On lung nerves and neurogenic injury

Area of Science:

• Pulmonary Medicine
• Neuroscience
• Respiratory Physiology

Background:

• Recent research reveals intricate lung innervation patterns.
• Vagal motor and sensory fibers supply conducting airways with redundancy and segmental distribution.
• Brain stem and intrinsic airway neuronal networks regulate airway smooth muscle tone and ventilation.

Purpose of the Study:

• To elucidate the complex innervation of the lungs.
• To understand the role of neural networks in regulating airway smooth muscle tone and ventilation.
• To investigate the consequences of lung denervation on airway function and inflammation.

Main Methods:

• Review of recent accumulated information on lung innervation.
• Analysis of vagal nerve fiber distribution and function.
• Examination of intrinsic neuronal roles in airway regulation and inflammation.

Main Results:

• Lung airways possess a redundant vagal nerve supply with contralateral crossover and segmental distribution.
• Brain stem and airway intrinsic neurons form networks integrating bronchomotor tone and ventilation.
• Lung denervation disrupts integrated bronchomotor and ventilatory control, potentially causing airway deformation and fibroproliferation.
• Denervation leaves behind denervated intrinsic neurons that may amplify inflammation.

Conclusions:

• The lung's nervous system is more complex than previously thought.
• Disruption of lung innervation, such as after transplantation, impairs integrated respiratory control and promotes adverse airway remodeling and inflammation.
• Intrinsic airway neurons play a critical role in local inflammatory modulation, which can become dysregulated upon denervation.