Bronchial asthma, a disease characterized by airway hyperresponsiveness and airway narrowing, is a potentially lethal, frequently disabling, and almost invariably associated with substantive emotional distress. Anxiety and the panic-fear symptom constellation has been shown to occur at higher rates in people with asthma compared to non-asthmatic subjects. In turn, disturbances in emotional state contribute to worsening of bronchial asthma and may act as risk factors for poor outcome. Neural pathways through which bronchial asthma generate fear and anger, causing autonomic changes that in turn exacerbate asthma at a psychophysiological level, are not known. Hence, the Iongterm objective of this proposal is to understand neural network and mechanisms that link emotional control with regulation airway homeostasis. Studies will focus on regulation of the airway geometry by the amygdaloid complex, which is thought to be involved in anxiety and the panic-fear syndrome. In the proposed studies, we will characterize operational network that link central amygdala with the vagal preganglionic neurons that innervate the tracheobronchial system, as a common pathway integrating the critical changes that set the stage for emotional distress and airway hyperresponsiveness. These studies will be performed in cats over a three-year period. The results of these studies will greatly enhance our understanding of the interrelationship between limbic system and central control of the airways and will have important implications for elucidating the pathophysiology of anxiety and the panic-fear expression with asthmatic attacks and designing therapeutic strategies to reduce or alleviate emotional and respiratory consequences of airway narrowing.
