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1.
Zhonghua Yan Ke Za Zhi ; 56(11): 811-814, 2020 Nov 11.
Artigo em Chinês | MEDLINE | ID: mdl-33152839

RESUMO

Visual electrophysiological examination, which features the advantage of being objective, noninvasive and quantitative, is an important method for visual function assessment. The problem yet to be resolved in clinical and medical authentication, is the standardization of application, particularly in terms of test procedure and results interpretation. Visual electrophysiology examination includes many tests. Each kind of test has its own clinical significance. There are many factors that may affect results. Therefore, the standardization in the examination procedure can ensure the accuracy and repeatability of the result. The interpretation of the report, which relies upon both clinical operation guidance and clinical experiences, also needs to be standardized. Focus should be put on the issues above in an effort to realize the reasonable application of visual electrophysiology in clinic diagnosis and medical authentication, and to avoid the misjudgment or misdiagnosis. (Chin J Ophthalmol, 2020, 56: 811-814).


Assuntos
Fenômenos Eletrofisiológicos , Visão Ocular , Eletrofisiologia , Humanos
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3897-3900, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018852

RESUMO

Understanding the joint encoding of multiple tactile stimulus features (e.g., spatial position, amplitude, and frequency of vibration) is a major goal of somatosensory neuroscience, and the development of experimental set-ups to probe joint encoding is important. We describe in detail a microcontroller-based, piezoelectric bender device for tactile experiments. The device comprises an Arduino Due microcontroller board with a 32-bit ARM Cortex-M3 RISC processor, and two 12-bit digital-to-analog converters, enabling precise, independent stimulation of adjacent epithelial points. Using laser doppler vibrometry, we developed a model of the benders' structural mechanics, which we implemented on the device. We used the device to delivered precise, reliable somatosensory stimulation in an experimental setting, recording electrophysiological responses in the peripheral nervous system of the Gisborne cockroach (Drymaplaneta semivitta) to sinusoidal vibration of tibial spines. We plotted tuning curves and derived bandwidths of multi-unit populations. We also stimulated rat facial vibrissae ex vivo. This microcontroller-based, low-cost, open-source system leverages a large developer community associated with Arduino, and may help speed advances in systems neuroscience.


Assuntos
Neurociências , Tato , Animais , Córtex Cerebral , Fenômenos Eletrofisiológicos , Ratos , Vibração
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3953-3956, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018865

RESUMO

Intestinal motility is coordinated by myogenic, neuronal and hormonal factors. Myogenic control of motility via bioelectric slow waves (SW) has been investigated using low-resolution and high-resolution (HR) electrical mapping techniques. Due to the highly conformable and irregular surface of the gut, suboptimal coverage of HR recordings may occur. In this study we designed and developed an inflatable cuff as a platform to apply even pressure across the intestinal surface to achieve consistent and reliable recordings. The inflatable cuff and a HR electrode array were applied in vivo to demonstrate the reliability of SW signal acquisition over a range of inflatable pressures (0 - 5 mm Hg). The frequency, amplitude, percentage of viable signals and signal to noise ratio metrics of the SW signals were computed and compared. Overall, with an increase in inflatable pressure from 0 to 5 mm Hg, the frequency did not change, but the amplitude of the SWs decreased from 0.10 to 0.07 mV. The noise levels were consistent across the range of inflatable pressure levels and the percentage of viable SW recordings improved significantly from 57% to 74% after application of 1 mm Hg of pressure. The inflatable and conformable cuff presented in this study provides a reliable platform for HR mapping of bioelectrical events in the intestines and other conformable organs.Clinical Relevance- This framework improves the quality and reliability of bioelectrical high-resolution recordings obtained from the small intestine. In the future, these recordings will improve our understanding of the pathophysiological mechanisms governing intestinal motility disorders and may provide clinicians with new strategies for diagnosis and treatment.


