scholarly journals Medial Entorhinal Cortex Lesions Only Partially Disrupt Hippocampal Place Cells and Hippocampus-Dependent Place Memory

Cell Reports ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. 893-901 ◽  
Author(s):  
Jena B. Hales ◽  
Magdalene I. Schlesiger ◽  
Jill K. Leutgeb ◽  
Larry R. Squire ◽  
Stefan Leutgeb ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Place Cells ◽  
Medial Entorhinal Cortex ◽  
Place Memory

scholarly journals Object and object-memory representations across the proximodistal axis of CA1

2020 ◽  
Author(s):  
Brianna Vandrey ◽  
James A. Ainge
Keyword(s):  
Episodic Memory ◽  
Entorhinal Cortex ◽  
Place Cells ◽  
Spatial Representations ◽  
Place Field ◽  
Medial Entorhinal Cortex ◽  
Object Memory ◽  
Place Memory ◽  
Object Locations ◽  
Memory Representations

AbstractEpisodic memory requires information about objects to be integrated into a spatial framework. Place cells in the hippocampus encode spatial representations of objects that could be generated through signalling from the entorhinal cortex. Projections from lateral and medial entorhinal cortex to the hippocampus terminate in distal and proximal CA1, respectively. We recorded place cells in distal and proximal CA1 as rats explored an environment that contained objects. Place cells in distal CA1 demonstrated higher measures of spatial tuning and expressed place fields closer to objects. Further, remapping to object displacement was modulated by place field proximity to objects in distal, but not proximal CA1. Finally, representations of previous object locations were more precise in distal CA1. Our data suggest that lateral entorhinal cortex inputs to the hippocampus support spatial representations that are more precise and responsive to objects in cue-rich environments. This is consistent with functional segregation in the entorhinal-hippocampal circuits underlying object-place memory.

scholarly journals Hippocampal Spike-Timing Correlations Lead to Hexagonal Grid Fields

2017 ◽  
Author(s):  
Mauro M Monsalve-Mercado ◽  
Christian Leibold
Keyword(s):  
Synaptic Plasticity ◽  
Pattern Formation ◽  
Entorhinal Cortex ◽  
Turing Instability ◽  
Place Cells ◽  
Spike Timing ◽  
Mammalian Brain ◽  
Inhibition Mechanism ◽  
Temporal Code ◽  
Medial Entorhinal Cortex

Space is represented in the mammalian brain by the activity of hippocampal place cells as well as in their spike-timing correlations. Here we propose a theory how this temporal code is transformed to spatial firing rate patterns via spike-timing-dependent synaptic plasticity. The resulting dynamics of synaptic weights resembles well-known pattern formation models in which a lateral inhibition mechanism gives rise to a Turing instability. We identify parameter regimes in which hexagonal firing patterns develop as they have been found in medial entorhinal cortex.

scholarly journals Field repetition and local mapping in the hippocampus and the medial entorhinal cortex

2017 ◽  
Vol 118 (4) ◽  
pp. 2378-2388 ◽  
Author(s):  
Roddy M. Grieves ◽  
Éléonore Duvelle ◽  
Emma R. Wood ◽  
Paul A. Dudchenko
Keyword(s):  
Entorhinal Cortex ◽  
Local Area ◽  
Place Cells ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Pattern Completion ◽  
Global Space ◽  
Local Environments ◽  
Neural Substrate ◽  
The Relationship

Hippocampal place cells support spatial cognition and are thought to form the neural substrate of a global “cognitive map.” A widely held view is that parts of the hippocampus also underlie the ability to separate patterns or to provide different neural codes for distinct environments. However, a number of studies have shown that in environments composed of multiple, repeating compartments, place cells and other spatially modulated neurons show the same activity in each local area. This repetition of firing fields may reflect pattern completion and may make it difficult for animals to distinguish similar local environments. In this review we 1) highlight some of the navigation difficulties encountered by humans in repetitive environments, 2) summarize literature demonstrating that place and grid cells represent local and not global space, and 3) attempt to explain the origin of these phenomena. We argue that the repetition of firing fields can be a useful tool for understanding the relationship between grid cells in the entorhinal cortex and place cells in the hippocampus, the spatial inputs shared by these cells, and the propagation of spatially related signals through these structures.

A MODEL OF GRID CELLS BASED ON A TWISTED TORUS TOPOLOGY

2007 ◽  
Vol 17 (04) ◽  
pp. 231-240 ◽  
Author(s):  
ALEXIS GUANELLA ◽  
DANIEL KIPER ◽  
PAUL VERSCHURE
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Entorhinal Cortex ◽  
Firing Frequency ◽  
Place Cells ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Triangular Grids ◽  
Multiple Regions ◽  
Robust To Noise

The grid cells of the rat medial entorhinal cortex (MEC) show an increased firing frequency when the position of the animal correlates with multiple regions of the environment that are arranged in regular triangular grids. Here, we describe an artificial neural network based on a twisted torus topology, which allows for the generation of regular triangular grids. The association of the activity of pre-defined hippocampal place cells with entorhinal grid cells allows for a highly robust-to-noise calibration mechanism, suggesting a role for the hippocampal back-projections to the entorhinal cortex.

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.

A role for medial entorhinal cortex in spatial and nonspatial forms of memory in rats

2021 ◽  
pp. 113259
Author(s):  
Jena B. Hales ◽  
Nicole T. Reitz ◽  
Jonathan L. Vincze ◽  
Amber C. Ocampo ◽  
Stefan Leutgeb ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Medial Entorhinal Cortex

scholarly journals P2-071: IMPAIRED IN VIVO GAMMA OSCILLATIONS IN THE MEDIAL ENTORHINAL CORTEX OF KNOCK-IN ALZHEIMER MODEL

2019 ◽  
Vol 15 ◽  
pp. P598-P598
Author(s):  
Heechul Jun ◽  
Shogo Soma ◽  
Ananya Dasgupta ◽  
Kei Igarashi
Keyword(s):  
Entorhinal Cortex ◽  
Gamma Oscillations ◽  
Medial Entorhinal Cortex

scholarly journals The Caudal Medial Entorhinal Cortex: a Selective Role in Recollection-Based Recognition Memory

2010 ◽  
Vol 30 (46) ◽  
pp. 15695-15699 ◽  
Author(s):  
M. M. Sauvage ◽  
Z. Beer ◽  
M. Ekovich ◽  
L. Ho ◽  
H. Eichenbaum
Keyword(s):  
Recognition Memory ◽  
Entorhinal Cortex ◽  
Medial Entorhinal Cortex
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