scholarly journals Computational Modeling of Spinal Locomotor Circuitry in the Age of Molecular Genetics

2021 ◽  
Vol 22 (13) ◽  
pp. 6835
Author(s):  
Jessica Ausborn ◽  
Natalia A. Shevtsova ◽  
Simon M. Danner
Keyword(s):  
Computational Modeling ◽  
Molecular Genetics ◽  
Experimental Studies ◽  
Locomotor Behavior ◽  
Review Literature ◽  
Afferent Feedback ◽  
Neuronal Populations ◽  
Spinal Circuitry ◽  
Neuronal Interactions ◽  
Muscle Activations

Neuronal circuits in the spinal cord are essential for the control of locomotion. They integrate supraspinal commands and afferent feedback signals to produce coordinated rhythmic muscle activations necessary for stable locomotion. For several decades, computational modeling has complemented experimental studies by providing a mechanistic rationale for experimental observations and by deriving experimentally testable predictions. This symbiotic relationship between experimental and computational approaches has resulted in numerous fundamental insights. With recent advances in molecular and genetic methods, it has become possible to manipulate specific constituent elements of the spinal circuitry and relate them to locomotor behavior. This has led to computational modeling studies investigating mechanisms at the level of genetically defined neuronal populations and their interactions. We review literature on the spinal locomotor circuitry from a computational perspective. By reviewing examples leading up to and in the age of molecular genetics, we demonstrate the importance of computational modeling and its interactions with experiments. Moving forward, neuromechanical models with neuronal circuitry modeled at the level of genetically defined neuronal populations will be required to further unravel the mechanisms by which neuronal interactions lead to locomotor behavior.

Experimental Studies and Computational Modeling on Cytochrome C Reduction by Quercetin: the role of oxidability and binding affinity

2021 ◽  
pp. 130995
Author(s):  
Gabriel Zazeri ◽  
Ana Paula Ribeiro Povinelli ◽  
Nathalia M. Pavan ◽  
Daniella Romano de Carvalho ◽  
Carmen Lúcia Cardoso ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Computational Modeling ◽  
Binding Affinity ◽  
Experimental Studies ◽  
Cytochrome C Reduction

scholarly journals Pengaruh Pemberian Kedelai terhadap Sistem Reproduksi

2019 ◽  
Vol 1 (1) ◽  
pp. 53-60
Author(s):  
Rizky Aprilia Wikayanti ◽  
Andre Parmonangan Panjaitan
Keyword(s):  
Menstrual Cycle ◽  
Reproductive System ◽  
Experimental Studies ◽  
Review Literature ◽  
Follicular Phase ◽  
Free Concentration ◽  
Human Reproductive ◽  
17Β Estradiol ◽  
Lh Secretion

Kedelai merupakan tanaman Leguminoceae, yang mengandung senyawa isoflavon. Struktur kimianya menyerupai 17β-estradiol yang memiliki kemampuan untuk berikatan dengan reseptor estrogen yang dapat berpengaruh terhadap sistem reproduksi manusia. Tujuan literatur review ini untuk mengetahui efek kedelai terhadap sistem reproduksi manusia. Metode yang digunakan adalah metode literatur review dari 50 artikel PubMed NCBI, Elsevier dan BMJ Journal yang diperoleh hanya 38 artikel yang digumakan dari tahun 2000 sampai dengan tahun 2018. Berbagai penelitian eksperimental yang dilakukan menunjukkan bahwa kedelai memiliki efek terhadap sistem reproduksi manusia. Kedelai dapat menyebabkan sekresi FSH, sekresi LH menurun dan meningkatkan konsentrasi estradiol bebas. Penurunan FSH dan LH dapat menyebabkan gangguan dalam siklus menstruasi terutama pada fase folikular dan  ovulasi, jika fase folikular terganggu maka siklus menstruasi akan menjadi  tidak teratur. Selain itu fitoestrogen yang terkandung dalam kedelai diketahui dapat menghambat 17-β hidroksisteroidoksidoreduktase sehingga mengakibatkan penurunan kadar testosteron.   Kata kunci: kedelai, manusia, reproduksi   THE ROLE OF SOYBEAN FOR REPRODUCTIVE SYSTEM   ABSTRACT Soybean is a Leguminoceae plant, which contains isoflavone compounds. Its chemical structure resembles 17β-estradiol which has ability to bind to estrogen receptors which can affect the human reproductive system. The purpose of this review literature is to determine the effect of soy on the human reproductive system. Using research articles and books related to the effect of soy on the reproductive system from 2000 to 2018. Various experimental studies conducted showed that soy has an effect on the human reproductive system. Soy can cause FSH secretion, decreased LH secretion and increasing the free concentration of estradiol. Decreased FSH and LH can cause disruption in the menstrual cycle, especially in the follicular phase and ovulation, if the follicular phase is disrupted then the menstrual cycle will become irregular. In addition, phytoestrogens contained in soy are known to inhibit 17-β hydroxysteroidoxidoreductase, resulting in a decrease in testosterone levels.   Keywords : human, reproductive, soybean

