scholarly journals Topography of Head Direction Cells in Medial Entorhinal Cortex

2014 ◽  
Vol 24 (3) ◽  
pp. 252-262 ◽  
Author(s):  
Lisa M. Giocomo ◽  
Tor Stensola ◽  
Tora Bonnevie ◽  
Tiffany Van Cauter ◽  
May-Britt Moser ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Head Direction ◽  
Head Direction Cells ◽  
Medial Entorhinal Cortex

scholarly journals Non-rhythmic head-direction cells in the parahippocampal region are not constrained by attractor network dynamics

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Olga Kornienko ◽  
Patrick Latuske ◽  
Mathis Bassler ◽  
Laura Kohler ◽  
Kevin Allen
Keyword(s):  
Entorhinal Cortex ◽  
Computational Models ◽  
Tuning Curve ◽  
Rhythmic Activity ◽  
External World ◽  
Head Direction ◽  
Visual Landmarks ◽  
Head Direction Cells ◽  
Medial Entorhinal Cortex ◽  
Attractor Network

Computational models postulate that head-direction (HD) cells are part of an attractor network integrating head turns. This network requires inputs from visual landmarks to anchor the HD signal to the external world. We investigated whether information about HD and visual landmarks is integrated in the medial entorhinal cortex and parasubiculum, resulting in neurons expressing a conjunctive code for HD and visual landmarks. We found that parahippocampal HD cells could be divided into two classes based on their theta-rhythmic activity: non-rhythmic and theta-rhythmic HD cells. Manipulations of the visual landmarks caused tuning curve alterations in most HD cells, with the largest visually driven changes observed in non-rhythmic HD cells. Importantly, the tuning modifications of non-rhythmic HD cells were often non-coherent across cells, refuting the notion that attractor-like dynamics control non-rhythmic HD cells. These findings reveal a new population of non-rhythmic HD cells whose malleable organization is controlled by visual landmarks.

scholarly journals Home, head direction stability, and grid cell distortion

2020 ◽  
Vol 123 (4) ◽  
pp. 1392-1406 ◽  
Author(s):  
Juan Ignacio Sanguinetti-Scheck ◽  
Michael Brecht
Keyword(s):  
Entorhinal Cortex ◽  
Home Cage ◽  
Cell Activity ◽  
Grid Cell ◽  
Head Direction ◽  
Grid Cells ◽  
Head Direction Cells ◽  
Medial Entorhinal Cortex ◽  
Abstract Approach ◽  
Globally Stable

The home is a unique location in the life of humans and animals. In rats, home presents itself as a multicompartmental space that involves integrating navigation through subspaces. Here we embedded the laboratory rat’s home cage in the arena, while recording neurons in the animal’s parasubiculum and medial entorhinal cortex, two brain areas encoding the animal’s location and head direction. We found that head direction signals were unaffected by home cage presence or translocation. Head direction cells remain globally stable and have similar properties inside and outside the embedded home. We did not observe egocentric bearing encoding of the home cage. However, grid cells were distorted in the presence of the home cage. While they did not globally remap, single firing fields were translocated toward the home. These effects appeared to be geometrical in nature rather than a home-specific distortion and were not dependent on explicit behavioral use of the home cage during a hoarding task. Our work suggests that medial entorhinal cortex and parasubiculum do not remap after embedding the home, but local changes in grid cell activity overrepresent the embedded space location and might contribute to navigation in complex environments. NEW & NOTEWORTHY Neural findings in the field of spatial navigation come mostly from an abstract approach that separates the animal from even a minimally biological context. In this article we embed the home cage of the rat in the environment to address some of the complexities of natural navigation. We find no explicit home cage representation. While both head direction cells and grid cells remain globally stable, we find that embedded spaces locally distort grid cells.

scholarly journals Head-direction cells escaping attractor dynamics in the parahippocampal region

