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Horcholle-Bossavit G, Quenet B. Neural network model of an amphibian ventilatory central pattern generator. J Comput Neurosci 2019; 46:299-320. [PMID: 31119525 DOI: 10.1007/s10827-019-00718-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 04/25/2019] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
The neuronal multiunit model presented here is a formal model of the central pattern generator (CPG) of the amphibian ventilatory neural network, inspired by experimental data from Pelophylax ridibundus. The kernel of the CPG consists of three pacemakers and two follower neurons (buccal and lung respectively). This kernel is connected to a chain of excitatory and inhibitory neurons organized in loops. Simulations are performed with Izhikevich-type neurons. When driven by the buccal follower, the excitatory neurons transmit and reorganize the follower activity pattern along the chain, and when driven by the lung follower, the excitatory and inhibitory neurons of the chain fire in synchrony. The additive effects of synaptic inputs from the pacemakers on the buccal follower account for (1) the low frequency buccal rhythm, (2) the intra-burst high frequency oscillations, and (3) the episodic lung activity. Chemosensitivity to acidosis is implemented by an increase in the firing frequency of one of the pacemakers. This frequency increase leads to both a decrease in the buccal burst frequency and an increase in the lung episode frequency. The rhythmogenic properties of the model are robust against synaptic noise and pacemaker jitter. To validate the rhythm and pattern genesis of this formal CPG, neurograms were built from simulated motoneuron activity, and compared with experimental neurograms. The basic principles of our model account for several experimental observations, and we suggest that these principles may be generic for amphibian ventilation.
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Affiliation(s)
- Ginette Horcholle-Bossavit
- Équipe de Statistique Appliquée, ESPCI-Paris, PSL Research University, F-75005, Paris, France.,Neurophysiologie respiratoire expérimentale et clinique, INSERM, UMRS1158, Sorbonne Université, F-75005, Paris, France
| | - Brigitte Quenet
- Équipe de Statistique Appliquée, ESPCI-Paris, PSL Research University, F-75005, Paris, France. .,Neurophysiologie respiratoire expérimentale et clinique, INSERM, UMRS1158, Sorbonne Université, F-75005, Paris, France.
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Reed MD, Iceman KE, Harris MB, Taylor BE. The rostral medulla of bullfrog tadpoles contains critical lung rhythmogenic and chemosensitive regions across metamorphosis. Comp Biochem Physiol A Mol Integr Physiol 2018; 225:7-15. [PMID: 29890210 DOI: 10.1016/j.cbpa.2018.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/14/2018] [Accepted: 05/30/2018] [Indexed: 11/18/2022]
Abstract
The development of amphibian breathing provides insight into vertebrate respiratory control mechanisms. Neural oscillators in the rostral and caudal medulla drive ventilation in amphibians, and previous reports describe ventilatory oscillators and CO2 sensitive regions arise during different stages of amphibian metamorphosis. However, inconsistent findings have been enigmatic, and make comparisons to potential mammalian counterparts challenging. In the current study we assessed amphibian central CO2 responsiveness and respiratory rhythm generation during two different developmental stages. Whole-nerve recordings of respiratory burst activity in cranial and spinal nerves were made from intact or transected brainstems isolated from tadpoles during early or late stages of metamorphosis. Brainstems were transected at the level of the trigeminal nerve, removing rostral structures including the nucleus isthmi, midbrain, and locus coeruleus, or transected at the level of the glossopharyngeal nerve, removing the putative buccal oscillator and caudal medulla. Removal of caudal structures stimulated the frequency of lung ventilatory bursts and revealed a hypercapnic response in normally unresponsive preparations derived from early stage tadpoles. In preparations derived from late stage tadpoles, removal of rostral or caudal structures reduced lung burst frequency, while CO2 responsiveness was retained. Our results illustrate that structures within the rostral medulla are capable of sensing CO2 throughout metamorphic development. Similarly, the region controlling lung ventilation appears to be contained in the rostral medulla throughout metamorphosis. This work offers insight into the consistency of rhythmic respiratory and chemosensitive capacities during metamorphosis.
