Microelectrodes: Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)Ion-Selective Electrodes: Electrodes which can be used to measure the concentration of particular ions in cells, tissues, or solutions.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Fluorocarbon PolymersExtracellular Space: Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.Electrodes, Implanted: Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.Microchip Analytical Procedures: The preparation and analysis of samples on miniaturized devices.Electrochemical Techniques: The utilization of an electrical current to measure, analyze, or alter chemicals or chemical reactions in solution, cells, or tissues.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Bicarbonates: Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.Chlorides: Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.Strophanthidin: 3 beta,5,14-Trihydroxy-19-oxo-5 beta-card-20(22)-enolide. The aglycone cardioactive agent isolated from Strophanthus Kombe, S. gratus and other species; it is a very toxic material formerly used as digitalis. Synonyms: Apocymarin; Corchorin; Cynotoxin; Corchorgenin.Electrodes: Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.Helix (Snails): A genus of chiefly Eurasian and African land snails including the principal edible snails as well as several pests of cultivated plants.Necturus: A genus of the Proteidae family with five recognized species, which inhabit the Atlantic and Gulf drainages.Micromanipulation: The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.Necturus maculosus: A neotenic aquatic species of mudpuppy (Necturus) occurring from Manitoba to Louisiana and Texas.Purkinje Fibers: Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.Conductometry: Determination of the quantity of a material present in a mixture by measurement of its effect on the electrical conductivity of the mixture. (Webster, 3d ed)Glass: Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Dielectric Spectroscopy: A technique of measuring the dielectric properties of materials, which vary over a range of frequencies depending on the physical properties of the material. The technique involves measuring, over a range of frequencies, ELECTRICAL IMPEDANCE and phase shift of an electric field as it passes through the material.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Intracellular Fluid: The fluid inside CELLS.Leeches: Annelids of the class Hirudinea. Some species, the bloodsuckers, may become temporarily parasitic upon animals, including man. Medicinal leeches (HIRUDO MEDICINALIS) have been used therapeutically for drawing blood since ancient times.Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.Carbon: A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.Diamond: Diamond. A crystalline form of carbon that occurs as hard, colorless or tinted isomeric crystals. It is used as a precious stone, for cutting glass, and as bearings for delicate mechanisms. (From Grant & Hackh's Chemical Dictionary, 5th ed)Potentiometry: Solution titration in which the end point is read from the electrode-potential variations with the concentrations of potential determining ions. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Biosensing Techniques: Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.Miniaturization: The design or construction of objects greatly reduced in scale.Ion Transport: The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.Partial Pressure: The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Dimethadione: An anticonvulsant that is the active metabolite of TRIMETHADIONE.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Electric Impedance: The resistance to the flow of either alternating or direct electrical current.Equipment Design: Methods of creating machines and devices.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Polarography: An electrochemical technique for measuring the current that flows in solution as a function of an applied voltage. The observed polarographic wave, resulting from the electrochemical response, depends on the way voltage is applied (linear sweep or differential pulse) and the type of electrode used. Usually a mercury drop electrode is used.4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid: A non-penetrating amino reagent (commonly called SITS) which acts as an inhibitor of anion transport in erythrocytes and other cells.4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid: An inhibitor of anion conductance including band 3-mediated anion transport.Ion Exchange: Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.Electroplating: Coating with a metal or alloy by electrolysis.LacquerQuaternary Ammonium Compounds: Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.Ethoxzolamide: A carbonic anhydrase inhibitor used as diuretic and in glaucoma. It may cause hypokalemia.Amiloride: A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)Cortical Spreading Depression: The decrease in neuronal activity (related to a decrease in metabolic demand) extending from the site of cortical stimulation. It is believed to be responsible for the decrease in cerebral blood flow that accompanies the aura of MIGRAINE WITH AURA. (Campbell's Psychiatric Dictionary, 8th ed.)Papillary Muscles: Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.Benzolamide: Selective renal carbonic anhydrase inhibitor. It may also be of use in certain cases of respiratory failure.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Brain Waves: Wave-like oscillations of electric potential between parts of the brain recorded by EEG.Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Barium: An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.Carbonic Anhydrase Inhibitors: A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES.Sodium-Bicarbonate Symporters: Proteins that cotransport sodium ions and bicarbonate ions across cellular membranes.Dark Adaptation: Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.Microtechnology: Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or MEMS. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.Iontophoresis: Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.Rana pipiens: A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.Buffers: A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.Tetrodotoxin: An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Extracellular Fluid: The fluid of the body that is outside of CELLS. It is the external environment for the cells.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Heart Conduction System: An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Endolymph: The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Acid-Base Equilibrium: The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.Alkalies: Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. (Grant & Hackh's Chemical Dictionary, 5th ed)Rana esculenta: An edible species of the family Ranidae, occurring in Europe and used extensively in biomedical research. Commonly referred to as "edible frog".Time Factors: Elements of limited time intervals, contributing to particular results or situations.Silicon: A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Nanocomposites: Nanometer-scale composite structures composed of organic molecules intimately incorporated with inorganic molecules. (Glossary of Biotechnology and Nanobiotechology Terms, 4th ed)Octanols: Isomeric forms and derivatives of octanol (C8H17OH).Muscles: Contractile tissue that produces movement in animals.Perilymph: The fluid separating the membranous labyrinth from the osseous labyrinth of the ear. It is entirely separate from the ENDOLYMPH which is contained in the membranous labyrinth. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1396, 642)Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Cell Membrane Permeability: A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.Gold: A yellow metallic element with the atomic symbol Au, atomic number 79, and atomic weight 197. It is used in jewelry, goldplating of other metals, as currency, and in dental restoration. Many of its clinical applications, such as ANTIRHEUMATIC AGENTS, are in the form of its salts.Ganglia: Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.Dopamine: One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.Rana temporaria: A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Photoreceptor Cells: Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.Sinoatrial Node: The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Dimethylpolysiloxanes: Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.Ammonium Chloride: An acidifying agent that has expectorant and diuretic effects. Also used in etching and batteries and as a flux in electroplating.Motion: Physical motion, i.e., a change in position of a body or subject as a result of an external force. It is distinguished from MOVEMENT, a process resulting from biological activity.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Catecholamines: A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Microchemistry: The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.Platinum: Platinum. A heavy, soft, whitish metal, resembling tin, atomic number 78, atomic weight 195.09, symbol Pt. (From Dorland, 28th ed) It is used in manufacturing equipment for laboratory and industrial use. It occurs as a black powder (platinum black) and as a spongy substance (spongy platinum) and may have been known in Pliny's time as "alutiae".Potassium Channels: Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.Peroneal Nerve: The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.Mechanoreceptors: Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.Acetylcholine: A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.Bumetanide: A sulfamyl diuretic.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.Diffusion: The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.Quinidine: An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.Potassium Channel Blockers: A class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.Submucous Plexus: One of two ganglionated neural networks which together form the enteric nervous system. The submucous (Meissner's) plexus is in the connective tissue of the submucosa. Its neurons innervate the epithelium, blood vessels, endocrine cells, other submucosal ganglia, and myenteric ganglia, and play an important role in regulating ion and water transport. (From FASEB J 1989;3:127-38)Automatic Data Processing: Data processing largely performed by automatic means.Osmosis: Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.Tetraethylammonium CompoundsSkin Physiological Phenomena: The functions of the skin in the human and animal body. It includes the pigmentation of the skin.Potassium Chloride: A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Artifacts: Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.Neuromuscular Junction: The synapse between a neuron and a muscle.Heart: The hollow, muscular organ that maintains the circulation of the blood.Chromaffin Cells: Cells that store epinephrine secretory vesicles. During times of stress, the nervous system signals the vesicles to secrete their hormonal content. Their name derives from their ability to stain a brownish color with chromic salts. Characteristically, they are located in the adrenal medulla and paraganglia (PARAGANGLIA, CHROMAFFIN) of the sympathetic nervous system.Ventricular Function: The hemodynamic and electrophysiological action of the HEART VENTRICLES.Exocytosis: Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Rana catesbeiana: A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Acidosis: A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.Anura: An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.Tetraethylammonium: A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)Motor Neurons: Neurons which activate MUSCLE CELLS.Somatosensory Cortex: Area of the parietal lobe concerned with receiving sensations such as movement, pain, pressure, position, temperature, touch, and vibration. It lies posterior to the central sulcus.Caffeine: A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.Cerebral Cortex: The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.Ammonia: A colorless alkaline gas. It is formed in the body during decomposition of organic materials during a large number of metabolically important reactions. Note that the aqueous form of ammonia is referred to as AMMONIUM HYDROXIDE.Astacoidea: A superfamily of various freshwater CRUSTACEA, in the infraorder Astacidea, comprising the crayfish. Common genera include Astacus and Procambarus. Crayfish resemble lobsters, but are usually much smaller.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Serotonin: A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.Glyburide: An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Acids: Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. (Grant & Hackh's Chemical Dictionary, 5th ed)Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Body Fluids: Liquid components of living organisms.Isoproterenol: Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.Electrophysiological Phenomena: The electrical properties, characteristics of living organisms, and the processes of organisms or their parts that are involved in generating and responding to electrical charges.Electroretinography: Recording of electric potentials in the retina after stimulation by light.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Chloride-Bicarbonate Antiporters: Electroneutral chloride bicarbonate exchangers that allow the exchange of BICARBONATE IONS exchange for CHLORIDE IONS across the cellular membrane. The action of specific antiporters in this class serve important functions such as allowing the efficient exchange of bicarbonate across red blood cell membranes as they passage through capillaries and the reabsorption of bicarbonate ions by the kidney.
