Rat neocortical neurons in cell culture were studied with the patch-clamp technique in order to determine the properties of a large-conductance K+ channel in excised inside-out patches. In the presence of a physiological ionic gradient for K+ across the patch membrane ([K+]i = 120 mM; [K+]o = 3 mM), outward channel activity was detected when the patches were brought to membrane potential values less negative than -30 mV. Depolarization of the membrane increased the magnitude of the current. The I-V relationship displayed rectification at negative membrane potentials. When the I-V curve was differentiated the slope conductance calculated at 0 mV membrane potential was 120 pS. The single-channel permeability was 5.2 x 10(-13) cm/s and the current flow through the open K+ channel could be modeled using the constant-field electrodiffusion theory. K+ channel opening was not observed following removal of Ca2+ from the intracellular surface of the membrane. Our experiments indicate that, as in other cell types, rat neocortical neurons in culture exhibit a large-conductance K+ channel which is activated by Ca2+ acting on the cytoplasmic surface.

Zona, C., Avoli, M. (1989). Calcium-activated potassium channels recorded from rat neocortical neurons in cell culture. NEUROSCIENCE LETTERS, 102(2-3), 223-228 [10.1016/0304-3940(89)90082-7].

Calcium-activated potassium channels recorded from rat neocortical neurons in cell culture

ZONA, CRISTINA;
1989-07-31

Abstract

Rat neocortical neurons in cell culture were studied with the patch-clamp technique in order to determine the properties of a large-conductance K+ channel in excised inside-out patches. In the presence of a physiological ionic gradient for K+ across the patch membrane ([K+]i = 120 mM; [K+]o = 3 mM), outward channel activity was detected when the patches were brought to membrane potential values less negative than -30 mV. Depolarization of the membrane increased the magnitude of the current. The I-V relationship displayed rectification at negative membrane potentials. When the I-V curve was differentiated the slope conductance calculated at 0 mV membrane potential was 120 pS. The single-channel permeability was 5.2 x 10(-13) cm/s and the current flow through the open K+ channel could be modeled using the constant-field electrodiffusion theory. K+ channel opening was not observed following removal of Ca2+ from the intracellular surface of the membrane. Our experiments indicate that, as in other cell types, rat neocortical neurons in culture exhibit a large-conductance K+ channel which is activated by Ca2+ acting on the cytoplasmic surface.
31-lug-1989
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/09 - FISIOLOGIA
English
Con Impact Factor ISI
Rats, Inbred Strains; Rats; Cerebral Cortex; Permeability; Animals; Calcium; Cells, Cultured; Neurons; Potassium; Membrane Potentials; Electrophysiology; Potassium Channels
Zona, C., Avoli, M. (1989). Calcium-activated potassium channels recorded from rat neocortical neurons in cell culture. NEUROSCIENCE LETTERS, 102(2-3), 223-228 [10.1016/0304-3940(89)90082-7].
Zona, C; Avoli, M
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/65129
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