Peripheral blood pressure changes induced by dobutamine do not alter BOLD signals in the human brain.
In extending the use of functional MRI to neuropharmacology, a primary area of concern is that peripheral blood pressure changes induced by pharmacological agents could independently produce a change in the blood oxygenation level-dependent (BOLD) signal, resulting in difficulties distinguishing or interpreting drug-induced neural activations. In the present study, we utilized intravenous dobutamine, a beta-adrenergic receptor agonist, to increase the mean arterial blood pressure (MABP), while examining the effects of MABP changes on the BOLD signal in cocaine-dependent participants. Dobutamine infusion significantly increased the MABP from 93 +/- 8 mm Hg to 106 +/- 12 mm Hg (P < 0.0005), but did not produce a significant global BOLD signal. Yet, a few voxels in the anterior cingulate showed BOLD signal changes that paralleled the changes in blood pressure (BP). Our observations support the conclusion that following the infusion of psychoactive agents, brain BOLD signals accurately reflect neuronal activity, even in the face of relatively large peripheral cardiovascular effects that transiently increase systemic BP.
Liu
Heng
H
Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Rainey
Charles
C
Lauer
Kathryn K
KK
Piacentine
Linda
L
Bloom
Alan
A
Risinger
Robert
R
Ward
B Douglas
BD
Stein
Elliot
E
Li
Shi-Jiang
SJ
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D004280:Dobutamine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood*
D000318:Adrenergic beta-Agonists; D004280:Dobutamine; D010100:Oxygen