Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-3-23
pubmed:abstractText
Cocaine primarily exerts its behavioral effects by enhancing dopaminergic neurotransmission, amplifying dopamine-encoded sensorimotor integration. The presumed mechanism for this effect is inhibition of the dopamine transporter, which blocks dopamine uptake and prolongs the duration of dopamine in the extracellular space. However, there is growing evidence that cocaine can also augment dopamine release. Here, we directly monitored the actions of cocaine on dopamine release by using electrochemical detection to measure extracellular dopamine in the striatum of anesthetized mice. Cocaine enhanced the levels of striatal dopamine produced by electrical stimulation of dopaminergic neurons. Even after pretreatment with alpha-methyl-p-tyrosine, which depletes the readily releasable pool of dopamine, cocaine was still capable of elevating dopamine levels. This suggests that cocaine enhances dopamine release by mobilizing a reserve pool of dopamine-containing synaptic vesicles. To test this hypothesis, we examined electrically evoked dopamine release in synapsin I/II/III triple knock-out mice, which have impaired synaptic vesicle reserve pools. Knock-out of synapsins greatly reduced the ability of cocaine to enhance dopamine release with long stimulus trains or after depletion of the newly synthesized pool. We therefore conclude that cocaine enhances dopamine release and does so by mobilizing a synapsin-dependent reserve pool of dopamine-containing synaptic vesicles. This capacity to enhance exocytotic release of dopamine may be important for the psychostimulant actions of cocaine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
22
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3206-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16554471-Animals, pubmed-meshheading:16554471-Brain, pubmed-meshheading:16554471-Cocaine, pubmed-meshheading:16554471-Cocaine-Related Disorders, pubmed-meshheading:16554471-Disease Models, Animal, pubmed-meshheading:16554471-Dopamine, pubmed-meshheading:16554471-Dopamine Uptake Inhibitors, pubmed-meshheading:16554471-Electric Stimulation, pubmed-meshheading:16554471-Enzyme Inhibitors, pubmed-meshheading:16554471-Medial Forebrain Bundle, pubmed-meshheading:16554471-Mice, pubmed-meshheading:16554471-Mice, Knockout, pubmed-meshheading:16554471-Neostriatum, pubmed-meshheading:16554471-Presynaptic Terminals, pubmed-meshheading:16554471-Reward, pubmed-meshheading:16554471-Synapsins, pubmed-meshheading:16554471-Synaptic Transmission, pubmed-meshheading:16554471-Synaptic Vesicles, pubmed-meshheading:16554471-Up-Regulation, pubmed-meshheading:16554471-Ventral Tegmental Area, pubmed-meshheading:16554471-alpha-Methyltyrosine
pubmed:year
2006
pubmed:articleTitle
Cocaine increases dopamine release by mobilization of a synapsin-dependent reserve pool.
pubmed:affiliation
Department of Chemistry, Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural