Task-related interaction between basal ganglia and cortical dopamine release.
Dopamine (DA) is a powerful neuromodulator for a wide variety of behaviors. Considerable evidence accumulated from rodent and monkey experiments over the last two decades suggests that DA activity in the frontal cortex is reciprocally linked to that in functionally related basal ganglia (BG) structures. However, the functional importance of this in humans is still unknown. To address this issue, we measured endogenous DA release using positron emission tomography in 15 healthy subjects as they practiced the first training session of a finger sequence learning task. Significant results were observed not only in striatal areas but also in extrastriatal "motor" regions, bilaterally. Faster learning was specifically coupled to lower DA release in the sensorimotor part of the globus pallidus pars interna (GPi) contralateral to the moving hand, which was paralleled by a higher increase in DA levels in the pre-supplementary motor area (pre-SMA). This finding provides original evidence supporting a motor-learning-related interaction between DA release in left GPi and pre-SMA, a mechanism that may also apply to other anatomically and functionally interconnected BG and frontal cortical areas as a function of behavior.
Garraux
Gaëtan
G
Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
Peigneux
Philippe
P
Carson
Richard E
RE
Hallett
Mark
M
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D002247:Carbon Isotopes / Q000378:metabolism; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism* / Q000494:pharmacology*; D005260:Female; D005385:Fingers / Q000502:physiology; D007839:Functional Laterality; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D049268:Positron-Emission Tomography; D011597:Psychomotor Performance / Q000502:physiology; D020891:Raclopride / Q000378:metabolism; D013997:Time Factors
D002247:Carbon Isotopes; D020891:Raclopride; D004298:Dopamine