scholarly journals The glass micropipette electrode: A history of its inventors and users to 1950

2017 ◽  
Vol 149 (4) ◽  
pp. 417-430 ◽  
Author(s):  
Allan H. Bretag
Keyword(s):  
Electrical Activity ◽  
Plant Cells ◽  
Living Cells ◽  
Cellular Level ◽  
Nerve Fibers ◽  
Mechanistic Explanations ◽  
Electrical Potentials ◽  
Micro Tool ◽  
History Of ◽  
Glass Micropipette

Soon after the glass micropipette was invented as a micro-tool for manipulation of single bacteria and the microinjection and microsurgery of living cells, it was seen to hold promise as a microelectrode to stimulate individual cells electrically and to study electrical potentials in them. Initial successes and accurate mechanistic explanations of the results were achieved in giant plant cells in the 1920s. Long known surface electrical activity in nerves and muscles was only resolved at a similar cellular level in the 1930s and 1940s after the discovery of giant nerve fibers and the development of finer tipped microelectrodes for normal-sized cells.

Handbook of Electrogastrography

2003 ◽  
Keyword(s):  
Electrical Activity ◽  
Neuromuscular Disorders ◽  
Relevant Information ◽  
Cellular Level ◽  
Clinical Practices ◽  
Physiological Basis ◽  
Gastric Dysrhythmias ◽  
History Of ◽  
Major Section ◽  
Cells Of Cajal

The Handbook of Electrogastrography is the first textbook dedicated to reviewing the physiology of gastric myelectrical activity and the measurement of this electrical activity with electrodes placed on the abdominal surface - the electrogastrogram. The Handbook is divided into three major sections. The first section (Chapters 1-3) focuses on the history of electrogastrography, electrical activity of the interstitial cells of Cajal, the cells from which gastric electrical rhythmicity emanates. The cellular level of gastric electrical rhythmicity provides an understanding of the physiological basis of the electrogastrogram signal. The second major section of the book (Chapters 4-6) incorporates the practical aspects of recording a high quality electrogastrogram and approaches to the analysis of the electrogastrogram using visual inspection and computer techniques. This section focuses on the authors' combined experience of examining EGG recordings for more than sixty years. From this rich research and clinical experience, the clinical application of EGG recordings in an approach to patients with unexplained nausea and vomiting is described. Neuromuscular disorders of the stomach involving gastric dysrhythmias are reviewed. The third major section of the book (Chapters 7-9) comprises many examples of gastric dysrythmias ranging from bradygastrias to tachygastrias and mixed dysrythmias. Current understanding of the mechanisms of gastric dysrhythmias is reviewed. Artifacts in the EGG signal, which may be confused with gastric dysrhythmias, are also presented. The Handbook of Electrogastrography will be a valuable reference for physicians interested in recording gastric electrical activity in clinical practices or in clinical research. Gastroenterologists, internists, psychologists and others with an interest in gastric myoelectrical events will also find extensive and relevant information for recording and interpreting EGGs in the Handbook.

An Electrophysiological Approach to the Study of Chemical Sensory Reception in Certain Insects

1953 ◽  
Vol 85 (5) ◽  
pp. 182-189 ◽  
Author(s):  
John A. Chapman ◽  
Roderick Craig
Keyword(s):  
Electrical Activity ◽  
Olfactory Nerve ◽  
Nerve Fibers ◽  
Receptor Activity ◽  
Sensory Receptors ◽  
The Past ◽  
Electrical Potentials ◽  
Sensory Reception

In the past twenty years or so many investigators have studied amplified electrical activity from nerve fibers supplving sensory receptors in many animals, including insects (see 2, 5, 8, 16, 19). With this technique much information has been secured concerning the characreristics of mechanical receptors (touch, pressure, sound, etc.) and photoreceptors. To a much lesser extent temperature, pain, taste and other chemical receptor activity in vertebrates has been studied although no electrical potentials appear to have been recorded from individual olfactory nerve fibers in any organism.

