Disrupted functional connectivity with dopaminergic midbrain in cocaine abusers.
BACKGROUND
Chronic cocaine use is associated with disrupted dopaminergic neurotransmission but how this disruption affects overall brain function (other than reward/motivation) is yet to be fully investigated. Here we test the hypothesis that cocaine addicted subjects will have disrupted functional connectivity between the midbrain (where dopamine neurons are located) and cortical and subcortical brain regions during the performance of a sustained attention task.


RESULTS
We measured brain activation and functional connectivity with fMRI in 20 cocaine abusers and 20 matched controls. When compared to controls, cocaine abusers had lower positive functional connectivity of midbrain with thalamus, cerebellum, and rostral cingulate, and this was associated with decreased activation in thalamus and cerebellum and enhanced deactivation in rostral cingulate.


CONCLUSIONS
These findings suggest that decreased functional connectivity of the midbrain interferes with the activation and deactivation signals associated with sustained attention in cocaine addicts.
Tomasi
Dardo
D
National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA. tomasi@bnl.gov
Volkow
Nora D
ND
Wang
Ruiliang
R
Carrillo
Jean H
JH
Maloney
Thomas
T
Alia-Klein
Nelly
N
Woicik
Patricia A
PA
Telang
Frank
F
Goldstein
Rita Z
RZ
D000328:Adult; D001519:Behavior / Q000502:physiology; D001931:Brain Mapping; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology*; D013647:Task Performance and Analysis; D013788:Thalamus / Q000503:physiopathology
D004298:Dopamine