Assuntos
Motilidade Gastrointestinal , Intestino Delgado , Fenômenos Eletrofisiológicos , Reprodutibilidade dos Testes , Razão Sinal-Ruído
4.
Nat Commun ; 11(1): 5076, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033264

RESUMO

Proper threat-reward decision-making is critical to animal survival. Emerging evidence indicates that the motor system may participate in decision-making but the neural circuit and molecular bases for these functions are little known. We found in C. elegans that GABAergic motor neurons (D-MNs) bias toward the reward behavior in threat-reward decision-making by retrogradely inhibiting a pair of premotor command interneurons, AVA, that control cholinergic motor neurons in the avoidance neural circuit. This function of D-MNs is mediated by a specific ionotropic GABA receptor (UNC-49) in AVA, and depends on electrical coupling between the two AVA interneurons. Our results suggest that AVA are hub neurons where sensory inputs from threat and reward sensory modalities and motor information from D-MNs are integrated. This study demonstrates at single-neuron resolution how motor neurons may help shape threat-reward choice behaviors through interacting with other neurons.


Assuntos
Caenorhabditis elegans/fisiologia , Neurônios GABAérgicos/metabolismo , Locomoção/fisiologia , Neurônios Motores/metabolismo , Animais , Aprendizagem da Esquiva , Viés , Proteínas de Caenorhabditis elegans/metabolismo , Quimiotaxia , Fenômenos Eletrofisiológicos , Junções Comunicantes/metabolismo , Glicerol/farmacologia , Interneurônios/metabolismo , Optogenética , Concentração Osmolar , Receptores Colinérgicos/metabolismo , Sinapses/metabolismo
5.
Yakugaku Zasshi ; 140(10): 1207-1212, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999199

RESUMO

T-type calcium channels are low-threshold voltage-gated calcium channel and characterized by unique electrophysiological properties such as fast inactivation and slow deactivation kinetics. All subtypes of T-type calcium channel (Cav3.1, 3.2 and 3.3) are widely expressed in the central nerve system, and they have an important role in homeostasis of sleep, pain response, and development of epilepsy. Recently, several reports suggest that T-type calcium channels may mediate neuronal plasticity in the mouse brain. We succeeded to develop T-type calcium channel enhancer ethyl 8'-methyl-2',4-dioxo-2-(piperidin-1-yl)-2'H-spiro[cyclopentane-1,3'-imidazo[1,2-a]pyridine]-2-ene-3-carboxylate (SAK3) which enhances Cav3.1 and 3.3 currents in each-channel expressed neuro2A cells. SAK3 can promote acetylcholine (ACh) release in the mouse hippocampus via enhancing T-type calcium channel. In this review, we have introduced the role of T-type calcium channel, especially Cav3.1 channel in the mouse hippocampus based on our previous data using SAK3 and Cav3.1 knockout mice.


Assuntos
Canais de Cálcio Tipo T/efeitos dos fármacos , Canais de Cálcio Tipo T/fisiologia , Imidazóis/farmacologia , Neurônios/fisiologia , Compostos de Espiro/farmacologia , Acetilcolina/metabolismo , Animais , Encéfalo/fisiologia , Canais de Cálcio Tipo T/genética , Canais de Cálcio Tipo T/metabolismo , Células Cultivadas , Sistema Nervoso Central/metabolismo , Fenômenos Eletrofisiológicos , Epilepsia/etiologia , Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Homeostase , Camundongos , Plasticidade Neuronal , Dor/etiologia , Ratos , Sono/fisiologia
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 5212-5215, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019159

RESUMO

Visualization techniques are an important tool for understanding high-resolution mapping data in gastric electrophysiology. Isochronal maps and animations provide excellent depictions of spatial propagation patterns, but fail to capture temporal features of electrical activity. In this work, 'trace mapping' was developed and validated as a method for visualizing high-resolution mapping data. A combination of dots and lines represent events and temporal groups, respectively, creating patterns that can be quickly and efficiently interpreted. This work outlines trace mapping methods and introduces a shape-based pattern recognition method for efficient interpretation of trace maps. These methods provide a new perspective for understanding and evaluating gastric electrophysiology.Clinical Relevance-This work provides new visualization methods that can help clinicians interpret and diagnose gastric electrical abnormalities in patients with functional gastrointestinal disorders.


