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Updated: May 10, 2026

MRI Mapping of Cerebrovascular Reactivity via Gas Inhalation Challenges
Published on: December 17, 2014
Carbon dioxide inhalation as a human experimental model of panic: the relationship between emotions and
Nicole K Leibold1, Wolfgang Viechtbauer, Liesbet Goossens
1Department of Psychiatry and Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, European Graduate School of Neuroscience (EURON), P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Abstract:
Inhaling carbon dioxide (CO2)-enriched air induces fear and panic symptoms resembling real-life panic attacks, the hallmark of panic disorder. The present study aimed to describe the emotional and cardiovascular effects evoked by inhaling CO2, taking shortcomings of previous studies into account. Healthy volunteers underwent a double inhalation of 0, 9, 17.5, and 35% CO2, according to a randomized, cross-over design. In addition to fear, discomfort, and panic symptom ratings, blood pressure and heart rate were continuously monitored. Results showed a dose-dependent increase in all self-reports. Systolic and diastolic blood pressure rose with increasing CO2 concentration, whereas heart rate results were less consistent. Diastolic blood pressure and heart rate variation correlated with fear and discomfort. Based on this relationship and the observation that the diastolic blood pressure most accurately mimicked the degree of self-reported emotions, it might serve as a putative biomarker to assess the CO2-reactivity in the future.
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