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 Antirealism/realism of Hintikka’s game-theoretical semantics

2018 ◽  
Vol 26 (3) ◽  
Author(s):  
Heda Festini
Keyword(s):  
Higher Order ◽  
Order Logic ◽  
First Order Logic ◽  
Higher Order Logic ◽  
First Order ◽  
Theory Of Meaning ◽  
Truth Conditional ◽  
Context Dependent ◽  
Extended Notion

Hintikka’s game-theoretical semantics (GTS) is presented as an anti-Tarskian semantical approach to the context-dependent fragments of Englisch, which overcomes the usual notion of semantical realism. Analysing Hintikka’s critique of Tarski’s interpretation of the truth-conditional theory of meaning, its recursive fashion and the narrow notion of realism, Hintikka’s basic conception is presented in the following manner:1. the Context-Principle vs. the Frege Principle,2.First-order logic together with higher-order logic vs. the primacy of first-order logic,3.verificationist/falsificationist theory vs. Taraski’s narrow truth- conditional theory.Comparing some reviews of Hintikka’s GTS (M. Dummett, E. Itkonen, E. Saarinen, M. Hand) with a short examination of the antirealistic/realistic controversis by C. Wright and M. Dummett, the following was reached:Hintikka’s GTS introduces a new, more extended notion of realism, which embraces Taraski-type realistic semantics, Hintikka’s GTS and with this the question of the possibility to also include Dummett’s neoverificationism or other orientations, remains open.

scholarly journals Distinct “driving” versus “modulatory” influences of different visual corticothalamic pathways

2021 ◽  
Author(s):  
Megan A. Kirchgessner ◽  
Alexis D. Franklin ◽  
Edward M. Callaway
Keyword(s):  
Cerebral Cortex ◽  
Visual Cortex ◽  
Superior Colliculus ◽  
Primary Visual Cortex ◽  
Cortical Layer ◽  
Single Neurons ◽  
Visual Responses ◽  
Thalamic Nuclei ◽  
Visual Thalamus

AbstractHigher-order (HO) thalamic nuclei interact extensively with the cerebral cortex and are innervated by excitatory corticothalamic (CT) populations in layers 5 and 6. While these distinct CT projections have long been thought to have different functional influences on the HO thalamus, this has never been directly tested. By optogenetically inactivating different CT populations in the primary visual cortex (V1) of awake mice, we demonstrate that layer 5, but not layer 6, CT projections drive visual responses in the HO visual pulvinar, even while both pathways provide retinotopic, baseline excitation to their thalamic targets. Inactivating the superior colliculus also suppressed visual responses in the pulvinar, demonstrating that cortical layer 5 and subcortical inputs both contribute to HO visual thalamic activity - even at the level of putative single neurons. Altogether, these results indicate a functional division of driver and modulator CT pathways from V1 to the visual thalamus in vivo.

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.

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.

Computational Models for Multilayered Composite Shells with Application to Tires

1996 ◽  
Vol 24 (1) ◽  
pp. 11-38 ◽  
Author(s):  
G. M. Kulikov
Keyword(s):  
Type Theory ◽  
Computational Models ◽  
Geometrical Nonlinearity ◽  
Higher Order ◽  
Stress Strain ◽  
Strain Fields ◽  
First Order ◽  
Timoshenko Type ◽  
Joint Influence ◽  
Discrete Layer

Abstract This paper focuses on four tire computational models based on two-dimensional shear deformation theories, namely, the first-order Timoshenko-type theory, the higher-order Timoshenko-type theory, the first-order discrete-layer theory, and the higher-order discrete-layer theory. The joint influence of anisotropy, geometrical nonlinearity, and laminated material response on the tire stress-strain fields is examined. The comparative analysis of stresses and strains of the cord-rubber tire on the basis of these four shell computational models is given. Results show that neglecting the effect of anisotropy leads to an incorrect description of the stress-strain fields even in bias-ply tires.

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