A NO way to BOLD? Dietary nitrate alters the hemodynamic response to visual stimulation
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A NO way to BOLD? Dietary nitrate alters the hemodynamic response to visual stimulation. / Aamand, Rasmus; Dalsgaard, Thomas; Ho, Yi-Ching Lynn; Møller, Arne; Roepstorff, Andreas; Lund, Torben E.
In: NeuroImage, Vol. 83, 12.2013, p. 397-407.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - A NO way to BOLD?
T2 - Dietary nitrate alters the hemodynamic response to visual stimulation
AU - Aamand, Rasmus
AU - Dalsgaard, Thomas
AU - Ho, Yi-Ching Lynn
AU - Møller, Arne
AU - Roepstorff, Andreas
AU - Lund, Torben E
N1 - © 2013 Elsevier Inc. All rights reserved.
PY - 2013/12
Y1 - 2013/12
N2 - Neurovascular coupling links neuronal activity to vasodilation. Nitric oxide (NO) is a potent vasodilator, and in neurovascular coupling NO production from NO synthases plays an important role. However, another pathway for NO production also exists, namely the nitrate-nitrite-NO pathway. On this basis, we hypothesized that dietary nitrate (NO3-) could influence the brain's hemodynamic response to neuronal stimulation. In the present study, 20 healthy male participants were given either sodium nitrate (NaNO3) or sodium chloride (NaCl) (saline placebo) in a crossover study and were shown visual stimuli based on the retinotopic characteristics of the visual cortex. Our primary measure of the hemodynamic response was the blood oxygenation level dependent (BOLD) response measured with high-resolution functional magnetic resonance imaging (0.64×0.64×1.8 mm) in the visual cortex. From this response, we made a direct estimate of key parameters characterizing the shape of the BOLD response (i.e. lag and amplitude). During elevated nitrate intake, corresponding to the nitrate content of a large plate of salad, both the hemodynamic lag and the BOLD amplitude decreased significantly (7.0±2% and 7.9±4%, respectively), and the variation across activated voxels of both measures decreased (12.3±4% and 15.3±7%, respectively). The baseline cerebral blood flow was not affected by nitrate. Our experiments demonstrate, for the first time, that dietary nitrate may modulate the local cerebral hemodynamic response to stimuli. A faster and smaller BOLD response, with less variation across local cortex, is consistent with an enhanced hemodynamic coupling during elevated nitrate intake. These findings suggest that dietary patterns, via the nitrate-nitrite-NO pathway, may be a potential way to affect key properties of neurovascular coupling. This could have major clinical implications, which remain to be explored.
AB - Neurovascular coupling links neuronal activity to vasodilation. Nitric oxide (NO) is a potent vasodilator, and in neurovascular coupling NO production from NO synthases plays an important role. However, another pathway for NO production also exists, namely the nitrate-nitrite-NO pathway. On this basis, we hypothesized that dietary nitrate (NO3-) could influence the brain's hemodynamic response to neuronal stimulation. In the present study, 20 healthy male participants were given either sodium nitrate (NaNO3) or sodium chloride (NaCl) (saline placebo) in a crossover study and were shown visual stimuli based on the retinotopic characteristics of the visual cortex. Our primary measure of the hemodynamic response was the blood oxygenation level dependent (BOLD) response measured with high-resolution functional magnetic resonance imaging (0.64×0.64×1.8 mm) in the visual cortex. From this response, we made a direct estimate of key parameters characterizing the shape of the BOLD response (i.e. lag and amplitude). During elevated nitrate intake, corresponding to the nitrate content of a large plate of salad, both the hemodynamic lag and the BOLD amplitude decreased significantly (7.0±2% and 7.9±4%, respectively), and the variation across activated voxels of both measures decreased (12.3±4% and 15.3±7%, respectively). The baseline cerebral blood flow was not affected by nitrate. Our experiments demonstrate, for the first time, that dietary nitrate may modulate the local cerebral hemodynamic response to stimuli. A faster and smaller BOLD response, with less variation across local cortex, is consistent with an enhanced hemodynamic coupling during elevated nitrate intake. These findings suggest that dietary patterns, via the nitrate-nitrite-NO pathway, may be a potential way to affect key properties of neurovascular coupling. This could have major clinical implications, which remain to be explored.
KW - Administration, Oral
KW - Adult
KW - Blood Flow Velocity
KW - Brain Mapping
KW - Cerebrovascular Circulation
KW - Cross-Over Studies
KW - Double-Blind Method
KW - Humans
KW - Magnetic Resonance Imaging
KW - Male
KW - Nitrates
KW - Nitric Oxide
KW - Nitrites
KW - Photic Stimulation
KW - Placebo Effect
KW - Reproducibility of Results
KW - Sensitivity and Specificity
KW - Visual Perception
U2 - 10.1016/j.neuroimage.2013.06.069
DO - 10.1016/j.neuroimage.2013.06.069
M3 - Journal article
C2 - 23827330
VL - 83
SP - 397
EP - 407
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
ER -
ID: 132052625