Inaugural Review Prize 2023: The exercise hyperpnoea dilemma: A 21st-century perspective

Area of Science:

• Neuroscience
• Respiratory Physiology
• Exercise Physiology

Background:

• Alveolar ventilation proportionally increases with metabolic rate during exercise, maintaining arterial CO2 homeostasis.
• The precise mechanisms driving exercise hyperpnoea have been debated for over a century.
• Recent neuroscience advancements offer new avenues for understanding respiratory control during physical activity.

Purpose of the Study:

• To review the ventilatory control system and the challenges posed by exercise.
• To explore novel hypotheses regarding the adaptive control of breathing during exercise.
• To propose the cerebellum as a potential site for encoding exercise ventilatory responses.

Main Methods:

• Review of existing literature on respiratory control, exercise physiology, and neuroscience.
• Discussion of feedforward, feedback, and adaptive control mechanisms in breathing.
• Exploration of cerebellar function in motor learning and its potential role in respiratory adaptation.

Main Results:

• The exercise ventilatory response may involve continuous adaptation and learning throughout life.
• The cerebellum's role in motor learning and its connections to respiratory centers suggest a potential role.
• Cerebellar microcircuits could encode the feedforward stimulus for exercise hyperpnoea.

Conclusions:

• Cerebellar learning may be crucial for accurate and adaptable respiratory adjustments during exercise.
• Investigating cerebellar microcircuits using techniques like optogenetics could elucidate exercise hyperpnoea mechanisms.
• Reframing the exercise hyperpnoea dilemma through a neuroscientific lens is essential for resolution.