scholarly journals Synaptic Properties of Thalamic and Intracortical Inputs to Layer 4 of the First- and Higher-Order Cortical Areas in the Auditory and Somatosensory Systems

2008 ◽  
Vol 100 (1) ◽  
pp. 317-326 ◽  
Author(s):  
Charles C. Lee ◽  
S. Murray Sherman
Keyword(s):  
Information Transfer ◽  
Higher Order ◽  
Thalamic Nuclei ◽  
First Order ◽  
Metabotropic Glutamate ◽  
Cortical Areas ◽  
Layer 4 ◽  
Auditory Systems ◽  
Initial Processing ◽  
Whole Cell Recordings

The thalamus is an essential structure in the mammalian forebrain conveying information topographically from the sensory periphery to primary neocortical areas. Beyond this initial processing stage, “higher-order” thalamocortical connections have been presumed to serve only a modulatory role, or are otherwise functionally disregarded. Here we demonstrate that these “higher-order” thalamic nuclei share similar synaptic properties with the “first-order” thalamic nuclei. Using whole cell recordings from layer 4 neurons in thalamocortical slice preparations in the mouse somatosensory and auditory systems, we found that electrical stimulation in all thalamic nuclei elicited large, glutamatergic excitatory postsynaptic potentials (EPSPs) that depress in response to repetitive stimulation and that fail to activate a metabotropic glutamate response. In contrast, the intracortical inputs from layer 6 to layer 4 exhibit facilitating EPSPs. These data suggest that higher-order thalamocortical projections may serve a functional role similar to the first-order nuclei, whereas both are physiologically distinct from the intracortical layer 6 inputs. These results suggest an alternate route for information transfer between cortical areas via a corticothalamocortical pathway.

First order connections of the visual sector of the thalamic reticular nucleus in marmoset monkeys (Callithrix jacchus)

2007 ◽  
Vol 24 (6) ◽  
pp. 857-874 ◽  
Author(s):  
THOMAS FITZGIBBON ◽  
BRETT A. SZMAJDA ◽  
PAUL R. MARTIN
Keyword(s):  
Visual Field ◽  
Callithrix Jacchus ◽  
Higher Order ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Lower Visual Field ◽  
First Order ◽  
Cortical Areas ◽  
Visual Areas

The thalamic reticular nucleus (TRN) supplies an important inhibitory input to the dorsal thalamus. Previous studies in non-primate mammals have suggested that the visual sector of the TRN has a lateral division, which has connections with first-order (primary) sensory thalamic and cortical areas, and a medial division, which has connections with higher-order (association) thalamic and cortical areas. However, the question whether the primate TRN is segregated in the same manner is controversial. Here, we investigated the connections of the TRN in a New World primate, the marmoset (Callithrix jacchus). The topography of labeled cells and terminals was analyzed following iontophoretic injections of tracers into the primary visual cortex (V1) or the dorsal lateral geniculate nucleus (LGNd). The results show that rostroventral TRN, adjacent to the LGNd, is primarily connected with primary visual areas, while the most caudal parts of the TRN are associated with higher order visual thalamic areas. A small region of the TRN near the caudal pole of the LGNd (foveal representation) contains connections where first (lateral TRN) and higher order visual areas (medial TRN) overlap. Reciprocal connections between LGNd and TRN are topographically organized, so that a series of rostrocaudal injections within the LGNd labeled cells and terminals in the TRN in a pattern shaped like rostrocaudal overlapping “fish scales.” We propose that the dorsal areas of the TRN, adjacent to the top of the LGNd, represent the lower visual field (connected with medial LGNd), and the more ventral parts of the TRN contain a map representing the upper visual field (connected with lateral LGNd).

scholarly journals Pathway-, layer- and cell-type-specific thalamic input to mouse barrel cortex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
B Semihcan Sermet ◽  
Pavel Truschow ◽  
Michael Feyerabend ◽  
Johannes M Mayrhofer ◽  
Tess B Oram ◽  
...  
Keyword(s):  
Thalamic Nucleus ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Cell Types ◽  
Excitatory Input ◽  
Higher Order ◽  
Inhibitory Neurons ◽  
Thalamic Nuclei ◽  
Thalamic Input ◽  
Layer 4

