Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
A transient, RCK4-like K+ current in cultured Xenopus olfactory bulb neurons.
Engel J
,
Rabba J
,
Schild D
.
???displayArticle.abstract???
A transient K+ current in cultured olfactory bulb neurons of Xenopus tadpoles was studied using the whole-cell patch-clamp technique. The current, which was resistant to 80 mM tetraethylammoniumchloride (TEA) and 10 nM charybdotoxin but blocked by 5 mM 4-aminopyridine (4-AP), activated between -60 and -40 mV and showed time- and voltage-dependent inactivation. Its peak amplitude was nearly independent of the extracellular K+ concentration ([K+]o) in the range of 0.05 to 10 mM, indicating that its conductance increased upon increasing [K+]o. The transient K+ current showed a slow recovery from inactivation with the time for half-maximum recovery from a conditioning pulse to 80 mV for 1 s varying from 100 ms to 500 ms. Complete recovery required as much as 5-10 s at -80 mV, but could be speeded up at hyperpolarized potentials. The current resembles the RCK4 (Kv1.4) current of rat neurons except that its recovery from inactivation was independent of [K+]o. High-frequency stimulation (20-67 Hz) of the neurons with short (5 ms) voltage pulses resulted in a frequency-dependent, progressive inactivation of the transient K+ current. This suggests that, during phasic responses of olfactory bulb neurons, inactivation of the transient K+ current occurs and may lead to lengthening of action potentials and facilitation of synaptic transmission.
Bischofberger,
Different spatial patterns of [Ca2+] increase caused by N- and L-type Ca2+ channel activation in frog olfactory bulb neurones.
1995, Pubmed,
Xenbase
Bischofberger,
Different spatial patterns of [Ca2+] increase caused by N- and L-type Ca2+ channel activation in frog olfactory bulb neurones.
1995,
Pubmed
,
Xenbase
Carmeliet,
K+ channels in cardiac cells: mechanisms of activation, inactivation, rectification and K+e sensitivity.
1989,
Pubmed
Connor,
Voltage clamp studies of a transient outward membrane current in gastropod neural somata.
1971,
Pubmed
Dubois,
Evidence for the existence of three types of potassium channels in the frog Ranvier node membrane.
1981,
Pubmed
Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed
Hamilton,
Intracellular potentials of salamander mitral/tufted neurons in response to odor stimulation.
1985,
Pubmed
Kauer,
Analysis of the onset phase of olfactory bulb unit responses to odour pulses in the salamander.
1977,
Pubmed
Kauer,
Response patterns of amphibian olfactory bulb neurones to odour stimulation.
1974,
Pubmed
Kues,
Heterogeneous Expression Patterns of Mammalian Potassium Channel Genes in Developing and Adult Rat Brain.
1992,
Pubmed
Ludewig,
A site accessible to extracellular TEA+ and K+ influences intracellular Mg2+ block of cloned potassium channels.
1993,
Pubmed
Lynch,
Action potentials initiated by single channels opening in a small neuron (rat olfactory receptor).
1989,
Pubmed
Pardo,
Extracellular K+ specifically modulates a rat brain K+ channel.
1992,
Pubmed
,
Xenbase
Rizzo,
Transient K current in the somatic membrane of cultured central neurons of embryonic rat.
1992,
Pubmed
,
Xenbase
Ruppersberg,
Regulation of fast inactivation of cloned mammalian IK(A) channels by cysteine oxidation.
1991,
Pubmed
,
Xenbase
Safronov,
Modulation of delayed rectifier K+ channel activity by external K+ ions in Xenopus axon.
1995,
Pubmed
,
Xenbase
Schild,
Amiloride-insensitive cation conductance in Xenopus laevis olfactory neurons: a combined patch clamp and calcium imaging analysis.
1994,
Pubmed
,
Xenbase
Schwarz,
Potassium inactivation in single myelinated nerve fibres of Xenopus laevis.
1971,
Pubmed
,
Xenbase
Stuart,
Active propagation of somatic action potentials into neocortical pyramidal cell dendrites.
1994,
Pubmed
Stühmer,
Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain.
1989,
Pubmed
,
Xenbase
Tseng,
Differential effects of elevating [K]o on three transient outward potassium channels. Dependence on channel inactivation mechanisms.
1992,
Pubmed
,
Xenbase
Yao,
Modulation of 4-AP block of a mammalian A-type K channel clone by channel gating and membrane voltage.
1994,
Pubmed
,
Xenbase