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Affiliation(s)
- Mitchell D Reed
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, United States.
| | - Kimberly E Iceman
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Department of Biology, Valparaiso University, Valparaiso, IN 46383, United States
| | - Michael B Harris
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Department of Biological Sciences, California State University Long Beach, Long Beach, CA 90840, United States
| | - Barbara E Taylor
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Department of Biological Sciences, California State University Long Beach, Long Beach, CA 90840, United States
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Oudiette D, Dodet P, Ledard N, Artru E, Rachidi I, Similowski T, Arnulf I. REM sleep respiratory behaviours mental content in narcoleptic lucid dreamers. Sci Rep 2018; 8:2636. [PMID: 29422603 PMCID: PMC5805737 DOI: 10.1038/s41598-018-21067-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/29/2018] [Indexed: 11/13/2022] Open
Abstract
Breathing is irregular during rapid eye-movement (REM) sleep, whereas it is stable during non-REM sleep. Why this is so remains a mystery. We propose that irregular breathing has a cortical origin and reflects the mental content of dreams, which often accompany REM sleep. We tested 21 patients with narcolepsy who had the exceptional ability to lucid dream in REM sleep, a condition in which one is conscious of dreaming during the dream and can signal lucidity with an ocular code. Sleep and respiration were monitored during multiple naps. Participants were instructed to modify their dream scenario so that it involved vocalizations or an apnoea, -two behaviours that require a cortical control of ventilation when executed during wakefulness. Most participants (86%) were able to signal lucidity in at least one nap. In 50% of the lucid naps, we found a clear congruence between the dream report (e.g., diving under water) and the observed respiratory behaviour (e.g., central apnoea) and, in several cases, a preparatory breath before the respiratory behaviour. This suggests that the cortico-subcortical networks involved in voluntary respiratory movements are preserved during REM sleep and that breathing irregularities during this stage have a cortical/subcortical origin that reflects dream content.
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Affiliation(s)
- Delphine Oudiette
- Sorbonne Université, IHU@ICM, INSERM, CNRS UMR7225, équipe MOV'IT, F-75013 Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France
| | - Pauline Dodet
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France
| | - Nahema Ledard
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France
| | - Emilie Artru
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France
| | - Inès Rachidi
- AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France
| | - Thomas Similowski
- Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013 Paris, France.,AP-HP, Hôpital Pitié-Salpêtrière, Service de Pneumologie et Réanimation Médicale (Département "R3S"), F-75013, Paris, France
| | - Isabelle Arnulf
- Sorbonne Université, IHU@ICM, INSERM, CNRS UMR7225, équipe MOV'IT, F-75013 Paris, France. .,AP-HP, Hôpital Pitié-Salpêtrière, Service des Pathologies du Sommeil (Département "R3S"), F-75013 Paris, France.
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Samson N, Praud JP, Quenet B, Similowski T, Straus C. New insights into sucking, swallowing and breathing central generators: A complexity analysis of rhythmic motor behaviors. Neurosci Lett 2016; 638:90-95. [PMID: 27956236 DOI: 10.1016/j.neulet.2016.12.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/25/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022]
Abstract
Sucking, swallowing and breathing are dynamic motor behaviors. Breathing displays features of chaos-like dynamics, in particular nonlinearity and complexity, which take their source in the automatic command of breathing. In contrast, buccal/gill ventilation in amphibians is one of the rare motor behaviors that do not display nonlinear complexity. This study aimed at assessing whether sucking and swallowing would also follow nonlinear complex dynamics in the newborn lamb. Breathing movements were recorded before, during and after bottle-feeding. Sucking pressure and the integrated EMG of the thyroartenoid muscle, as an index of swallowing, were recorded during bottle-feeding. Nonlinear complexity of the whole signals was assessed through the calculation of the noise limit value (NL). Breathing and swallowing always exhibited chaos-like dynamics. The NL of breathing did not change significantly before, during or after bottle-feeding. On the other hand, sucking inconsistently and significantly less frequently than breathing exhibited a chaos-like dynamics. Therefore, the central pattern generator (CPG) that drives sucking may be functionally different from the breathing CPG. Furthermore, the analogy between buccal/gill ventilation and sucking suggests that the latter may take its phylogenetic origin in the gill ventilation CPG of the common ancestor of extant amphibians and mammals.