Assuntos
Trato Gastrointestinal , Eletricidade , Fenômenos Eletrofisiológicos , Trato Gastrointestinal/diagnóstico por imagem , Humanos , Estômago/diagnóstico por imagem
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2388-2391, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018487

RESUMO

The contractions of the stomach are governed by an electrophysiological event that can be detected noninvasively from the body-surface. Diagnosis of gastric motility disorders remains challenging due to the limited information provided by symptoms and standard electrogastrography (EGG). Body-surface gastric mapping (BSGM) is a novel technique that measures the resultant body-surface potentials using an array of multiple cutaneous electrodes. However, there is no established protocol to guide the placement of the mapping array and to account for the effects of biodiversity on the interpretation of gastric BSGM data. This study aims to quantify the effect of anatomical variation of the stomach on body-surface potentials. To this end, 44 subject specific models of the stomach and torso were developed. Anatomical parameters such as the Euclidean distance from the xiphoid process (88.1 ± 21.9 mm), orientation relative to the axial plane (202.8 ± 14.0°) and tissue volume (47.5 ± 29.5 mL) were quantified. Electrophysiological simulations demonstrated strong correlation (0.73 ± 0.16) between stomach and body-surface activities, with variations in the location of maximum amplitude relative to the xiphoid process (103.7 ± 44.2 mm). In general, there was an agreement between the location of the stomach and the location of the maximum amplitude, and an extended coverage was required to account for the biodiversity. The findings of this study will aid BSGM electrode array design and placement protocol in clinical practices.


Assuntos
Motilidade Gastrointestinal , Estômago , Mapeamento Potencial de Superfície Corporal , Eletromiografia , Fenômenos Eletrofisiológicos , Humanos , Estômago/diagnóstico por imagem
8.
Artigo em Inglês | MEDLINE | ID: mdl-33017928

RESUMO

Transient electrophysiological anomalies in the human brain have been associated with neurological disorders such as epilepsy, may signal impending adverse events (e.g, seizurse), or may reflect the effects of a stressor, such as insufficient sleep. These, typically brief, high-frequency and heterogeneous signal anomalies remain poorly understood, particularly at long time scales, and their morphology and variability have not been systematically characterized. In continuous neural recordings, their inherent sparsity, short duration and low amplitude makes their detection and classification difficult. In turn, this limits their evaluation as potential biomarkers of abnormal neurodynamic processes (e.g., ictogenesis) and predictors of impending adverse events. A novel algorithm is presented that leverages the inherent sparsity of high-frequency abnormalities in neural signals recorded at the scalp and uses spectral clustering to classify them in very high-dimensional signals spanning several days. It is shown that estimated clusters vary dynamically with time and their distribution changes substantially both as a function of time and space.


Assuntos
Encéfalo , Epilepsia , Algoritmos , Análise por Conglomerados , Fenômenos Eletrofisiológicos , Epilepsia/diagnóstico , Humanos
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 398-401, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018012

RESUMO

We propose a framework for studying the electrophysiological correlates of BOLD-fMRI. This framework relies on structured coupled matrix-tensor factorization (sCMTF), a joint multidimensional decomposition which reveals dynamical interactions between LFP/EEG oscillatory features and BOLD-fMRI data. We test whether LFP/EEG-BOLD co-fluctuations and regional hemodynamic response functions can be estimated by sCMTF using whole-brain modelling of restingstate activity. We produce permuted datasets to show that our framework extracts EEG/LFP temporal patterns that correlate significantly with BOLD signal fluctuations. Our framework is also capable of estimating HRFs that accurately embodies simulated hemodynamics, with a word of caution regarding initialization of the sCMTF algorithm.


