scholarly journals Peripheral chemoreceptors determine the respiratory sensitivity of central chemoreceptors to CO2

2010 ◽  
Vol 588 (13) ◽  
pp. 2455-2471 ◽  
Author(s):  
Gregory M. Blain ◽  
Curtis A. Smith ◽  
Kathleen S. Henderson ◽  
Jerome A. Dempsey
Keyword(s):  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Respiratory Sensitivity

scholarly journals Peripheral chemoreceptors determine the respiratory sensitivity of central chemoreceptors to CO2: role of carotid body CO2

2015 ◽  
Vol 593 (18) ◽  
pp. 4225-4243 ◽  
Author(s):  
Curtis. A. Smith ◽  
Grégory M. Blain ◽  
Kathleen S. Henderson ◽  
Jerome A. Dempsey
Keyword(s):  
Carotid Body ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Respiratory Sensitivity

Role of central and peripheral chemoreceptors in diving responses of ducks

1982 ◽  
Vol 243 (5) ◽  
pp. R537-R545 ◽  
Author(s):  
D. R. Jones ◽  
W. K. Milsom ◽  
G. R. Gabbott
Keyword(s):  
Carotid Body ◽  
Significant Contribution ◽  
Cardiovascular Responses ◽  
Peripheral Circulation ◽  
Blood Gas ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
The Right ◽  
Stimulation Of

Using techniques of vascular isolation and subsequent perfusion we have investigated the effects of altering blood gas tensions, in the cerebral and carotid body circulations, on some cardiovascular responses to diving in unanesthetized ducks. After denervating the right carotid body, perfusion of the innervated left carotid body with hyperoxic blood significantly reduced diving bradycardia and reduced the increase in hindlimb vascular resistance (HLVR) in 1-min dives compared with dives in which the innervated carotid body was autoperfused. Denervation of systemic arterial baroreceptors reduced the fall in heart rate (HR) and increased the rise in HLVR in all dives. Cross-perfusion of the head, from a donor with blood of normal blood gas tensions, did not significantly affect HR or HLVR in 2-min dives compared with dives in which the head was autoperfused. however, cross-perfusing the cerebral circulation with blood of elevated PaCO2 caused significantly greater increases in HLVR than when high PaCO2 only affected the peripheral circulation. We conclude that peripheral chemoreceptors cause virtually all the bradycardia in the later stages of a dive but only about one-half the increase in HLVR, a significant contribution comes from the stimulation of central chemoreceptors with blood of high PaCO2.

Role of peripheral and central chemoreceptors in the initiation of fetal respiration

1975 ◽  
Vol 38 (3) ◽  
pp. 407-410 ◽  
Author(s):  
V. Chernick ◽  
E. E. Faridy ◽  
R. D. Pagtakhan
Keyword(s):  
Carotid Sinus ◽  
Blood Gases ◽  
Fetal Sheep ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Bilateral Carotid ◽  
Fetal Respiration ◽  
A Minor ◽  
The Relationship

The relationship between fetal femoral arterial P02 and PC02 was evalulated in 13 fetal sheep with intact and denervated peripheral chemoreceptors. With intact chemoreceptors, a significant relationship was found between fetal Pa02 and PaC02 at the time of the first breath (Pa02 = 2.57 + 0.09 PaC02; r = 0.62, P less than 0.05)mfollowing bilateral carotid sinus nerve section (CSN) or total peripheral chemodenervation (TD), PaC02. Comparison of the intact, CSN, and TD blood gases at the time of the first breath demonstrated that a) severe hypoxemia stimulates fetal respiration even following total peripheral chemodenervation; b) fetal central chemoreceptors do not respond to PaC02; c) PaC02 acting via peripheral chemoreceptors has a minor modulating effect on the degree of hypoxemia required to initiate fetal respiration. At a PaC02 below 40 mmHg this effect is inhibitory, acting via the carotid body. At a PaC02 above 90 mmHg this effect is stimulatory, acting via both carotid and aortic bodies.

scholarly journals Central and peripheral chemoreceptors evoke distinct responses in simultaneously recorded neurons of the raphé-pontomedullary respiratory network

2009 ◽  
Vol 364 (1529) ◽  
pp. 2501-2516 ◽  
Author(s):  
Sarah C. Nuding ◽  
Lauren S. Segers ◽  
Roger Shannon ◽  
Russell O'Connor ◽  
Kendall F. Morris ◽  
...  
Keyword(s):  
Network Architecture ◽  
Motor Pattern ◽  
Specific Interaction ◽  
Raphe Nuclei ◽  
Short Time Scale ◽  
Peripheral Chemoreceptor ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Raphé Nuclei ◽  
Stimulation Of