Improved Simulation of Heel Contact During Normal Walking

2011 ◽  
Author(s):  
Arash Mahboobin ◽  
Rakié Cham ◽  
Stephen J. Piazza
Keyword(s):  
Computational Modeling ◽  
Dynamic Systems ◽  
Experimental Studies ◽  
Forward Dynamics ◽  
Research Needs ◽  
Normal Walking ◽  
Complex Dynamic ◽  
Complex Dynamic Systems ◽  
Heel Contact ◽  
Dynamics Simulations

Causes of slips and falls involve the interaction of complex environmental and human factors [1]. While experimental studies have been useful to identify biomechanical variables that may impact slipping severity, it is unclear how these factors interact. Relying on experiments alone to acquire this knowledge and establishing cause-effect relationships in complex dynamic systems is difficult. Computational modeling and forward dynamics simulations of walking and slipping are needed to meet these research needs.

Brainstem neuronal populations activated in the model of ovalbumine induced allergic rhinitis in guinea pigs — the c-Fos study

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Jana Plevková ◽  
Ivan Poliaček ◽  
Marian Adamkov ◽  
Katarina Svirlochová ◽  
Ivan Varga
Keyword(s):  
Guinea Pigs ◽  
Clinical Symptoms ◽  
Saline Group ◽  
Nasal Symptom ◽  
Nucleus Ambiguus ◽  
Noxious Stimulation ◽  
Neuronal Populations ◽  
Neuronal Interactions ◽  
Brainstem Slices ◽  
Stimulation Of

AbstractCentral neuronal interactions may contribute to up regulation of cough in subjects with rhinitis. Previously we have shown that noxious stimulation of the nose induces considerable Fos-like immunoreactivity (FLI) in the solitary nuclei and the region of ventral respiratory group and these neurons are involved in the cough pattern generator. Recent study addressed the question, which additional groups are activated in model of trigeminal hyperresponsiveness and whether some of them might also cooperate with cough pattern gating areas. 24 guinea pigs were sensitized with intraperitoneal ovalbumin (OVA) and later were once weekly challenged with intranasal OVA to develop the neural hyperresponsiveness, 12 animals were left unsensitized. The nasal symptom score was evaluated after each challenge. Finally, animals were anaesthetized and the latest challenges with nasal OVA, capsaicin and saline were applied to induce c-Fos expression in designed groups. Following the survival time animals were deeply anaesthetized, exsanguinated, and transcardially perfused with heparinised saline (200 ml) and paraformaldehyde fixation (200 ml). The brainstems were removed, postfixed, and brainstem slices were processed immunohistochemically (c-Fos, Calbiochem, SR). FLI at the level of obex and areas relative to the obex was analyzed. In all groups (excluding the saline group) the FLI was detected bilaterally in the trigeminal complex, nuclei of solitary tract, lateral reticular and nucleus ambiguus. There were no differences between the OVA and capsaicin groups. Count of Fos-positive neurons within the trigeminal complex does not correlate with the magnitude of clinical symptoms, which gradually increased each week in OVA induced model of hyperresponsiveness. Whereas trigeminal hyperresponsiveness contributes to the up-regulation of cough in animal models, it does not induce any additional neuronal FLI at the middle medulla than observed in naive animals.