2018 ◽  
Author(s):  
Olga Kornienko ◽  
Patrick Latuske ◽  
Laura Kohler ◽  
Kevin Allen
Keyword(s):  
Entorhinal Cortex ◽  
Computational Models ◽  
Head Direction ◽  
Grid Cells ◽  
Visual Landmarks ◽  
Head Direction Cells ◽  
Medial Entorhinal Cortex ◽  
Attractor Dynamics ◽  
Freely Moving ◽  
Uniform Population

AbstractNavigation depends on the activity of head-direction (HD) cells. Computational models postulate that HD cells form a uniform population that reacts coherently to changes in landmarks. We tested whether this applied to HD cells of the medial entorhinal cortex and parasubiculum, areas where the HD signal contributes to the periodic firing of grid cells. Manipulations of the visual landmarks surrounding freely-moving mice altered the tuning of HD cells. Importantly, these tuning modifications were often non-coherent across cells, refuting the notion that HD cells form a uniform population constrained by attractor-like dynamics. Instead, examination of theta rhythmicity 1revealed two types of HD cells, theta rhythmic and non-rhythmic cells. Larger tuning alterations were observed predominantly in non-rhythmic HD cells. Moreover, only non-rhythmic HD cells reorganized their firing associations in response to visual land-mark changes. These findings reveal a theta non-rhythmic HD signal whose malleable organization is controlled by visual landmarks.

scholarly journals Functional connectivity of the entorhinal–hippocampal space circuit

2014 ◽  
Vol 369 (1635) ◽  
pp. 20120516 ◽  
Author(s):  
Sheng-Jia Zhang ◽  
Jing Ye ◽  
Jonathan J. Couey ◽  
Menno Witter ◽  
Edvard I. Moser ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Cell Types ◽  
Place Cells ◽  
Projection Neurons ◽  
Border Cells ◽  
Head Direction ◽  
Grid Cells ◽  
Head Direction Cells ◽  
Dynamic Interactions ◽  
Cell Groups

The mammalian space circuit is known to contain several functionally specialized cell types, such as place cells in the hippocampus and grid cells, head-direction cells and border cells in the medial entorhinal cortex (MEC). The interaction between the entorhinal and hippocampal spatial representations is poorly understood, however. We have developed an optogenetic strategy to identify functionally defined cell types in the MEC that project directly to the hippocampus. By expressing channelrhodopsin-2 (ChR2) selectively in the hippocampus-projecting subset of entorhinal projection neurons, we were able to use light-evoked discharge as an instrument to determine whether specific entorhinal cell groups—such as grid cells, border cells and head-direction cells—have direct hippocampal projections. Photoinduced firing was observed at fixed minimal latencies in all functional cell categories, with grid cells as the most abundant hippocampus-projecting spatial cell type. We discuss how photoexcitation experiments can be used to distinguish the subset of hippocampus-projecting entorhinal neurons from neurons that are activated indirectly through the network. The functional breadth of entorhinal input implied by this analysis opens up the potential for rich dynamic interactions between place cells in the hippocampus and different functional cell types in the entorhinal cortex (EC).

scholarly journals Home, head direction stability and grid cell distortion

2019 ◽  
Author(s):  
Juan Ignacio Sanguinetti-Scheck ◽  
Michael Brecht
Keyword(s):  
Entorhinal Cortex ◽  
Home Cage ◽  
Grid Cell ◽  
Neural Representation ◽  
Head Direction ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Home Location ◽  
Single Firing ◽  
Behavioral Studies

AbstractThe home is a unique location in the life of humans and animals. Numerous behavioral studies investigating homing indicate that many animals maintain an online representation of the direction of the home, a home vector. Here we placed the rat’s home cage in the arena, while recording neurons in the animal’s parasubiculum and medial entorhinal cortex. From a pellet hoarding paradigm it became evident that the home cage induced locomotion patterns characteristic of homing behaviors. We did not observe home-vector cells. We found that head-direction signals were unaffected by home location. However, grid cells were distorted in the presence of the home cage. While they did not globally remap, single firing fields were translocated towards the home. These effects appeared to be geometrical in nature rather than a home-specific distortion. Our work suggests that medial entorhinal cortex and parasubiculum do not contain an explicit neural representation of the home direction.