Molecular dynamics of the sodium channel pore vary with gating: interactions between P-segment motions and inactivation. (1/2595)Disulfide trapping studies have revealed that the pore-lining (P) segments of voltage-dependent sodium channels undergo sizable motions on a subsecond time scale. Such motions of the pore may be necessary for selective ion translocation. Although traditionally viewed as separable properties, gating and permeation are now known to interact extensively in various classes of channels. We have investigated the interaction of pore motions and voltage-dependent gating in micro1 sodium channels engineered to contain two cysteines within the P segments. Rates of catalyzed internal disulfide formation (kSS) were measured in K1237C+W1531C mutant channels expressed in oocytes. During repetitive voltage-clamp depolarizations, increasing the pulse duration had biphasic effects on the kSS, which first increased to a maximum at 200 msec and then decreased with longer depolarizations. This result suggested that occupancy of an intermediate inactivation state (IM) facilitates pore motions. Consistent with the known antagonism between alkali metals and a component of slow inactivation, kSS varied inversely with external [Na+]o. We examined the converse relationship, namely the effect of pore flexibility on gating, by measuring recovery from inactivation in Y401C+E758C (YC/EC) channels. Under oxidative conditions, recovery from inactivation was slower than in a reduced environment in which the spontaneous YC/EC cross-link is disrupted. The most prominent effects were slowing of a component with intermediate recovery kinetics, with diminution of its relative amplitude. We conclude that occupancy of an intermediate inactivation state facilitates motions of the P segments; conversely, flexibility of the P segments alters an intermediate component of inactivation. (+info)
Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking. (2/2595)Pathophysiological, lesion, and electrophysiological studies suggest that the cerebellar cortex is important for controlling the direction and speed of movement. The relationship of cerebellar Purkinje cell discharge to the control of arm movement parameters, however, remains unclear. The goal of this study was to examine how movement direction and speed and their interaction-velocity-modulate Purkinje cell simple spike discharge in an arm movement task in which direction and speed were independently controlled. The simple spike discharge of 154 Purkinje cells was recorded in two monkeys during the performance of two visuomotor tasks that required the animals to track targets that moved in one of eight directions and at one of four speeds. Single-parameter regression analyses revealed that a large proportion of cells had discharge modulation related to movement direction and speed. Most cells with significant directional tuning, however, were modulated at one speed, and most cells with speed-related discharge were modulated along one direction; this suggested that the patterns of simple spike discharge were not adequately described by single-parameter models. Therefore, a regression surface was fitted to the data, which showed that the discharge could be tuned to specific direction-speed combinations (preferred velocities). The overall variability in simple spike discharge was well described by the surface model, and the velocities corresponding to maximal and minimal discharge rates were distributed uniformly throughout the workspace. Simple spike discharge therefore appears to integrate information about both the direction and speed of arm movements, thereby encoding movement velocity. (+info)
Neural encoding in orbitofrontal cortex and basolateral amygdala during olfactory discrimination learning. (3/2595)Orbitofrontal cortex (OFC) is part of a network of structures involved in adaptive behavior and decision making. Interconnections between OFC and basolateral amygdala (ABL) may be critical for encoding the motivational significance of stimuli used to guide behavior. Indeed, much research indicates that neurons in OFC and ABL fire selectively to cues based on their associative significance. In the current study recordings were made in each region within a behavioral paradigm that allowed comparison of the development of associative encoding over the course of learning. In each recording session, rats were presented with novel odors that were informative about the outcome of making a response and had to learn to withhold a response after sampling an odor that signaled a negative outcome. In some cases, reversal training was performed in the same session as the initial learning. Ninety-six of the 328 neurons recorded in OFC and 60 of the 229 neurons recorded in ABL exhibited selective activity during evaluation of the odor cues after learning had occurred. A substantial proportion of those neurons in ABL developed selective activity very early in training, and many reversed selectivity rapidly after reversal. In contrast, those neurons in OFC rarely exhibited selective activity during odor evaluation before the rats reached the criterion for learning, and far fewer reversed selectivity after reversal. The findings support a model in which ABL encodes the motivational significance of cues and OFC uses this information in the selection and execution of an appropriate behavioral strategy. (+info)
Correlated firing in rabbit retinal ganglion cells. (4/2595)A ganglion cell's receptive field is defined as that region on the retinal surface in which a light stimulus will produce a response. While neighboring ganglion cells may respond to the same stimulus in a region where their receptive fields overlap, it generally has been assumed that each cell makes an independent decision about whether to fire. Recent recordings from cat and salamander retina using multiple electrodes have challenged this view of independent firing by showing that neighboring ganglion cells have an increased tendency to fire together within +/-5 ms. However, there is still uncertainty about which types of ganglion cells fire together, the mechanisms that produce coordinated spikes, and the overall function of coordinated firing. To address these issues, the responses of up to 80 rabbit retinal ganglion cells were recorded simultaneously using a multielectrode array. Of the 11 classes of rabbit ganglion cells previously identified, coordinated firing was observed in five. Plots of the spike train cross-correlation function suggested that coordinated firing occurred through two mechanisms. In the first mechanism, a spike in an interneuron diverged to produce simultaneous spikes in two ganglion cells. This mechanism predominated in four of the five classes including the ON brisk transient cells. In the second mechanism, ganglion cells appeared to activate each other reciprocally. This was the predominant pattern of correlated firing in OFF brisk transient cells. By comparing the receptive field profiles of ON and OFF brisk transient cells, a peripheral extension of the OFF brisk transient cell receptive field was identified that might be produced by lateral spike spread. Thus an individual OFF brisk transient cell can respond both to a light stimulus directed at the center of its receptive field and to stimuli that activate neighboring OFF brisk transient cells through their receptive field centers. (+info)
Thapsigargin inhibits a potassium conductance and stimulates calcium influx in the intact rat lens. (5/2595)1. An increase in lens cell calcium has long been associated with cortical cataract. Recently, it has been shown that thapsigargin induces a rise in lens cell calcium by release from endoplasmic reticulum stores. The effects of this rise on the optical and membrane characteristics of the lens were studied in the isolated rat lens. 2. The electrical characteristics of the isolated, perifused rat lens were measured using a two-internal microelectrode technique that permits measurement of plasma membrane conductance (Gm), membrane potential (Vm) and junctional conductance in the intact lens. 3. Thapsigargin (1 microM) induced a rapid overall depolarization of Vm that was accompanied by first a decrease and then an increase in Gm. 4. Replacing external Na+ with tetraethylammonium (TEA) abolished the decrease in Gm. However, a transient increase phase was still observed. 5. The changes in conductance were further characterized by measuring 22Na+ and 45Ca2+ influxes into the isolated lens. Thapsigargin (1 microM) induced a transient increase in 45Ca2+, but did not affect Na+ influx. 6. The Ca2+ channel blocker La3+ (10 microM) totally inhibited the thapsigargin-induced Ca2+ influx. It also blocked the increase in Gm observed in control and in Na+-free-TEA medium. In the absence of external calcium, thapsigargin induced a small depolarization in Vm. 7. These data indicate that thapsigargin induces both a decrease in K+ conductance and an increase in Ca2+ conductance. These probably result from release of stored Ca2+ and subsequent activation of store-operated Ca2+ channels (capacitative Ca2+ entry). 8. Thapsigargin application over the time course of these experiments (24 h) had no effect on junctional conductance or on the transparency of the lens. (+info)
Nitric oxide release in penile corpora cavernosa in a rat model of erection. (6/2595)1. Nitric oxide (NO) levels were measured in the corpus cavernosum of urethane-anaesthetized rats by using differential normal pulse voltammetry with carbon fibre microelectrodes coated with a polymeric porphyrin and a cation exchanger (Nafion). A NO oxidation peak could be recorded at 650 mV vs. a Ag-AgCl reference electrode every 100 s. 2. This NO signal was greatly decreased by the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), given by local and systemic routes, and enhanced by the NO precursor L-arginine. Treatment with L-arginine reversed the effect of L-NAME on the NO peak. 3. Both the NO signal and the intracavernosal pressure (ICP) were increased by electrical stimulation of cavernosal nerves (ESCN). However, the rise in the NO levels long outlived the rapid return to baseline of the ICP values at the end of nerve stimulation. 4. The ICP and the NO responses to ESCN were suppressed by local and systemic injections of L-NAME. Subsequent treatment with L-arginine of L-NAME-treated animals restored the NO signal to basal levels and the NO response to ESCN. The ICP response to ESCN was restored only in part by L-arginine. 5. The observed temporal dissociation between the NO and ICP responses could be accounted for by several factors, including the buffering of NO by the blood filling the cavernosal spaces during erection. 6. These findings indicate that an increased production of NO in the corpora cavernosa is necessary but not sufficient for maintaining penile erection and suggest a complex modulation of the NO-cGMP-cavernosal smooth muscle relaxation cascade. (+info)
