Peripheral neural circuitry in cough

• Distinct airway afferent subtypes have distinct activation profiles.
• Cough is evoked by stimulation of extrapulmonary Aδ fibers in anesthetized animals.
• Cough is evoked by stimulation of jugular C fibers in conscious animals.
• Central interactions of multiple afferent pathways modulate the cough reflex.
• Inflammatory mediators alter afferent excitability and protein expression.

Cough is a reflex that serves to protect the airways. Excessive or chronic coughing is a major health issue that is poorly controlled by current therapeutics. Significant effort has been made to understand the mechanisms underlying the cough reflex. The focus of this review is the evidence supporting the role of specific airway sensory nerve (afferent) populations in the initiation and modulation of the cough reflex in health and disease.