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

Biomems Microprobe for Electrical Activity Recording of Living Cells

2007 ◽  
Author(s):  
C. Moldovan ◽  
R. Iosub ◽  
C.P. Lungu ◽  
A.M. Lungu ◽  
B. Firtat ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Living Cells

Transducer for recording electrical and mechanical chronic intestinal activity

1976 ◽  
Vol 41 (6) ◽  
pp. 942-945 ◽  
Author(s):  
A. Lambert ◽  
R. Eloy ◽  
J. F. Grenier
Keyword(s):  
Electrical Activity ◽  
Wheatstone Bridge ◽  
Displacement Transducer ◽  
Intestinal Wall ◽  
Mechanical Activity ◽  
Strain Gauges ◽  
Mechanical Displacement ◽  
Electrical Potentials ◽  
Intestinal Activity ◽  
Long Duration

An extraluminal displacement transducer has been developed for simultaneously recording the mechanical activity in two perpendicular directions andthe electrical activity of the intestinal serosa. The length variations in two perpendicular directions were measured by means of strain gauges bounded on two pairs of lamellae embedded in a rigid stand. The electrical activity was recorded by means of four electrodes situated at the extremity of these lamellae. The electrical gauges of each pair of lamellae are connected to form a Wheatstone bridge. This device allows establishment of a correlation between the mechanical displacement of the intestinal wall serosa and electrical potentials by means of studies of long duration.

scholarly journals The Electrical Activity of the Orbicularis Oris Muscle in Children with Down Syndrome—A Preliminary Study

2021 ◽  
Vol 10 (23) ◽  
pp. 5611
Author(s):  
Liliana Szyszka-Sommerfeld ◽  
Magdalena Sycińska-Dziarnowska ◽  
Krzysztof Woźniak ◽  
Monika Machoy ◽  
Sławomir Wilczyński ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Electrical Activity ◽  
Healthy Children ◽  
Exclusion Criteria ◽  
Children With Down Syndrome ◽  
Electrical Potentials ◽  
Study Results ◽  
Orbicularis Oris Muscle ◽  
Preliminary Study ◽  
Muscular Effort

The aim of this study was to assess the electrical activity of the superior (SOO) and inferior (IOO) orbicularis oris muscles in children with Down syndrome (DS) and in children without DS. After applying the inclusion and exclusion criteria, 30 subjects were eligible to participate in the later stages of the research—15 subjects with DS (mean age 10.1 ± 1.1) and 15 healthy controls (mean age 9.8 ± 1.0). The electrical potentials of the SOO and IOO muscles were recorded using a DAB-Bluetooth electromyography machine (Zebris Medical GmbH, Germany) during the following tasks: At clinical rest, saliva swallowing, lip protrusion, lip compression, and production of the syllable/pa/. The Mann–Whitney U test was conducted to compare the study results between the groups. An analysis of the electromyographical (EMG) recordings showed that the electrical activity of the orbicularis oris muscle in children with DS and lip incompetence was significantly higher compared to healthy children during saliva swallowing, lip compression, and when producing the syllable/pa/, and this may suggest greater muscular effort due to the need to seal the lips during these functional conditions.

scholarly journals Extracellular Electrophysiology in the Prostate Cancer Cell Model PC-3

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 139 ◽  
Author(s):  
Miguel Cabello ◽  
Haobo Ge ◽  
Carmen Aracil ◽  
Despina Moschou ◽  
Pedro Estrela ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Electrical Activity ◽  
Cell Model ◽  
Treatment Strategies ◽  
Electrode Array ◽  
Cellular Level ◽  
Low Noise ◽  
Cellular Growth ◽  
Male Population ◽  
Depth Analysis

Although prostate cancer is one of the most common cancers in the male population, its basic biological function at a cellular level remains to be fully understood. This lack of in depth understanding of its physiology significantly hinders the development of new, targeted and more effective treatment strategies. Whilst electrophysiological studies can provide in depth analysis, the possibility of recording electrical activity in large populations of non-neuronal cells remains a significant challenge, even harder to address in the picoAmpere-range, which is typical of cellular level electrical activities. In this paper, we present the measurement and characterization of electrical activity of populations of prostate cancer cells PC-3, demonstrating for the first time a meaningful electrical pattern. The low noise system used comprises a multi-electrode array (MEA) with circular gold electrodes on silicon oxide substrates. The extracellular capacitive currents present two standard patterns: an asynchronous sporadic pattern and a synchronous quasi-periodic biphasic spike pattern. An amplitude of ±150 pA, a width between 50–300 ms and an inter-spike interval around 0.5 Hz characterize the quasi-periodic spikes. Our experiments using treatment of cells with Gd3⁺, known as an inhibitor for the Ca2⁺ exchanges, suggest that the quasi-periodic signals originate from Ca2⁺ channels. After adding the Gd3⁺ to a population of living PC-3 cells, their electrical activity considerably decreased; once the culture was washed, thus eliminating the Gd3⁺ containing medium and addition of fresh cellular growth medium, the PC-3 cells recovered their normal electrical activity. Cellular viability plots have been carried out, demonstrating that the PC-3 cells remain viable after the use of Gd3⁺, on the timescale of this experiment. Hence, this experimental work suggests that Ca2⁺ is significantly affecting the electrophysiological communication pattern among PC-3 cell populations. Our measuring platform opens up new avenues for real time and highly sensitive investigations of prostate cancer signalling pathways.