In vitro simultaneous measurements of relaxation and nitric oxide concentration in rat superior mesenteric artery. (7/2595)1. The relationship between nitric oxide (NO) concentration measured with an NO-specific microelectrode and endothelium-dependent relaxation was investigated in isolated rat superior mesenteric artery contracted with 1 microM noradrenaline. 2. Acetylcholine (10 microM) induced endothelium-dependent simultaneous increases in luminal NO concentration of 21 +/- 6 nM, and relaxations with pD2 values and maximum of 6.95 +/- 0.32 and 97.5 +/- 0.7 % (n = 7), respectively. An inhibitor of NO synthase, N G-nitro-L-arginine (L-NOARG, 100 microM) inhibited the relaxations and increases in NO concentration induced by acetylcholine. 3. Oxyhaemoglobin (10 microM) reversed the relaxations and increases in NO concentrations induced by acetylcholine, S-nitroso-N-acetylpenicillamine (SNAP) and S-morpholino-sydnonimine (SIN-1), but not the relaxations induced with forskolin. Oxyhaemoglobin also decreased the NO concentration below baseline level. 4. In the presence of L-NOARG (100 microM), a small relaxation to acetylcholine (10 microM) of noradrenaline-contracted segments was still seen; oxyhaemogobin inhibited this relaxation and decreased the NO concentration by 14 +/- 4 nM (n = 4). 5. The NO concentration-relaxation relationship for acetylcholine resembled that for SNAP and SIN-1 more than for authentic NO. Thus while 7-17 nM NO induced half-maximal relaxations in response to SNAP or SIN-1, 378 +/- 129 nM NO (n = 4) was needed for half-maximal relaxation to authentic NO. 6. The present study provides direct evidence that the relaxation of the rat superior mesenteric artery with the endothelium-dependent vasodilator acetylcholine is correlated to the endogeneous release of NO. The study also suggests that NO mediates the L-NOARG-resistant relaxations in this artery, and that there is a basal NO release. (+info)
Firing properties of single vasoconstrictor neurones in human subjects with high levels of muscle sympathetic activity. (8/2595)1. Single-unit recordings were made from 19 postganglionic muscle vasoconstrictor axons via tungsten microelectrodes in the peroneal nerve in seven healthy subjects with many multi-unit sympathetic discharges at rest ('high group', 75 +/- 5 multi-unit bursts per 100 heart beats, mean +/- s.e.m.). The results were compared with previous data from 14 units in subjects with 21 +/- 2 multi-unit bursts per 100 heart beats ('low group'). 2. In the 'high group' the units fired spontaneously in 35 +/- 4 % of all cardiac intervals. One unit only ever fired once per cardiac interval, 14 units (74 %) generated maximally two to three spikes, and four units (21 %) up to four to five spikes. Of those cardiac intervals in which a unit fired, a single spike occurred in 78 %, two spikes in 18 %, three spikes in 4 % and four spikes in less than 1 % of cardiac intervals. Measured as the inverse of all interspike intervals, the mean rate was 0.33 +/- 0.04 Hz and the mean intraburst frequency 22.2 +/- 1.6 Hz. Most results were similar to those in the 'low group', but in the 'low group' heart rate was higher (64.5 vs. 50.4 beats min-1) and mean firing frequency was higher (0.49 +/- 0.06 Hz). 3. During increases of multi-unit burst activity evoked by sustained inspiratory-capacity apnoea the firing probability of nine units in the 'high group' increased from 33 +/- 6 to 56 +/- 3 % of the cardiac intervals. Simultaneously, the incidence of single spikes decreased and the incidence of multiple spikes per cardiac interval increased, resulting in an increase of mean firing frequency from 0. 23 +/- 0.04 Hz at rest to 1.04 +/- 0.14 Hz during the apnoea. 4. We conclude that single muscle vasoconstrictor neurones usually fire only a solitary spike during sympathetic bursts both in subjects with a high and in subjects with a low number of bursts at rest. Presumably, differences in the numbers of bursts are due mainly to differences in firing probability and recruitment of sympathetic fibres. During acute increases of multi-unit activity, both increases in discharge frequency and recruitment of additional neurones contribute to the increased intensity of an individual sympathetic burst. (+info)
Studies on neuronal network activity of olfactory bulb, spinal cord and frontal cortex grown on microelectrode arrays in vitro ...
The four compounds tested generated interesting, and in one case paradoxical effects. Frontal cortex cultures were all inhibited in a dose-dependent manner, which included total cessation of activity by halothane, CBX, I-octanol, or oleamide (at concentrations 250 muM, 100 muM, 20 muM, 20 muM, respectively). All cultures showed spontaneous recovery at lower concentrations and reversibility after culture medium changes at higher concentrations. In addition, measurements of network burst rates and coefficients of variation of burst period indicate that burst coordination among channels was reduced by these compounds. These responses were generally mirrored in the spinal cord, except for CBX, which produced a paradoxical transient intense increase in network spike and burst production ...
Unscramble impalement | Words unscrambled from letters impalement | Scrabble Word impalement | Words Made with the Letters...
Dorsal root ganglia neurite outgrowth measured as a function of changes in microelectrode array resistance
Current research in prosthetic device design aims to mimic natural movements using a feedback system that connects to the patients own nerves to control the device. The first step in using neurons to control motion is to make and maintain contact between neurons and the feedback sensors. Therefore, the goal of this project was to determine if changes in electrode resistance could be detected when a neuron extended a neurite to contact a sensor. Dorsal root ganglia (DRG) were harvested from chick embryos and cultured on a collagen-coated carbon nanotube microelectrode array for two days. The DRG were seeded along one side of the array so the processes extended across the array, contacting about half of the electrodes. Electrode resistance was measured both prior to culture and after the two day culture period. Phase contrast images of the microelectrode array were taken after two days to visually determine which electrodes were in contact with one or more DRG neurite or tissue. Electrodes in contact
"MICROELECTRODE ARRAY STUDIES OF NORMAL AND DISEASE-ALTERED L-GLUTAMATE" by Brian Keith Day
L-glutamate (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system. Monitoring extracellular Glu is critical to understanding Glu regulation to discriminate physiological and pathological roles. To overcome the limitations of previous in vivo extracellular Glu studies, we developed Glu selective microelectrode arrays with better spatial and temporal resolutions than commonly used techniques like microdialysis. We used these microelectrode arrays to characterize basal and potassium-evoked Glu neurotransmission in the normal rat brain. We then investigated disease-related Glu alterations in a rat model of Parkinsons disease and normal Glu regulation in young and aged rhesus monkeys. In the normal anesthetized rat striatum and frontal cortex, basal Glu was regulated by active release and uptake mechanisms, fully TTX-dependent, and measured at ~2 micromolar levels. Potassium-evoked Glu kinetics were fast, concentration-dependent, and rapidly reproducible at 15-20 seconds
Transmembrane Na+ and Ca2+ electrochemical gradients in cardiac muscle and their relationship to force development. | JGP
Na+- and CA2+-sensitive microelectrodes were used to measure intracellular Na+ and Ca2+ activities (alpha iCa) of sheep ventricular muscle and Purkinje strands to study the interrelationship between Na+ and Ca2+ electrochemical gradients (delta muNa and delta muCa) under various conditions. In ventricular muscle, alpha iNa was 6.4 +/- 1.2 mM and alpha iCa was 87 +/- 20 nM ([Ca/+] = 272 nM). A graded decrease of external Na+ activity (alpha oNa) resulted in decrease of alpha iNa, and increase of alpha iCa. There was increase of twitch tension in low-alpha oNa solutions, and occasional increase of resting tension in 40% alpha oNa. Increase of external Ca2+ (alpha oCa) resulted in increase of alpha iCa and decrease of alpha iNa. Decrease of alpha oCa resulted in decrease of alpha iCa and increase of alpha iNa. The apparent resting Na-Ca energy ratio (delta muCa/delta muNa) was between 2.43 and 2.63. When the membrane potential (Vm) was depolarized by 50 mM K+ in ventricular muscle, Vm depolarized ...
Patent WO2007042999A2 - Modular multichannel microelectrode array and methods of making same - Google Patents
Some embodiments of the invention comprise a customizable multichannel microelectrode array with a modular planar microfabricated electrode array attached to a carrier and a high density of recording and/or stimulation electrode sites disposed thereon. Novel methods of making and using same are also disclosed.
Real-time cell electrophysiology using a multi-channel dielectrophoretic-dot microelectrode array. - Surrey Research Insight...
Dielectrophoresis (DEP) has been used for many years for the analysis of the electrophysiological properties of cells. However, such analyses have in the past been time-consuming, such that it can take 30 min or more to collect sufficient data to make valid interpretations from a single DEP spectrum. This has limited the application of the technology to a rapid tool for non-invasive, label-free research in areas from drug discovery to diagnostics. In this paper we present the development of a programmable, multi-channel DEP system for rapid biophysical assessment of populations of biological cells. A new assay format has been developed for continuous near-real-time monitoring, using simultaneous application of up to eight alternating current electrical signals to independently addressable dot microelectrodes in an array format, allowing a DEP spectrum to be measured in 20 s, with a total cycle time between measurements of 90 s. To demonstrate the system, human leukaemic K562 cells were monitored ...
