
Durations are defined by a beginning and an end, and a major distinction is drawn between durations that start in the present and end in the future (‘prospective timing’) and durations that start in the past and end either in the past or the present (‘retrospective timing’). Different psychological processes are thought to be engaged in each of the...
Preprint
Objects and landmarks are crucial for guiding navigation and must be integrated into the cognitive map of space. Studies of object coding in the hippocampus have primarily focused on activity of single cells. Here we record simultaneously from large numbers of hippocampal CA1 neurons to determine how the presence of a salient object in the environm...
Preprint
The medial entorhinal cortex (MEC) hosts many of the brain's circuit elements for spatial navigation and episodic memory, operations that require neural activity to be organized across long durations of experience[1]. While location is known to be encoded by a plethora of spatially tuned cell types in this brain region[2-6], little is known about h...
Article
Full-text available
Neuronal firing patterns are the result of inputs converging onto single cells. Identifying these inputs, anatomically and functionally, is essential to understand how neurons integrate information. Single-cell electroporation of helper genes and subsequent local injection of recombinant rabies viruses enable precise mapping of inputs to individual...
Article
The representation of an animal’s position in the medial entorhinal cortex (MEC) is distributed across several modules of grid cells, each characterized by a distinct spatial scale. The population activity within each module is tightly coordinated and preserved across environments and behavioral states. Little is known, however, about the coordinat...
Article
We developed a miniaturized two-photon microscope (MINI2P) for fast, high-resolution, multiplane calcium imaging of over 1,000 neurons at a time in freely moving mice. With a microscope weight below 3 g and a highly flexible connection cable, MINI2P allowed stable imaging with no impediment of behavior in a variety of assays compared to untethered,...
Article
Full-text available
Significance The investigation of the topographic organization of spatially coding cell types in the medial entorhinal cortex (MEC) has so far been held back by the lack of appropriate tools that enable the precise recording of both the anatomical location and activity of large populations of cells while animals forage in open environments. In this...
Article
Full-text available
The medial entorhinal cortex is part of a neural system for mapping the position of an individual within a physical environment¹. Grid cells, a key component of this system, fire in a characteristic hexagonal pattern of locations², and are organized in modules³ that collectively form a population code for the animal’s allocentric position¹. The inv...
Article
Full-text available
Object-vector (OV) cells are cells in the medial entorhinal cortex (MEC) that track an animal’s distance and direction to objects in the environment. Their firing fields are defined by vectorial relationships to free-standing 3-dimensional (3D) objects of a variety of identities and shapes. However, the natural world contains a panorama of objects,...
Preprint
Full-text available
Neuronal firing patterns are the result of inputs converging onto single cells. Identifying these inputs, anatomically and functionally, is essential to understand how neurons integrate information. Single-cell electroporation of helper genes and subsequent local injection of recombinant rabies viruses enable precise mapping of inputs to individual...
Preprint
Full-text available
The medial entorhinal cortex (MEC) creates a map of local space, based on the firing patterns of grid, head direction (HD), border, and object-vector (OV) cells. How these cell types are organized anatomically is debated. In-depth analysis of this question requires collection of precise anatomical and activity data across large populations of neuro...
Preprint
Full-text available
The representation of an animal's position in the medial entorhinal cortex (MEC) is distributed across several modules of grid cells, each characterized by a distinct spatial scale. The population activity within each module is tightly coordinated and preserved across environments and behavioral states. Little is known, however, about the coordinat...
Preprint
Full-text available
Object-vector (OV) cells are cells in the medial entorhinal cortex (MEC) that track an animal's distance and direction to objects in the environment. Their firing fields are defined by vectorial relationships to free-standing 3-dimensional (3D) objects of a variety of identities and shapes. However, the natural world contains a panorama of objects,...
Article
Full-text available
CA1 and subiculum (SUB) connect the hippocampus to numerous output regions. Cells in both areas have place-specific firing fields, although they are more dispersed in SUB. Weak responses to head direction and running speed have been reported in both regions. However, how such information is encoded in CA1 and SUB and the resulting impact on downstr...
Article
Recording many neurons for a long time The ultimate aim of chronic recordings is to sample from the same neuron over days and weeks. However, this goal has been difficult to achieve for large populations of neurons. Steinmetz et al. describe the development and testing of Neuropixels 2.0. This new electrophysiological recording tool is a miniaturiz...
