The role of the peripheral and central adrenergic system in the construction of the subjective emotional experience of panic

Rationale Although the study of emotions can look back to over 100 years of research, it is unclear which information the brain uses to construct the subjective experience of an emotion. Objective In the current study, we assess the role of the peripheral and central adrenergic system in this respect. Methods Healthy volunteers underwent a double inhalation of 35% CO 2 , which is a well-validated procedure to induce an intense emotion, namely panic. In a randomized, cross-over design, 34 participants received either a β 1 -blocker acting selectively in the peripheral nervous system (atenolol), a β 1 -blocker acting in the peripheral and central nervous system (metoprolol), or a placebo before the CO 2 inhalation. Results Heart rate and systolic blood pressure were reduced in both β-blocker conditions compared to placebo, showing effective inhibition of the adrenergic tone. Nevertheless, the subjective experience of the induced panic was the same in all conditions, as measured by self-reported fear, discomfort, and panic symptom ratings. Conclusions These results indicate that information from the peripheral and central adrenergic system does not play a major role in the construction of the subjective emotion.