Downloads - NMI.de
Activation Procedures | SpringerLink
Microarrays can be fabricated using a variety of technologies, including printing with fine-pointed pins onto glass slides, photolithography using pre-made masks, photolithography using dynamic micromirror devices, ink-jet printing, or electrochemistry on microelectrode arrays.. In spotted microarrays, the probes are oligonucleotides, cDNA or small fragments of PCR products that correspond to mRNAs. The probes are synthesized prior to deposition on the array surface and are then "spotted" onto glass. A common approach utilizes an array of fine pins or needles controlled by a robotic arm that is dipped into wells containing DNA probes and then depositing each probe at designated locations on the array surface. The resulting "grid" of probes represents the nucleic acid profiles of the prepared probes and is ready to receive complementary cDNA or cRNA "targets" derived from experimental or clinical samples. This technique is used by research scientists around the world to produce "in-house" ...
DIGITAL.CSIC: Towards Membrane-Free Amperometric gas sensors: a microelectrode array approach
Room temperature ionic liquids (RTILs) have been applied to a microelectrode array,and been demonstrated to form effective, membrane-free amperometric gas sensors. Determining the RTIL [P6,6,6,14][FAP] as the most appropriate choice for extended use, the amperometric quantification of oxygen has been demonstrated. The response of the sensor was quantified by both cyclic voltammetry and chronoamperometry. A range of O2 contents (2 to 13 % v/v) and RTIL layer thicknesses (from ca. 6 to 125 μm) have been investigated. The combination of microelectrode array and RTIL, as well as the absence of membrane and volatile solvent, results in an elegant, easy to calibrate gas sensor with potential utility in standard and non-standard conditions ...
Amperometry and Cyclic Voltammetry with Carbon Fiber Microelectrodes at Single Cells - Current Protocols
Modulation of epileptogenesis: A paradigm for the integration of enzyme-based microelectrode arrays and optogenetics<...
TY - JOUR. T1 - Modulation of epileptogenesis. T2 - A paradigm for the integration of enzyme-based microelectrode arrays and optogenetics. AU - Butler, Corwin R.. AU - Boychuk, Jeffery A.. AU - Pomerleau, Francois. AU - Alcala, Ramona. AU - Huettl, Peter. AU - Ai, Yi. AU - Jakobsson, Johan. AU - Whiteheart, Sidney W.. AU - Gerhardt, Greg A.. AU - Smith, Bret N.. AU - Slevin, John T.. PY - 2020/1. Y1 - 2020/1. N2 - Background: Genesis of acquired epilepsy includes transformations spanning genetic-to- network-level modifications, disrupting the regional excitatory/inhibitory balance. Methodology concurrently tracking changes at multiple levels is lacking. Here, viral vectors are used to differentially express two opsin proteins in neuronal populations within dentate gyrus (DG) of hippocampus. When activated, these opsins induced excitatory or inhibitory neural output that differentially affected neural networks and epileptogenesis. In vivo measures included behavioral observation coupled to ...
NMR and microelectrode studies of hydrodynamics and kinetics in biofilms
Profiles of flow velocity and dissolved oxygen concentration were studied by NMR and microelectrodes near mixed population biofilms growing on polycarbonate substratum. The profile of dissolved oxygen concentration within the diffusion boundary layer and profiles of flow velocity within the hydrodynamic boundary layer can be described by exponential equations ...
Ion transport in roots: measurement of fluxes using ion-selective microelectrodes to characterize transporter function
The transport of mineral ions into and out of tissues and cells is central to the life of plants. Ion transport and the plasma membrane transporters themselves have been studied using a variety of techniques. In the last 15 years, measurement of specific ion fluxes has contributed to the characteriz …
In vivo brain glucose measurements: differential normal pulse...
The site of impulse origination in surviving rabbit atria has been localized electrically. With the aid of the ultramicroelectrode, membrane potentials during spontaneous activity were recorded from pacemaker and from non-pacemaker regions.. The pacemaker region lies in a flat band of tissue separating the two caval orifices in the right atrium. In contrast to sites elsewhere in the atria, recordings from this area exhibit a diastolic prepotential, relatively slow depolarization and slow repolarization. The magnitude of the resting membrane potential is less in pacemaker cells and overshoot during activity characteristically is diminished or absent. By means of a second microelectrode to establish a time reference, pacemaker cells showing early firing may be located, although all cells associated with a prepotential are not necessarily the site of impulse origination.. Shifts in pacemaker locus are demonstrated and often appear following the application of drugs acting on the sinoatrial ...
3D-UME | Center for Electrochemistry
This program models a basic SECM configuration, using an ultramicroelectrode (UME) tip and a substrate with Butler-Volmer conditions for the electrochemistry of two redox pairs (o1/r1 at the tip and o2/r2 at the substrate). You can use this program to become familiarized with the 3D environment and to get some examples on how to build your own 3D simulations ...
Explore Biological analysis
Description: Extracellular electrophysiology recordings by two electrophysiology setups for extracellular recordings, including: Faraday cage; Amplifiers, filters and signal integrators for electrophysiology (Digitimer: Neurolog 900; Grass DC and AC amplifiers); Digitizer for electrophysiology (Axon Instruments: Digidata 1322A + Axoscope software); Stereo microscope adapted to electrophysiology cabin (Olympus + light source); Horizontal pipette puller (Narishige) for glass microelectrodes; and Electrodes and other accessories. Potential application: Electro-olfactogram (EOG), Electroencephalogram (EEG), Multi-unit nerve recordings. Type of samples: In vivo organisms e.g. fish, molluscs, crustaceans. ...
Intracellular recording - Scholarpedia
The electrolyte inside creates a (distributed) resistor, but normally most (probably more than half) of the resistance resides in the tip. Typical resistances of intracellular electrodes to DC-current are 10-500 Megaohms. The resistance depends not only on the length of the electrode shank and the size of the tip, but also on the nature of the conductive electrolyte inside (cf. Brown and Flaming, 1986). As an example of the latter, a typical 100 Megaohm electrode (with 3 M KCl filling) with a shank of about 15 mm and with a tip outer diameter of about 70 nm will have a resistance of about 600 Megaohms or more when filled with the neuron-marking solution Lucifer Yellow (5 % LY with 0.1 % LiCl), which has much lower mobility than potassium or chloride ions. The electrode resistance may also depend on the current used to measure the resistance. Typically glass microelectrodes have a very non-linear current-voltage relation, and often the response may saturate (i.e. no larger currents can be pushed ...
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Microelectrode array for MEA2100-HS120:. TiN electrodes, SiN isolator, contact pads and tracks opaque (Ti), with 4 internal reference electrodes, electrode grid 12x10, 120 electrodes, electrode spacing 1000 µm vertical, 1500 µm horizontal, electrode diameter 30 µm, with plastic ring with thread, warranty: 6 months.. ...
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Injecting noise - www.neuron.yale.edu
Good question. You have just described the difference between the sign convention used for transmembrane currents and the convention used for currents that are applied with a microelectrode. Most users who want a "noise current" typically want something that mimics the effect of spontaneous fluctuation of transmembrane current, e.g. channel noise or background synaptic noise. Thats why the current generated by InGauss is declared to be a NONSPECIFIC_CURRENT. An SEClamp or IClamp, however, is an external signal source that injects charge directly into the interior of a cell through a microelectrode, and you will see that the currents generated by those mechanisms are declared to be ELECTRODE_CURRENTs ...
Carbon Fiber - Felt Bicycles
Carbon fiber, in its raw form, is a conjoining of thin, strong fibers. These fibers come in a variety of grades based on overall strength and stiffness. The higher the modulus, the stiffer and lighter it is. However, this doesnt mean that the best bikes are completely constructed from high modulus carbon fiber. On the contrary, the key to building bikes is to mix and match modulus, finding the ideal characteristic balance stiffness, strength, weight and cost ...
Benro GH5C Carbon Fiber Gimbal Head with PL100LW Plate GH5C B&H
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Microelectrodes. Carbon fibers are used for fabrication of carbon-fiber microelectrodes. In this application typically a ... Carbon-fiber microelectrodes are used either in amperometry or fast-scan cyclic voltammetry for detection of biochemical ... At the tip the capillary is either sealed with epoxy and polished to make carbon-fiber disk microelectrode or the fiber is cut ...
Gerard-Graham-Ling microelectrode. Also known as the Ling-Gerard microelectrode and after the 1940s further developed ... In 1947 he co-developed the Gerard-Graham-Ling microelectrode, a device that allows scientists to more accurately measure the ... John Eccles applied the microelectrode to studies of activity of individual units within the spinal cord and brain and Andrew ... The microelectrode in use today is essentially the same as this, except that it usually contains a concentrated salt solution, ...
... they are primarily glass micro-pipettes or metal microelectrodes made of platinum or tungsten. Microelectrodes can be carefully ... A microelectrode is inserted into the brain, where it can record the rate of change in voltage with respect to time. These ... When a microelectrode is inserted into an aqueous ionic solution, there is a tendency for cations and anions to react with the ... Different types of microelectrodes can be used for single-unit recordings; they are typically high-impedance, fine-tipped and ...
TEVC microelectrodes can provide only a spatial point source of current that may not uniformly affect all parts of an ... However: Microelectrodes are imperfect conductors; in general, they have a resistance of more than a million ohms. They rectify ... The microelectrodes are filled with conductive solution and inserted into the cell to artificially control membrane potential. ... The microelectrodes compare the membrane potential against a command voltage, giving an accurate reproduction of the currents ...