Article
Full-text available
Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address this need, we introduce the Neuropixels 2.0 probe together with newly designed analysis algorithms. The probe has more than 5000 sites and is miniaturized to facilitate chronic imp...
Preprint
Full-text available
The medial entorhinal cortex (MEC) is part of a neural system for mapping a subject's position within a physical environment. Grid cells, a key component of this system, fire in a characteristic hexagonal pattern of locations, and are organized in modules which collectively form a population code for the animal's allocentric position1. The invarian...
Article
Full-text available
The theta rhythm organizes neural activity across hippocampus and entorhinal cortex. A role for theta oscillations in spatial navigation is supported by half a century of research reporting that theta frequency encodes running speed linearly so that displacement can be estimated through theta frequency integration. We show that this relationship is...
Preprint
Full-text available
To study the dynamics of neural processing across timescales, we require the ability to follow the spiking of thousands of individually separable neurons over weeks and months, during unrestrained behavior. To address this need, we introduce the Neuropixels 2.0 probe together with novel analysis algorithms. The new probe has over 5,000 sites and is...
Article
Full-text available
Locomotion activates an array of sensory inputs that may help build the self-position map of the medial entorhinal cortex (MEC). In this map, speed-coding neurons are thought to dynamically update representations of the animal's position. A possible origin for the entorhinal speed signal is the mesencephalic locomotor region (MLR), which is critica...
Preprint
Full-text available
CA1 and subiculum (SUB) connect the hippocampus to numerous output regions. Cells in both areas have place-specific firing fields, although they are more dispersed in SUB. Weak responses to head direction and running speed have been reported in both regions. However, how such information is encoded in CA1 and SUB, and the resulting impact on downst...
Article
Full-text available
The grid cell network in the medial entorhinal cortex (MEC) has been subject to thorough testing and analysis, and many theories for their formation have been suggested. To test some of these theories, we re-analyzed data from Bonnevie et al., 2013, in which the hippocampus was inactivated and grid cells were recorded in the rat MEC. We investigate...
Article
Navigation requires the integration of many sensory inputs to form a multi-modal cognitive map of the environment, which is believed to be implemented in the hippocampal region by spatially tuned cells [1-10]. These cells encode various aspects of the environment in a world-based (allocentric) reference frame. Although the cognitive map is represen...
Article
Full-text available
The network of grid cells in the medial entorhinal cortex (MEC) forms a fixed reference frame for mapping physical space. The mechanistic origin of the grid representation is unknown, but continuous attractor network models explain multiple fundamental features of grid cell activity. An untested prediction of these models is that the grid cell netw...
Article
Full-text available
The hippocampus and the medial entorhinal cortex are part of a brain system that maps self-location during navigation in the proximal environment1,2. In this system, correlations between neural firing and an animal’s position or orientation are so evident that cell types have been given simple descriptive names, such as place cells³, grid cells⁴, b...
Preprint
Full-text available
The means by which grid cells form regular, hexagonal spatial firing patterns has been an enigma since their discovery in the medial entorhinal cortex (MEC). Here we re-analyzed data from Bonnevie et al. (2013), in which the hippocampus was inactivated and grid cells were recorded in the MEC, to investigate whether grid cells form an intrinsic netw...
Article
Grid cells fire in a triangular pattern that tessellates the environment [1]. The pattern displays a global distortion that is well described by a shearing transformation of an idealized grid [2]. However, in addition, distortions often differ across parts of the environment, suggesting that the grid interacts with the environment locally [2–5]. Ho...
Article
The hippocampal formation has long been suggested to underlie both memory formation and spatial navigation. We discuss how neural mechanisms identified in spatial navigation research operate across information domains to support a wide spectrum of cognitive functions. In our framework, place and grid cell population codes provide a representational...
Article
Full-text available
Layer II of the medial entorhinal cortex (MEC) contains two principal cell types: pyramidal cells and stellate cells. Accumulating evidence suggests that these two cell types have distinct molecular profiles, physiological properties, and connectivity. The observations hint at a fundamental functional difference between the two cell populations but...
Article
Full-text available
The encoding of time and its binding to events are crucial for episodic memory, but how these processes are carried out in hippocampal-entorhinal circuits is unclear. Here we show in freely foraging rats that temporal information is robustly encoded across time scales from seconds to hours within the overall population state of the lateral entorhin...
