scholarly journals Functional properties of stellate cells in medial entorhinal cortex layer II

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
David C Rowland ◽  
Horst A Obenhaus ◽  
Emilie R Skytøen ◽  
Qiangwei Zhang ◽  
Cliff G Kentros ◽  
...  
Keyword(s):  
Entorhinal Cortex ◽  
Stellate Cell ◽  
Pyramidal Cells ◽  
Stellate Cells ◽  
Cell Types ◽  
Functional Difference ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Transgenic Mouse Line ◽  
Firing Properties

Layer II of the medial entorhinal cortex (MEC) contains two principal cell types: pyramidal cells and stellate cells. Accumulating evidence suggests that these two cell types have distinct molecular profiles, physiological properties, and connectivity. The observations hint at a fundamental functional difference between the two cell populations but conclusions have been mixed. Here, we used a tTA-based transgenic mouse line to drive expression of ArchT, an optogenetic silencer, specifically in stellate cells. We were able to optogenetically identify stellate cells and characterize their firing properties in freely moving mice. The stellate cell population included cells from a range of functional cell classes. Roughly one in four of the tagged cells were grid cells, suggesting that stellate cells contribute not only to path-integration-based representation of self-location but also have other functions. The data support observations suggesting that grid cells are not the sole determinant of place cell firing.

scholarly journals Shedding light on stellate cells

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Andrew S Alexander ◽  
Michael E Hasselmo
Keyword(s):  
Entorhinal Cortex ◽  
Stellate Cells ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
The Relationship

The relationship between grid cells and two types of neurons found in the medial entorhinal cortex has been clarified.

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

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Hugh Pastoll ◽  
Derek L 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

Distinctions between cell types underpin organizational 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 the 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 found that integrative properties vary between mice and, in contrast to the modularity of grid cell spatial scales, have a continuous dorsoventral organization. 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 Structural development and dorsoventral maturation of the medial entorhinal cortex

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Saikat Ray ◽  
Michael Brecht
Keyword(s):  
Entorhinal Cortex ◽  
Spatial Scales ◽  
Pyramidal Cells ◽  
Stellate Cells ◽  
Superficial Layer ◽  
Cholinergic Innervation ◽  
Structural Development ◽  
Medial Entorhinal Cortex ◽  
Functional Maturation ◽  
Layer 2

We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin – a marker of immature neurons – suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits – representing larger spatial-scales – follows later around the onset of exploratory behavior.

scholarly journals Structural modularity and grid activity in the medial entorhinal cortex

2018 ◽  
Vol 119 (6) ◽  
pp. 2129-2144 ◽  
Author(s):  
Robert K. Naumann ◽  
Patricia Preston-Ferrer ◽  
Michael Brecht ◽  
Andrea Burgalossi
Keyword(s):  
Entorhinal Cortex ◽  
Cell Types ◽  
Modular System ◽  
Anatomical Location ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Freely Moving ◽  
Open Question ◽  
To Receive ◽  
Cortical Architecture

Following the groundbreaking discovery of grid cells, the medial entorhinal cortex (MEC) has become the focus of intense anatomical, physiological, and computational investigations. Whether and how grid activity maps onto cell types and cortical architecture is still an open question. Fundamental similarities in microcircuits, function, and connectivity suggest a homology between rodent MEC and human posteromedial entorhinal cortex. Both are specialized for spatial processing and display similar cellular organization, consisting of layer 2 pyramidal/calbindin cell patches superimposed on scattered stellate neurons. Recent data indicate the existence of a further nonoverlapping modular system (zinc patches) within the superficial MEC layers. Zinc and calbindin patches have been shown to receive largely segregated inputs from the presubiculum and parasubiculum. Grid cells are also clustered in the MEC, and we discuss possible structure-function schemes on how grid activity could map onto cortical patch systems. We hypothesize that in the superficial layers of the MEC, anatomical location can be predictive of function; thus relating functional properties and neuronal morphologies to the cortical modules will be necessary for resolving how grid activity maps onto cortical architecture. Imaging or cell identification approaches in freely moving animals will be required for testing this hypothesis.

Hyperexcitability of entorhinal cortex and hippocampus after application of aminooxyacetic acid (AOAA) to layer III of the rat medial entorhinal cortex in vitro

1996 ◽  
Vol 76 (5) ◽  
pp. 2986-3001 ◽  
Author(s):  
H. E. Scharfman
Keyword(s):  
Nmda Receptor ◽  
Evoked Potentials ◽  
Entorhinal Cortex ◽  
Pyramidal Cells ◽  
Aminooxyacetic Acid ◽  
Field Potentials ◽  
Medial Entorhinal Cortex ◽  
Extracellular Recordings ◽  
Extracellular Potentials

