TY - JOUR
T1 - D2 receptor genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans
AU - Fazio, Leonardo
AU - Blasi, Giuseppe
AU - Taurisano, Paolo
AU - Papazacharias, Apostolos
AU - Romano, Raffaella
AU - Gelao, Barbara
AU - Ursini, Gianluca
AU - Quarto, Tiziana
AU - Lo Bianco, Luciana
AU - Di Giorgio, Annabella
AU - Mancini, Marina
AU - Popolizio, Teresa
AU - Rubini, Giuseppe
AU - Bertolino, Alessandro
PY - 2011/2/14
Y1 - 2011/2/14
N2 - Objective: Pre-synaptic D2 receptors regulate striatal dopamine release and DAT activity, key factors for modulation of motor pathways. A functional SNP of DRD2 (rs1076560 G>T) is associated with alternative splicing such that the relative expression of D2S (mainly pre-synaptic) vs. D2L (mainly post-synaptic) receptor isoforms is decreased in subjects with the T allele with a putative increase of striatal dopamine levels. To evaluate how DRD2 genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans, we have investigated the association of rs1076560 with BOLD fMRI activity during a motor task. To further evaluate the relationship of this circuitry with dopamine signaling, we also explored the correlation between genotype based differences in motor brain activity and pre-synaptic striatal DAT binding measured with [123I] FP-CIT SPECT. Methods: Fifty healthy subjects, genotyped for DRD2 rs1076560 were studied with BOLD-fMRI at 3T while performing a visually paced motor task with their right hand; eleven of these subjects also underwent [123I]FP-CIT SPECT. SPM5 random-effects models were used for statistical analyses. Results: Subjects carrying the T allele had greater BOLD responses in left basal ganglia, thalamus, supplementary motor area, and primary motor cortex, whose activity was also negatively correlated with reaction time at the task. Moreover, left striatal DAT binding and activity of left supplementary motor area were negatively correlated. Interpretation: The present results suggest that DRD2 genetic variation was associated with focusing of responses in the whole motor network, in which activity of predictable nodes was correlated with reaction time and with striatal pre-synaptic dopamine signaling. Our results in humans may help shed light on genetic risk for neurobiological mechanisms involved in the pathophysiology of disorders with dysregulation of striatal dopamine like Parkinson's disease.
AB - Objective: Pre-synaptic D2 receptors regulate striatal dopamine release and DAT activity, key factors for modulation of motor pathways. A functional SNP of DRD2 (rs1076560 G>T) is associated with alternative splicing such that the relative expression of D2S (mainly pre-synaptic) vs. D2L (mainly post-synaptic) receptor isoforms is decreased in subjects with the T allele with a putative increase of striatal dopamine levels. To evaluate how DRD2 genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans, we have investigated the association of rs1076560 with BOLD fMRI activity during a motor task. To further evaluate the relationship of this circuitry with dopamine signaling, we also explored the correlation between genotype based differences in motor brain activity and pre-synaptic striatal DAT binding measured with [123I] FP-CIT SPECT. Methods: Fifty healthy subjects, genotyped for DRD2 rs1076560 were studied with BOLD-fMRI at 3T while performing a visually paced motor task with their right hand; eleven of these subjects also underwent [123I]FP-CIT SPECT. SPM5 random-effects models were used for statistical analyses. Results: Subjects carrying the T allele had greater BOLD responses in left basal ganglia, thalamus, supplementary motor area, and primary motor cortex, whose activity was also negatively correlated with reaction time at the task. Moreover, left striatal DAT binding and activity of left supplementary motor area were negatively correlated. Interpretation: The present results suggest that DRD2 genetic variation was associated with focusing of responses in the whole motor network, in which activity of predictable nodes was correlated with reaction time and with striatal pre-synaptic dopamine signaling. Our results in humans may help shed light on genetic risk for neurobiological mechanisms involved in the pathophysiology of disorders with dysregulation of striatal dopamine like Parkinson's disease.
KW - Dopamine D2 Receptor Polymorphism
KW - FMRI
KW - Imaging genetics
KW - Motor brain activity
KW - Multimodal
KW - [I] FP-CIT SPECT
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U2 - 10.1016/j.neuroimage.2010.11.034
DO - 10.1016/j.neuroimage.2010.11.034
M3 - Article
C2 - 21087673
AN - SCOPUS:78650930398
SN - 1053-8119
VL - 54
SP - 2915
EP - 2921
JO - NeuroImage
JF - NeuroImage
IS - 4
ER -