Linked Life Data

8972390

Source:http://linkedlifedata.com/resource/pubmed/id/8972390

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-3-18
pubmed:abstractText
Mechanisms underlying action potential generation in the newt olfactory receptor cell were investigated by using the whole-cell version of the patch-clamp technique. Isolated olfactory cells had a resting membrane potential of -70 +/- 9 mV. Injection of a depolarizing current step triggered action potentials under current clamp condition. The amplitude of the action potential was reduced by lowering external Na+ concentration. After a complete removal of Na+, however, cells still showed action potentials which was abolished either by Ca2+ removal or by an application of Ca2+ channel blocker (Co2+ or Ni2+), indicating an involvement of Ca2+ current in spike generation of newt olfactory receptor cells. Under the voltage clamp condition, depolarization of the cell to -40 mV from the holding voltage of -100 mV induced a fast transient inward current, which consisted of Na+ (INa) and T-type Ca2+ (ICa.T) currents. The amplitude of ICa,T was about one fourth of that of INa. Depolarization to more positive voltages also induced L-type Ca2+ current (ICa,L). ICa,L was as small as a few pA in normal Ringer solution. The activating voltage of ICa,T was approximately 10 mV more negative than that of INa. Under current clamp, action potentials generated by a least effective depolarization was almost completely blocked by 0.1 mM Ni2+ (a specific T-type Ca2+ channel blocker) even in the presence of Na+. These results suggest that ICa,T contributes to action potential in the newt olfactory receptor cell and lowers the threshold of spike generation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1295
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
525-35
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
T-type Ca2+ channel lowers the threshold of spike generation in the newt olfactory receptor cell.
pubmed:affiliation
Department of Information Physiology, National Institute for Physiological Sciences, Okazaki, Japan. kawai@nips.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't