Electrical characteristics in an excitable element of lipid membrane. 1991

K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
Department of Electronics, Faculty of Engineering, Kyushu University, Fukuoka, Japan.

Electrical characteristics in a membrane constructed from a porous filter adsorbed with a lipid analogue, dioleoyl phosphate (DOPH), were investigated in a situation interposed between 100 mM NaCl + 3 mM CaCl2 and 100 mM KCl. Calcium ions affected significantly the membrane characteristics. The membrane potential was negative on the KCl side, which implies the higher permeability to K+ than Na+; this tendency was increased by a tiny amount of Ca2+. While the membrane showed a low electrical resistance of several k omega . cm2 under K+/Na+ gradient, it showed several M omega . cm2 by Ca2+. The surface structure of the membrane exhibited many voids in the low-resistance state, but the surface was covered by oil droplets in the high-resistance state. Oscillations of the membrane potential appeared spontaneously with application of the electrical current from the KCl side to the NaCl + CaCl2 side. The frequency was increased with the electrical current. All these results were explained comprehensively using an electrochemical kinetic model taking account of the Ca2+ binding effect, where DOPH assemblies make a phase transition between oil droplets due to Ca2+ and multi-bilayers with excess K+. The oscillation arises from coupling of the phase transition to accumulation and release of K+ or Ca2+. This membrane can be used as an excitable element regulated by Ca2+ in neuro-computer devices.

UI MeSH Term Description Entries
D008563 Membrane Lipids Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation. Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D008564 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). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D008855 Microscopy, Electron, Scanning Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY. Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D010539 Permeability Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions. Permeabilities
D011188 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.
D002118 Calcium A basic element found in nearly all 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. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004553 Electric Conductivity The ability of a substrate to allow the passage of ELECTRONS. Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D012964 Sodium A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23. Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23

Related Publications

K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
December 1970, Nihon Ika Daigaku zasshi,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
January 1972, Advances in biophysics,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
November 1987, Biophysical chemistry,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
August 1979, The Journal of general physiology,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
January 1970, Tsitologiia,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
July 1990, Biophysical chemistry,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
January 1977, Journal de physiologie,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
July 1990, Biophysical chemistry,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
December 1984, Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme,
K Toko, and N Ozaki, and S Iiyama, and K Yamafuji, and Y Matsui, and K Yamafuji, and M Saito, and M Kato
November 1992, Brain research,
Copied contents to your clipboard!