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Affiliation(s)
- Nathalie Samson
- Neonatal Respiratory Research Unit, Department of Pediatric and Pharmacology-Physiology, Université de Sherbrooke, Qc, Canada
| | - Jean-Paul Praud
- Neonatal Respiratory Research Unit, Department of Pediatric and Pharmacology-Physiology, Université de Sherbrooke, Qc, Canada
| | - Brigitte Quenet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; Equipe de Statistique Appliquée ESPCI-Paris, PSL Research University, Paris, France
| | - Thomas Similowski
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service de Pneumologie et Réanimation Médicale (Département R3S), F-75013, Paris, France
| | - Christian Straus
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Service d'Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département R3S), F-75013, Paris, France.
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Ranohavimparany A, Bautin N, Fiamma MN, Similowski T, Straus C. Source of ventilatory complexity in the postmetamorphic tadpole brainstem, Pelophylax ridibundus: A pharmacological study. Respir Physiol Neurobiol 2016; 224:27-36. [DOI: 10.1016/j.resp.2014.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/22/2014] [Accepted: 11/06/2014] [Indexed: 10/24/2022]
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Diving into the mammalian swamp of respiratory rhythm generation with the bullfrog. Respir Physiol Neurobiol 2015; 224:37-51. [PMID: 26384027 DOI: 10.1016/j.resp.2015.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 11/20/2022]
Abstract
All vertebrates produce some form of respiratory rhythm, whether to pump water over gills or ventilate lungs. Yet despite the critical importance of ventilation for survival, the architecture of the respiratory central pattern generator has not been resolved. In frogs and mammals, there is increasing evidence for multiple burst-generating regions in the ventral respiratory group. These regions work together to produce the respiratory rhythm. However, each region appears to be pivotally important to a different phase of the motor act. Regions also exhibit differing rhythmogenic capabilities when isolated and have different CO2 sensitivity and pharmacological profiles. Interestingly, in both frogs and rats the regions with the most robust rhythmogenic capabilities when isolated are located in rhombomeres 7/8. In addition, rhombomeres 4/5 in both clades are critical for controlling phases of the motor pattern most strongly modulated by CO2 (expiration in mammals, and recruitment of lung bursts in frogs). These key signatures may indicate that these cell clusters arose in a common ancestor at least 400 million years ago.
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Does trans-spinal direct current stimulation alter phrenic motoneurons and respiratory neuromechanical outputs in humans? A double-blind, sham-controlled, randomized, crossover study. J Neurosci 2015; 34:14420-9. [PMID: 25339753 DOI: 10.1523/jneurosci.1288-14.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although compelling evidence has demonstrated considerable neuroplasticity in the respiratory control system, few studies have explored the possibility of altering descending projections to phrenic motoneurons (PMNs) using noninvasive stimulation protocols. The present study was designed to investigate the immediate and long-lasting effects of a single session of transcutaneous spinal direct current stimulation (tsDCS), a promising technique for modulating spinal cord functions, on descending ventilatory commands in healthy humans. Using a double-blind, controlled, randomized, crossover approach, we examined the effects of anodal, cathodal, and sham tsDCS delivered to the C3-C5 level on (1) diaphragm motor-evoked potentials (DiMEPs) elicited by transcranial magnetic stimulation and (2) spontaneous ventilation, as measured by respiratory inductance plethysmography. Both anodal and cathodal tsDCS induced a progressive increase in DiMEP amplitude during stimulation that persisted for at least 15 min after current offset. Interestingly, cathodal, but not anodal, tsDCS induced a persistent increase in tidal volume. In addition, (1) short-interval intracortical inhibition, (2) nonlinear complexity of the tidal volume signal (related to medullary ventilatory command), (3) autonomic function, and (4) compound muscle action potentials evoked by cervical magnetic stimulation were unaffected by tsDCS. This suggests that tsDCS-induced aftereffects did not occur at brainstem or cortical levels and were likely not attributable to direct polarization of cranial nerves or ventral roots. Instead, we argue that tsDCS could induce sustained changes in PMN output. Increased tidal volume after cathodal tsDCS opens up the perspective of harnessing respiratory neuroplasticity as a therapeutic tool for the management of several respiratory disorders.
