Depolarization Currents
Mostrando 1-12 de 556 artigos, teses e dissertações.
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1. Estudos das propriedades estruturais e ópticas de vidros teluritos / Studies of the structural and optical properties of the tellurite glasses
Vidros teluritos são considerados fortes candidatos para aplicações em lasers e óptica não linear devido a importantes características, como o elevado índice de refração, baixa energia de fônons, baixa temperatura de transição vítrea e sua fácil preparação. Neste trabalho foram produzidas amostras dos sistemas vítreos TeO2- ZnO-Na2O, TeO2-Nb
Publicado em: 2011
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2. Correntes de despolarização termicamente estimuladas, ressonância paramagnética eletrônica e absorção óptica aplicadas no estudo de defeitos dipolares em MgAl2O4 / Depolarization currents
Neste trabalho foram utilizadas as técnicas de Ressonância Para-magnética Eletrônica (RPE), Absorção Óptica (AO) e Correntes de despolarização Termicamente Estimuladas (CDTE) no estudo de defeitos de origem dipolar no óxido de alumínio e magnésio MgAl2O4. O espectro de CDTE das amostras denominadas R apresentaram 3 picos, dois deles centrados em
Publicado em: 2008
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3. Electrophysiological evidence for the presence of NR2C subunits of N-methyl-D-aspartate receptors in rat neurons of the nucleus tractus solitarius
The nucleus tractus solitarius (NTS) plays an important role in the control of autonomic reflex functions. Glutamate, acting on N-methyl-D-aspartate (NMDA) and non-NMDA ionotropic receptors, is the major neurotransmitter in this nucleus, and the relative contribution of each receptor to signal transmission is unclear. We have examined NMDA excitatory postsyn
Brazilian Journal of Medical and Biological Research. Publicado em: 2005-01
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4. Chloride current induced by injection of calcium into Xenopus oocytes.
Membrane currents of Xenopus oocytes were studied with the membrane under voltage clamp. Intracellular injection of the calcium-chelating agent EGTA reduced, or abolished, the transient outward chloride current normally activated by membrane depolarization. Intracellular injection of calcium ions evoked large membrane currents, which inverted direction close
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5. Voltage-gated sodium and calcium currents in rat osteoblasts.
1. The whole-cell voltage-clamp mode of the patch-clamp technique was used to investigate the presence of voltage-gated inward currents in osteoblasts from newborn rat calvaria. 2. In K+-free solutions, three kinds of inward currents could be activated by depolarization: a voltage-gated Na+ current and two different types of Ca2+ currents. 3. The Na+ current
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6. Ionic currents of solitary horizontal cells isolated from goldfish retina.
Solitary horizontal cells, dissociated from papain-treated goldfish retinas, produce action potentials and show a non-linear current-voltage relationship. Underlying ion-conductance mechanisms were analysed by a single-micro-electrode voltage-clamp technique. Pharmacological and ion-substitution experiments revealed that ionic currents could be separated int
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7. Transient outward currents and changes of their gating properties after cell activation in thrombocytes of the newt.
1. The electrical properties of the cell membrane of thrombocytes in the newt, Triturus pyrrhogaster, were studied using the whole-cell variation of the patch-electrode voltage-clamp technique. 2. In medium containing Ca2+ (1.8 mM), activated thrombocytes became round and then spread on the glass. Activation of thrombocytes was inhibited by the removal of ex
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8. Evidence for multiple open states of the Ca2+ channels in smooth muscle cells isolated from the guinea-pig detrusor.
1. Whole-cell voltage clamp techniques were used to examine the properties of voltage-dependent Ca2+ channel currents in single smooth muscle cells enzymatically dissociated from guinea-pig urinary bladder. Potassium currents were blocked with intracellular Cs+. A holding potential of -60 mV was normally applied. 2. When the membrane potential was returned t
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9. Voltage-dependent inactivation of a calcium channel.
The inactivation of Ca currents in unfertilized eggs of the marine polychaete Neanthes arenaceodentata was investigated by using a voltage clamp technique. These Ca currents do not appear to be masked by other currents in the voltage range studied. Inactivation increased monotonically with increasing depolarization and occurred at potentials more negative th
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10. Mechanisms underlying short-term modulation of transmitter release by presynaptic depolarization
Presynaptic terminal depolarization modulates the efficacy of transmitter release. Residual Ca2+ remaining after presynaptic depolarization is thought to play a critical role in facilitation of transmitter release, but its downstream mechanism remains unclear. By making simultaneous pre- and postsynaptic recordings at the rodent calyx of Held synapse, we hav
Blackwell Science Inc.
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11. Voltage-gated sodium and potassium currents and their variation in calcitonin-secreting cells of the chick.
1. The electrical properties of dissociated ultimobranchial cells from chick embryos (18-20 days after fertilization) were studied using whole-cell patch electrodes. Antibodies for immunohistological identification of calcitonin-secreting cells in the preparation were obtained by immunizing rabbits with a conjugated analogue of eel calcitonin. 2. In a propor
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12. Kinetics of calcium-dependent inactivation of calcium current in voltage-clamped neurones of Aplysia californica.
Ca currents flowing during voltage-clamp depolarizations were examined in axotomized Aplysia neurones under conditions that virtually eliminated other currents. Moderate to large currents exhibited a two-component time course of relaxation that can be approximated reasonably well by the sum of two exponentials. The rapid phase (tau 1 approximately equal to 7