He established the Biophysics / Neurophysics research group there, and perfected a multi-micro-electrode recording technique he ... 1991). ": Adaptation of the Reitböck method of multiple microelectrode recording". J. Neurosci. Meth. 36 (1): 77-84. doi: ... Reitböck, H.J. (1983). "Fiber microelectrodes for electrophysiological recordings". J..Neurosc. Meth. 8 (3): 249-262. doi: ... "A 19-channel matrix drive with individually controllable fiber microelectrodes for neurophysiological applications". IEEE Trans ...
Cultured neuronal network
A multi-electrode array (MEA), also commonly called a microelectrode array, is a patterned array of electrodes laid out in a ... Ghezzi D, Menegon A, Pedrocchi A, Valtorta F, Ferrigno G (2008). "A Micro-Electrode Array Device Coupled to a Laser-Based ... Meeting on Substrate-Integrated Microelectrodes. pp. 22-25. Wagenaar DA, Pine J, Potter SM (2006). "An Extremely Rich ...
Extracellular field potential
Fast-scan cyclic voltammetry
Electrical discharge machining
Ida Henrietta Hyde
Another microelectrode was supposedly invented another time, about twenty years after Ida was said to have made her version of ... Ida's microelectrode can be used for stimulating cells at the micro level while recording electrical activity within the cell ... Then in the 1950s, Gerard was nominated for a Nobel Prize, because of his developed model of the microelectrode. Notes on the ... Hyde's possible microelectrode invention was reported in 1921, several others also created electrodes similar to Ida's, while ...
Anne Warner (scientist)
The tungsten microelectrodes have a shaft diameter of 100-200 μm, a tip diameter of 1-5 μm, and they are insulated to the tip ... The microelectrode is then inserted 1-2 cm from the probe, ideally in a 90° angle to the ultrasonic beam. This generates the ... On the other hand, the particular physical conditions involving a microelectrode freely floating in the tissue preclude brisk ... Knutsson, E; Widén L (1967). "Impulses from single nerve fibres recorded in man using microelectrodes". Nature. 213: 606-607. ...
Cognitive neuroscience of visual object recognition
Department of Neurobiology, Harvard Medical School
IEEE Nanotechnology Council
R. J. Forster "Microelectrodes: new dimensions in electrochemistry", Chemistry Society Reviews, vol. 23, pp. 289-297, 1994. C. ... 15-267, 1989 A. M. Bond, "Past, present and future contributions of microelectrodes to analytical studies employing ... K. Stulik, C. Amatore, K. Holub, V. Maracek & W. Kutner, "Microelectrodes. Definitions, characterization, and applications ( ...
Techniques: Glass microelectrodes, ion-sensitive microelectrodes, patch clamp, rapid application of drugs, standard ... 47:291-5, 1998, BBA 2008 etc). 3. Ion-selective microelectrodes for K+ and Na+ in nerve and muscle tissue. He performed first ... his best known are his publications in the field of ion-selective microelectrodes in the brain and in work on human muscles, ...
Huntington Medical Research Institutes
Antonio Castellanos Mata
Microelectrode arrays can be divided up into subcategories based on their potential use: in vitro and in vivo arrays. The ... A miniature microelectrode array to monitor the bioelectric activity of cultured cells. Exp Cell Res. 74: 61-66. Minerbi A, ... Silicon-based microelectrode arrays include two specific models: the Michigan and Utah arrays. Michigan arrays allow a higher ... Microelectrode arrays for electrophysiological monitoring of hippocampal organotypic slice cultures. IEEE Trans Biomed Eng. 44 ...
Inhibitory postsynaptic potential
Center for Biofilm Engineering
Patent WO2007042999A2 - Modular multichannel microelectrode array and methods of making same - Google Patents
Some embodiments of the invention comprise a customizable multichannel microelectrode array with a modular planar ... having a carrier with at least one planar microelectrode array attached to the carrier, the planar microelectrode array ... The microelectrode array is then placed onto this epoxy. Note that if the carrier is of the hollow tubing type that the ... Flexible tubular microelectrode and preparation method thereof. EP2397071A1. 17 Jun 2010. 21 Dec 2011. Imec. Neural probe with ...
Dorsal root ganglia neurite outgrowth measured as a function of changes in microelectrode array resistance
Studies on neuronal network activity of olfactory bulb, spinal cord and frontal cortex grown on microelectrode arrays in vitro ...
"MICROELECTRODE ARRAY STUDIES OF NORMAL AND DISEASE-ALTERED L-GLUTAMATE" by Brian Keith Day
We used these microelectrode arrays to characterize basal and potassium-evoked Glu neurotransmission in the normal rat brain. ... To overcome the limitations of previous in vivo extracellular Glu studies, we developed Glu selective microelectrode arrays ... We used these microelectrode arrays to characterize basal and potassium-evoked Glu neurotransmission in the normal rat brain. ... Day, Brian Keith, "MICROELECTRODE ARRAY STUDIES OF NORMAL AND DISEASE-ALTERED L-GLUTAMATE REGULATION IN THE MAMMALIAN CENTRAL ...
Microelectrode - Wikipedia
Initially, pulled glass pipette microelectrode was used with later introduction of insulated metal wires. These microelectrodes ... More recent advances in lithography yielded to silicon based microelectrodes. Single-unit recording Microelectrode array Cogan ... A microelectrode is an electrode of very small size, used in electrophysiology for either recording of neural signals or ... This article about application of microelectrodes in electrophysiology. For application in electroanalytical chemistry see ...
Sensors | Free Full-Text | Conducting Polymer 3D Microelectrodes
Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of ... Keywords: conducting polymers; micro-fabrication; micro-electrodes conducting polymers; micro-fabrication; micro-electrodes ... Conducting Polymer 3D Microelectrodes. Sensors. 2010; 10(12):10986-11000. Chicago/Turabian Style. Sasso, Luigi; †, Patricia ... Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of ...
Thin Film Microelectrodes (Part 1/7)
Laboratory Electrodes - Microelectrodes by SI Analytics - a ...
For example Pharmacy and all Life Science sectors offer the most application areas for Microelectrodes. ... ... For that purposes Microelectrodes are the best choice. They have been developed especially for these circumstances and hence ... For example Pharmacy and all Life Science sectors offer the most application areas for Microelectrodes. Measurement often takes ... Microelectrodes by SI Analytics - a Xylem brand. ... No reviews were found for Microelectrodes. Be the first to ...
Computer Simulation of Oxygen Microelectrode Measurements in Tissues | SpringerLink
Toma-Daşu I., Daşu A., Waites A., Denekamp J. (2003) Computer Simulation of Oxygen Microelectrode Measurements in Tissues. In: ... Theoretical simulation of oxygen tension measurement in tissues using a microelectrode: I. The response function of the ... Theoretical simulation of oxygen tension measurement in tissues using a microelectrode: II. Simulated measurements in tissues, ...
Microelectrode Voltage Clamp: The Cardiac Purkinje Fiber | SpringerLink
An adaptation of the jet stream microelectrode beveler. Science 205: 1302, 1979.PubMedCrossRefGoogle Scholar ... Three-microelectrode voltage clamp experiments in calf cardiac Purkinje fibers: is slow inward current adequately measured? J. ... In: Smith T.G., Lecar H., Redman S.J., Gage P.W. (eds) Voltage and Patch Clamping with Microelectrodes. Springer, New York, NY ... A new technique for beveling extremely fine microelectrodes and micropipettes. Pfluegers Arch. 381: 287-288, 1979.CrossRef ...
Close-Packed Silicon Microelectrodes for Scalable Spatially Oversampled Neural Recording - IEEE Journals & Magazine
Fluorinated xerogel-derived microelectrodes for amperometric nitric oxide sensing.
... microelectrode is described. A range of fluorine-modified xerogel polymers were synthesized via the cohydrolysis and ... The resulting NO microelectrode had a conical tip of approximately 20 microm in diameter and approximately 55 microm in length ... An amperometric fluorinated xerogel-derived nitric oxide (NO) microelectrode is described. A range of fluorine-modified xerogel ...
Can nanostructured microelectrodes be used to analyze biomarkers? An interview with Dr Shana Kelley
... *Download PDF Copy ... Can nanostructured microelectrodes be used to analyze biomarkers? An interview with Dr Shana Kelley. News-Medical. 25 June ... Can nanostructured microelectrodes be used to analyze biomarkers? An interview with Dr Shana Kelley. News-Medical, viewed 25 ... Ultra-Small Microelectrode Biosensors for Brain Injury Analysis. Stéphane Marinesco. An interview with Stéphane Marinesco, ...
Patent US8195267 - Microelectrode with laterally extending platform for reduction of tissue ... - Google Patents
Novel methods of designing, making, and using an implantable microelectrode or biosensor resulting in reduced tissue ... an implantable microelectrode is provided with a shank comprised of a laterally extending platform whose thickness and/or ... shows several microelectrode designs with subcellular dimensions.. FIGS. 6 and 7. are cross-sectional views of microelectrodes ... In some embodiments, a microelectrode 1 is comprised of conductive interconnects disposed within the microelectrode between ...
