A novel approach to map induced activation of neuronal networks using chemogenetics and functional neuroimaging

This chapter addresses and reconciles often conflicting conclusions published in the professional functional neuroimaging literature regarding the neuronal networks that may mediate consciousness viewed as a function, as well as neuronal circuits that represent specific products of that function, such as concepts, percepts, and experiences that are also referred to as the “contents” or the constituents of the stream of consciousness. The relevant literature is critically reviewed in order to answer the following questions: First, whether and to what degree consciousness-specific networks have been visualized and what are the prospects of their further specification in the future; second, whether imaging of resting neuronal networks can be used for diagnostic and prognostic purposes in cases of compromised consciousness among comatose patients or patients in the vegetative state; and third, whether visualization of the neuronal circuits that represent knowledge in the form of concepts and intentions is feasible.

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Imaging the Networks of Encoding, Consolidation, and Retrieval

10.1093/oxfordhb/9780199764228.013.21 ◽

2017 ◽

Author(s):

Andrew C. Papanicolaou ◽

Nicole Shay ◽

Christen M. Holder

Keyword(s):

Neuronal Networks ◽

Functional Neuroimaging ◽

Medial Temporal Lobes ◽

Temporal Lobes ◽

Spontaneous Retrieval ◽

Encoding And Retrieval

In this chapter, the authors examine the contributions of the functional neuroimaging literature to the specification of the neuronal networks of the mnemonic operations of encoding, consolidation, and retrieval. Although the most basic expectation regarding the involvement of parts of the medial temporal lobes, such as the hippocampus, in these operations was not consistently supported by the results of the neuroimaging studies reviewed, other expectations, such as the material-specific lateralization of activation were adequately supported. The several reasons that account for the limited contributions of neuroimaging to the neurophysiology of memory thus far, ranging from constraints imposed by the nature of the mnemonic operations (e.g., the fact that encoding and retrieval occur in tandem) to practical ones (e.g., difficulties in studying spontaneous retrieval), are outlined.

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Imaging the Networks of Motor Cognition

10.1093/oxfordhb/9780199764228.013.23 ◽

2017 ◽

Author(s):

Marina Kilintari ◽

Andrew C. Papanicolaou

Keyword(s):

Embodied Cognition ◽

Neuronal Network ◽

Neuronal Networks ◽

Final Section ◽

Subjective Experience ◽

Functional Neuroimaging ◽

Mirror Neuron ◽

General Notion ◽

Motor Cognition ◽

Experimental Findings

It has been suggested that we comprehend and imagine voluntary actions through the use of essentially the same neuronal networks that mediate their execution. Two hypotheses, named in the literature the “mirror” neuron and the “simulation” theory, both variants of the general notion of “embodied cognition” are briefly reviewed in the first section of this chapter in order to provide a context for the experimental findings presented in subsequent sections. The second and third sections juxtapose functional neuroimaging evidence largely supporting the embodied cognition theory insofar as recognition of actions and imagining of actions are concerned. The fourth and final section explores the clinical and the functional neuroimaging literature for evidence of a neuronal network that mediates our subjective experience of ownership of our own body.

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Looking from the top: enhanced top-down sensorimotor processing in somatic anxiety

10.1101/2021.12.02.471029 ◽

2021 ◽

Author(s):

Ismail Bouziane ◽

Moumita Das ◽

Cesar Caballero-Gaudes ◽

Dipanjan Ray

Keyword(s):

Empirical Bayes ◽

Hierarchical Modeling ◽

Functional Neuroimaging ◽

Effective Connectivity ◽

Causal Modeling ◽

Cortical Processing ◽

Top Down ◽

Somatic Anxiety ◽

Novel Approach ◽

Human Connectome Project

AbstractBackgroundFunctional neuroimaging research on anxiety has traditionally focused on brain networks associated with the complex psychological aspects of anxiety. In this study, instead, we target the somatic aspects of anxiety. Motivated by the growing recognition that top-down cortical processing plays crucial roles in perception and action, we investigate effective connectivity among hierarchically organized sensorimotor regions and its association with (trait) anxiety.MethodsWe selected 164 participants from the Human Connectome Project based on psychometric measures. We used their resting-state functional MRI data and Dynamic Causal Modeling (DCM) to assess effective connectivity within and between key regions in the exteroceptive, interoceptive, and motor hierarchy. Using hierarchical modeling of between-subject effects in DCM with Parametric Empirical Bayes we first established the architecture of effective connectivity in sensorimotor networks and investigated its association with fear somatic arousal (FSA) and fear affect (FA) scores. To probe the robustness of our results, we implemented a leave-one-out cross validation analysis.ResultsAt the group level, the top-down connections in exteroceptive cortices were inhibitory in nature whereas in interoceptive and motor cortices they were excitatory. With increasing FSA scores, the pattern of top-down effective connectivity was enhanced in all three networks: an observation that corroborates well with anxiety phenomenology. Anxiety associated changes in effective connectivity were of effect size sufficiently large to predict whether somebody has mild or severe somatic anxiety. Interestingly, the enhancement in top-down processing in sensorimotor cortices were associated with FSA but not FA scores, thus establishing the (relative) dissociation between somatic and cognitive dimensions of anxiety.ConclusionsOverall, enhanced top-down effective connectivity in sensorimotor cortices emerges as a promising and quantifiable candidate marker of trait somatic anxiety. These results pave the way for a novel approach into investigating the neural underpinnings of anxiety based on the recognition of anxiety as an embodied phenomenon and the emerging interest in top-down cortical processing.

