Recovery of breathing pattern after 15 min of cerebral ischemia in rabbits

Pluta, Ryszard; Romaniuk, J. R.

doi:10.1152/jappl.1990.69.5.1676

Cited by 8 publications

(7 citation statements)

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“…Changing tracheal pressure between 1 and 10 cmH 2 O in the in situ preparation altered the phrenic pattern in a manner consistent with the Hering-Breuer expiratory-promoting reflex observed during eupnea in vivo in rats and other mammals (5,7,8,13,19,20,33,34). Thus we presume that increasing tracheal pressure altered the phrenic pattern through tonic activation of slowly adapting pulmonary stretch receptors via the Hering-Breuer reflex mechanism.…”

Section: Discussionsupporting

confidence: 71%

“…Scale bar, 2 s. and gasping are modified by the activation of pulmonary stretch receptors. This finding is important as the gasping respiratory pattern is generally considered to be insensitive to modulatory influences and specifically regarded as uninfluenced by vagal feedback (1,10,11,20,22). Our results demonstrate that the presumption concerning gasping is not accurate.…”

Section: Discussionmentioning

confidence: 99%

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Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

Harris

John

2003

American Journal of Physiology-Regulatory, Integrative and Comp

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Harris, Michael B. and Walter M. St.-John. Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation. Am J Physiol Regul Integr Comp Physiol 285: R215-R221, 2003. First published March 6, 2003 10.1152/ajpregu.00112.2003.-The perfused in situ juvenile rat preparation produces phrenic discharge patterns comparable to eupnea and gasping in vivo. These ventilatory patterns of eupnea and gasping differ in multiple aspects, including most prominently the rate of rise of inspiratory activity. Because gasping, but not eupnea, appeared similar after vagotomy in spontaneous breathing preparations, it has been assumed that gasping was unresponsive to afferent stimuli from pulmonary stretch receptors. In the present study, efferent activity of the phrenic nerve was recorded during eupnea and gasping in the in situ juvenile rat preparation. Gasping was induced in hypoxichypercapnia or ischemia. An increase in the pressure of tonic lung inflation from 1 to 10 cmH2O caused a prolongation of the duration between phrenic bursts in both eupnea or gasping. Bilateral vagotomy eliminated these changes. We conclude that the neural substrate mediating the Hering-Breuer reflex is retained in the in situ preparation and that the brain stem circuitry generating the respiratory patterns responds to tonic activation of pulmonary stretch receptors in a similar manner in eupnea and gasping. These findings support the homology of eupnea-like phrenic discharge patterns in the reduced in situ preparation and eupnea in vivo and disprove the common supposition that gasping is insensitive to vagal afferent feedback from pulmonary stretch receptor mechanisms.Hering-Breuer; slowly adapting pulmonary stretch receptors; vagus; eupnea; gasp THE IN SITU juvenile rat brain stem preparation exhibits an incrementing phrenic discharge pattern similar to eupnea in vivo (15)(16)(17)28). With severe hypoxia or ischemia, the eupnea-like discharge pattern is replaced by a decrementing pattern similar to gasping in vivo (28,29,31).Afferent fibers from slowly adapting pulmonary stretch receptors project to the brain stem through the vagus nerve. Pulmonary afferent information is integrated within the brain stem and modulates the activity of brain stem respiratory neurons (2,6,7,9,35). The most commonly recognized influences of pulmonary stretch receptor feedback on eupneic breathing are the Hering-Breuer reflexes. Phasic pulmonary inflation and vagal feedback act primarily to regulate the resting breathing pattern by modulating the duration and volume of inspiration (3, 4; see Refs. 5 and 13 for review). Tonic pulmonary inflation and vagal feedback primarily regulate the duration of expiration and have little or no influence on either the inspiratory duration or tidal volume (5,8,13,19,33). Ventilatory responses to stimuli that mimic tonic slowly adapting pulmonary stretch receptor activation are described as a HeringBreuer expiratory-promoting reflex. The duration of expiration generally increases and the breathin...

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Section: Discussionsupporting

confidence: 71%

Section: Discussionmentioning

confidence: 99%

Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

Harris

John

2003

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Vagal reactivity predominantly regulates the resistance of peripheral airways during inspiration (6). The HeringBreuer reflex may be abolished during acutely developed cerebral ischemia and restored by recovery of ischemic cerebral processes (1,20). In the present study, it is shown that SAH causes not only cerebral ischemic insult, but also brainstem and cranial nerve injuries.…”

Section: Discussionmentioning

confidence: 50%

“…In late phase SAH, irreversible axonal injury may mimic a blockade of the vagal nerves. The HeringBreuer reflex may be abolished during acutely developed cerebral ischemia and restored by recovery of ischemic cerebral processes (1,20). It is well known that axon density of vagal nerves plays an important role in their activities (14).…”

