ABSTRACT
Central to our understanding of cough is the modulation of the cough
reflex. We have all experienced cough as a useful phenomenon protecting the airways from accidental but potentially harmful aspiration. What is
striking, however, is the transformation of the cough reflex into the debili-
tating and detrimental hypersensitivity seen in disease. We cough uncon-
trollably during viral upper respiratory tract infections to minor tussive
stimuli such as a change in atmospheric conditions. Patients with chronic
cough usually describe paroxysms precipitated by nonspecific irritants such
as perfume or cigarette smoke. How this dramatic transformation of the
cough reflex is regulated is largely unknown but important clues can be garnered from clinical observation, the effect of drugs, animal models, and,
more recently, the expression and molecular pharmacology of the putative
cough receptors themselves in vitro.