The brainstem network for generating and modulating the respiratory motor pattern includes neurons of the medullary ventrolateral respiratory column (VRC), dorsolateral pons (PRG) and raphé nuclei. Midline raphé neurons are proposed to be elements of a distributed brainstem system of central chemoreceptors, as well as modulators of central chemoreceptors at other sites, including the retrotrapezoid nucleus. Stimulation of the raphé system or peripheral chemoreceptors can induce a long-term facilitation of phrenic nerve activity; central chemoreceptor stimulation does not. The network mechanisms through which each class of chemoreceptor differentially influences breathing are poorly understood. Microelectrode arrays were used to monitor sets of spike trains from 114 PRG, 198 VRC and 166 midline neurons in six decerebrate vagotomized cats; 356 were recorded during sequential stimulation of both receptor classes via brief CO 2 -saturated saline injections in vertebral (central) and carotid arteries (peripheral). Seventy neurons responded to both stimuli. More neurons were responsive only to peripheral challenges than those responsive only to central chemoreceptor stimulation (PRG, 20 : 4; VRC, 41 : 10; midline, 25 : 13). Of 16 474 pairs of neurons evaluated for short-time scale correlations, similar percentages of reference neurons in each brain region had correlation features indicative of a specific interaction with at least one target neuron: PRG (59.6%), VRC (51.0%) and raphé nuclei (45.8%). The results suggest a brainstem network architecture with connectivity that shapes the respiratory motor pattern via overlapping circuits that modulate central and peripheral chemoreceptor-mediated influences on breathing.

scholarly journals The apneic threshold during non-REM sleep in dogs: sensitivity of carotid body vs. central chemoreceptors

2007 ◽  
Vol 103 (2) ◽  
pp. 578-586 ◽  
Author(s):  
C. A. Smith ◽  
B. J. Chenuel ◽  
K. S. Henderson ◽  
J. A. Dempsey
Keyword(s):  
Carotid Body ◽  
Pressure Support Ventilation ◽  
Pressure Support ◽  
Systemic Circulation ◽  
Peripheral Chemoreceptors ◽  
Support Ventilation ◽  
Stimulus Response ◽  
Central Chemoreceptors ◽  
End Tidal ◽  
Carotid Body Chemoreceptors

The relative importance of peripheral vs. central chemoreceptors in causing apnea/unstable breathing during sleep is unresolved. This has never been tested in an unanesthetized preparation with intact carotid bodies. We studied three unanesthetized dogs during normal sleep in a preparation in which intact carotid body chemoreceptors could be reversibly isolated from the systemic circulation and perfused. Apneic thresholds and the CO2 reserve (end-tidal Pco2 eupneic − end-tidal Pco2 apneic threshold) were determined using a pressure support ventilation technique. Dogs were studied when both central and peripheral chemoreceptors sensed transient hypocapnia induced by the pressure support ventilation and again with carotid body isolation such that only the central chemoreceptors sensed the hypocapnia. We observed that the CO2 reserve was ≅4.5 Torr when the carotid chemoreceptors sensed the transient hypocapnia but more than doubled (>9 Torr) when only the central chemoreceptors sensed hypocapnia. Furthermore, the expiratory time prolongations observed when only central chemoreceptors were exposed to hypocapnia differed from those obtained when both the central and peripheral chemoreceptors sensed the hypocapnia in that they 1) were substantially shorter for a given reduction in end-tidal Pco2, 2) showed no stimulus: response relationship with increasing hypocapnia, and 3) often occurred at a time (>45 s) beyond the latency expected for the central chemoreceptors. These findings agree with those previously obtained using an identical pressure support ventilation protocol in carotid body-denervated sleeping dogs (Nakayama H, Smith CA, Rodman JR, Skatrud JB, Dempsey JA. J Appl Physiol 94: 155–164, 2003). We conclude that hypocapnia sensed at the carotid body chemoreceptor is required for the initiation of apnea following a transient ventilatory overshoot in non-rapid eye movement sleep.

scholarly journals Contributions of central and peripheral chemoreceptors to the ventilatory response to CO2/H+

2010 ◽  
Vol 108 (4) ◽  
pp. 989-994 ◽  
Author(s):  
H. V. Forster ◽  
C. A. Smith
Keyword(s):  
Ventilatory Response ◽  
Control Mechanisms ◽  
Additive Interaction ◽  
Ventilatory Control ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Different Types ◽  
Simple Summation ◽  
Ventilatory Response To Co2 ◽  
Stimulation Of

