Title
Dopamine increases in striatum do not elicit craving in cocaine abusers unless they are coupled with cocaine cues
Abstract
Imaging studies have shown an association between dopamine increases in striatum and cue induced craving in cocaine abusers. However, the extent to which dopamine increases reflect a primary rather than a secondary response to the cues remains unclear. Here we evaluated the extent to which dopamine increases by themselves can induce craving in cocaine abusers. Using PET and [11C]raclopride (D2 receptor radioligand sensitive to competition with endogenous dopamine) we show that in cocaine abusers (n=20) oral methylphenidate (20 mg), which significantly increased dopamine in striatum, did not induce craving unless subjects were concomitantly exposed to cocaine cues (video scenes of subjects self-administering cocaine). This suggests that dopamine increases associated with conditioned cues are not primary responses but reflect downstream stimulation of dopamine cells (presumably glutamatergic afferents from prefrontal cortex and/or amygdala). Inasmuch as afferent stimulation of dopamine neurons results in phasic cell firing these findings suggest that “fast” dopamine increases, in contrast to the “slow” dopamine increases as achieved when using oral methylphenidate (mimicking tonic dopamine cell firing), are required for cues to trigger craving. The fact that methylphenidate induced craving only when given with the cocaine cues highlights the context dependency of methylphenidate’s effects and suggests that its use for the treatment of ADHD subjects with co-morbid drug abuse should not increase craving.
Year
DOI
Venue
2008
10.1016/j.neuroimage.2007.09.059
NeuroImage
Keywords
Field
DocType
PET imaging,Raclopride,Addiction,Caudate,Putamen,Conditioned responses,D2 receptors
Developmental psychology,Craving,Neuroscience,Nucleus accumbens,Addiction,Raclopride,Striatum,Psychology,Dopamine,Methylphenidate,Stimulant
Journal
Volume
Issue
ISSN
39
3
1053-8119
Citations 
PageRank 
References 
0
0.34
0
Authors
9
Name
Order
Citations
PageRank
Nora D Volkow16711.55
Gene-Jack Wang24410.04
Frank Telang3224.24
Joanna S. Fowler4387.50
Jean Logan5245.52
Anna Rose Childress6372.53
Millard Jayne7112.60
yeming ma8202.94
Christopher Wong9276.26