MER: Micro-electrode Recording
The MCE100C micro-electrode amplifier is designed to work with a wide range of micro-electrodes in a variety of measurement ... General micro-electrode signal amplification. Designed to work with a wide range of micro-electrodes in a variety of ... Advanced Tools for Microelectrode Recording & Data Analysis. Record signals from a wide range of micro-electrodes on organisms ... Ion-Selective Micro-Electrode Interface: Use ion-specific electrodes to monitor the change in a preparations ion concentration ...
Description - Microelectrode tungsten
IKA offers the perfect lab shaker for mixing and shaking tasks. In addition to the tried and tested orbital shakers and horizontal shakers, the innovative incubator shaker KS 4000 is gaining popularity in laboratories. Its precise temperature control makes the incubator shaker a reliable asset in every lab. IKA products boast speeds of up to 3,000 revolutions per minute during continuous operations. A digital display, timer function, and controlling options via the lab software Labworldsoft ensure optimal working conditions. Integrated end point positioning allows for automated sampling. An extensive array of attachments enables the use of vessels in every shape and size. Functionality, safety, and longevity are the main goals in the development of IKA lab shakers. ...
Microelectrode Brain-Machine Interface for Individuals With Tetraplegia - Full Text View - ClinicalTrials.gov
Pulse voltammetry wine defects identification by means of miniaturized microelectrodes | (2007) | Francioso | Publications |...
The microelectrodes were fabricated as patterned platinum thin films on silicon wafers by means of silicon fabrication ... Pulse voltammetry wine defects identification by means of miniaturized microelectrodes Author(s): L. Francioso; R. Bjorklund; P ... a silicon nitride passivation permits a selective exposure of microelectrodes to electrolyte. Principal Component Analysis (PCA ...
Quantification of noise sources for amperometric measurement of quantal exocytosis using microelectrodes - Analyst (RSC...
Electrochemical microelectrodes are commonly used to record amperometric spikes of current that result from oxidation of ... The admittance of microelectrodes is well described by a constant phase element model such that both the real and imaginary ... Electrochemical microelectrodes are commonly used to record amperometric spikes of current that result from oxidation. of ... We measured the current power spectral density (SI) of electrochemical microelectrodes to understand the physical basis of ...
190 - Micro-Electrode Amplifier Guidelines - MCE100C | BIOPAC
190 - Micro-Electrode Amplifier Guidelines - MCE100C. Home , Application Notes , 190 - Micro-Electrode Amplifier Guidelines - ... MER: Micro-electrode Recording - Use micro-electrodes and MCE100C amplifier to record in-vivo or in-vitro from organisms, ... Micro Electrode Module. Micro Pressure Measurement System. Noninvasive Blood Pressure. Temperature. Transducer Amplifiers. ... Micro Electrode Module. Micro Pressure Measurement System. Noninvasive Blood Pressure. Temperature. Transducer Amplifiers. ...
UAB - Magazine - Microelectrode Arrays Could Restore Sight | UAB Magazine Spring 2010
UAB psychology professor and neurophysiologist Franklin Amthor has designed microelectrode arrays that could do the job of ... Franklin Amthors microelectrode arrays stimulate the specialized nerve cells that transmit visual information to the brain.. ... he continues to develop his innovative prosthetic microelectrode arrays even when funds are scarce. He says he is glad to be ... tiny electronic networks called microelectrode arrays that could do the job of damaged neurons and help restore sight. ...
Micromachines | Free Full-Text | Liquid Crystal Elastomer-Based Microelectrode Array for In Vitro Neuronal Recordings | HTML
LCEs are also not functionally neurotoxic as determined by exposing cortical neurons cultured on conventional microelectrode ... we demonstrate that LCEs are cellular compatible materials that can be used as substrates for fabricating microelectrode arrays ... arrays to LCE extract for 48 h. Microelectrode arrays fabricated on LCEs are stable, as determined by electrochemical impedance ... of prominent extracellular biopotentials comparable to those achieved with conventional commercially-available microelectrode ...
Free magnesium in sheep, ferret and frog striated muscle at rest measured with ion-selective micro-electrodes
Omnidirectional Printing of Flexible, Stretchable, and Spanning Silver Microelectrodes | Science
Straining these microelectrodes up to 200 cycles does not result in fatigue-induced failure at the contact points (Fig. 3F). ... As a first example, we patterned silver microelectrodes (w = 15 μm, h = 13 μm) onto a silicon solar microcell (w = 45 μm, h = ... S3A). For this experiment, a linear array of 10 silver microelectrodes (w = 23 μm, h = 12 μm, and length l = 1 cm) spaced 0.5 ... C) Aspect ratio as a function of number of printed layers for the silver microelectrodes shown in Fig. 2B. (D) SEM images of ...
High-rate in-plane micro-supercapacitors scribed onto photo paper using in situ femtolaser-reduced graphene oxide/Au...
NL04) Tungsten Micro-Electrode Holder | Warner Instruments
Mean cross-correlograms between one reference microelectrode and all other microelectrodes for three subjects during large- ... Large-Scale Microelectrode Recordings of High-Frequency Gamma Oscillations in Human Cortex during Sleep. Michel Le Van Quyen, ... 3A). Figure 3B plots the number of active microelectrodes for each gamma event detected across the entire recording session of ... First, we used microelectrodes that can record from local cortical generators rather than EEG recordings, which reflect the ...
Direct arsenic(iii) sensing by a renewable gold plated Ir-based microelectrode - Analyst (RSC Publishing)
... we introduce here a microelectrode capable of quantifying As(iii) that ... we introduce here a microelectrode capable of quantifying As(III) that consists of a gold plated Ir-based microelectrode (Au- ... Direct arsenic(III) sensing by a renewable gold plated Ir-based microelectrode R. Touilloux, M. Tercier-Waeber and E. Bakker, ... Direct arsenic(iii) sensing by a renewable gold plated Ir-based microelectrode† ...
Bi-directional microelectrode array platform for 2D and 3D in vitro electrophysiology - Ferret
microelectrode array platform for 2D and 3D in-vitro electrophysiology.. Also known as a multi-electrode array (MEA) platform ... Bi-directional microelectrode array platform for 2D and 3D in vitro electrophysiology. June 15, 2019, 12:00 am. November 26, ... 18kHz and induce electrical stimulation at any of the 4,096 microelectrodes.. In addition to this micrometre-precise electrical ... Bi-directional microelectrode array platform for 2D and 3D in vitro electrophysiology. ...
Microelectrode Techniques for Cell Physiology | Marine Biological Association
Ultra-sensitive detection of brain-derived neurotrophic factor (BDNF) in the brain of freely moving mice using an...
Here, we developed an interdigitated microelectrode (IME) biosensor coated with an anti-BDNF an anti-BDNF antibody in a ... in the brain of freely moving mice using an interdigitated microelectrode (IME) biosensor.. Yoo YK1,2, Lee J3, Kim J1, Kim G1, ... in the brain of freely moving mice using an interdigitated microelectrode (IME) biosensor ... in the brain of freely moving mice using an interdigitated microelectrode (IME) biosensor ...
DIGITAL.CSIC: A microelectrode-cell sensor model for real time monitoring
In this paper the application of a cellmicroelectrode model to cell biometry experiments is proposed, using the cell-electrode area overlap as main parameter. The model can be applied to cell size identification, cell count, and their extension to cell growth and dosimetry protocols. Experimental results using AA8 cell line are presented, obtaining promising results ...