Assuntos
Mapeamento Encefálico , Imagem por Ressonância Magnética , Eletroencefalografia , Fenômenos Eletrofisiológicos , Hemodinâmica
10.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(4): 386-394, 2020 Apr 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-32879062

RESUMO

OBJECTIVES: To establish an electrophysiological model of alcoholic cardiomyopathy by inducing pluripotent stem cells (iPSCs) to differentiate into cardiomyocytes (iPSC-CM) in vitro. METHODS: The human iPSC were expanded in vitro and differentiated into iPSC-CM. The iPSC-CM were divided into a blank control group, an alcoholic experiment group (according to the concentration of alcoholic, the alcoholic experiment was also divided into many subgroups), and a KN93 treatment group. Then the efficiency of iPSC differentiated to iPSC-CM was detected by immunofluorescence, the function of iPSC-CM was detected by cell counting kit-8 (CCK8) assay and lactate dehydrogenase (LDH) activity assay kit. The electrophysiological activity of iPSC-CM was monitored by real time cellular analysis (RTCA), the injury of iPSC-CM caused by alcohol was further verified by the mitochondrial membrane potential fluorescence probe JC-1 staining combined with RTCA analysis. RESULTS: Compared with the blank control group, the different doses (25, 50, 100, 150, 200, 250, 300 mmol/L) of alcohol could significantly inhibit the proliferation of iPSC-CM in a dose-dependent manner (all P<0.05). Compared with the blank control group, the activity of iPSC-CM was significantly reduced by 100 mmol/L alcohol, resulting in the increase of LDH release, the decrease of mitochondrial membrane potential, the amplitude and beating rate (all P<0.05). Compared with the 100 mg/mL alcoholic experiment group, the KN93 treatment group significantly alleviated the damage of alcohol to iPSC-CM by blocking the necrotic apoptotic pathway, resulting in the decrease of LDH release, the increase of mitochondrial membrane potential, the amplitude and beating rate (all P<0.05). CONCLUSIONS: The electrophysiological model of alcoholic cardiomyopathy based on the differentiation of cardiomyocytes are successfully established, which can be used to study the electrophysiological activity and the molecular mechanism for relevant diseases, and it may provide a more reasonable and effective research tool for drug screening and clinical study.


Assuntos
Cardiomiopatia Alcoólica , Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Fenômenos Eletrofisiológicos , Humanos , Miócitos Cardíacos
11.
PLoS Comput Biol ; 16(9): e1008198, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32931495

RESUMO

Calcium imaging with fluorescent protein sensors is widely used to record activity in neuronal populations. The transform between neural activity and calcium-related fluorescence involves nonlinearities and low-pass filtering, but the effects of the transformation on analyses of neural populations are not well understood. We compared neuronal spikes and fluorescence in matched neural populations in behaving mice. We report multiple discrepancies between analyses performed on the two types of data, including changes in single-neuron selectivity and population decoding. These were only partially resolved by spike inference algorithms applied to fluorescence. To model the relation between spiking and fluorescence we simultaneously recorded spikes and fluorescence from individual neurons. Using these recordings we developed a model transforming spike trains to synthetic-imaging data. The model recapitulated the differences in analyses. Our analysis highlights challenges in relating electrophysiology and imaging data, and suggests forward modeling as an effective way to understand differences between these data.


Assuntos
Cálcio/metabolismo , Fenômenos Eletrofisiológicos/fisiologia , Modelos Neurológicos , Imagem Molecular/métodos , Neurônios , Potenciais de Ação/fisiologia , Animais , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Camundongos , Neurônios/metabolismo , Neurônios/fisiologia , Imagem Óptica
12.
Zhonghua Yan Ke Za Zhi ; 56(7): 489-491, 2020 Jul 11.
Artigo em Chinês | MEDLINE | ID: mdl-32842331

RESUMO

Clinical visual electrophysiological examination is a method that can objectively reflect visual function. It has become one of the important methods of ophthalmological examination, and the operation process has strict specifications. This article introduces the history, formulation and content of international clinical visual electrophysiological examination standards, which will help ophthalmologists understand the importance of the standardization of the operation process, so as to better promote and standardize the clinical visual electrophysiological examination in China. ( Chin J Ophthalmol, 2020, 56: 489-491).


