Carotid body excision significantly changes ventilatory control in awake rats

Olson, E. B.; Vidruk, Edward H.; Dempsey, Jerome A.

doi:10.1152/jappl.1988.64.2.666

Cited by 67 publications

(63 citation statements)

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“…In intact rats breathing room air, blood gases were as previously reported for quietly resting unstressed rats (Olson et al, 1988a). Weight normalized values for basal ventilation on room air were similar to prior published values for the same rat strain (Strohl et al, 1997;Mouradian et al, 2012).…”

Section: Recovery Of Normal Ventilation and Blood Gases A Week After supporting

confidence: 84%

“…Further support for this hypothesis is that hyperoxia, which is assumed to silence the carotid bodies, produces very little hypopnea in intact rodents (present results and (Olson et al, 1988a;Basting et al, 2015)). …”

Section: Central Chemoreflex Plasticity After Carotid Body Denervatiosupporting

confidence: 74%

“…This recovery took ten weeks in one study (Olson et al, 1988a), between four and ten days in another (Mouradian et al, 2012). In the present study blood gases in resting rats breathing room air were at control levels seven days after CBD while the hypoxic ventilatory reflex was still greatly depressed.…”

Section: Recovery Of Normal Ventilation and Blood Gases A Week After supporting

confidence: 43%

“…The surgical procedure used to remove the carotid bodies and their innervation may influence the degree and duration of the subsequent hypoventilation and hypercapnia (Olson et al, 1988a;Mouradian et al, 2012). Therefore, collateral damage to structures other than the carotid bodies may also contribute to the breathing changes.…”

Section: Introductionmentioning

confidence: 99%

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Neural Control of Respiration by the Retrotrapezoid Nucleus.

Basting¹

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Rationale and objectives: Central respiratory chemoreceptors (CRCs) detect brain PaCO 2 and adjust lung ventilation to maintain PaCO 2 and pH constant regardless of the absolute level of lung ventilation. They perform this function in cooperation with the carotid bodies, sensory organs that respond to hypoxia in a pH-dependent manner. The existence of CRCs has been known for over a century but their cellular nature and location have remained highly controversial until recently. The retrotrapezoid nucleus (RTN), a collection of ~2000 glutamatergic neurons in rats that are activated by hypercapnia in vivo and by acidification in slices, had been identified as a CRC candidate just prior to my PhD work. My first objective was to seek additional and critical evidence that RTN neurons are CRCs by determining whether these neurons stimulate breathing in proportion to arterial PCO 2 in intact unanesthetized rats.Having verified that this was the case I tested a logical corollary of this theory namely that RTN is silenced under hypoxic conditions due to respiratory alkalosis. Then I proceeded to test whether RTN neurons sustain breathing automaticity during sleep. Finally, I tested whether RTN compensates for the lack peripheral chemoreceptor input.Methods: RTN neurons were bilaterally transduced to express the proton pump archaerhodopsin using a lentiviral vector. Using anesthetized rats, I confirmed that RTN neurons were silenced by activating archaerhodopsin with green light. I examined the effect of short periods of RTN inhibition (10s) on breathing (plethysmography), EEG and neck EMG in conscious rats in which arterial pH was changed by exposing the animals to various FiO 2 levels alone or with the addition of 3% FiCO 2 or acetazolamide (ACTZ). Rats were studied in different states of vigilance (quiet awake/non-REM/REM). Arterial blood gases (PaO 2 , PaCO 2 ), pHa and HCO 3 were measured under each condition.ii Results: RTN inhibition (bilateral) reduced breathing frequency and amplitude in direct proportion to arterial plasma pH (pHa) below a threshold of 7.53. Above this level, RTN inhibition had no effect suggesting that the nucleus was silent. In normoxia, RTN inhibition reduced breathing equally during non-REM sleep and quiet wake. By contrast RTN inhibition had very little effect on breathing during REM sleep.Conclusions: RTN drives breathing in direct proportion to arterial PCO 2 in intact unaesthetized rats, consistent with the theory that these neurons are CRCs. RTN neurons are silent above pHa 7.5 and increasingly active below this value. RTN regulates breathing automaticity about equally during non-REM sleep and quiet waking, conditions under which the respiratory pattern generator is autorhythmic. By contrast, RTN has a much reduced influence on breathing during Viar for surgery skills, science advice, life advice, wanted/unwanted music advice and so much more. Together, they made a dynamic group of personalities that provided a stimulating and encouraging atmosphere that will never be forgotten....

