Synaptic connections between medullary respiratory neurons and considerations on the genesis of respiratory rhythm

Ezure, Kazuhisa

doi:10.1016/0301-0082(90)90030-k

Cited by 351 publications

(286 citation statements)

References 105 publications

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“…How do animals use the same muscles to generate such various different behaviors? During normal breathing, laryngeal motoneurons are driven by outputs from the brainstem respiratory circuitry, which generates the breathing rhythm and breathing activity of respiratory muscles (Ezure, 1990;Ono et al, 2006). Most of the central pattern generators (CPGs) are not dedicated to producing a fixed motor pattern, but can assume different functional configurations and produce various motor patterns according to afferent inputs (Morton and Chiel, 1994;Dickinson, 1995;Marder and Calabrese, 1996).…”

Section: Introductionmentioning

confidence: 99%

Multifunctional Laryngeal Premotor Neurons: Their Activities during Breathing, Coughing, Sneezing, and Swallowing

Shiba¹,

Nakazawa²,

Ono³

et al. 2007

J. Neurosci.

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To examine whether motor commands of two or more distinct laryngeal motor patterns converge onto a common premotor network, we conducted dual recordings from the laryngeal adductor motoneuron and its premotor neuron within the brainstem respiratory circuitry during fictive breathing, coughing, sneezing, and swallowing in decerebrate paralyzed cats. Expiratory neurons with an augmenting firing pattern (EAUG), whose action potentials evoked monosynaptic IPSPs in the adductor motoneurons, sharply fired during the expulsive phases of fictive coughing and sneezing, during which the adductor motoneurons transiently repolarized. In contrast, these premotor neurons were silent during the swallow-related hyperpolarization in adductor motoneurons. These results show that one class of medullary respiratory neuron, EAUG, is multifunctional and shared among the central pattern generators (CPGs) for breathing, coughing, and sneezing. In addition, although the CPGs underlying these three behaviors and the swallowing CPG do overlap, EAUG neurons are not part of the swallowing CPG and, in contrast to the other three behaviors, are not a source of inhibitory input to adductor motoneurons during swallowing.

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Section: Introductionmentioning

confidence: 99%

Multifunctional Laryngeal Premotor Neurons: Their Activities during Breathing, Coughing, Sneezing, and Swallowing

Shiba¹,

Nakazawa²,

Ono³

et al. 2007

J. Neurosci.

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“…The results suggest that larger numbers of respiratory center neurons may be excited to encourage the compensatory respiratory movement adaptation and to restore satisfactory respiratory function after phrenicotomy for the maintenance of the normal respiratory conditions Furthermore, in the present study, the numbers of c-Fos-ir neurons were markedly greater in VRG than in DRG. Respiratory neurons are known to be widely distributed in these two regions in the medulla oblongata [25][26][27][28][29] . DRG neurons mainly consist of augmenting types of inspiratory neurons, …”

Section: Discussionmentioning

confidence: 99%

“…Some descend to the spinal cord and inhibit the activity of phrenic nerve cells 32) . The majority of rVRG (≥80%) consists of inspiratory neurons, accompanied with other cells including augmenting types of expiratory neurons 27,33) . The pre-BÖT (the rostral end of the rVRG that is in contact with the BÖT) consists of cell groups exhibiting various discharge patterns 29,34) .…”

Section: Phrenicotomy Rats Control Ratsmentioning

confidence: 99%

“…The pre-BÖT (the rostral end of the rVRG that is in contact with the BÖT) consists of cell groups exhibiting various discharge patterns 29,34) . The caudal area mostly comprises augmenting types of expiratory neurons that discharge during the second expiratory phase, accompanied by small numbers of decrementing types of inspiratory neurons and decrementing types of expiratory neurons 27,33) . The axons of these augmenting types of expiratory neurons project onto the thoracic and lumbar spinal cords and drive the expiratory muscles.…”

Section: Phrenicotomy Rats Control Ratsmentioning

confidence: 99%

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Changes in Neuronal Expression of c-Fos Protein in the Medulla Oblongata after Unilateral Phrenicotomy in Wistar Rats

Tomita

Takayama

2008

J Phys Ther Sci

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Abstract.[Purpose] The purpose of this study was to examine changes in neuronal expression of c-Fos protein in the medulla oblongata after unilateral phrenicotomy in Wistar rats. [Subjects and Methods] After left side phrenicotomy, rats were maintained for 4 weeks (test experiments), then transcardially perfused with fixatives. Brain sections were prepared, and c-Fos protein induced in neurons in the medulla oblongata was immunohistochemically stained by the ABC method. Control rats were maintained for the same period after sham operation, and the brain sections were similarly processed as in the test experiments.[Results] The number of c-Fos immunoreactive (c-Fos-ir) neurons in the medulla oblongata was counted and their spatial distributions were mapped. In both sides of the ventral respiratory group (VRG) and the left side of dorsal respiratory group (DRG), numbers of c-Fos-ir neurons were significantly increased in phrenicotomy rats compared to the control rats (P<0.05). In the right side of the DRG, the number of cFos-ir neurons also increased but without statistical significance. Numbers of c-Fos-ir neurons in the VRG were greater than that in the DRG.[Conclusion] The present results suggest that phrenicotomy may result in an increase in the activity of medullary respiratory neurons during the recovery of respiration after the phrenicotomy. The specific activation of the neurons in the VRG and DRG during unilateral phrenic nerve paralysis could underlie the changes in regulation of the respiratory control center following unilateral phrenicotomy.

