scholarly journals Object-vector coding in the medial entorhinal cortex

2018 ◽  
Author(s):  
Øyvind Arne Høydal ◽  
Emilie Ranheim Skytøen ◽  
May-Britt Moser ◽  
Edvard I. Moser
Keyword(s):  
Entorhinal Cortex ◽  
Head Direction ◽  
Test Arena ◽  
Medial Entorhinal Cortex ◽  
Vector Coding ◽  
Neural Representations ◽  
Object Locations ◽  
Novel Objects ◽  
Freely Moving ◽  
Representations Of Space

SummaryMammals 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 is at a given distance and direction from a spatially confined object. These ‘object-vector cells’ are tuned similarly to a spectrum of discrete objects, irrespective of their location in the test arena. The vector relationships are expressed from the outset in novel environments with novel objects. Object-vector cells are distinct from grid cells, which use a distal reference frame, but the cells exhibit some mixed selectivity with head-direction and border cells. Collectively, these observations show that object locations are integrated in metric representations of self-location, with specific subsets of MEC neurons encoding vector relationships to individual objects.

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 Mouse entorhinal cortex encodes a diverse repertoire of self-motion signals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Caitlin S. Mallory ◽  
Kiah Hardcastle ◽  
Malcolm G. Campbell ◽  
Alexander Attinger ◽  
Isabel I. C. Low ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Medial Temporal Lobe ◽  
Visual Cues ◽  
Neural Circuits ◽  
Sensory Cues ◽  
Medial Entorhinal Cortex ◽  
Representation Of Space ◽  
Self Motion ◽  
Information Streams ◽  
Representations Of Space

AbstractNeural circuits generate representations of the external world from multiple information streams. The navigation system provides an exceptional lens through which we may gain insights about how such computations are implemented. Neural circuits in the medial temporal lobe construct a map-like representation of space that supports navigation. This computation integrates multiple sensory cues, and, in addition, is thought to require cues related to the individual’s movement through the environment. Here, we identify multiple self-motion signals, related to the position and velocity of the head and eyes, encoded by neurons in a key node of the navigation circuitry of mice, the medial entorhinal cortex (MEC). The representation of these signals is highly integrated with other cues in individual neurons. Such information could be used to compute the allocentric location of landmarks from visual cues and to generate internal representations of space.

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 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.

scholarly journals Dynamic and reversible remapping of network representations in an unchanging environment

2020 ◽  
Author(s):  
Isabel I. C. Low ◽  
Alex H. Williams ◽  
Malcolm G. Campbell ◽  
Scott W. Linderman ◽  
Lisa M. Giocomo
Keyword(s):  
Entorhinal Cortex ◽  
Neural Coding ◽  
Environmental Changes ◽  
Sensory Information ◽  
Population Level ◽  
Spatial Coding ◽  
Medial Entorhinal Cortex ◽  
Neural Representations ◽  
Cell Firing ◽  
Firing Properties

AbstractIn response to environmental changes, the medial entorhinal cortex alters its single-cell firing properties. This flexibility in neural coding is hypothesized to support navigation and memory by dividing sensory experience into unique contextual episodes. However, it is unknown how the entorhinal circuit transitions between different representations, particularly when sensory information is not delineated into discrete contexts. Here, we describe spontaneous and abrupt transitions between multiple spatial maps of an unchanging task and environment. These remapping events were synchronized across hundreds of medial entorhinal neurons and correlated with changes in running speed. While remapping altered spatial coding in individual neurons, we show that features of the environment were statistically preserved at the population-level, enabling simple decoding strategies. These findings provoke a reconsideration of how medial entorhinal cortex dynamically represents space and broadly suggest a remarkable capacity for higher-order cortical circuits to rapidly and substantially reorganize their neural representations.

scholarly journals Egocentric coding of external items in the lateral entorhinal cortex

Science ◽  
2018 ◽  
Vol 362 (6417) ◽  
pp. 945-949 ◽  
Author(s):  
Cheng Wang ◽  
Xiaojing Chen ◽  
Heekyung Lee ◽  
Sachin S. Deshmukh ◽  
D. Yoganarasimha ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Spatial Cognition ◽  
Entorhinal Cortex ◽  
Essential Role ◽  
Reference Frames ◽  
Single Neurons ◽  
Spatial Coding ◽  
Medial Entorhinal Cortex ◽  
Neural Representations ◽  
Conscious Recollection

Episodic memory, the conscious recollection of past events, is typically experienced from a first-person (egocentric) perspective. The hippocampus plays an essential role in episodic memory and spatial cognition. Although the allocentric nature of hippocampal spatial coding is well understood, little is known about whether the hippocampus receives egocentric information about external items. We recorded in rats the activity of single neurons from the lateral entorhinal cortex (LEC) and medial entorhinal cortex (MEC), the two major inputs to the hippocampus. Many LEC neurons showed tuning for egocentric bearing of external items, whereas MEC cells tended to represent allocentric bearing. These results demonstrate a fundamental dissociation between the reference frames of LEC and MEC neural representations.

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