Brain scans reveal link between stress and asthma

• Using brain scanning techniques, researchers have located a specific part of the brain that causes people with asthma to wheeze and gasp for breath when under emotional stress.
• Asthma sufferers often note that anxiety and emotional turmoil make the symptoms of an attack much worse, and in some cases, emotion alone can precipitate an attack.
• Previous research has shown, for example, that college students with asthma have greater airway inflammation when they are exposed to an allergen during exam week than when the exposure occurs at a less stressful time.
• Richard J. Davidson, the senior author of the paper and a professor of psychology and psychiatry at the University of Wisconsin, said the work showed that when people with asthma are exposed to their allergen, "you find certain centers in the brain that we know are intimately involved in emotions that get activated."
• First, the inhalation of an allergen provokes a release of chemicals that cause smooth muscles to contract.
• Together, these reactions bring on airway obstruction and difficulty in breathing.
• In the new study, the researchers exposed six volunteers with mild allergic asthma to two different substances, one that caused muscle constriction and a second that caused inflammation.
• At one hour and four hours after the exposure, the participants' brains were scanned using functional MRI, essentially photographing the brain's activity during the muscle constriction stage and then at the inflammation stage of the attack.
• The researchers found that brain activity in the early muscle contracting phase of the asthma attack differed from that in the later inflammatory phase.
• They also found that the presentation of words on a screen specifically associated with asthma attacks caused increased activity in the inflammatory phase in parts of the brain that govern emotions.