Section: Introductionmentioning

confidence: 99%

The role of vagal nerve root injury on respiration disturbances in subarachnoid hemorrhage

Çakır¹,

Atalay²,

Çakır³

et al. 2014

Turkish Neurosurgery

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AIm:We examined whether there is a relationship between vagal nerve root injury and the severity of respiration disorders associated with subarachnoid hemorrhage (SAH). mAterIAl and methOds:This study was conducted on 20 rabbits. Experimental SAH was induced by injecting homologous blood into the cisterna magna. During the experiment, electrocardiography and respiratory rhythms were measured daily. After the experiment, any axonal injury or changes to the arterial nervorums of the vagal nerves were examined. All respiratory irregularities and vagal nerve degenerations were statistically analyzed.results: Normal respiration rate, as measured in the control group, was 30±6 bpm. In the SAH-induced group, respiration rates were initially 20±4 bpm, increasing to 40±9/min approximately ten hours later, with severe tachypneic and apneic variation. In histopathological examinations, axon density of vagal nerves was 28500±5500 in both control and sham animals, whereas axon density was 22250±3500 in survivors and 16450±2750 in dead SAH animals. The severity of axonal degeneration of vagal nerves was greater in the six dead animals than in the survivors.COnClusIOn: If vagal nerves are lesioned, the muscles of respiration are paralyzed and respiratory reflexes are disrupted. That the ischemic and mechanical factors created by SAH cause vagal nerve root injury and respiration disorders may be inevitable and fatal. BulGulAr: Kontrol grubunda ölçüldüğü şekilde normal solunum hızı 30±6 dk şeklindeydi. SAK indüklenmiş grupta solunum hızları başlangıçta 20±4 dk iken, on saat sonrasında şiddetli takipneik ve apneik varyasyonla 40±9/dk değerine yükseldi. Histopatolojik incelemelerde vagal sinirlerin akson yoğunluğu hem kontrol hem taklit (sham) deneklerinde 28500±5500 iken yaşayan SAK deneklerinde 22250±3500 ve ölü SAK deneklerinde 16450±2750 bulundu. Vagal sinirlerde aksonal dejenerasyonun şiddeti 6 ölü denekte yaşayanlardan daha fazlaydı. sOnuÇ: Vagal sinirlerde lezyon oluşursa, solunum kasları felce uğrar ve solunum refleksleri bozulur. SAK'nın oluşturduğu iskemik ve mekanik faktörlerin vagal sinir kök hasarı ve solunum bozuklukları oluşturması kaçınılmaz ve ölümcül olabilir.

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“…One study reported a seeming lack of influence of pulmonary inflations on gasping (29). However, in this study, evaluations were performed during the recovery from prolonged cerebral ischemia and apnea.…”

Section: Discussionmentioning

confidence: 92%

Phasic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

Harris

John

2005

American Journal of Physiology-Regulatory, Integrative and Comp

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The perfused in situ juvenile rat preparation produces patterns of phrenic discharge comparable to eupnea and gasping in vivo. These ventilatory patterns differ in multiple aspects, including most prominently the rate of rise of inspiratory activity. Although we have recently demonstrated that both eupnea and gasping are similarly modulated by a Hering-Breuer expiratory-promoting reflex to tonic pulmonary stretch, it has generally been assumed that gasping was unresponsive to afferent stimuli from pulmonary stretch receptors. In the present study, we recorded eupneic and gasplike efferent activity of the phrenic nerve in the in situ juvenile rat perfused brain stem preparation, with and without phrenic-triggered phasic pulmonary inflation. We tested the hypothesis that phasic pulmonary inflation produces reflex responses in situ akin to those in vivo and that both eupnea and gasping are similarly modulated by phasic pulmonary stretch. In eupnea, we found that phasic pulmonary inflation decreases inspiratory burst duration and the period of expiration, thus increasing burst frequency of the phrenic neurogram. Phasic pulmonary inflation also decreases the duration of expiration and increases the burst frequency during gasping. Bilateral vagotomy eliminated these changes. We conclude that the neural substrate mediating the Hering-Breuer reflex is retained in the in situ preparation and that the brain stem circuitry generating the respiratory patterns respond to phasic activation of pulmonary stretch receptors in both eupnea and gasping. These findings support the homology of eupneic phrenic discharge patterns in the reduced in situ preparation and eupnea in vivo and disprove the common supposition that gasping is insensitive to vagal afferent feedback from pulmonary stretch receptor mechanisms.

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Recovery of breathing pattern after 15 min of cerebral ischemia in rabbits

Cited by 8 publications

References 0 publications

Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

Tonic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

The role of vagal nerve root injury on respiration disturbances in subarachnoid hemorrhage

Phasic pulmonary stretch receptor feedback modulates both eupnea and gasping in an in situ rat preparation

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