Hendriks-Balk, Marielle C.Megdiche, FatmaPezzi, LauraReynaud, OlivierDa Costa, SandraBueti, DomenicaVan de Ville, DimitriWuerzner, Gregoire2020-03-082020-03-082020-03-082020-01-3110.3389/fnins.2020.00039https://infoscience.epfl.ch/handle/20.500.14299/167111WOS:000515632700001Introduction Modern imaging techniques such as blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) allow the non-invasive and indirect measurement of brain activity. Whether changes in signal intensity can be detected in small brainstem regions during a cold pressor test (CPT) has not been explored thoroughly. The aim of this study was to measure whole brain and brainstem BOLD signal intensity changes in response to a modified CPT. Methods BOLD fMRI was measured in healthy normotensive participants during a randomized crossover study (modified CPT vs. control test) using ultra-high field 7 Tesla MRI scanner. Data were analyzed using Statistical Parametric Mapping (SPM) in a whole-brain approach, and with a brainstem-specific analysis using the spatially unbiased infra-tentorial template (SUIT) toolbox. Blood pressure (BP) and hormonal responses (norepinephrine and epinephrine levels) were also measured. Paired t-test statistics were used to compare conditions. Results Eleven participants (six women, mean age 28 +/- 8.9 years) were analyzed. Mean arterial BP increased from 83 +/- 12 mm Hg to 87 +/- 12 mm Hg (p = 0.0009) during the CPT. Whole-brain analysis revealed significant activations linked to the CPT in the right supplementary motor cortex, midcingulate (bilateral) and the right anterior insular cortex. The brainstem-specific analysis showed significant activations in the dorsal medulla. Conclusion Changes in BOLD fMRI signal intensity in brainstem regions during a CPT can be detected, and show an increased response during a cold stress in healthy volunteers. Consequently, BOLD fMRI at 7T is a promising tool to explore and acquire new insights in the comprehension of neurogenic hypertension.NeurosciencesNeurosciences & Neurologycold pressor testbrainstemboldfmriblood pressuresympathetic nervous systemsympathetic-nerve activityblood-pressurehypertensionactivationresponsessupplementarychallengesdrivesitesCIBM-AITtext::journal::journal article::research article