Entorhinal Cortex

2017 ◽  
pp. 227-244
Author(s):  
Edvard I. Moser ◽  
Menno P. Witter ◽  
May-Britt Moser
Keyword(s):  
Entorhinal Cortex ◽  
Grid Cell ◽  
Cell Types ◽  
Structure And Function ◽  
Modular Organization ◽  
Head Direction ◽  
Head Direction Cells ◽  
Terra Incognita ◽  
And Function ◽  
Hippocampal Structure

While decades of study have unraveled some of the basic principles of hippocampal structure and function, the adjacent entorhinal cortex (EC) has remained terra incognita in many respects. Recent studies suggest that the medial part of the entorhinal cortex is part of a two-dimensional metric map of the animal’s changing location in the environment. A key component of this map is the grid cell, which fires selectively at hexagonally spaced positions in the animal’s environment. Grid cells colocalize with other recently discovered medial entorhinal cell types, such as head direction cells, conjunctive grid × head direction cells, border cells, and speed cells. This chapter provides an overview of these functional cell types, their possible relationship to morphological cell types, the intrinsic architecture of the system (including laminar, longitudinal, and modular organization), and the extrinsic connectivity and possible function of both the medial and lateral subdivisions of the entorhinal cortex.

scholarly journals Functional network topography of the medial entorhinal cortex

2021 ◽  
Author(s):  
Horst A. Obenhaus ◽  
Weijian Zong ◽  
R. Irene Jacobsen ◽  
Tobias Rose ◽  
Flavio Donato ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Grid Cell ◽  
Cell Types ◽  
List Type ◽  
Head Direction ◽  
Grid Cells ◽  
Activity Data ◽  
Medial Entorhinal Cortex ◽  
Depth Analysis ◽  
Low Levels

SummaryThe 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 neurons during unrestrained behavior, which neither electrophysiological nor previous imaging methods fully afford. Here we examined the topographic arrangement of spatially modulated neurons in MEC and adjacent parasubiculum using miniaturized, portable two-photon microscopes, which allow mice to roam freely in open fields. Grid cells exhibited low levels of co-occurrence with OV cells and clustered anatomically, while border, HD and OV cells tended to intermingle. These data suggest that grid-cell networks might be largely distinct from those of border, HD and OV cells and that grid cells exhibit strong coupling among themselves but weaker links to other cell types.Highlights- Grid and object vector cells show low levels of regional co-occurrence- Grid cells exhibit the strongest tendency to cluster among all spatial cell types- Grid cells stay separate from border, head direction and object vector cells- The territories of grid, head direction and border cells remain stable over weeks

scholarly journals Microcircuits for spatial coding in the medial entorhinal cortex

2021 ◽  
Author(s):  
John J Tukker ◽  
Prateep Beed ◽  
Michael Brecht ◽  
Richard Kempter ◽  
Edvard I Moser ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Hippocampal Formation ◽  
Spatial Navigation ◽  
Cell Types ◽  
Head Direction ◽  
Spatial Coding ◽  
Grid Pattern ◽  
Medial Entorhinal Cortex ◽  
Attractor Dynamics ◽  
Discharge Patterns

The hippocampal formation is critically involved in learning and memory, and contains a large proportion of neurons encoding aspects of the organism's spatial surroundings. In the medial entorhinal cortex (MEC), this includes grid cells with their distinctive hexagonal firing fields, as well as a host of other functionally defined cell types including head-direction cells, speed cells, border cells, and object vector cells. Such spatial coding emerges from the processing of external inputs by local microcircuits. However, it remains unclear exactly how local microcircuits and their dynamics within the MEC contribute to spatial discharge patterns. In this review we focus on recent investigations of intrinsic MEC connectivity, which have started to describe and quantify both excitatory and inhibitory wiring in the superficial layers of the MEC. Although the picture is far from complete, it appears that these layers contain robust recurrent connectivity that could sustain the attractor dynamics posited to underlie grid-pattern formation. These findings pave the way to a deeper understanding of the mechanisms underlying spatial navigation and memory.

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