Linked Life Data

15501598

Source:http://linkedlifedata.com/resource/pubmed/id/15501598

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-10-25
pubmed:abstractText
There is little evidence to date to indicate if mesoaccumbens dopamine function at the neurochemical level is altered during early abstinence from chronic i.v. nicotine self-administration. Thus, a quantitative microdialysis (no-net-flux) approach was used to measure basal extracellular concentrations and extraction fractions of dopamine in the nucleus accumbens (ACB) of rats that self-administered nicotine i.v. for 25 days, as well as in rats serving as yoked comparison groups (yoked nicotine and yoked saline). After 24-48 h of the final self-administration session, there was a significant reduction in basal extracellular dopamine levels in the ACB of the self-administration group compared with the yoked saline group (1.35+/-0.15 nM versus 3.70+/-0.28 nM). The basal extracellular dopamine levels in the yoked nicotine group (1.46+/-0.20 nM) were not significantly different compared with the nicotine self-administration group. The in vivo extraction fraction of dopamine, an indirect measure of dopamine uptake, was significantly increased in the nicotine self-administration (86%) and yoked nicotine (91%) groups compared with the yoked saline group (77%). In addition, a marked reduction in the elevation of extracellular dopamine levels in the ACB occurred after a nicotine challenge as measured by conventional microdialysis in the self-administration (112% of basal) and yoked nicotine (121% of basal) groups as compared with a yoked saline (154% of basal) group. The reduced basal ACB dopamine levels in the nicotine groups during early abstinence appears to be due to increased clearance, suggesting increased dopamine uptake is occurring as a result of the chronic nicotine treatment. The reduced elevation of extracellular dopamine levels in the ACB upon nicotine challenge suggests a functional desensitization or downregulation phenomenon involving acetylcholine receptors (nicotinic nAChRs). Overall, these results provide clear evidence for a neuroadaptive change that alters dopamine transmission in the ACB during abstinence from chronic i.v. nicotine exposure.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
129
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
415-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: a microdialysis study.
pubmed:affiliation
Smoking and Nicotine Dependence Research, Neuroscience Department, Centre for Addiction and Mental Health, University of Toronto, 33 Russell Street, Toronto, Ontario, M5S 2S1 Canada. shafiq_rahman@camh.net
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.