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Growing neuronal islands on multi-electrode arrays using an Accurate Positioning-μCP device

10.1101/026401 ◽

2015 ◽

Author(s):

Robert Samhaber ◽

Manuel Schottdorf ◽

Ahmed El Hady ◽

Kai Broeking ◽

Andreas Daus ◽

...

Keyword(s):

Cell Culture ◽

Neuronal Networks ◽

Standard Cell ◽

Electrode Arrays ◽

Unit Recording ◽

Contact Printing ◽

Novel Approach ◽

Custom Made ◽

Typical Cell

Multi-electrode arrays (MEAs) allow non-invasive multi-unit recording in-vitro from cultured neuronal networks. For sufficient neuronal growth and adhesion on such MEAs, substrate preparation is required. Plating of dissociated neurons on a uniformly prepared MEA's surface results in the formation of spatially extended random networks with substantial inter-sample variability. Such cultures are not optimally suited to study the relationship between defined structure and dynamics in neuronal networks. To overcome these shortcomings, neurons can be cultured with pre-defined topology by spatially structured surface modification. Spatially structuring a MEA surface accurately and reproducibly with the equipment of a typical cell-culture laboratory is challenging. In this paper, we present a novel approach utilizing micro-contact printing (μCP) combined with a custom-made device to accurately position patterns on MEAs with high precision. We call this technique AP-μCP (accurate positioning micro-contact printing). Other approaches presented in the literature using μCP for patterning either relied on facilities or techniques not readily available in a standard cell culture laboratory, or they did not specify means of precise pattern positioning. Here we present a relatively simple device for reproducible and precise patterning in a standard cell-culture laboratory setting. The patterned neuronal islands on MEAs provide a basis for high throughput electrophysiology to study the dynamics of single neurons and neuronal networks.

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Prosodic Impairment in Dementia: Review of the Literature

Current Alzheimer Research ◽

10.2174/1567205014666171030115624 ◽

2018 ◽

Vol 15 (2) ◽

pp. 157-163 ◽

Cited By ~ 5

Author(s):

Sylwia Misiewicz ◽

Adam M. Brickman ◽

Giuseppe Tosto

Keyword(s):

Alzheimer’S Disease ◽

Speech Production ◽

Neuronal Networks ◽

Right Hemisphere ◽

Functional Neuroimaging ◽

Spoken Language ◽

Frontal Area ◽

Emotional Prosody ◽

Review Of The Literature ◽

The Right

Objective: Prosody, an important aspect of spoken language, is defined as the emphasis placed on certain syllables, changes in tempo or timing, and variance in pitch and intonation. Most studies investigating expression and comprehension of prosody have focused primarily on emotional prosody and less extensively on supralexical prosody. The distinction is indeed important, as the latter conveys information such as interrogative or assertive mode, whereas the former delivers emotional connotation, such as happiness, anger, and sadness. These functions appear to rely on distinct neuronal networks, supported by functional neuroimaging studies that show activation of the right hemisphere, specifically in the right inferior frontal area during emotional detection. Conclusion: This review summarizes the studies conducted on prosody impairment in Alzheimer's disease and other dementias, with emphasis on experiments designed to investigate the emotional vs. the supralexical aspect of speech production. We also discussed the available tools validated to test and quantify the prosodic impairment.

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Imaging the Networks of Voluntary Actions

10.1093/oxfordhb/9780199764228.013.22 ◽

2017 ◽

Author(s):

Marina Kilintari ◽

Andrew C. Papanicolaou

Keyword(s):

Decision Making ◽

Neuronal Networks ◽

Final Section ◽

Functional Neuroimaging ◽

Neuronal Mechanism ◽

The Will

The concept of voluntary actions is inextricably related to the concept of the will. Accordingly, in the first section of this chapter, the authors examine briefly the neuroimaging evidence for a neuronal mechanism of human will and decision-making and conclude that what evidence is brought to bear on the issue may not be relevant to it after all. In the second section, a review of the known mechanism for self-initiated as well as externally mediated voluntary actions is presented against which the contributions of functional neuroimaging to improving our knowledge for simple and complex actions can be judged. In the final section differences in the neuronal networks mediating decisions as to when to act and what action to select are explored.

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Imaging the Networks of Language

10.1093/oxfordhb/9780199764228.013.15 ◽

2017 ◽

Author(s):

Andrew C. Papanicolaou ◽

Marina Kilintari

Keyword(s):

Clinical Studies ◽

Neuronal Networks ◽

Functional Neuroimaging ◽

Language Models ◽

Main Task ◽

Language Function ◽

Sign Languages ◽

Anatomical Structures ◽

The Past ◽

The Brain

Among the “higher” functions, language and its cerebral networks is the most intensively explored through behavioral or clinical studies and, more recently, through functional neuroimaging. From the former studies, several models (only partially congruent) have emerged during the past three centuries regarding the organization and topography of the brain mechanisms of the acoustic, phonological, semantic, syntactic, and pragmatic operations in which psycholinguists have divided the language function. The main task of this chapter is to extract from the vast functional neuroimaging literature of language reliable evidence that would be used to disconfirm the various hypotheses comprising the current language models. Most of these hypotheses concern the anatomical structures that could be considered nodes or hubs of the neuronal networks mediating the above-mentioned linguistic operations. Using the same criteria, the authors present neuroimaging evidence relevant to the issue of the neuronal mediation of sign languages, reading, and dyslexia.

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