Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2003-5-30
pubmed:abstractText
Extracellular dopamine contents in the caudate nucleus, nucleus accumbens, and prefrontal cortex of the rat brain were measured during two sessions of extinction of an acoustic startle reaction--each consisting of ten sound stimuli, the two sessions separated by 24 h--with simultaneous recording of freezing behavior. The results demonstrated a decrease in extracellular dopamine levels in the caudate nucleus and an increase in the nucleus accumbens during both sessions of extinction, with return to initial immediately after sessions ended. During the second session, the amplitude of startle responses and the magnitude of changes in dopamine levels in both structures were significantly smaller than during the first session. Between the sessions, dopamine levels in the caudate nucleus remained constant, while those in the nucleus accumbens decreased. The prefrontal cortex showed increases in dopamine levels during both sessions of extinction, as well as between the two sessions. The amplitude of the startle reaction was found to correlate with dopamine levels in the prefrontal cortex after the end of the corresponding extinction session and with the dopamine level before the start of the second session. The freezing time before the start of sound stimulation in the second session, this being a measure of conditioned fear, correlated with the dopamine level in the caudate nucleus on the training day and with the dopamine level in the nucleus accumbens before the start of the second session. The role of the dopaminergic system in the mechanisms forming and realizing the various components of defensive behavior are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0097-0549
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
307-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Dynamics of intracellular dopamine contents in the rat brain during the formation of conditioned contextual fear and extinction of an acoustic startle reaction.
pubmed:affiliation
P. K. Anokhin Science Research Institute of Normal Physiology, Russian Academy of Medical Sciences, Moscow.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't