Brand equity, online reviews, and message trust: the moderating role of persuasion knowledge

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fayez Ahmad ◽  
Francisco Guzmán
Keyword(s):  
Brand Equity ◽  
Experimental Studies ◽  
Online Reviews ◽  
Review Literature ◽  
Online Review ◽  
Persuasion Knowledge ◽  
Content Type ◽  
Mediating Role ◽  
The Relationship

Purpose This paper aims to investigate whether a message from a brand with stronger brand equity generates more trust than a message from a brand with lower brand equity, and thus is more likely to encourage consumers to write online reviews. This paper also explores what happens when consumers become aware that brands are trying to persuade them to write a review. Design/methodology/approach Through three experimental studies, where participants were randomly assigned to a brand that has either a stronger or weaker brand equity, participants’ intention to write reviews was measured. Trust in the message was measured to study its mediating role, and persuasion knowledge of the participants was manipulated to investigate its moderating effect. Findings The findings confirm that consumers are more likely to write online reviews when a message comes from a brand that has stronger brand equity, trust in the message mediates the relationship between brand equity and consumer intention to write an online review, and persuasion knowledge has a differential effect on consumer intention to write reviews. Originality/value The study adds to the brand equity and online review literature by providing evidence that a higher level of consumer trust on brands that have stronger brand equity leads to an increased intention to write a review for the brand. It also shows that consumers’ awareness of the motive of the brand is more beneficial for brands with strong brand equity, contributing to persuasion knowledge literature.

scholarly journals Persistent Organic Pollutant-Mediated Insulin Resistance

2019 ◽  
Vol 16 (3) ◽  
pp. 448 ◽  
Author(s):  
Yeon Kim ◽  
Joon Park ◽  
Min Woo ◽  
Sang Lee ◽  
Hye Kim ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Organic Pollutant ◽  
Experimental Studies ◽  
Epidemiological Studies ◽  
Review Literature ◽  
Range Transport ◽  
Hydrophobic Pollutants ◽  
Metabolic Degradation ◽  
Dm Type 2

Persistent organic pollutants (POPs) such as organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) have become wide-spread environmental contaminants as a consequence of their extensive use, long-range transport, and persistence. Because POPs are highly resistant to metabolic degradation, humans bioaccumulate these lipophilic and hydrophobic pollutants in fatty tissues for many years. Previous studies have demonstrated that POPs including PCBs are involved in the development of diabetes mellitus (DM) type 2 and insulin resistance. Numerous epidemiological studies suggest an association between POP burden and DM type 2/metabolic syndrome. In addition, several experimental studies have provided additional evidence supporting the association between POP exposure and DM type 2 or insulin resistance. Epidemiological and experimental studies have provided compelling evidence indicating that exposure to POPs increases the risk of developing insulin resistance and metabolic disorders. However, the detailed molecular mechanism underlying POP-induced insulin resistance is yet to be elucidated. In this article, we review literature that has reported on the association between POP burden and insulin resistance and the mechanism underlying POP-induced insulin resistance, and discuss implications for public health.

scholarly journals Dynamic Transitions of Epilepsy Waveforms Induced by Astrocyte Dysfunction and Electrical Stimulation

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Honghui Zhang ◽  
Zhuan Shen ◽  
Qiangui Zhao ◽  
Luyao Yan ◽  
Lin Du ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Low Frequency ◽  
Single Pulse ◽  
Neuronal Population ◽  
Absence Epilepsy ◽  
Neuronal Populations ◽  
Stimulation Mode ◽  
Thalamic Relay ◽  
Relay Nucleus ◽  
Feedforward Inhibition

Experimental studies have shown that astrocytes participate in epilepsy through inducing the release of glutamate. Meanwhile, considering the disinhibition circuit among inhibitory neuronal populations with different time scales and the feedforward inhibition connection from thalamic relay nucleus to cortical inhibitory neuronal population, here, we propose a modified thalamocortical field model to systematically investigate the mechanism of epilepsy. Firstly, our results show that rich firing activities can be induced by astrocyte dysfunction, including high or low saturated state, high- or low-frequency clonic, spike-wave discharge (SWD), and tonic. More importantly, with the enhancement of feedforward inhibition connection, SWD and tonic oscillations will disappear. In other words, all these pathological waveforms can be suppressed or eliminated. Then, we explore the control effects after different external stimulations applying to thalamic neuronal population. We find that single-pulse stimulation can not only suppress but also induce pathological firing patterns, such as SWD, tonic, and clonic oscillations. And we further verify that deep brain stimulation can control absence epilepsy by regulating the amplitude and pulse width of stimulation. In addition, based on our modified model, 3 : 2 coordinated reset stimulation strategies with different intensities are compared and a more effective and safer stimulation mode is proposed. Our conclusions are expected to give more theoretical insights into the treatment of epilepsy.

Sign in / Sign up

Export Citation Format

Share Document