Cholinergic Activation of M2 Receptors Leads to Context-Dependent Modulation of Feedforward Inhibition in the Visual Thalamus

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.

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Context-Dependent and Dynamic Functional Influence of Corticothalamic Pathways to First- and Higher-Order Visual Thalamus

SSRN Electronic Journal ◽

10.2139/ssrn.3438368 ◽

2019 ◽

Author(s):

Megan Anne Kirchgessner ◽

Alexis D. Franklin ◽

Edward Callaway

Keyword(s):

Higher Order ◽

Visual Thalamus ◽

Context Dependent

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2002080117 ◽

2020 ◽

Vol 117 (23) ◽

pp. 13066-13077 ◽

Cited By ~ 8

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.

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Forming Impressions of Personality

Social Psychology ◽

10.1027/1864-9335/a000179 ◽

2014 ◽

Vol 45 (3) ◽

pp. 153-163 ◽

Cited By ~ 13

Author(s):

Sanne Nauts ◽

Oliver Langner ◽

Inge Huijsmans ◽

Roos Vonk ◽

Daniël H. J. Wigboldus

Keyword(s):

Impression Formation ◽

Context Dependent

Asch’s seminal research on “Forming Impressions of Personality” (1946) has widely been cited as providing evidence for a primacy-of-warmth effect, suggesting that warmth-related judgments have a stronger influence on impressions of personality than competence-related judgments (e.g., Fiske, Cuddy, & Glick, 2007 ; Wojciszke, 2005 ). Because this effect does not fit with Asch’s Gestalt-view on impression formation and does not readily follow from the data presented in his original paper, the goal of the present study was to critically examine and replicate the studies of Asch’s paper that are most relevant to the primacy-of-warmth effect. We found no evidence for a primacy-of-warmth effect. Instead, the role of warmth was highly context-dependent, and competence was at least as important in shaping impressions as warmth.

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Memorial Consequences of Environmental Context Change in Children and Adults

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000056 ◽

2010 ◽

Vol 57 (6) ◽

pp. 455-461 ◽

Cited By ~ 5

Author(s):

Alp Aslan ◽

Anuscheh Samenieh ◽

Tobias Staudigl ◽

Karl-Heinz T. Bäuml

Keyword(s):

Elementary School ◽

Young Adults ◽

Episodic Memory ◽

Middle Childhood ◽

First Graders ◽

Fourth Graders ◽

Environmental Context ◽

Context Change ◽

Context Dependent

Changing environmental context during encoding can influence episodic memory. This study examined the memorial consequences of environmental context change in children. Kindergartners, first and fourth graders, and young adults studied two lists of items, either in the same room (no context change) or in two different rooms (context change), and subsequently were tested on the two lists in the room in which the second list was encoded. As expected, in adults, the context change impaired recall of the first list and improved recall of the second. Whereas fourth graders showed the same pattern of results as adults, in both kindergartners and first graders no memorial effects of the context change arose. The results indicate that the two effects of environmental context change develop contemporaneously over middle childhood and reach maturity at the end of the elementary school days. The findings are discussed in light of both retrieval-based and encoding-based accounts of context-dependent memory.

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