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Section: Recovery Of Normal Ventilation and Blood Gases A Week After supporting

confidence: 84%

Section: Central Chemoreflex Plasticity After Carotid Body Denervatiosupporting

confidence: 74%

Section: Recovery Of Normal Ventilation and Blood Gases A Week After supporting

confidence: 43%

Section: Introductionmentioning

confidence: 99%

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Neural Control of Respiration by the Retrotrapezoid Nucleus.

Basting¹

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“…3'26'28'30 tes rares donn6es de la litt6rature sont en accord avec ce que l'on conna~t des effets respiratoires de anesth6siques, chez les autres esp6ces animales et chez l'homme: ranesth6sie entra3ne une diminution de PaOz et une augmentation de PaCO2. Les effets de la ch6mod6nervation sur les gaz du sang art6riel chez le rat 6veill6, observ6s dans la pr6sente 6tude, sont tout A fait comparables A ceux rapport6s par Olson et aL 29 Ces auteurs, chez 36 rats, ont not6 les valeurs suivantes: pHa ---7,403 -t-0,004; PaO2 = 81,0 + 2,3 mmHg, PaCO2 = 48,4 -I-1,1 mmHg; HCO3-= 29,8 + 6,7 mmol. L-L Les modifications des gaz du sang provoqu6es par la ch6mod6nervadon s'expliquent par une hypoventilation alv6olaire, ainsi que l'ont montr6 MartinBody et al io Ces auteurs, ufilisant la m~me technique de d6nervafion que nous, ont observ6 une diminution significafive de la ventilation minute (-19,7%), du volume courant (-9,8%), et de la fr6quence respiratoire (-13,3%).…”

Section: Discussionunclassified

Effets de l’halothane sur les gaz du sang et l’équilibre acido-basique artériels chez le rat intact et chez le rat chémodénervé

et al. 1993

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Central respiratory chemoreception

Guyenet¹,

Stornetta²,

Bayliss³

2010

J of Comparative Neurology

211

187

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Summary By definition central respiratory chemoreceptors (CRCs) are cells that are sensitive to changes in brain PCO2 or pH and contribute to the stimulation of breathing elicited by hypercapnia or metabolic acidosis. CO2 most likely works by lowering pH. The pertinent proton receptors have not been identified and may be ion channels. CRCs are probably neurons but may also include acid-sensitive glia and vascular cells that communicate with neurons via paracrine mechanisms. Retrotrapezoid nucleus (RTN) neurons are the most completely characterized CRCs. Their high sensitivity to CO2 in vivo presumably relies on their intrinsic acid-sensitivity, excitatory inputs from the carotid bodies and brain regions such as raphe and hypothalamus, and facilitating influences from neighboring astrocytes. RTN neurons are necessary for the respiratory network to respond to CO2 during the perinatal period and under anesthesia. In conscious adults, RTN neurons contribute to an unknown degree to the pH-dependent regulation of breathing rate, inspiratory and expiratory activity. The abnormal prenatal development of RTN neurons probably contributes to the congenital central hypoventilation syndrome. Other CRCs presumably exist but the supportive evidence is less complete. The proposed locations of these CRCs are the medullary raphe, the nucleus tractus solitarius, the ventrolateral medulla, the fastigial nucleus and the hypothalamus. Several wake-promoting systems (serotonergic and catecholaminergic neurons, orexinergic neurons) are also putative CRCs. Their contribution to central respiratory chemoreception may be behavior-dependent or vary according to the state of vigilance.

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Carotid body excision significantly changes ventilatory control in awake rats

Cited by 67 publications

References 0 publications

Neural Control of Respiration by the Retrotrapezoid Nucleus.

Neural Control of Respiration by the Retrotrapezoid Nucleus.

Effets de l’halothane sur les gaz du sang et l’équilibre acido-basique artériels chez le rat intact et chez le rat chémodénervé

Central respiratory chemoreception

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