Assuntos
Oftalmologistas , Atenção , China , Fenômenos Eletrofisiológicos , Humanos , Visão Ocular
13.
Artigo em Chinês | MEDLINE | ID: mdl-32791605

RESUMO

Objective:To reveal the response characteristics of semicircular canal neurons(SCN) in the nonlinear perceptual interval, and to establish and screen out the precise SCN information coding model and function expression, which lays a foundation for the optimization and improvement of neuromodulation strategy of multichannel vestibular prosthesis. Method:The perceptual electrophysiological information data of the SCNs during the rotational stimulation was recorded in the nonlinear perceptual interval. The nonlinear least-squares algorithm was used to fit the electrophysiological information data to establish the linear-nonlinear models. The Akaike information criterion was used to calculate the goodness of fit of each model to determine the optimal expression function. Result:In the frequency experiment, the accurate information coding model of more than 85% of SCNs is a quadratic polynomial, and the frequency has no significant effect on the linear-nonlinear selection of the SCNs information coding model(P>0.05). In the amplitude experiment, the accurate information coding model of more than 83.33% of SCNs is quadratic polynomial when the maximum angular velocity is>80 deg/s, and the amplitude has a significant effect on the linear-nonlinear selection of the SCNs information coding model(P=0.038). Conclusion:The information coding models of SCN population in the nonlinear perceptual interval have two expressions, linear and nonlinear function, which is closely related to angular velocity. The quadratic polynomial function is more accurate and more advantageous and it can be used to design the precise neuromodulation strategy of multichannel vestibular prosthesis.


Assuntos
Vestíbulo do Labirinto , Fenômenos Eletrofisiológicos , Neurônios , Próteses e Implantes , Canais Semicirculares
14.
PLoS One ; 15(8): e0237426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813731

RESUMO

Transplantation of human embryonic stem cell (hESC)-derived neural progenitors is a potential treatment for neurological disorders, but relatively little is known about the time course for human neuron maturation after transplantation and the emergence of morphological and electrophysiological properties. To address this gap, we transplanted hESC-derived human GABAergic interneuron progenitors into the mouse hippocampus, and then characterized their electrophysiological properties and dendritic arborizations after transplantation by means of ex vivo whole-cell patch clamp recording, followed by biocytin staining, confocal imaging and neuron reconstruction software. We asked whether particular electrophysiological and morphological properties showed maturation-dependent changes after transplantation. We also investigated whether the emergence of particular electrophysiological properties were linked to increased complexity of the dendritic arbors. Human neurons were classified into five distinct neuronal types (Type I-V), ranging from immature to mature fast-spiking interneurons. Hierarchical clustering of the dendritic morphology and Sholl analyses suggested four morphologically distinct classes (Class A-D), ranging from simple/immature to highly complex. Incorporating all of our data regardless of neuronal classification, we investigated whether any electrophysiological and morphological features correlated with time post-transplantation. This analysis demonstrated that both dendritic arbors and electrophysiological properties matured after transplantation.


Assuntos
Fenômenos Eletrofisiológicos , Hipocampo/citologia , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/transplante , Interneurônios/citologia , Interneurônios/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Camundongos
15.
J Vis Exp ; (161)2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32744516