Mouse primary somatosensory barrel cortex (wS1) processes whisker sensory information, receiving input from two distinct thalamic nuclei. The first-order ventral posterior medial (VPM) somatosensory thalamic nucleus most densely innervates layer 4 (L4) barrels, whereas the higher-order posterior thalamic nucleus (medial part, POm) most densely innervates L1 and L5A. We optogenetically stimulated VPM or POm axons, and recorded evoked excitatory postsynaptic potentials (EPSPs) in different cell-types across cortical layers in wS1. We found that excitatory neurons and parvalbumin-expressing inhibitory neurons received the largest EPSPs, dominated by VPM input to L4 and POm input to L5A. In contrast, somatostatin-expressing inhibitory neurons received very little input from either pathway in any layer. Vasoactive intestinal peptide-expressing inhibitory neurons received an intermediate level of excitatory input with less apparent layer-specificity. Our data help understand how wS1 neocortical microcircuits might process and integrate sensory and higher-order inputs.

scholarly journals Hierarchical Organization of Corticothalamic Projections to the Pulvinar

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Reza Abbas Farishta ◽  
Denis Boire ◽  
Christian Casanova
Keyword(s):  
Higher Order ◽  
Hierarchical Organization ◽  
Hierarchical Level ◽  
Thalamic Nuclei ◽  
Cortical Areas ◽  
Visual Areas ◽  
Cortical Hierarchy ◽  
Area 21A ◽  
Extrastriate Areas ◽  
Corticothalamic Projections

Abstract Signals from lower cortical visual areas travel to higher-order areas for further processing through cortico-cortical projections, organized in a hierarchical manner. These signals can also be transferred between cortical areas via alternative cortical transthalamic routes involving higher-order thalamic nuclei like the pulvinar. It is unknown whether the organization of transthalamic pathways may reflect the cortical hierarchy. Two axon terminal types have been identified in corticothalamic (CT) pathways: the types I (modulators) and II (drivers) characterized by thin axons with small terminals and by thick axons and large terminals, respectively. In cats, projections from V1 to the pulvinar complex comprise mainly type II terminals, whereas those from extrastriate areas include a combination of both terminals suggesting that the nature of CT terminals varies with the hierarchical order of visual areas. To test this hypothesis, distribution of CT terminals from area 21a was charted and compared with 3 other visual areas located at different hierarchical levels. Results demonstrate that the proportion of modulatory CT inputs increases along the hierarchical level of cortical areas. This organization of transthalamic pathways reflecting cortical hierarchy provides new and fundamental insights for the establishment of more accurate models of cortical signal processing along transthalamic cortical pathways.

Thalamic higher-order driver inputs as sensorimotor links

2017 ◽  
Author(s):  
Ray Guillery
Keyword(s):  
Motor Control ◽  
Functional Significance ◽  
Higher Order ◽  
Extensive Review ◽  
Thalamic Nuclei ◽  
Cortical Areas ◽  
Thalamic Relay ◽  
Branching Patterns ◽  
Action And Perception

This chapter provides a closer look at the branching patterns of driver inputs to higher-order thalamic nuclei, and introduces their functional significance for discussion in later chapters. Their thalamic branches bring information for relay to higher cortical levels, including a copy of the information carried in the motor branches about anticipated cortical contributions to the control of actions and consequent changes in perceptions. In this way, the cortex can add to the control of an action when there is a mismatch between action and perception. Most of these branched axons that have so far been described come from early sensory areas and only a few from other, higher areas have been studied. These branching inputs are a part of the hierarchy of cortical areas that provide an opportunity for higher areas to monitor lower areas and, when needed, contribute to the motor control of the phylogenetically older brainstem and spinal centres. A far more extensive review of the branched thalamic driver inputs and their contributions to the control of actions than we have at present will be crucial for understanding the full complexity of the thalamic relay.

scholarly journals Context-dependent and dynamic functional influence of corticothalamic pathways to first- and higher-order visual thalamus

2019 ◽  
Author(s):  
Megan A. Kirchgessner ◽  
Alexis D. Franklin ◽  
Edward M. Callaway
Keyword(s):  
Higher Order ◽  
Inhibitory Influence ◽  
Complex Frequency ◽  
Thalamic Nuclei ◽  
First Order ◽  
Visual Thalamus ◽  
Animal Remains ◽  
Context Dependent ◽  
Stimulation Paradigm

