Linked Life Data

17699694

Source:http://linkedlifedata.com/resource/pubmed/id/17699694

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-11-16
pubmed:abstractText
Blocking the small-conductance (SK) calcium-activated potassium channel promotes burst firing in dopamine neurons both in vivo and in vitro. In vitro, the bursting is unusual in that spiking persists during the hyperpolarized trough and frequently terminates by depolarization block during the plateau. We focus on the underlying plateau potential oscillation generated in the presence of both apamin and TTX, so that action potentials are not considered. We find that although the plateau potentials are mediated by a voltage-gated Ca(2+) current, they do not depend on the accumulation of cytosolic Ca(2+), then use a computational model to test the hypothesis that the slowly voltage-activated ether-a-go-go-related gene (ERG) potassium current repolarizes the plateaus. The model, which includes a material balance on calcium, is able to reproduce the time course of both membrane potential and somatic calcium concentration, and can also mimic the induction of plateau potentials by the calcium chelator BAPTA. The principle of separation of timescales was used to gain insight into the mechanisms of oscillation and its modulation using nullclines in the phase space. The model predicts that the plateau will be elongated and ultimately result in a persistent depolarization as the ERG current is reduced. This study suggests that the ERG current may play a role in burst termination and the relief of depolarization block in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3006-22
pubmed:meshHeading
pubmed-meshheading:17699694-1-Naphthylamine, pubmed-meshheading:17699694-Animals, pubmed-meshheading:17699694-Animals, Newborn, pubmed-meshheading:17699694-Apamin, pubmed-meshheading:17699694-Calcium, pubmed-meshheading:17699694-Chelating Agents, pubmed-meshheading:17699694-Computer Simulation, pubmed-meshheading:17699694-Dopamine, pubmed-meshheading:17699694-Dopamine Antagonists, pubmed-meshheading:17699694-Egtazic Acid, pubmed-meshheading:17699694-Haloperidol, pubmed-meshheading:17699694-Male, pubmed-meshheading:17699694-Membrane Potentials, pubmed-meshheading:17699694-Mesencephalon, pubmed-meshheading:17699694-Models, Neurological, pubmed-meshheading:17699694-Neurons, pubmed-meshheading:17699694-Potassium Channel Blockers, pubmed-meshheading:17699694-Rats, pubmed-meshheading:17699694-Rats, Sprague-Dawley, pubmed-meshheading:17699694-Small-Conductance Calcium-Activated Potassium Channels
pubmed:year
2007
pubmed:articleTitle
Computational model predicts a role for ERG current in repolarizing plateau potentials in dopamine neurons: implications for modulation of neuronal activity.
pubmed:affiliation
Neuroscience Center, Louisiana State University Health Sciences Center, New Orleans 70112, USA. ccanav@lsuhsc.edu
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural