Peripheral blood pressure changes induced by dobutamine do not alter BOLD signals in the human brain

Department of Biophysics , Medical College of Wisconsin, Milwaukee, Wisconsin, United States
NeuroImage (Impact Factor: 6.36). 05/2006; 30(3):745-52. DOI: 10.1016/j.neuroimage.2005.10.047
Source: PubMed


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.

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    • "A second consideration is that drugs might alter overall cerebral blood flow and blood volume and hence change the magnitude of localised BOLD responses (Brown and Eyler, 2006) complicating interpretation of drug effects. These may occur with centrally acting vasoactive agents such as carbon dioxide and acetazolamide (Brown and Eyler, 2006) whereas autoregulation of cerebral blood flow is sufficient to compensate for changes in peripheral blood pressure over a wide 'normal' physiological range (Gozzi et al., 2007; Liu et al., 2006). In general 5-HT manipulations are not thought to have significant central vasoactive effects. "
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