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 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

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 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 Entorhinal velocity signals reflect environmental geometry

2019 ◽  
Author(s):  
Robert G K Munn ◽  
Caitlin S Mallory ◽  
Kiah Hardcastle ◽  
Dane M Chetkovich ◽  
Lisa M Giocomo
Keyword(s):  
Environmental Change ◽  
Grid Cell ◽  
Cell Types ◽  
Dependent Manner ◽  
Head Direction ◽  
Neural Signals ◽  
Head Direction Cells ◽  
Knockout Mouse Model ◽  
Size And Shape ◽  
Environmental Geometry

SummaryThe entorhinal cortex contains neural signals for representing self-location, including grid cells that fire in periodic locations and velocity signals that encode an animal’s speed and head direction. Recent work revealed that the size and shape of the environment influences grid patterns. Whether entorhinal velocity signals are equally influenced or provide a universal metric for self-motion across environments remains unknown. Here, we report that changes to the size and shape of the environment result in re-scaling in entorhinal speed codes. Moreover, head direction cells re-organize in an experience-dependent manner to align with the axis of environmental change. A knockout mouse model allows a dissociation of the coordination between cell types, with grid and speed, but not head direction, cells responding in concert to environmental change. These results align with predictions of grid cell attractor models and point to inherent flexibility in the coding features of multiple functionally-defined entorhinal cell types.

Effects of Glucocorticoids on Age-Related Impairments of Hippocampal Structure and Function in Mice

2007 ◽  
Vol 28 (2) ◽  
pp. 277-291 ◽  
Author(s):  
Wen-Bin He ◽  
Jun-Long Zhang ◽  
Jin-Feng Hu ◽  
Yun Zhang ◽  
Takeo Machida ◽  
...  
Keyword(s):  
Structure And Function ◽  
Age Related ◽  
And Function ◽  
Hippocampal Structure

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

Erratum to “Genetic influences on hippocampal structure and function in recombinant inbred mice” [Behav. Brain Res. 196 (2009) 78–83]

2009 ◽  
Vol 199 (2) ◽  
pp. 364
Author(s):  
Maureen V. Martin ◽  
James D. Churchill ◽  
Hongxin Dong ◽  
David F. Wozniak ◽  
James M. Cheverud ◽  
...  
Keyword(s):  
Recombinant Inbred ◽  
Inbred Mice ◽  
Structure And Function ◽  
Genetic Influences ◽  
Recombinant Inbred Mice ◽  
And Function ◽  
Hippocampal Structure

Lifestyle and Genetic Contributions to Cognitive Decline and Hippocampal Structure and Function in Healthy Aging

2012 ◽  
Vol 9 (4) ◽  
pp. 436-446 ◽  
Author(s):  
John L. Woodard ◽  
Michael A. Sugarman ◽  
Kristy A. Nielson ◽  
J. Carson Smith ◽  
Michael Seidenberg ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Healthy Aging ◽  
Structure And Function ◽  
And Function ◽  
Genetic Contributions ◽  
Hippocampal Structure

scholarly journals Emerging concepts in smooth muscle contributions to airway structure and function: implications for health and disease

2016 ◽  
Vol 311 (6) ◽  
pp. L1113-L1140 ◽  
Author(s):  
Y. S. Prakash
Keyword(s):  
Smooth Muscle ◽  
Cell Types ◽  
Structure And Function ◽  
Normal Lung ◽  
Future Research ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Health And Disease ◽  
Growth And Aging ◽  
And Function

Airway structure and function are key aspects of normal lung development, growth, and aging, as well as of lung responses to the environment and the pathophysiology of important diseases such as asthma, chronic obstructive pulmonary disease, and fibrosis. In this regard, the contributions of airway smooth muscle (ASM) are both functional, in the context of airway contractility and relaxation, as well as synthetic, involving production and modulation of extracellular components, modulation of the local immune environment, cellular contribution to airway structure, and, finally, interactions with other airway cell types such as epithelium, fibroblasts, and nerves. These ASM contributions are now found to be critical in airway hyperresponsiveness and remodeling that occur in lung diseases. This review emphasizes established and recent discoveries that underline the central role of ASM and sets the stage for future research toward understanding how ASM plays a central role by being both upstream and downstream in the many interactive processes that determine airway structure and function in health and disease.

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