AbstractLayer 6 (L6) is the sole purveyor of corticothalamic (CT) feedback to first-order thalamus and also sends projections to higher-order thalamus, yet how it engages the full corticothalamic circuit to contribute to sensory processing in an awake animal remains unknown. We sought to elucidate the functional impact of L6CT projections from primary visual cortex to visual thalamic nuclei dLGN (first-order) and pulvinar (higher-order) using optogenetics and extracellular electrophysiology in awake mice. While sustained L6CT photostimulation suppresses activity in both visual thalamic nuclei in vivo, moderate-frequency (10Hz) stimulation powerfully facilitates thalamic spiking. We show that each stimulation paradigm differentially influences the balance between monosynaptic excitatory and disynaptic inhibitory corticothalamic pathways to dLGN and pulvinar as well as the prevalence of burst versus tonic firing. Altogether, our results support a model in which L6CTs modulate first- and higher-order thalamus through parallel excitatory and inhibitory pathways that are highly dynamic and context-dependent.SignificanceLayer 6 corticothalamic (L6CT) projections play important modulatory roles in thalamic processing, yet how this modulation is executed is unclear. While some studies suggest fundamentally inhibitory influence of L6CTs over first-order thalamus, potential complex, frequency-dependent effects have not been investigated in vivo. Moreover, how L6CTs affect higher-order nuclei in vivo has not been explored. This study utilizes various optogenetic manipulations of L6CTs with single-unit recordings from multiple thalamic nuclei in awake mice to address these questions. Our results illustrate similar effects of L6CTs on first- and higher-order visual thalamic nuclei, yet very different effects within-nucleus depending on how L6CTs are engaged. These findings suggest that L6CT modulation is not simply inhibitory by nature, but instead is dynamic and context-dependent.

scholarly journals Context-dependent and dynamic functional influence of corticothalamic pathways to first- and higher-order visual thalamus

2020 ◽  
Vol 117 (23) ◽  
pp. 13066-13077 ◽  
Author(s):  
Megan A. Kirchgessner ◽  
Alexis D. Franklin ◽  
Edward M. Callaway
Keyword(s):  
Sensory Processing ◽  
Higher Order ◽  
Thalamic Nuclei ◽  
Tonic Firing ◽  
First Order ◽  
Visual Thalamus ◽  
Animal Remains ◽  
Context Dependent ◽  
Stimulation Paradigm

Layer 6 (L6) is the sole purveyor of corticothalamic (CT) feedback to first-order thalamus and also sends projections to higher-order thalamus, yet how it engages the full corticothalamic circuit to contribute to sensory processing in an awake animal remains unknown. We sought to elucidate the functional impact of L6CT projections from the primary visual cortex to the dorsolateral geniculate nucleus (first-order) and pulvinar (higher-order) using optogenetics and extracellular electrophysiology in awake mice. While sustained L6CT photostimulation suppresses activity in both visual thalamic nuclei in vivo, moderate-frequency (10 Hz) stimulation powerfully facilitates thalamic spiking. We show that each stimulation paradigm differentially influences the balance between monosynaptic excitatory and disynaptic inhibitory corticothalamic pathways to the dorsolateral geniculate nucleus and pulvinar, as well as the prevalence of burst versus tonic firing. Altogether, our results support a model in which L6CTs modulate first- and higher-order thalamus through parallel excitatory and inhibitory pathways that are highly dynamic and context-dependent.

scholarly journals Distinct recruitment of feed-forward and recurrent pathways across higher-order areas of mouse visual cortex

2020 ◽  
Author(s):  
Jennifer Y. Li ◽  
Charles A. Hass ◽  
Ian Matthews ◽  
Amy C. Kristl ◽  
Lindsey L. Glickfeld
Keyword(s):  
Visual Processing ◽  
Higher Order ◽  
Feed Forward ◽  
Cortical Areas ◽  
Physiological Properties ◽  
Cortical Visual Processing ◽  
Visual Cortical ◽  
Mouse Visual Cortex ◽  
Whole Cell Recordings