ArraysCarbon-fiber microelectrodesMulti-microelectrodeImplantableSilicon based microelectrodesElectrophysiologyStimulationElectrodesNeuronsBiosensorArraySituCorticalRecordingsAbstractMeasurementsExtracellularAmperometricSignal to noDetectionExperimentsRetinalCharacterizationSubstratesMethodsSensitivityNeuronal networksMembraneStereotacticNerveImpedanceFabricationProbeTissuesStudyCellsFluxSignificantlyElectricalRecordingMicroscopyAdaptationSelectiveExperimentMagneticStability
- To overcome the limitations of previous in vivo extracellular Glu studies, we developed Glu selective microelectrode arrays with better spatial and temporal resolutions than commonly used techniques like microdialysis. (uky.edu)
- We used these microelectrode arrays to characterize basal and potassium-evoked Glu neurotransmission in the normal rat brain. (uky.edu)
- Surface-patterned microchip electrodes can have a noise performance that is superior to that of carbon-fiber microelectrodes of the same area. (rsc.org)
- This unit describes the isolation of several cell types known for their exocytotic properties, the fabrication and calibration of carbon fiber microelectrodes, as well as some of the equipment and software requirements for obtaining electrochemically generated data. (currentprotocols.com)
- The multi-microelectrode probe (microprobe) is a device that has been developed mainly for CNS applications. (bio.net)
- It has been suggested that multi-microelectrode probes (microprobes) implanted into the peripheral nervous system can be used to detect signals originating from the body's own sensors. (surrey.ac.uk)
- In some embodiments, an implantable microelectrode is provided with a shank comprised of a laterally extending platform whose thickness and/or configuration contributes to reduced tissue encapsulation, with at least one electrode site disposed at least partially on or in the laterally extending platform. (google.com)
- Novel methods of designing, making, and using an implantable microelectrode or biosensor resulting in reduced tissue encapsulation are also disclosed. (google.com)
- 2. The implantable microelectrode of claim 1 , wherein the laterally extending platform further comprises at least one longitudinal rib and at least one radially projecting rib projecting from the portion and wherein the configuration of the longitudinal rib, the radially extending rib, and the backbone portion form at least one open space in the laterally extending platform. (google.com)
- 3. The implantable microelectrode of claim 2 , wherein at least one electrode site is disposed at least partially on or in the longitudinal rib. (google.com)
- 4. The implantable microelectrode of claim 1 or 2 , wherein the laterally extending platform has a thickness between about 0.5 and 10 microns. (google.com)
- 5. The implantable microelectrode of claim 1 or 2 , wherein the at least one electrode site includes a plurality of microelectrodes disposed on the laterally extending platform. (google.com)
- 6. The implantable microelectrode of claim 5 , wherein at least one of the electrode sites is disposed on the most lateral edge of the laterally extending platform or within about 10 microns of the most lateral edge. (google.com)
- 7. The implantable microelectrode of claim 1 or 2 , wherein the shank further comprises a tip whose shape is chiseled, conical, frusto-conical, or any combination thereof. (google.com)
- 8. The implantable microelectrode of claim 1 or 2 , wherein the backbone portion and the laterally extending platform further comprise at least one layer of a non-conductive material and a layer of electrically conductive material comprising at least one electrical channel on top of the non-conductive material or between multiple layers of a non-conductive material. (google.com)
- 10. The implantable microelectrode of claim 9 , wherein the at least one electrode site disposed at least partially on or in the laterally extending platform comprises surface area disposed at least partially on or in the top, bottom, and/or most lateral sides of the laterally extending platform. (google.com)
- Implantable microelectrodes have the potential to become part of neural prostheses to restore lost nerve function after nerve damage. (surrey.ac.uk)
- The initial adsorption of proteins to materials for implantable microelectrodes is an important factor in determining the longevity and stability of the implant. (surrey.ac.uk)
- The aim of this study was to identify an optimum material for electrode recording sites on implantable microelectrodes. (surrey.ac.uk)
- The adsorbed protein layers on gold (after 7 and 28 days of exposure to serum) were the smoothest and the thinnest compared to all the other substrate materials, indicating that gold is the material of choice for electrode recording sites on implantable microelectrodes. (surrey.ac.uk)
Silicon based microelectrodes1
- This article about application of microelectrodes in electrophysiology. (wikipedia.org)
- A microelectrode is an electrode of very small size, used in electrophysiology for either recording of neural signals or electrical stimulation of nervous tissue. (wikipedia.org)
- Scitech introduces BioCAM DupleX by 3Brain, a fully bi-directional microelectrode array platform for 2D and 3D in-vitro electrophysiology. (ferret.com.au)
- Some embodiments of the invention comprise a customizable multichannel microelectrode array with a modular planar microfabricated electrode array attached to a carrier and a high density of recording and/or stimulation electrode sites disposed thereon. (google.com.au)
- The neuroprobe system of Claim 8, further comprising a wire microelectrode for recording and/or stimulation which is disposed in the lumen. (google.com.au)
- The neuroprobe system of Claim 1, wherein the wire comprises a microelectrode for recording and/or stimulation. (google.com.au)
- Also known as a multi-electrode array (MEA) platform for powerful in-vitro functional imaging, BioCAM DupleX boasts bidirectional capabilities that allow researchers to simultaneously record high-density electrophysiological data at 18kHz and induce electrical stimulation at any of the 4,096 microelectrodes. (ferret.com.au)
- In patients suffering from retinal degenerative diseases, e.g., retinitis pigmentosa, functionality can be regained by prostheses, where electrical stimulation of surviving retinal cells is induced by microelectrodes that interface with neuronal tissue. (arvojournals.org)
- Described herein are microelectrode array devices, and methods of fabrication and use of the same, to provide highly localized and efficient electrical stimulation of a neurological target. (epfl.ch)
- Tests of the Pt microelectrodes' stability under stimulation showed a stable behavior up to 35,000 voltage stimuli and the biocompatibility was assessed with the cultures of dissociated rat's cortical neurons achieving cultures' viability up to 60 days in vitro. (rero.ch)
- The effective surface area of individual microelectrodes is significantly increased using electrochemical activation, a procedure that may also be employed to restore the properties of the electrodes as required. (epfl.ch)
- Depending on the desired application, different 3D carbon microelectrodes can be fabricated (figure 1.B). Figure 1.C shows the electrochemical characterization of a three electrodes system, comparing planar and 3D carbon working electrodes. (dtu.dk)
- A new microelectrode design with decreased diameter was introduced in May 2004, and data from the 2 types of electrodes were compared. (nih.gov)
- The results obtained for the poly(aniline)-(polystyrene sulfonate) coated microelectrode are compared to those for a poly(aniline)-poly(vinyl sulfonate) coated microelectrode and to the results of an earlier study of the reaction at poly(aniline)-poly(vinyl sulfonate) coated rotating disc electrodes. (soton.ac.uk)
- Methods and Results We studied the effects of 10 and 25 μmol/L pinacidil, an ATP-sensitive K channel opener that provides metabolic protection to the ischemic myocardium, on the rise in [K + ] e recorded by K-sensitive electrodes, the change in action potential duration (APD) recorded by microelectrodes, and the changes in activation during ischemia in in situ pig hearts and Tyrode-perfused rabbit interventricular septa. (ahajournals.org)
- Unlike in bulk electroporation, where hundreds of volts may be applied between electrodes, a rather small voltage is applied to a microelectrode in single-cell electroporation. (chalmers.se)
- We report here a novel MEMS (Micro Electro Mechanical Systems) based technology that can move microelectrodes in the event of deterioration in neural signal to sample a new set of neurons. (pubmedcentralcanada.ca)
- One of the most commonly used implants for the brain is the microelectrode that is used to either record or stimulate single neurons or neuronal networks in the brain. (pubmedcentralcanada.ca)
- They have the potential capability of moving past the glial sheath surrounding the microelectrodes to restore the electrical interface with functional neurons in long-term experiments. (pubmedcentralcanada.ca)
- The microelectrode elements are dimensioned and shaped so as to target individual neurons, groups of neurons, and neural tissue as may be located in an animal nervous system, such as along a region of a cortex of a human brain. (epfl.ch)
- The microelectrode array (MEA) has become a key component in retinal experiments because it enables simultaneous neural recording from a population of retinal neurons. (scienceopen.com)
- Here, we developed an interdigitated microelectrode (IME) biosensor coated with an anti-BDNF an anti-BDNF antibody in a polydimethylsiloxane (PDMS)-based microfluidic channel chip. (nih.gov)
- A simple, single-masked gold interdigitated triple-microelectrodes biosensor is presented by taking the advantage of an effective self-assembled monolayer (SAM) using an amino-silanization technique for the early detection of a prostate cancer's biomarker, the prostate-specific antigen (PSA). (bath.ac.uk)
- Single-unit recording Microelectrode array Cogan, Stuart F. (August 2008). (wikipedia.org)
- The image on the right is a magnification of a microelectrode array tip with 50 × 150 μm 2 sites. (nih.gov)
- Room temperature ionic liquids (RTILs) have been applied to a microelectrode array,and been demonstrated to form effective, membrane-free amperometric gas sensors. (csic.es)
- The combination of microelectrode array and RTIL, as well as the absence of membrane and volatile solvent, results in an elegant, easy to calibrate gas sensor with potential utility in standard and non-standard conditions. (csic.es)
- At Axion Biosystems, his team identifies, develops, and implements advanced applications for the Maestro Pro and Maestro Edge multiwell microelectrode array platforms. (labroots.com)
- Enter the microelectrode array (MEA) and the Maestro platform from Axion BioSystems: a simple approach to measuring complex, functional neural responses at the throughput level you need. (labroots.com)
- Processing and analysis of the signals from the microelectrode array demonstrated distinct ECG signals: namely, atrial conduction (P waves), ventricular contraction (QRS), and ventricular repolarization (QT interval). (caltech.edu)
- To this end, we have realized and functionally characterized a Pt microelectrode array with an integrated EPON SU-8 clustering structure, allowing to confine five relatively large yet interconnected spontaneously developing neuronal networks (i.e. thousands of cells). (rero.ch)
