Mechanisms of acute cough.

The physiology of cough has become one of the primary focuses of recent research into the cough reflex. Peripherally, interest in differentiating subtypes of airway afferent fibres to determine their contributions to the cough reflex has led to the discovery of an RAR-fibre subtype that responds exclusively to tussive stimuli in the anaesthetized guinea pig and has been hypothesized to initiate the normal defensive cough reflex. Further investigations have begun to more fully differentiate these and other afferent fibre types pharmacologically. Centrally, investigations into the involvement of respiratory networks and gating mechanisms in the cough reflex have contributed to our understanding of the control of cough. Pathological changes in the cough reflex resulting from disease are also beginning to be elucidated. Further research in this area should lead to a more complete understanding of cough and a more rational approach to its treatment.