Related Experiment Videos
Do carotid chemoreceptors inhibit the hyperventilatory response to heavy exercise?
1John Rankin Laboratory of Pulmonary Medicine, University of Wisconsin-Madison 53705.
Summary
Carotid chemoreceptors do not primarily drive exercise hyperventilation. Instead, these chemoreceptors may inhibit breathing, with exercise responses originating from locomotor-linked stimuli.
Area of Science:
- Exercise Physiology
- Respiratory Control
- Neuroscience
Background:
- The carotid bodies are traditionally considered key sensors for exercise-induced hyperventilation.
- Their role in mediating the respiratory response to heavy exercise remains debated.
Purpose of the Study:
- To investigate the role of carotid chemoreceptors in mediating hyperventilation during heavy exercise.
- To explore alternative mechanisms for exercise-induced respiratory stimulation.
Main Methods:
- Carotid-body denervation in ponies subjected to heavy exercise.
- Assessment of ventilatory and tidal volume responses in awake dogs and goats at rest with induced hypocapnia in isolated carotid chemoreceptors.
Main Results:
- Carotid-body denervation in ponies resulted in an increased hyperventilatory response to heavy exercise.
- Hypocapnia of isolated carotid chemoreceptors in awake dogs and goats led to significant depression of tidal volume and ventilation.
Conclusions:
- Carotid chemoreceptors appear to be inhibitory to respiratory motor output during heavy exercise.
- Extrachemoreceptor, locomotor-linked, feed-forward stimuli are proposed as the primary drivers of exercise hyperventilation.