- The study presents a dielectrophoretic cell separation method via three-dimensional (3D) nonuniform electric fields generated by employing a periodic array of discrete but locally asymmetric triangular bottom microelectrodes and a continuous top electrode. (ntu.edu.sg)
- The cells that experience stronger positive dielectrophoresis are streamed further in the perpendicular direction to the fluid flow, leaving the cells that experience weak positive dielectrophoresis, which continue to traverse the microelectrode array essentially along the laminar flow streamlines. (ntu.edu.sg)
- A key component of the proposed assay utilizes human stem cell derived cardiomyocytes (hSC-CMs) and microelectrode array (MEA) technology to evaluate the proarrhythmic risk of candidate compounds . (technologynetworks.com)
- In this experiment, the microelectrodes in the array are used as anodes in order to oxidize an iron species (typically ferrocene or ferricyanide) in the solution covering the array. (wustl.edu)
- When a receptor (M 1 R) is added to the solution above the array and binds to ligands on the array (M 1 , M 2 , etc.) the iron species is impeded from reaching the neighboring microelectrodes. (wustl.edu)
- Adaptation of Microelectrode Array Technology for the Study of Anesthesia-induced Neurotoxicity in the Intact Piglet Brain. (smarttots.org)
- This protocol adapts the use of enzyme-based microelectrode array (MEA) technology as a novel way to study the mechanism(s) of anesthesia-induced neurotoxicity (AIN). (smarttots.org)
- Structure and function of a nitrifying biofilm as determined by in situ hybridization and the use of microelectrodes. (asm.org)
- Electrical potential and resistance were measured with microelectrodes in in situ and isolated nuclei of gland cells of Drosophila flavorepleta . (rupress.org)
- Microelectrodes and fluorescent in situ hybridization (FISH) in biofilm research have been used to investigate the spatial distributions of various microbial activities in biofilms and have led to new experimental findings as well as modifications of the homogeneous assumptions in the biofilm kinetic models. (iwaponline.com)
- The objective of this study is to try the combination of two methods, both FISH and microelectrode measurements, and to provide reliable and in situ information on nitrifying bacterial activity in biofilms. (iwaponline.com)
- Further improvements in packaging and surgical techniques will potentially enable movable microelectrodes to record cortical neuronal activity in chronic experiments. (pubmedcentralcanada.ca)
- Long-term functionality of the microelectrode implants in the brain is critical for the success of emerging applications in cortical neural prostheses and other long-term neurobiology studies on the progression of disease states, learning and memory, development of neuronal networks etc. (pubmedcentralcanada.ca)
- In this study, we examined the existence of gamma oscillations during polysomnographically defined sleep-wake states using large-scale microelectrode recordings (up to 56 channels), with single-cell and spike-time precision, in epilepsy patients. (jneurosci.org)
- Multi-unit recordings obtained from current fixed microelectrode technologies typically show deterioration in signal quality with time and almost all of them fail over periods ranging from few weeks to few years. (pubmedcentralcanada.ca)
- Further, the same microelectrode technology can often yield successful multi-unit recordings for widely varying durations of time before they fail. (pubmedcentralcanada.ca)
- Recent studies and prior reports indicate changes in enzyme activity and selectivity with certain glutaraldehyde cross-linking procedures that may jeopardize the performance of microelectrode recordings and lead to falsely elevated responses in biological systems. (nih.gov)
- In this study, we propose and evaluate a technique known as common average referencing (CAR) to generate a more ideal reference electrode for microelectrode recordings. (semanticscholar.org)
- Toma-Daşu I., Daşu A., Waites A., Denekamp J. (2003) Computer Simulation of Oxygen Microelectrode Measurements in Tissues. (springer.com)
- Shabala, SN and Babourina, OK and Rengel, Z and Nemchinov, LG, Non-invasive microelectrode potassium flux measurements as a potential tool for early recognition of virus-host compatibility in plants, Planta: An International Journal of Plant Biology, 232, (4) pp. 807-815. (edu.au)
- Trans sarcolemmal Ca movements in rabbit and rat ventricular muscle were compared using extracellular double-barreled Ca-selective microelectrodes. (elsevier.com)
- An alternative approach, useful for rapidly transporting Malpighian tubules, is to position an extracellular K + -selective microelectrode in the unstirred layer adjacent the basolateral membrane. (biologists.org)
- Fluorinated xerogel-derived microelectrodes for amperometric nitric oxide sensing. (biomedsearch.com)
- An amperometric fluorinated xerogel-derived nitric oxide (NO) microelectrode is described. (biomedsearch.com)
- Electrochemical microelectrodes are commonly used to record amperometric spikes of current that result from oxidation of transmitter released from individual vesicles during exocytosis. (rsc.org)
- The cyclic voltammograms performed in 10mM ferri-ferrocyanide show higher peak current (2 folds higher) for the 3D microelectrodes compared to the 2D ones (figure 1.C). The 3D microelectrodes potentially increase the overall sensitivity in amperometric monitoring of cell response due to the increase surface area and enhanced interaction with cells . (dtu.dk)
Signal to no2
- The microelectrode electrical signals allowed for a high level of both temporal and spatial resolution (~20 μm), and the signal to noise ratio of the epicardial ECG was comparable to that of surface electrode ECG (7.1 dB vs. 7.4 dB, respectively). (caltech.edu)
- With regard to charge transfer capacity and signal-to-noise ratio, microelectrode properties can be optimized by nano modification, e.g., coating with nano-lawn structures. (arvojournals.org)
- Ultrasensitive Electrochemical Biomolecular Detection using Nanostructured Microelectrodes. (news-medical.net)
- In view of a future application of a gel integrated electrochemical detection approach to reduce fouling and to control mass transport, we introduce here a microelectrode capable of quantifying As( III ) that consists of a gold plated Ir-based microelectrode (Au-IrM). (rsc.org)
- Ultra-sensitive detection of brain-derived neurotrophic factor (BDNF) in the brain of freely moving mice using an interdigitated microelectrode (IM. (nih.gov)
- A straightforward approach for liquid-liquid extractive detection of aromatic amines and phenols is described based on the spontaneous transfer of the molecule from the aqueous to an organic phase and subsequent electrochemical detection in the latter phase using a microelectrode. (diva-portal.org)
- Three-microelectrode voltage clamp experiments in calf cardiac Purkinje fibers: is slow inward current adequately measured? (springer.com)
- Two of the twelve movable microelectrode chips were not moved over a period of 3 weeks and were treated as control experiments. (pubmedcentralcanada.ca)
- The results of this study demonstrate that MEMS based technologies can move microelectrodes in rodent brains in long-term experiments resulting in improvements in signal quality. (pubmedcentralcanada.ca)
- However, current microelectrode technologies are inconsistent in their performance and unreliable in long-term experiments. (pubmedcentralcanada.ca)
- As expected, characterization of bare microelectrodes in buffer and tracking experiments with HeLa cells over 16 hours demonstrate that the coplanar configuration provides a higher sensitivity to cell adhesion and spreading (Cell Index = 1.6 vs. 0.4) albeit at a higher frequency of maximum sensitivity (100kHz vs. 24 kHz). (dtu.dk)
- This paper describes improved sensitivity when using biosensors based on microfabricated microelectrodes to detect DNA, with the goal of progressing towards a low cost and mass manufacturable assay for antibiotic resistance in tuberculosis (TB). (strath.ac.uk)
- The microelectrodes gave a near 20 times improvement in sensitivity compared to polycrystalline macroelectrodes. (strath.ac.uk)
- In this study, believed to be the first quantitative, large-scale microelectrode recording in human cortex, we examined gamma patterns during sleep using multiple microwires (up to 56) in patients with epilepsy who required presurgical clinical evaluation. (jneurosci.org)
- In this study, a total of 12 movable microelectrode chips were individually implanted in adult rats. (pubmedcentralcanada.ca)
- All microelectrode-guided DBS procedures performed at our institution between January 2000 and March 2008 were included in this study. (nih.gov)
- A detailed kinetic study is provided for the oxidation of ascorbate at poly(aniline)-poly(styrene sulfonate) coated microelectrodes. (soton.ac.uk)
- Schematic diagram (not to scale) showing the self-referencing ion-selective (SeRIS) microelectrode for the study of K + transport by isolated Malpighian tubules. (biologists.org)
- Traversing through the microelectrodes, heterogeneous cells are electrically polarized to experience different strengths of positive dielectrophoretic forces, in response to the 3D nonuniform electric fields. (ntu.edu.sg)
- In 1947 he co-developed the Gerard-Graham-Ling microelectrode , a device that allows scientists to more accurately measure the electrical potentials of living cells. (wikipedia.org)
- The new microelectrode design significantly decreased the number of hemorrhages (P = 0.04). (nih.gov)
- In addition, the new microelectrode design significantly decreased the rate of intraventricular hemorrhage, given a ventricular penetration (P = 0.01). (nih.gov)
- Hypertension, sex, and number of microelectrodes passed did not significantly contribute to hemorrhage rates in our population. (nih.gov)
- A new microelectrode design minimizing the volume of brain parenchyma penetrated during microelectrode recording leads to decreased rates of hemorrhage, particularly if the ventricles are breached. (nih.gov)
- This series describes the outcomes of 79 consecutive patients that underwent bilateral STN DBS at the National Hospital for Neurology and Neurosurgery between November 2002 and November 2008 using an MRI-guided surgical technique without microelectrode recording. (bmj.com)
- This series confirms that image-guided STN DBS without microelectrode recording can lead to substantial improvements in motor disability of well-selected PD patients with accompanying improvements in quality of life and most importantly, with very low morbidity. (bmj.com)
- The accuracy of electrode placement has been studied by the use of intraoperative imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT),3,4 as well as the continued use of microelectrode recording (MER).2,5-10 MER can be used to map out the target nucleus and define the best location for lead placement. (deepdyve.com)
- a silicon nitride passivation permits a selective exposure of microelectrodes to electrolyte. (spie.org)
- This report focuses on the global key players (Abbott Point of Care, Thermo Fisher Scientific, Alfa Wassermann, Van London-Phoenix Company, Beckman Coulter, Microelectrodes and F. Hoffmann-La Roche) performing at a global level, to explain, define and analyze the multiple aspects of the Ion-Selective Clinical Lab Analyzers market. (pharmiweb.com)
- Transport of K + by the lower, main and distal segments of the Malpighian tubules of Drosophila melanogaster was analyzed using self-referencing K + -selective microelectrodes. (biologists.org)