The major objective of this review is to evaluate existing information and reach conclusions regarding whether there is interaction between Pco2/H+ stimulation of carotid (peripheral) and intracranial (central) chemoreceptors. Interaction is defined as a ventilatory response to simultaneous changes in the degree of Pco2/H+ stimulation of both chemoreceptors that is greater (hyperadditive) or less (hypoadditive) than the sum of the responses when stimulation of each set of chemoreceptors is individually altered. Simple summation of the simultaneous changes in stimuli results in no interaction (i.e., additive interaction). Knowledge of the nature of central/peripheral interaction is crucial for determining the physiological significance of newer models of ventilatory control based on recent neuroanatomic observations of the circuitry of key elements of the ventilatory control system. In this review, we will propose that these two sets of receptors are not functionally separate but rather that they are dependent on one another such that the sensitivity of the medullary chemoreceptors is critically determined by input from the peripheral chemoreceptors and possibly other breathing-related reflex afferents as well. The short format of this minireview demands that we be somewhat selective in developing our ideas. We will briefly discuss the limitations of experiments used to study CO2/H+ sensitivity and interaction to date, traditional views of the relative contributions of peripheral and central chemoreceptors to CO2/H+ sensitivity, the evidence for and against different types of interaction, and the effect of tonic carotid chemoreceptor afferent activity on central control mechanisms.

Ventilatory interaction between hypoxia and [H+] at chemoreceptors of man

1975 ◽  
Vol 39 (2) ◽  
pp. 292-296 ◽  
Author(s):  
R. A. Gabel ◽  
R. B. Weiskopf
Keyword(s):  
Experimental Design ◽  
High Altitude ◽  
Sea Level ◽  
Acute Hypoxia ◽  
Simulated Altitude ◽  
Peripheral Chemoreceptor ◽  
Peripheral Chemoreceptors ◽  
Central Chemoreceptors ◽  
Progressive Hypoxia ◽  
The Mean

By measuring ventilation during isocapnic progressive hypoxia, peripheral chemoreceptor sensitivity to acute hypoxia (deltaV40) was measured in five normal young men under four sets of conditions: 1) at sea level at the subject's resting PCO2, 2) at sea level with PCO2 5 Torr above resting PCO2, 3) after 24 h at a simulated altitude of 4,267 m (PB = 447 Torr) at the subject's resting PCO2 measured during acute hyperoxia, and 4) after 24 h at high altitude, with PCO2 elevated to the subject's sea-level resting PCO2. With this experimental design, we were able to systematically vary the PCO2 and [H+] at the peripheral and central chemoreceptors of man. When mean pHa was decreased from 7.424 to 7.377 without significant change in PACO2, the mean deltaV40 increased from 18.0 to 55.9 1/min. Conversely, when mean PACO2 was altered between 33.8 and 41.6 Torr with pHa held relatively constant, the mean deltaV40 did not change. This suggests that it is the H+ and not CO2 which interacts with hypoxia in stimulating the ventilation of man. An additional finding was that the intrinsic sensitivity of the peripheral chemoreceptors to acute hypoxia did not change during 24 h of acclimatization to high altitude.

Differential role of the paraventricular nucleus of the hypothalamus in modulating the sympathoexcitatory component of peripheral and central chemoreflexes

2005 ◽  
Vol 289 (3) ◽  
pp. R789-R797 ◽  
Author(s):  
Maram K. Reddy ◽  
Kaushik P. Patel ◽  
Harold D. Schultz
Keyword(s):  
Paraventricular Nucleus ◽  
Potassium Cyanide ◽  
Reflex Response ◽  
Nerve Activity ◽  
Peripheral Chemoreceptor ◽  
Peripheral Chemoreceptors ◽  
Arterial Blood ◽  
Central Chemoreceptors ◽  
Stimulation Of

In the present study we investigated the involvement of the hypothalamic paraventricular nucleus (PVN) in the modulation of sympathoexcitatory reflex activated by peripheral and central chemoreceptors. We measured mean arterial blood pressure (MAP), heart rate (HR), renal sympathetic nerve activity (RSNA), and phrenic nerve activity (PNA) before and after blocking neurotransmission within the PVN by bilateral microinjection of 2% lidocaine (100 nl) during specific stimulation of peripheral chemoreceptors by potassium cyanide (KCN, 75 μg/kg iv, bolus dose) or stimulation of central chemoreceptors with hypercapnia (10% CO2). Typically stimulation of peripheral chemoreceptors evoked a reflex response characterized by an increase in MAP, RSNA, and PNA and a decrease in HR. Bilateral microinjection of 2% lidocaine into the PVN had no effect on basal sympathetic and cardiorespiratory variables; however, the RSNA and PNA responses evoked by peripheral chemoreceptor stimulation were attenuated ( P < 0.05). Bilateral microinjection of bicuculline (50 pmol/50 nl, n = 5) into the PVN augmented the RSNA and PNA response to peripheral chemoreceptor stimulation ( P < 0.05). Conversely, the GABA agonist muscimol (0.2 nmol/50 nl, n = 5) injected into the PVN attenuated these reflex responses ( P < 0.05). Blocking neurotransmission within the PVN had no effect on the hypercapnia-induced central chemoreflex responses in carotid body denervated animals. These results suggest a selective role of the PVN in processing the sympathoexcitatory and ventilatory component of the peripheral, but not central, chemoreflex.

Sign in / Sign up

Export Citation Format

Share Document