Article
During navigation, hippocampal spatial maps are thought to interact with action-planning systems in other regions of cortex. We here report a key role for spike-time coordination in functional coupling of the medial prefrontal cortex (mPFC) to the hippocampus through the thalamic nucleus reuniens (NR). When rats perform a T-maze alternation task, s...
Preprint
Full-text available
The sense of direction is a vital computation, whose neural basis is considered to be carried out by head-direction cells. One way to estimate head-direction is by integrating head angular-velocity over time. However, this process results in error accumulation resembling a random walk, proportional to , which constitutes a mark for a path integrati...
Preprint
Mammals use distances and directions from local objects to calculate trajectories during navigation but how such vectorial operations are implemented in neural representations of space has not been determined. Here we show in freely moving mice that a population of neurons in the medial entorhinal cortex (MEC) responds specifically when the animal...
Article
Full-text available
The mammalian positioning system contains a variety of functionally specialized cells in the medial entorhinal cortex (MEC) and the hippocampus. In order for cells in these systems to dynamically update representations in a way that reflects ongoing movement in the environment, they must be able to read out the current speed of the animal. Speed is...
Article
Full-text available
Place cells in the hippocampus and grid cells in the medial entorhinal cortex rely on self-motion information and path integration for spatially confined firing. Place cells can be observed in young rats as soon as they leave their nest at around 2.5 wk of postnatal life. In contrast, the regularly spaced firing of grid cells develops only after we...
Article
Full-text available
Natural environments are represented by local maps of grid cells and place cells that are stitched together. The manner by which transitions between map fragments are generated is unknown. We recorded grid cells while rats were trained in two rectangular compartments, A and B (each 1 m × 2 m), separated by a wall. Once distinct grid maps were estab...
Article
An episodic memory goes through three different stages: acquisition, consolidation and recall. A new study suggests that distinct microcircuits in the hippocampus underlie the process of memory acquisition and recall.
Article
Since the first place cell was recorded and the cognitive-map theory was subsequently formulated, investigation of spatial representation in the hippocampal formation has evolved in stages. Early studies sought to verify the spatial nature of place cell activity and determine its sensory origin. A new epoch started with the discovery of head direct...
Preprint
Full-text available
The network of grid cells in the medial entorhinal cortex forms a fixed reference frame for mapping physical space. The mechanistic origin of the grid representation is unknown, but continuous attractor network (CAN) models explain multiple fundamental features of grid-cell activity. An untested prediction of CAN grid models is that the grid-cell n...
Article
Full-text available
The medial entorhinal cortex (MEC) contains several discrete classes of GABAergic interneurons, but their specific contributions to spatial pattern formation in this area remain elusive. We employed a pharmacogenetic approach to silence either parvalbumin (PV)- or somatostatin (SOM)-expressing interneurons while MEC cells were recorded in freely mo...
Article
The neural representation of space relies on a network of entorhinal-hippocampal cell types with firing patterns tuned to different abstract features of the environment. To determine how this network is set up during early postnatal development, we monitored markers of structural maturation in developing mice, both in naïve animals and after tempor...
Article
This cover image corresponds to the commentary Hippocampus 25 by Howard Eichenbaum et al., DOI: 10.1002/hipo.22616. Design Credit: Jarret Frank.
Article
The journal Hippocampus has passed the milestone of 25 years of publications on the topic of a highly studied brain structure, and its closely associated brain areas. In a recent celebration of this event, a Boston memory group invited 16 speakers to address the question of progress in understanding the hippocampus that has been achieved. Here we p...
Article
Neuroscientists are increasingly using virtual reality to facilitate studies of animal behaviour, but whether behaviour in the virtual world mimics that in real life is a matter for debate. Here, scientists discuss the strengths and limitations of the approach.
Chapter
Full-text available
The cortical circuit for spatial representation has multiple functionally distinct components, each dedicated to a highly specific aspect of spatial processing. The circuit includes place cells in the hippocampus as well as grid cells, head direction cells and border cells in the medial entorhinal cortex. In this review we discuss the functional or...
Article
Full-text available
The medial entorhinal cortex (MEC) creates a neural representation of space through a set of functionally dedicated cell types: grid cells, border cells, head direction cells, and speed cells. Grid cells, the most abundant functional cell type in the MEC, have hexagonally arranged firing fields that tile the surface of the environment. These cells...
