Linked Life Data

10751672

Source:http://linkedlifedata.com/resource/pubmed/id/10751672

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-8-2
pubmed:abstractText
Spreading depression (SD) consists of a transient suppression of all neuronal activity that spreads slowly across regions of gray matter. The paper is divided into three parts. Martins-Ferreira describes 30 years of research on SD in the isolated retina. Much of this work has relied on the prominent intrinsic optical signals that accompany SD in the retina. By inducing SD to propagate in circles with a velocity of 3.7 mm min(-1), it is possible to investigate the finely balanced electrochemical equilibrium that maintains the traveling wave. SD is accompanied by a slow negative extracellular voltage and ion movements that are greatest in the inner plexiform layer of the retina. Nedergaard discusses the role of astrocytes in SD propagation. Astrocytes mediate slowly moving waves of intracellular Ca(2+) increase, for which gap junctions are essential. SD is accompanied by entry of Ca(2+) into cells and fails when gap junctions are blocked. SD, however, is blocked by glutamate receptor antagonists but glial Ca(2+) waves are not. Astrocytic Ca(2+) waves are probably involved in the initiation of SD but other factors, including K(+), glutamate and purinergic receptors, are necessary for sustained propagation. Nicholson describes studies on the different preparations that helped clarify the role of extracellular space in SD. It has long been known that extracellular K(+) reaches levels of 50 mM or more during SD. Studies with ion-selective microelectrodes showed that extracellular Na(+) and Cl(-) fall by as much as 100 mM during SD, and water leaves the extracellular space. Further work showed that extracellular Ca(2+) falls 10-fold during SD and significant changes in extracellular pH and ascorbate occur. These studies imply that large perturbations of the extracellular milieu occur during SD and are an essential part of the interlocking cascade of events that produce this still mysterious phenomenon.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:author
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
215-34
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Perspectives on spreading depression.
pubmed:affiliation
Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Bloco G, Universidade Federal do Rio de Janeiro, Brazil.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't