scholarly journals Differences in Visual-Spatial Input May Underlie Different Compression Properties of Firing Fields for Grid Cell Modules in Medial Entorhinal Cortex

2015 ◽  
Vol 11 (11) ◽  
pp. e1004596 ◽  
Author(s):  
Florian Raudies ◽  
Michael E. Hasselmo
Keyword(s):  
Entorhinal Cortex ◽  
Grid Cell ◽  
Medial Entorhinal Cortex ◽  
Compression Properties ◽  
Visual Spatial ◽  
Cell Modules

scholarly journals Neuronal rebound spiking, resonance frequency and theta cycle skipping may contribute to grid cell firing in medial entorhinal cortex

2014 ◽  
Vol 369 (1635) ◽  
pp. 20120523 ◽  
Author(s):  
Michael E. Hasselmo
Keyword(s):  
Resonance Frequency ◽  
Entorhinal Cortex ◽  
Functional Role ◽  
Grid Cell ◽  
Medial Septum ◽  
Medial Entorhinal Cortex ◽  
Spatial Periodicity ◽  
Cell Firing ◽  
Rebound Spiking ◽  
Relationship Of

Data show a relationship of cellular resonance and network oscillations in the entorhinal cortex to the spatial periodicity of grid cells. This paper presents a model that simulates the resonance and rebound spiking properties of entorhinal neurons to generate spatial periodicity dependent upon phasic input from medial septum. The model shows that a difference in spatial periodicity can result from a difference in neuronal resonance frequency that replicates data from several experiments. The model also demonstrates a functional role for the phenomenon of theta cycle skipping in the medial entorhinal cortex.

scholarly journals How to build a grid cell

2014 ◽  
Vol 369 (1635) ◽  
pp. 20120520 ◽  
Author(s):  
Christoph Schmidt-Hieber ◽  
Michael Häusser
Keyword(s):  
Entorhinal Cortex ◽  
Action Potentials ◽  
Path Integration ◽  
Grid Cell ◽  
Medial Entorhinal Cortex ◽  
Synaptic Inputs ◽  
New Findings ◽  
Cell Firing

Neurons in the medial entorhinal cortex fire action potentials at regular spatial intervals, creating a striking grid-like pattern of spike rates spanning the whole environment of a navigating animal. This remarkable spatial code may represent a neural map for path integration. Recent advances using patch-clamp recordings from entorhinal cortex neurons in vitro and in vivo have revealed how the microcircuitry in the medial entorhinal cortex may contribute to grid cell firing patterns, and how grid cells may transform synaptic inputs into spike output during firing field crossings. These new findings provide key insights into the ingredients necessary to build a grid cell.

scholarly journals ARM-Cortex M3-Based Two-Wheel Robot for Assessing Grid Cell Model of Medial Entorhinal Cortex: Progress towards Building Robots with Biologically Inspired Navigation-Cognitive Maps

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
J. Cuneo ◽  
L. Barboni ◽  
N. Blanco ◽  
M. del Castillo ◽  
J. Quagliotti
Keyword(s):  
Embedded System ◽  
Entorhinal Cortex ◽  
Cell Model ◽  
Systems Design ◽  
Grid Cell ◽  
Network Models ◽  
Time Algorithm ◽  
Neural Network Models ◽  
Biologically Inspired ◽  
Medial Entorhinal Cortex

This article presents the implementation and use of a two-wheel autonomous robot and its effectiveness as a tool for studying the recently discovered use of grid cells as part of mammalian’s brains space-mapping circuitry (specifically the medial entorhinal cortex). A proposed discrete-time algorithm that emulates the medial entorhinal cortex is programed into the robot. The robot freely explores a limited laboratory area in the manner of a rat or mouse and reports information to a PC, thus enabling research without the use of live individuals. Position coordinate neural maps are achieved as mathematically predicted although for a reduced number of implemented neurons (i.e., 200 neurons). However, this type of computational embedded system (robot’s microcontroller) is found to be insufficient for simulating huge numbers of neurons in real time (as in the medial entorhinal cortex). It is considered that the results of this work provide an insight into achieving an enhanced embedded systems design for emulating and understanding mathematical neural network models to be used as biologically inspired navigation system for robots.