1. Injection of aminooxyacetic acid (AOAA) into the entorhinal cortex in vivo produces acute seizures and cell loss in medial entorhinal cortex. To understand these effects, AOAA was applied directly to the medial entorhinal cortex in slices containing both the entorhinal cortex and hippocampus. Extracellular and intracellular recordings were made in both the entorhinal cortex and hippocampus to study responses to angular bundle stimulation and spontaneous activity. 2. AOAA was applied focally by leak from a micropipette or by pressure ejection. Evoked potentials increased gradually within 5 min of application, particularly the late, negative components. Evoked potentials continued to increase for up to 1 h, and these changes persisted for the remainder of the experiment (up to 5 h after drug application). 3. Paired pulse facilitation (100-ms interval) was also enhanced after AOAA application. Increasing stimulus frequency to 1-10 Hz increased evoked potentials further, and after several seconds of such stimulation multiple field potentials occurred. When stimulation was stopped at this point, repetitive field potentials occurred spontaneously for 1-2 min. These recordings, and simultaneous extracellular recordings in different layers, indicated that spontaneous synchronous activity occurred in entorhinal neurons. Intracellularly labeled cortical pyramidal cells depolarized and discharged during spontaneous and evoked field potentials. 4. The effects of AOAA were blocked reversibly by bath application of the N-methyl-D-aspartate (NMDA) receptor antagonist D-amino-5-phosphonovalerate (D-APV; 25 microM) or focal application of D-APV to the medial entorhinal cortex. 5. Simultaneous extracellular recordings from the entorhinal cortex and hippocampus demonstrated that spontaneous synchronous activity in layer III was often followed within several milliseconds by negative field potentials in the terminal zones of the perforant path (stratum moleculare of the dentate gyrus and stratum lacunosum-moleculare of area CA1). The extracellular potentials recorded in the dentate gyrus corresponded to excitatory postsynaptic potentials and action potentials in dentate granule cells. However, extracellular potentials in area CA1 were small and rarely correlated with discharge in CA1 pyramidal cells. 6. The results demonstrate that AOAA application leads to an NMDA-receptor-dependent enhancement of evoked potentials in medial entorhinal cortical neurons, which appears to be irreversible. The potentials can be facilitated by repetitive stimulation, and lead to synchronized discharges of entorhinal neurons. The discharges invade other areas such as the hippocampus, indicating how seizure activity may spread after AOAA injection in vivo. These data suggest that AOAA may be a useful tool to study longlasting changes in NMDA receptor function that lead to epileptiform activity and neurodegeneration.

scholarly journals A geometric attractor mechanism for self-organization of entorhinal grid modules

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Louis Kang ◽  
Vijay Balasubramanian
Keyword(s):  
Entorhinal Cortex ◽  
Network Models ◽  
Recurrent Inhibition ◽  
Modular Structure ◽  
Self Organization ◽  
Periodic Lattice ◽  
Grid Cells ◽  
Medial Entorhinal Cortex ◽  
Attractor Network ◽  
Discrete Values

Grid cells in the medial entorhinal cortex (MEC) respond when an animal occupies a periodic lattice of ‘grid fields’ in the environment. The grids are organized in modules with spatial periods, or scales, clustered around discrete values separated on average by ratios in the range 1.4–1.7. We propose a mechanism that produces this modular structure through dynamical self-organization in the MEC. In attractor network models of grid formation, the grid scale of a single module is set by the distance of recurrent inhibition between neurons. We show that the MEC forms a hierarchy of discrete modules if a smooth increase in inhibition distance along its dorso-ventral axis is accompanied by excitatory interactions along this axis. Moreover, constant scale ratios between successive modules arise through geometric relationships between triangular grids and have values that fall within the observed range. We discuss how interactions required by our model might be tested experimentally.

scholarly journals Cholinergic Modulation of the Resonance Properties of Stellate Cells in Layer II of Medial Entorhinal Cortex

2010 ◽  
Vol 104 (1) ◽  
pp. 258-270 ◽  
Author(s):  
James G. Heys ◽  
Lisa M. Giocomo ◽  
Michael E. Hasselmo
Keyword(s):  
Patch Clamp ◽  
Resonance Frequency ◽  
Entorhinal Cortex ◽  
Stellate Cells ◽  
Cholinergic Modulation ◽  
Medial Entorhinal Cortex ◽  
Whole Cell ◽  
Whole Cell Patch Clamp ◽  
Resonance Properties

In vitro whole cell patch-clamp recordings of stellate cells in layer II of medial entorhinal cortex show a subthreshold membrane potential resonance in response to a sinusoidal current injection of varying frequency. Physiological recordings from awake behaving animals show that neurons in layer II medial entorhinal cortex, termed “grid cells,” fire in a spatially selective manner such that each cell's multiple firing fields form a hexagonal grid. Both the spatial periodicity of the grid fields and the resonance frequency change systematically in neurons along the dorsal to ventral axis of medial entorhinal cortex. Previous work has also shown that grid field spacing and acetylcholine levels change as a function of the novelty to a particular environment. Using in vitro whole cell patch-clamp recordings, our study shows that both resonance frequency and resonance strength vary as a function of cholinergic modulation. Furthermore, our data suggest that these changes in resonance properties are mediated through modulation of h-current and m-current.

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