RESUMO

The retinal pigment epithelium (RPE) is a specialized monolayer of cells strategically located between the retina and the choriocapillaris that maintain the overall health and structural integrity of the photoreceptors. The RPE is polarized, exhibiting apically and basally located receptors or channels, and performs vectoral transport of water, ions, metabolites, and secretes several cytokines. In vivo noninvasive measurements of RPE function can be made using direct-coupled ERGs (DC-ERGs). The methodology behind the DC-ERG was pioneered by Marmorstein, Peachey, and colleagues using a custom-built stimulation recording system and later demonstrated using a commercially available system. The DC-ERG technique uses glass capillaries filled with Hank's buffered salt solution (HBSS) to measure the slower electrical responses of the RPE elicited from light-evoked concentration changes in the subretinal space due to photoreceptor activity. The prolonged light stimulus and length of the DC-ERG recording make it vulnerable to drift and noise resulting in a low yield of useable recordings. Here, we present a fast, reliable method for improving the stability of the recordings while reducing noise by using vacuum pressure to reduce/eliminate bubbles that result from outgassing of the HBSS and electrode holder. Additionally, power line artifacts are attenuated using a voltage regulator/power conditioner. We include the necessary light stimulation protocols for a commercially available ERG system as well as scripts for analysis of the DC-ERG components: c-wave, fast oscillation, light peak, and off response. Due to the improved ease of recordings and rapid analysis workflow, this simplified protocol is particularly useful in measuring age-related changes in RPE function, disease progression, and in the assessment of pharmacological intervention.


Assuntos
Fenômenos Eletrofisiológicos/efeitos da radiação , Eletrorretinografia , Luz , Epitélio Pigmentado da Retina/fisiologia , Epitélio Pigmentado da Retina/efeitos da radiação , Envelhecimento/fisiologia , Animais , Camundongos
16.
Proc Natl Acad Sci U S A ; 117(33): 20171-20179, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32747561

RESUMO

Extracellular electron transfer (EET) allows microorganisms to gain energy by linking intracellular reactions to external surfaces ranging from natural minerals to the electrodes of bioelectrochemical renewable energy technologies. In the past two decades, electrochemical techniques have been used to investigate EET in a wide range of microbes, with emphasis on dissimilatory metal-reducing bacteria, such as Shewanella oneidensis MR-1, as model organisms. However, due to the typically bulk nature of these techniques, they are unable to reveal the subpopulation variation in EET or link the observed electrochemical currents to energy gain by individual cells, thus overlooking the potentially complex spatial patterns of activity in bioelectrochemical systems. Here, to address these limitations, we use the cell membrane potential as a bioenergetic indicator of EET by S. oneidensis MR-1 cells. Using a fluorescent membrane potential indicator during in vivo single-cell-level fluorescence microscopy in a bioelectrochemical reactor, we demonstrate that membrane potential strongly correlates with EET. Increasing electrode potential and associated EET current leads to more negative membrane potential. This EET-induced membrane hyperpolarization is spatially limited to cells in contact with the electrode and within a near-electrode zone (<30 µm) where the hyperpolarization decays with increasing cell-electrode distance. The high spatial and temporal resolution of the reported technique can be used to study the single-cell-level dynamics of EET not only on electrode surfaces, but also during respiration of other solid-phase electron acceptors.


Assuntos
Membrana Externa Bacteriana/fisiologia , Transporte de Elétrons/fisiologia , Potenciais da Membrana/fisiologia , Shewanella/fisiologia , Benzotiazóis/metabolismo , Fenômenos Eletrofisiológicos , Corantes Fluorescentes , Análise de Célula Única/métodos , Gravação em Vídeo
18.
Proc Natl Acad Sci U S A ; 117(29): 17260-17268, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32632007

RESUMO

Understanding how a network of interconnected neurons receives, stores, and processes information in the human brain is one of the outstanding scientific challenges of our time. The ability to reliably detect neuroelectric activities is essential to addressing this challenge. Optical recording using voltage-sensitive fluorescent probes has provided unprecedented flexibility for choosing regions of interest in recording neuronal activities. However, when recording at a high frame rate such as 500 to 1,000 Hz, fluorescence-based voltage sensors often suffer from photobleaching and phototoxicity, which limit the recording duration. Here, we report an approach called electrochromic optical recording (ECORE) that achieves label-free optical recording of spontaneous neuroelectrical activities. ECORE utilizes the electrochromism of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) thin films, whose optical absorption can be modulated by an applied voltage. Being based on optical reflection instead of fluorescence, ECORE offers the flexibility of an optical probe without suffering from photobleaching or phototoxicity. Using ECORE, we optically recorded spontaneous action potentials in cardiomyocytes, cultured hippocampal and dorsal root ganglion neurons, and brain slices. With minimal perturbation to cells, ECORE allows long-term optical recording over multiple days.


