Linked Life Data

8261095

Source:http://linkedlifedata.com/resource/pubmed/id/8261095

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-1-27
pubmed:abstractText
Midbrain dopamine neurons in vivo discharge in a single-spike firing pattern or in a burst-firing pattern. Such activity in vivo strikingly contrasts with the pacemaker activity of the same dopamine neurons recorded in vitro. We have recently shown that burst activity in vivo of midbrain dopamine neurons is due to the local activation of excitatory amino acid receptors, as microapplication of the broad-spectrum antagonist of excitatory amino acids, kynurenic acid, strongly regularized the spontaneous firing pattern of these dopamine neurons. In the present study, we investigated which subtypes of excitatory amino acid receptors are involved in the burst-firing of midbrain dopamine neurons in chloral hydrate-anaesthetized rats, iontophoretic or pressure microejections of 6-cyano, 7-nitroquinoxaline-2,3-dione (CNQX), a non-N-methyl-D-aspartate (NMDA) receptor antagonist, did not alter the spontaneous burst firing of dopamine neurons (n = 36). In contrast, similar ejections of (+-)2-amino,5-phosphonopentanoic acid (AP-5), a specific antagonist at NMDA receptors, markedly regularized the firing pattern by reducing the occurrence of bursts (n = 52). In addition, iontophoretic ejections of NMDA, but not kainate or quisqualate, elicited a discharge of these dopamine neurons in bursts (n = 20, 12 and 14, respectively). These data suggest that burst-firing of midbrain dopamine neurons in vivo results from the tonic activation of NMDA receptors by endogenous excitatory amino acids. In view of the critical dependency of catecholamine release on the discharge pattern of source neurons, excitatory amino acid inputs to midbrain dopamine neurons may constitute a major physiological substrate in the control of the dopamine level in target areas.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
137-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Tonic activation of NMDA receptors causes spontaneous burst discharge of rat midbrain dopamine neurons in vivo.
pubmed:affiliation
INSERM U 171 and CNRS URA 1195, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't