AbstractCortical visual processing transforms features of the external world into increasingly complex and specialized neuronal representations. These transformations arise in part through target-specific routing of information; however, within-area computations may also contribute to area-specific function. Here, we sought to determine whether higher-order visual cortical areas LM, AL, PM, and AM have specialized anatomical and physiological properties by using a combination of whole-cell recordings and optogenetic stimulation of V1 axons in vitro. We discovered area-specific differences in the strength of recruitment of interneurons through feed-forward and recurrent pathways, as well as differences in cell-intrinsic properties and interneuron densities. These differences were most striking when comparing across medial and lateral areas, suggesting that these areas have distinct profiles for net excitability and integration of V1 inputs. Thus, cortical areas are not defined simply by the information they receive, but also by area-specific circuit properties that enable specialized filtering of these inputs.

scholarly journals Modulatory effects of activation of metabotropic glutamate receptors on GABAergic circuits in the mouse cortex

2014 ◽  
Vol 111 (11) ◽  
pp. 2287-2297 ◽  
Author(s):  
Tingting Liu ◽  
Iraklis Petrof ◽  
S. Murray Sherman
Keyword(s):  
Glutamate Receptors ◽  
Metabotropic Glutamate Receptors ◽  
Bathing Solution ◽  
Adjacent Layer ◽  
Metabotropic Glutamate ◽  
Group I ◽  
Mouse Cortex ◽  
Layer 4 ◽  
The Central Nervous System ◽  
Whole Cell Recordings

Metabotropic glutamate receptors (mGluRs) have a ubiquitous distribution in the central nervous system and often serve to regulate the release of neurotransmitters. We have previously shown that activation of both presynaptic and postsynaptic mGluRs can affect the gain of glutamatergic inputs in both thalamus and cortex. In the present study, we sought to determine the effect of mGluR activation on GABAergic inputs in cortex. Using whole cell recordings in a mouse slice preparation of either primary visual or auditory cortex (V1 or A1), we tested the effects on mGluRs by applying various agonists to the slice. Two pathways were tested in each area: the GABAergic inputs in layers 2/3 activated from layer 4 and the GABAergic inputs in layer 4 activated from adjacent layer 4. In both of these pathways, we found that activation of mGluRs significantly reduced the amplitude of the evoked inhibitory postsynaptic currents. Because the effects were not blocked by the addition of GDPβS to the recording electrode, and because mGluR agonists did not affect responses to photostimulation of GABA in a low-Ca2+ and high-Mg2+ bathing solution, we concluded this reduction was due to activation of presynaptic mGluRs. Furthermore, using specific mGluR agonists, we found that group II mGluRs, but not group I mGluRs, were involved in these modulatory effects. Because similar results were found in both pathways in V1 and A1, a possible cortical pattern for these effects is suggested.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Challenging the Multidimensional Conception of Perceived Person-Environment Fit

2020 ◽  
pp. 1-9
Author(s):  
Julian M. Etzel ◽  
Gabriel Nagy
Keyword(s):  
Higher Education ◽  
University Students ◽  
Educational Outcomes ◽  
Factor Model ◽  
Higher Order ◽  
Substantial Proportion ◽  
Unique Variance ◽  
First Order ◽  
Person Environment Fit ◽  
Order Factor

Abstract. In the current study, we examined the viability of a multidimensional conception of perceived person-environment (P-E) fit in higher education. We introduce an optimized 12-item measure that distinguishes between four content dimensions of perceived P-E fit: interest-contents (I-C) fit, needs-supplies (N-S) fit, demands-abilities (D-A) fit, and values-culture (V-C) fit. The central aim of our study was to examine whether the relationships between different P-E fit dimensions and educational outcomes can be accounted for by a higher-order factor that captures the shared features of the four fit dimensions. Relying on a large sample of university students in Germany, we found that students distinguish between the proposed fit dimensions. The respective first-order factors shared a substantial proportion of variance and conformed to a higher-order factor model. Using a newly developed factor extension procedure, we found that the relationships between the first-order factors and most outcomes were not fully accounted for by the higher-order factor. Rather, with the exception of V-C fit, all specific P-E fit factors that represent the first-order factors’ unique variance showed reliable and theoretically plausible relationships with different outcomes. These findings support the viability of a multidimensional conceptualization of P-E fit and the validity of our adapted instrument.

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