Inhibition of stimulated dopamine release and hemodynamic response in the brain through electrical stimulation of rat forepaw.
The subcortical response to peripheral somatosensory stimulation is not well studied. Prior literature suggests that somatosensory stimulation can affect dopaminergic tone. We studied the effects of electrical stimulation near the median nerve on the response to an amphetamine-induced increase in synaptic dopamine. We applied the electrical stimulation close to the median nerve 20 min after administration of 3mg/kg amphetamine. We used fMRI and microdialysis to measure markers of dopamine (DA) release, together with the release of associated neurotransmitters of striatal glutamate (Glu) and gamma-aminobutyric acid (GABA). Changes in cerebral blood volume (CBV), a marker used in fMRI, indicate that electrical stimulation significantly attenuated increased DA release (due to AMPH) in the striatum, thalamus, medial prefrontal and cingulate cortices. Microdialysis showed that electrical stimulation increased Glu and GABA release and attenuated the AMPH-enhanced DA release. The striatal DA dynamics correlated with the CBV response. These results demonstrate that electrical stimulation near the median nerve activates Glu/GABA release, which subsequently attenuate excess striatal DA release. These data provide evidence for physiologic modulation caused by electroacupuncture at points near the median nerve.
Chen
Y Iris
YI
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Room 2301, Charlestown, MA 02129, USA. iris@nmr.mgh.harvard.edu
Ren
Jiaqian
J
Wang
Fu-Nien
FN
Xu
Haibo
H
Mandeville
Joseph B
JB
Kim
Young
Y
Rosen
Bruce R
BR
Jenkins
Bruce G
BG
Hui
Kathleen K S
KK
Kwong
Kenneth K
KK
D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004558:Electric Stimulation / Q000379:methods*; D006439:Hemodynamics / Q000187:drug effects / Q000528:radiation effects*; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008663:Metacarpus / Q000294:innervation / Q000528:radiation effects*; D009433:Neural Inhibition / Q000187:drug effects / Q000528:radiation effects*; D010100:Oxygen / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D000697:Central Nervous System Stimulants; D005680:gamma-Aminobutyric Acid; D000661:Amphetamine; D010100:Oxygen; D004298:Dopamine