Article
Scientists are discovering how the brain navigates
Article
Hippocampal place cells undergo remapping when the environment is changed. The mechanism of hippocampal remapping remains elusive but spatially modulated cells in the medial entorhinal cortex (MEC) have been identified as a possible contributor. Using pharmacogenetic and optogenetic approaches, we tested the role of MEC cells by examining in mice w...
Article
We asked whether the structural heterogeneity of the hippocampal CA3-CA2 axis is reflected in how space is mapped onto place cells in CA3-CA2. Place fields were smaller and sharper in proximal CA3 than in distal CA3 and CA2. The proximodistal shift was accompanied by a progressive loss in the ability of place cells to distinguish configurations of...
Article
Grid cells in the medial entorhinal cortex have spatial firing fields that repeat periodically in a hexagonal pattern. When animals move, activity is translated between grid cells in accordance with the animal's displacement in the environment. For this translation to occur, grid cells must have continuous access to information about instantaneous...
Article
Spatial navigation requires information about the relationship between current and future positions. The activity of hippocampal neurons appears to reflect such a relationship, representing not only instantaneous position but also the path towards a goal location. However, how the hippocampus obtains information about goal direction is poorly under...
Article
Grid cells are neurons with periodic spatial receptive fields (grids) that tile two-dimensional space in a hexagonal pattern. To provide useful information about location, grids must be stably anchored to an external reference frame. The mechanisms underlying this anchoring process have remained elusive. Here we show in differently sized familiar s...
Article
Full-text available
The hippocampal system is critical for storage and retrieval of declarative memories, including memories for locations and events that take place at those locations. Spatial memories place high demands on capacity. Memories must be distinct to be recalled without interference and encoding must be fast. Recent studies have indicated that hippocampal...
Article
Full-text available
The contribution of hippocampal circuits to high-capacity episodic memory is often attributed to the large number of orthogonal activity patterns that may be stored in these networks. Evidence for high-capacity storage in the hippocampus is missing, however. When animals are tested in pairs of environments, different combinations of place cells are...
Article
Full-text available
Mammalian navigation is thought to depend on an internal map of space consisting of functionally specialized cells in the hippocampus and the surrounding parahippocampal cortices [1-7]. Basic properties of this map are present when rat pups explore the world outside of their nest for the first time, around postnatal day 16-18 (P16-P18) [8-10]. One...
Article
The precise functional role of the hippocampus remains a topic of much debate. The dominant view is that the dorsal (or posterior) hippocampus is implicated in memory and spatial navigation and the ventral (or anterior) hippocampus mediates anxiety-related behaviours. However, this 'dichotomy view' may need revision. Gene expression studies demonst...
Article
Full-text available
One of the grand challenges in neuroscience is to comprehend neural computation in the association cortices, the parts of the cortex that have shown the largest expansion and differentiation during mammalian evolution and that are thought to contribute profoundly to the emergence of advanced cognition in humans. In this Review, we use grid cells in...
Article
Decades of neuroscience research have shed light on the hippocampus as a key structure for the formation of episodic memory. The hippocampus is divided into distinct subfields - CA1, CA2 and CA3. While accumulating evidence points to cellular and synaptic heterogeneity within each subfield, this heterogeneity has not received much attention in comp...
Article
Grid cells have been proposed to reflect competitive interactions in inhibitory neural networks. Experimental results obtained using optogenetics to identify spikes emitted specifically by parvalbumin interneurons now constrain the mechanisms by which such networks could give rise to grid cells.
Article
Accumulating evidence points to cortical oscillations as a mechanism for mediating interactions among functionally specialized neurons in distributed brain circuits. A brain function that may use such interactions is declarative memory-that is, memory that can be consciously recalled, such as episodes and facts. Declarative memory is enabled by cir...
Article
Local space is represented by a number of functionally specific cell types, including place cells in the hippocampus and grid cells, head direction cells, and border cells in the medial entorhinal cortex (MEC). These cells form a functional map of external space already at the time when rat pups leave the nest for the first time in their life, at t...
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Full-text available
Editor’s Note: In 2005, our authors discovered grid cells, which are types of neurons that are central to how the brain calculates location and navigation. Since that time, they have worked to learn how grid cells communicate with other types of neurons—place cells, border cells, and head direction cells—to affect spatial awareness, memory, and dec...