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Quenet B, Straus C, Fiamma MN, Rivals I, Similowski T, Horcholle-Bossavit G. New insights in gill/buccal rhythm spiking activity and CO(2) sensitivity in pre- and postmetamorphic tadpoles (Pelophylax ridibundus). Respir Physiol Neurobiol 2014; 191:26-37. [PMID: 24200645 DOI: 10.1016/j.resp.2013.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 11/29/2022]
Abstract
Central CO(2) chemosensitivity is crucial for all air-breathing vertebrates and raises the question of its role in ventilatory rhythmogenesis. In this study, neurograms of ventilatory motor outputs recorded in facial nerve of premetamorphic and postmetamorphic tadpole isolated brainstems, under normo- and hypercapnia, are investigated using Continuous Wavelet Transform spectral analysis for buccal activity and computation of number and amplitude of spikes during buccal and lung activities. Buccal bursts exhibit fast oscillations (20-30Hz) that are prominent in premetamorphic tadpoles: they result from the presence in periodic time windows of high amplitude spikes. Hypercapnia systematically decreases the frequency of buccal rhythm in both pre- and postmetamorphic tadpoles, by a lengthening of the interburst duration. In postmetamorphic tadpoles, hypercapnia reduces buccal burst amplitude and unmasks small fast oscillations. Our results suggest a common effect of the hypercapnia on the buccal part of the Central Pattern Generator in all tadpoles and a possible effect at the level of the motoneuron recruitment in postmetamorphic tadpoles.
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Affiliation(s)
- Brigitte Quenet
- ESPCI-ParisTech, Equipe de Statistique Appliquée, F-75005 Paris, France.
| | - Christian Straus
- UPMC Univ Paris 06, ER 10 UPMC, F-75013 Paris, France; Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Service Central d'Explorations Fonctionnelles Respiratoires, F-75013 Paris, France
| | | | - Isabelle Rivals
- ESPCI-ParisTech, Equipe de Statistique Appliquée, F-75005 Paris, France
| | - Thomas Similowski
- UPMC Univ Paris 06, ER 10 UPMC, F-75013 Paris, France; Assistance Publique - Hôpitaux de Paris, Groupe Hospitalier Pitié-Salpêtrière, Service de Pneumologie et Réanimation Médicale, F-75013 Paris, France
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Leclère R, Straus C, Similowski T, Bodineau L, Fiamma MN. Persistent lung oscillator response to CO2 after buccal oscillator inhibition in the adult frog. Respir Physiol Neurobiol 2012; 183:166-9. [PMID: 22772313 DOI: 10.1016/j.resp.2012.06.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 11/13/2022]
Abstract
The automatic ventilatory drive in amphibians depends on two oscillators interacting with each other, the gill/buccal and lung oscillators. The lung oscillator would be homologous to the mammalian pre-Bötzinger complex and the gill/buccal oscillator homologous to the mammalian parafacial respiratory group/retrotrapezoid nucleus (pFRG/RTN). Dysfunction of the pFRG/RTN has been involved in the development of respiratory diseases associated to the loss of CO(2) chemosensitivity such as the congenital central hypoventilation syndrome. Here, on adult in vitro isolated frog brainstem, consequences of the buccal oscillator inhibition (by reducing Cl(-)) were evaluated on the respiratory rhythm developed by the lung oscillator under hypercapnic challenges. Our results show that under low Cl(-) concentration (i) the buccal oscillator is strongly inhibited and the lung burst frequency and amplitude decreased and (ii) it persists a powerful CO(2) chemosensitivity. In conclusion, in frog, the CO(2) chemosensitivity depends on cellular contingent(s) whose the functioning is independent of the concentration of Cl(-) and origin remains unknown.
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Affiliation(s)
- Renaud Leclère
- UPMC Univ Paris 06, ER 10, Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013 Paris, France
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