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“…O conhecimento desse padrão formado por 3 fases levou a uma série de estudos que se iniciaram em 1970 por Richter e colaboradores em gatos anestesiados utilizando registros intracelulares (RICHTER, 1982). Esses estudos demonstraram que, durante o processo respiratório, atividades fásicas são geradas na região ventral do bulbo sem a necessidade de uma retroalimentação periférica, envolvendo uma rede neuronal coordenada por interações sinápticas que foi chamada posteriormente de coluna respiratória ventral (SMITH et al, 1991 (GUYENET et al, 2005;MULKEY et al, 2004;TAKAKURA et al, 2006;WANG et al, 2013 2) Complexo Bötzinger, um grupamento que contém interneurônios inibitórios predominantemente expiratórios (EZURE, 1990;SCHREIHOFER;GUYENET, 1997).…”

Section: Mecanismos Encefálicos De Controle Da Respiraçãounclassified

Envolvimento do núcleo Kölliker-Fuse e do núcleo parabraquial lateral no controle cardiorrespiratório promovido pela ativação dos quimiorreceptores centrais e periféricos.

Damasceno¹,

Moreira²

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The pontine nuclei, particularly the Kölliker-Fuse (KF) and the lateral parabrachial nucleus (LPBN) have been implicated in the maintenance of cardiorespiratory control. However, most of the experiments showing the role of pontine KF region were done in anesthetized animals. Here we investigated the involvement of KF region and LPBN in the cardiorespiratory responses elicited by chemoreceptor activation in conscious rats. Male Wistar rats (280-300g, n=5-9) with bilateral stainless steel guide-cannulas implanted into the KF region or LPBN were used. In conscious rats, injections of muscimol (100 and 200 pmol/100 nl) into the KF decreased resting ventilation (1140 ± 68 and 978 ± 100, vs. saline: 1436 ± 155 ml/kg/min) without change mean arterial pressure (MAP) and heart rate (HR). Bilateral injection of the GABA-A antagonist bicuculline (1 nmol/100 nl) into the KF blocked the inhibitory effect on ventilation (1418 ± 138, vs. muscimol: 978 ± 100 ml/kg/min) elicited by muscimol within the KF. Muscimol injection into the KF reduced the increase in ventilation produced by hypoxia (8% O 2 -10 min) (1827 ± 61, vs. saline: 3179 ± 325 ml/kg/min) or hypercapnia (7% CO 2 -10 min) (1488 ± 277, vs. saline: 3539 ± 374 ml/kg/min) in unanesthetized rats. Bilateral injection of bicuculline into the KF was able to block the decrease in ventilation produced by muscimol into the KF during peripheral or central chemoreflex activation. Bilateral injection of muscimol into the LPBN did not change resting ventilation, or the increase in ventilation elicited by hypoxia or hypercapnia. The injection of muscimol into the LPBN increased resting MAP (119 ± 2, vs. saline: 104 ± 2 mmHg), without change resting HR. Muscimol into the LPBN did not change the increase in ventilation elicited by hypoxia or hypercapnia in unanesthetized rats. Selective bilateral lesion with antidopamine-β-hydroxylase-saporin (anti-DβH-SAP) into the A7 region promoted a reduction of hyperventilation (1667 ± 180, vs. saline: 2209 ± 358 ml/kg/min), without changing the tachycardia (471 ± 18, vs. saline: 509 ± 12 bpm) elicited by hypoxia (8% O 2 -10 min) in unanesthetized rats. Bilateral injection of anti-DβH-SAP into the A7 region was able to attenuate the hypotension elicited by hypoxia (112 ± 3, vs. saline: 99 ± 5 mmHg). Anti-DβH-SAP into the A7 region was also able to reduce hyperventilation (1513 ± 167 vs saline: ± 144 2333 ml/kg/min) elicited by hypercapnia (7% CO2 -10 min) in unanesthetized rats. The results of the present study suggest that KF region, but not LPBN, have mechanisms to control the ventilation in resting, hypoxic or hypercapnic conditions in conscious rats.

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Synaptic connections between medullary respiratory neurons and considerations on the genesis of respiratory rhythm

Cited by 351 publications

References 105 publications

Multifunctional Laryngeal Premotor Neurons: Their Activities during Breathing, Coughing, Sneezing, and Swallowing

Multifunctional Laryngeal Premotor Neurons: Their Activities during Breathing, Coughing, Sneezing, and Swallowing

Changes in Neuronal Expression of c-Fos Protein in the Medulla Oblongata after Unilateral Phrenicotomy in Wistar Rats

Envolvimento do núcleo Kölliker-Fuse e do núcleo parabraquial lateral no controle cardiorrespiratório promovido pela ativação dos quimiorreceptores centrais e periféricos.

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