title: Effect of simple motor performance on regional dopamine release in the striatum in Parkinson disease patients and healthy subjects: a positron emission tomography study.
abstract: To investigate changes in dopamine release in the striatum during motor exercise in human subjects with and without striatal dopamine denervation, eight healthy subjects and eight patients with Parkinson disease (PD) were measured during unilateral foot extension/flexion movement using positron emission tomography with [11C]raclopride. Five subjects in each group were later scanned in the resting condition. Estimation of binding potential (k3/k4) of [11C]raclopride was based on Logan plot method. Significant reductions in [11C]raclopride k3/k4 were found in the dorsal putamen contralateral to the exercise side in the healthy group and ipsilaterally in the PD group. Spearman rank correlation analysis showed that [11C]raclopride k3/k4 correlated inversely with the decrease in performance (velocity and motion range) in the dorsal putamen contralaterally in the healthy group and ipsilaterally in the PD group. These results suggest that simple but laborious motor exercise (motor stimulation) generates significant dopamine release in the dorsal striatum contralateral to the motor execution in humans. Lack of the crossed pattern and ipsilateral increase in dopamine release in the dorsal striatum during the unilateral limb movement may reflect the pathophysiology for hypokinetic and insufficient coordinating movement in PD.
authors.affiliation: Positron Medical Center, Department of Neurology, Hamamatsu Medical Center, Hamamatsu, Japan.
authors.forename: Yasuomi
authors.initials: Y
authors.lastname: Ouchi
authors.forename: Etsuji
authors.initials: E
authors.lastname: Yoshikawa
authors.forename: Masami
authors.initials: M
authors.lastname: Futatsubashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Torizuka
authors.forename: Masanobu
authors.initials: M
authors.lastname: Sakamoto
mesh_terms: D000368:Aged; D002250:Carbon Radioisotopes; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D005260:Female; D005528:Foot; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000503:physiopathology; D020891:Raclopride; D014055:Tomography, Emission-Computed
chemical_list: D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D020891:Raclopride; D004298:Dopamine