TY - JOUR
T1 - Speech-induced striatal dopamine release is left lateralized and coupled to functional striatal circuits in healthy humans
T2 - A combined PET, fMRI and DTI study
AU - Simonyan, Kristina
AU - Herscovitch, Peter
AU - Horwitz, Barry
N1 - Funding Information:
We would like to thank the PET Department of the NIH Clinical Center for assistance with PET data acquisition, Pamela Kearney, M.D., for subject evaluation, and Richard Reynolds, M.S., for help with data processing. Supported by DC009629 grant to KS, the Intramural Programs of the National Institute of Neurological Disorders and Stroke , the National Institute on Deafness and Other Communication Disorders , and the NIH Clinical Center .
PY - 2013/4/5
Y1 - 2013/4/5
N2 - Considerable progress has been recently made in understanding the brain mechanisms underlying speech and language control. However, the neurochemical underpinnings of normal speech production remain largely unknown. We investigated the extent of striatal endogenous dopamine release and its influences on the organization of functional striatal speech networks during production of meaningful English sentences using a combination of positron emission tomography (PET) with the dopamine D2/D3 receptor radioligand [11C]raclopride and functional MRI (fMRI). In addition, we used diffusion tensor tractography (DTI) to examine the extent of dopaminergic modulatory influences on striatal structural network organization. We found that, during sentence production, endogenous dopamine was released in the ventromedial portion of the dorsal striatum, in both its associative and sensorimotor functional divisions. In the associative striatum, speech-induced dopamine release established a significant relationship with neural activity and influenced the left-hemispheric lateralization of striatal functional networks. In contrast, there were no significant effects of endogenous dopamine release on the lateralization of striatal structural networks. Our data provide the first evidence for endogenous dopamine release in the dorsal striatum during normal speaking and point to the possible mechanisms behind the modulatory influences of dopamine on the organization of functional brain circuits controlling normal human speech.
AB - Considerable progress has been recently made in understanding the brain mechanisms underlying speech and language control. However, the neurochemical underpinnings of normal speech production remain largely unknown. We investigated the extent of striatal endogenous dopamine release and its influences on the organization of functional striatal speech networks during production of meaningful English sentences using a combination of positron emission tomography (PET) with the dopamine D2/D3 receptor radioligand [11C]raclopride and functional MRI (fMRI). In addition, we used diffusion tensor tractography (DTI) to examine the extent of dopaminergic modulatory influences on striatal structural network organization. We found that, during sentence production, endogenous dopamine was released in the ventromedial portion of the dorsal striatum, in both its associative and sensorimotor functional divisions. In the associative striatum, speech-induced dopamine release established a significant relationship with neural activity and influenced the left-hemispheric lateralization of striatal functional networks. In contrast, there were no significant effects of endogenous dopamine release on the lateralization of striatal structural networks. Our data provide the first evidence for endogenous dopamine release in the dorsal striatum during normal speaking and point to the possible mechanisms behind the modulatory influences of dopamine on the organization of functional brain circuits controlling normal human speech.
KW - Dopamine
KW - Speech functional networks
KW - Striatum
KW - Structural networks
UR - http://www.scopus.com/inward/record.url?scp=84872292474&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2012.12.042
DO - 10.1016/j.neuroimage.2012.12.042
M3 - Article
C2 - 23277111
AN - SCOPUS:84872292474
SN - 1053-8119
VL - 70
SP - 21
EP - 32
JO - NeuroImage
JF - NeuroImage
ER -