Assuntos
Eletrofisiologia/métodos , Neurônios/fisiologia , Poliestirenos , Tiofenos , Potenciais de Ação/fisiologia , Encéfalo/citologia , Encéfalo/fisiologia , Técnicas Eletroquímicas/métodos , Fenômenos Eletrofisiológicos , Corantes Fluorescentes , Gânglios Espinais/citologia , Gânglios Espinais/fisiologia , Humanos , Imagem Óptica , Óptica e Fotônica/métodos
19.
Proc Natl Acad Sci U S A ; 117(29): 17330-17337, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32632015

RESUMO

Purkinje cells, the principal neurons of cerebellar computations, are believed to comprise a uniform neuronal population of cells, each with similar functional properties. Here, we show an undiscovered heterogeneity of adult zebrafish Purkinje cells, revealing the existence of anatomically and functionally distinct cell types. Dual patch-clamp recordings showed that the cerebellar circuit contains all Purkinje cell types that cross-communicate extensively using chemical and electrical synapses. Further activation of spinal central pattern generators (CPGs) revealed unique phase-locked activity from each Purkinje cell type during the locomotor cycle. Thus, we show intricately organized Purkinje cell networks in the adult zebrafish cerebellum that encode the locomotion rhythm differentially, and we suggest that these organizational properties may also apply to other cerebellar functions.


Assuntos
Locomoção/fisiologia , Células de Purkinje/fisiologia , Peixe-Zebra/fisiologia , Potenciais de Ação , Animais , Comportamento Animal , Encéfalo , Geradores de Padrão Central/fisiologia , Cerebelo/fisiologia , Análise por Conglomerados , Fenômenos Eletrofisiológicos , Feminino , Masculino , Modelos Animais , Medula Espinal
20.
J Phys Chem Lett ; 11(12): 4897-4900, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: covidwho-456421

RESUMO

SARS-CoV-2, since emerging in Wuhan, China, has been a major concern because of its high infection rate and has left more than six million infected people around the world. Many studies endeavored to reveal the structure of the SARS-CoV-2 compared to the SARS-CoV, in order to find solutions to suppress this high infection rate. Some of these studies showed that the mutations in the SARS-CoV spike (S) protein might be responsible for its higher affinity to the ACE2 human cell receptor. In this work, we used molecular dynamics simulations and Monte Carlo sampling to compare the binding affinities of the S proteins of SARS-CoV and SARS-CoV-2 to the ACE2. Our results show that the protein surface of the ACE2 at the receptor binding domain (RBD) exhibits negative electrostatic potential, while a positive potential is observed for the S proteins of SARS-CoV/SARS-CoV-2. In addition, the binding energies at the interface are slightly higher for SARS-CoV-2 because of enhanced electrostatic interactions. The major contributions to the electrostatic binding energies result from the salt bridges forming between R426 and ACE-2-E329 in the case of SARS-CoV and K417 and ACE2-D30 in the SARS-CoV-2. In addition, our results indicate that the enhancement in the binding energy is not due to a single mutant but rather because of the sophisticated structural changes induced by all these mutations together. This finding suggests that it is implausible for the SARS-CoV-2 to be a lab-engineered virus.


Assuntos
Betacoronavirus/química , Receptor Tipo 2 de Angiotensina/química , Vírus da SARS/química , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/genética , Simulação por Computador , Infecções por Coronavirus , Fenômenos Eletrofisiológicos , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Método de Monte Carlo , Mutação/genética , Pandemias , Pneumonia Viral , Receptor Tipo 2 de Angiotensina/efeitos dos fármacos , Receptor Tipo 2 de Angiotensina/genética , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/genética
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