We assessed the speed of the ventilatory response to square-wave changes in alveolar P(CO2) and the relative gains of the steady-state ventilatory response to CO2 of the central chemoreceptors vs. the carotid body chemoreceptors in intact, unanesthetized dogs. We used extracorporeal perfusion of the reversibly isolated carotid sinus to maintain normal tonic activity of the carotid body chemorec...

Key points This study demonstrates that both CO 2 ‐induced respiratory and cardiovascular responses are augmented in spontaneously hypertensive rats (SHRs). Genetic ablation of the retrotrapezoid nucleus (RTN) neurons depresses enhanced hypercapnic ventilatory response eliminates ‐stimulated increase arterial pressure heart rate SHRs. SHRs have a high protein level pH‐sensitive channels RTN, in...

Peripheral chemoreceptors (carotid and aortic bodies) detect changes in arterial blood oxygen and initiate reflexes that are important for maintaining homeostasis during hypoxemia. This mini-review summarizes the importance of peripheral chemoreceptor reflexes in various physiological and pathophysiological conditions. Carotid bodies are important for eliciting hypoxic ventilatory stimulation i...

Cardiorespiratory activity is controlled by a network of neurons located within the lower brainstem. The basic rhythm of breathing is generated by neuronal circuits within the medullary pre-Bötzinger complex, modulated by pontine and other inputs from cell groups within the medulla oblongata and then transmitted to bulbospinal pre-motor neurons that relay the respiratory pattern to cranial and ...

HIGH BLOOD PRESSURE associated with sympathetic overactivity is often associated with cardiovascular related mortality and/or morbidity. A therapeutic approach now considered for the treatment of resistant forms of the disease involves the selective denervation of the kidney (16, 51, 52, 57). Kidney function is known to be of primary importance in the long-term regulation and maintenance of art...

Panneton WM, Gan Q, Dahms TE. Cardiorespiratory and neural consequences of rats brought past their aerobic dive limit. J Appl Physiol 109: 1256–1269, 2010. First published August 12, 2010; doi:10.1152/japplphysiol.00110.2010.—The mammalian diving response is a dramatic autonomic adjustment to underwater submersion affecting heart rate, arterial blood pressure, and ventilation. The bradycardia i...

The mammalian diving response is a dramatic autonomic adjustment to underwater submersion affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is known to be modulated by the parasympathetic nervous system, arterial blood pressure is modulated via the sympathetic system, and still other circuits modulate the respiratory changes. In the present study, we investigate th...

The present study aimed to determine whether peripheral and/or central chemoreflex function is altered in chronic heart failure (CHF) and whether altered chemoreflex function contributes to sympathetic activation in CHF. A rabbit model of pacing-induced CHF was employed. The development of CHF (3-4 wk of pacing) was characterized by an enlarged heart, an attenuated contractility, and an elevate...