Behavioral Induction of a High Beta State in Sensorimotor Cortex Leads to Movement Slowing

2021 ◽  
pp. 1-18
Author(s):  
Vignesh Muralidharan ◽  
Adam R. Aron

Abstract The sensorimotor beta rhythm (∼13–30 Hz) is commonly seen in relation to movement. It is important to understand its functional/behavioral significance in both health and disease. Sorting out competing theories of sensorimotor beta is hampered by a paucity of experimental protocols in humans that manipulate/induce beta oscillations and test their putative effects on concurrent behavior. Here, we developed a novel behavioral paradigm to generate beta and then test its functional relevance. In two human experiments with scalp EEG (n = 11 and 15), we show that a movement instruction generates a high beta state (postmovement beta rebound), which then slows down subsequent movements required during that state. We also show that this high initial beta rebound related to reduced mu–beta desynchronization for the subsequent movement and further that the temporal features of the beta state, that is, the beta bursts related to the degree of slowing. These results suggest that increased sensorimotor beta in the postmovement period corresponds to an inhibitory state—insofar as it retards subsequent movement. By demonstrating a behavioral method by which people can proactively create a high beta state, our paradigm provides opportunities to test the effect of this state on sensations and affordances. It also suggests related experiments using motor imagery rather than actual movement, and this could later be clinically relevant, for example, in tic disorder.

Author(s):  
Tibor Hortobágyi ◽  
Urs Granacher ◽  
Miguel Fernandez-del-Olmo ◽  
Glyn Howatson ◽  
Andrea Manca ◽  
...  

2017 ◽  
Vol 49 (4) ◽  
pp. 243-252 ◽  
Author(s):  
Mark R. Paterson ◽  
Alison J. Kriegel

MicroRNAs are small, noncoding, RNAs known for their powerful modulation of molecular processes, making them a major focus for studying pathological mechanisms. The human miR-146 family of microRNAs consists of two member genes, MIR146A and MIR146B. These two microRNAs are located on different chromosomes and exhibit differential regulation in many cases. However, they are nearly identical in sequence, sharing a seed region, and are thus predicted to target the same set of genes. A large proportion of the microRNA (miR)-146 literature focuses on its role in regulating the innate immune response in the context of various pathologies by modulating two widely studied target genes in the toll-like receptor signaling cascade. A growing subset of the literature reports a role of miR-146 in cardiovascular and renal disease, and data suggest there is exciting potential for miR-146 as a diagnostic and therapeutic target. Nevertheless, the published literature is confounded by unclear and imprecise language concerning the specific effects of the two miR-146 family members. The present review will compare the genomic origin and regulation of miR-146a and miR-146b, discuss some approaches to overcome analytical and experimental challenges, and summarize findings in major areas of miR-146 research. Moving forward, careful evaluation of miR-146a/b specificity in analytical and experimental approaches will aid researchers in elucidating the functional relevance of differential regulation of the miR-146 family members in health and disease.


2019 ◽  
Vol 48 (1) ◽  
pp. 297-319 ◽  
Author(s):  
Ashok Sekhar ◽  
Lewis E. Kay

Biological molecules are often highly dynamic, and this flexibility can be critical for function. The large range of sampled timescales and the fact that many of the conformers that are continually explored are only transiently formed and sparsely populated challenge current biophysical approaches. Solution nuclear magnetic resonance (NMR) spectroscopy has emerged as a powerful method for characterizing biomolecular dynamics in detail, even in cases where excursions involve short-lived states. Here, we briefly review a number of NMR experiments for studies of biomolecular dynamics on the microsecond-to-second timescale and focus on applications to protein and nucleic acid systems that clearly illustrate the functional relevance of motion in both health and disease.


Author(s):  
Simon Rogers ◽  
Virgilio L. Lew

AbstractWe introduce here a new multiplatform JAVA-based mathematical-computational model of RBC homeostasis for investigating the dynamics of changes in RBC homeostasis in health and disease. We provide a brief overview on the homeostasis of human RBCs and on the general biophysical principles guiding the modelling design. By way of a detailed tutorial we apply the model to investigate in depth the multiple effects associated with RBC dehydration induced by potassium permeabilization, a necessary preliminary for understanding the pathophysiology of a wide group of inherited haemolytic anaemias, a subject of intense current research and clinical interest. Using the red cell model (RCM), we design and run in silico representations of experimental protocols to study global RBC responses to calcium and potassium permeabilization covering a wide range of experimental, physiological and pathological conditions. Model outputs report the evolution in time of all the homeostatic variables in the system allowing, for the first time, a detailed and comprehensive account of the complex processes shaping global cell responses. Analysis of the results explains the mechanisms by which the entangled operation of all the RBC components link cell dehydration and protein crowding to cell acidification and to the generation of hypertonic, alkaline effluents. Open access to the RCM in a GitHub repository, together with the tutorial primed for a specific investigation pave the way for researchers and clinicians to apply the model on many different aspects of RBC physiology and pathology.


Author(s):  
Sarah A. Luse

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.


1995 ◽  
Vol 38 (5) ◽  
pp. 1014-1024 ◽  
Author(s):  
Robert L. Whitehead ◽  
Nicholas Schiavetti ◽  
Brenda H. Whitehead ◽  
Dale Evan Metz

The purpose of this investigation was twofold: (a) to determine if there are changes in specific temporal characteristics of speech that occur during simultaneous communication, and (b) to determine if known temporal rules of spoken English are disrupted during simultaneous communication. Ten speakers uttered sentences consisting of a carrier phrase and experimental CVC words under conditions of: (a) speech, (b) speech combined with signed English, and (c) speech combined with signed English for every word except the CVC word that was fingerspelled. The temporal features investigated included: (a) sentence duration, (b) experimental CVC word duration, (c) vowel duration in experimental CVC words, (d) pause duration before and after experimental CVC words, and (e) consonantal effects on vowel duration. Results indicated that for all durational measures, the speech/sign/fingerspelling condition was longest, followed by the speech/sign condition, with the speech condition being shortest. It was also found that for all three speaking conditions, vowels were longer in duration when preceding voiced consonants than vowels preceding their voiceless cognates, and that a low vowel was longer in duration than a high vowel. These findings indicate that speakers consistently reduced their rate of speech when using simultaneous communication, but did not violate these specific temporal rules of English important for consonant and vowel perception.


2011 ◽  
Vol 21 (3) ◽  
pp. 112-117 ◽  
Author(s):  
Elizabeth Erickson-Levendoski ◽  
Mahalakshmi Sivasankar

The epithelium plays a critical role in the maintenance of laryngeal health. This is evident in that laryngeal disease may result when the integrity of the epithelium is compromised by insults such as laryngopharyngeal reflux. In this article, we will review the structure and function of the laryngeal epithelium and summarize the impact of laryngopharyngeal reflux on the epithelium. Research investigating the ramifications of reflux on the epithelium has improved our understanding of laryngeal disease associated with laryngopharyngeal reflux. It further highlights the need for continued research on the laryngeal epithelium in health and disease.


1965 ◽  
Vol 48 (6) ◽  
pp. 758-767 ◽  
Author(s):  
Lansing C. Hoskins ◽  
Norman Zamcheck

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