scholarly journals Theta-frequency resonance as the scale of input-output mapping in the medial entorhinal cortex

2018 ◽  
Author(s):  
Nupur Katyare ◽  
Sujit Sikdar
Keyword(s):  
Firing Rate ◽  
Entorhinal Cortex ◽  
Grid Cell ◽  
Synaptic Activity ◽  
Spatial Period ◽  
Hcn Channels ◽  
Medial Entorhinal Cortex ◽  
Frequency Resonance ◽  
Theta Frequency

Grid cell spatial period is thought to be dictated by a mapping between the speed-direction modulated excitatory inputs, and consequent modulation of the firing rate, yet, the exact underlying mechanisms are not known. Here, through experiments on the medial entorhinal cortex stellate cells, subjected to in-vivo like stochastic synaptic activity through the dynamic clamp, we show that such mapping can emerge from a theta-frequency resonance in the signal gain, which is HCN sensitive, robust to noise, and is potent enough to modulate the synaptic responses in the theta frequency. This modulation also extends to the corresponding theta-gamma modulation of the firing rate, the slope of whose excitation mediated increase is steeper in the presence of HCN channels. We also show that in the cells devoid of HCN channels, inhibition can emulate their role. Considering the dorso-ventral gradients of HCN and inhibition, which are present aligned to the grid spacing gradient in the medial entorhinal cortex, these findings should be noteworthy.

scholarly journals Inter- and intra-animal variation of integrative properties of stellate cells in the medial entorhinal cortex

2019 ◽  
Author(s):  
Hugh Pastoll ◽  
Derek Garden ◽  
Ioannis Papastathopoulos ◽  
Gülşen Sürmeli ◽  
Matthew F. Nolan
Keyword(s):  
Entorhinal Cortex ◽  
Ex Vivo ◽  
Spatial Scales ◽  
Phenotypic Variability ◽  
Grid Cell ◽  
Stellate Cells ◽  
Cell Types ◽  
Functional Variation ◽  
Medial Entorhinal Cortex ◽  
Nervous System Function

AbstractDistinctions between cell types underpin organisational principles for nervous system function. Functional variation also exists between neurons of the same type. This is exemplified by correspondence between grid cell spatial scales and synaptic integrative properties of stellate cells (SCs) in the medial entorhinal cortex. However, we know little about how functional variability is structured either within or between individuals. Using ex-vivo patch-clamp recordings from up to 55 SCs per mouse, we find that integrative properties vary between mice and, in contrast to modularity of grid cell spatial scales, have a continuous dorsoventral organisation. Our results constrain mechanisms for modular grid firing and provide evidence for inter-animal phenotypic variability among neurons of the same type. We suggest that neuron type properties are tuned to circuit level set points that vary within and between animals.

scholarly journals Tuning of Synaptic Integration in the Medial Entorhinal Cortex to the Organization of Grid Cell Firing Fields

Neuron ◽  
2008 ◽  
Vol 60 (5) ◽  
pp. 875-889 ◽  
Author(s):  
Derek L.F. Garden ◽  
Paul D. Dodson ◽  
Cian O'Donnell ◽  
Melanie D. White ◽  
Matthew F. Nolan
Keyword(s):  
Entorhinal Cortex ◽  
Grid Cell ◽  
Synaptic Integration ◽  
Medial Entorhinal Cortex ◽  
Cell Firing

scholarly journals Recurrent circuits within medial entorhinal cortex superficial layers support grid cell firing

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Ipshita Zutshi ◽  
Maylin L. Fu ◽  
Varoth Lilascharoen ◽  
Jill K. Leutgeb ◽  
Byung Kook Lim ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Grid Cell ◽  
Medial Entorhinal Cortex ◽  
Cell Firing ◽  
Support Grid

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.

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