scholarly journals Protective Roles of Cytosolic and Plastidal Proteasomes on Abiotic Stress and Pathogen Invasion

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 832
Author(s):  
Md. Sarafat Ali ◽  
Kwang-Hyun Baek
Keyword(s):  
Abiotic Stress ◽  
Cell Survival ◽  
Plant Cells ◽  
Cellular Level ◽  
26S Proteasome ◽  
Pathogen Invasion ◽  
Cellular Environment ◽  
Abiotic Stressors ◽  
Different Types ◽  
Clp Proteases

Protein malfunction is typically caused by abiotic stressors. To ensure cell survival during conditions of stress, it is important for plant cells to maintain proteins in their respective functional conformation. Self-compartmentalizing proteases, such as ATP-dependent Clp proteases and proteasomes are designed to act in the crowded cellular environment, and they are responsible for degradation of misfolded or damaged proteins within the cell. During different types of stress conditions, the levels of misfolded or orphaned proteins that are degraded by the 26S proteasome in the cytosol and nucleus and by the Clp proteases in the mitochondria and chloroplasts increase. This allows cells to uphold feedback regulations to cellular-level signals and adjust to altered environmental conditions. In this review, we summarize recent findings on plant proteolytic complexes with respect to their protective functions against abiotic and biotic stressors.

Cell-Based Model of the Limulus Lateral Eye

1998 ◽  
Vol 80 (4) ◽  
pp. 1800-1815 ◽  
Author(s):  
Christopher L. Passaglia ◽  
Frederick A. Dodge ◽  
Robert B. Barlow
Keyword(s):  
Optic Nerve ◽  
Natural Habitat ◽  
Correlation Coefficients ◽  
Visual Space ◽  
Cellular Level ◽  
Nerve Fibers ◽  
Lateral Eye ◽  
Horseshoe Crabs ◽  
Parametric Analyses ◽  
Nerve Recordings

Passaglia, Christopher L., Frederick A. Dodge, and Robert B. Barlow. Cell-based model of the Limulus lateral eye. J. Neurophysiol. 80: 1800–1815, 1998. We present a cell-based model of the Limulus lateral eye that computes the eye's input to the brain in response to any specified scene. Based on the results of extensive physiological studies, the model simulates the optical sampling of visual space by the array of retinal receptors (ommatidia), the transduction of light into receptor potentials, the integration of excitatory and inhibitory signals into generator potentials, and the conversion of generator potentials into trains of optic nerve impulses. By simulating these processes at the cellular level, model ommatidia can reproduce response variability resulting from noise inherent in the stimulus and the eye itself, and they can adapt to changes in light intensity over a wide operating range. Programmed with these realistic properties, the model eye computes the simultaneous activity of its ensemble of optic nerve fibers, allowing us to explore the retinal code that mediates the visually guided behavior of the animal in its natural habitat. We assess the accuracy of model predictions by comparing the response recorded from a single optic nerve fiber to that computed by the model for the corresponding receptor. Correlation coefficients between recorded and computed responses were typically >95% under laboratory conditions. Parametric analyses of the model together with optic nerve recordings show that animal-to-animal variation in the optical and neural properties of the eye do not alter significantly its response to objects having the size and speed of horseshoe crabs. The eye appears robustly designed for encoding behaviorally important visual stimuli. Simulations with the cell-based model provide insights about the design of the Limulus eye and its encoding of the animal's visual world.

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