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Venner A, Todd WD, Fraigne J, Bowrey H, Eban-Rothschild A, Kaur S, Anaclet C. Newly identified sleep-wake and circadian circuits as potential therapeutic targets. Sleep 2020; 42:5306564. [PMID: 30722061 DOI: 10.1093/sleep/zsz023] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/25/2019] [Indexed: 02/06/2023] Open
Abstract
Optogenetics and chemogenetics are powerful tools, allowing the specific activation or inhibition of targeted neuronal subpopulations. Application of these techniques to sleep and circadian research has resulted in the unveiling of several neuronal populations that are involved in sleep-wake control, and allowed a comprehensive interrogation of the circuitry through which these nodes are coordinated to orchestrate the sleep-wake cycle. In this review, we discuss six recently described sleep-wake and circadian circuits that show promise as therapeutic targets for sleep medicine. The parafacial zone (PZ) and the ventral tegmental area (VTA) are potential druggable targets for the treatment of insomnia. The brainstem circuit underlying rapid eye movement sleep behavior disorder (RBD) offers new possibilities for treating RBD and neurodegenerative synucleinopathies, whereas the parabrachial nucleus, as a nexus linking arousal state control and breathing, is a promising target for developing treatments for sleep apnea. Therapies that act upon the hypothalamic circuitry underlying the circadian regulation of aggression or the photic regulation of arousal and mood pathway carry enormous potential for helping to reduce the socioeconomic burden of neuropsychiatric and neurodegenerative disorders on society. Intriguingly, the development of chemogenetics as a therapeutic strategy is now well underway and such an approach has the capacity to lead to more focused and less invasive therapies for treating sleep-wake disorders and related comorbidities.
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Affiliation(s)
- Anne Venner
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
| | - William D Todd
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
| | - Jimmy Fraigne
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Hannah Bowrey
- Department of Psychiatry, Rutgers Biomedical Health Sciences, Rutgers University, Newark, NJ.,Save Sight Institute, The University of Sydney, Sydney, New South Wales, Australia
| | | | - Satvinder Kaur
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA.,Department of Neurology, Harvard Medical School, Boston, MA
| | - Christelle Anaclet
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, NeuroNexus Institute, Graduate Program in Neuroscience - Graduate School of Biomedical Sciences, University of Massachusetts Medical School, Worcester, MA
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2
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Kaur S, Saper CB. Neural Circuitry Underlying Waking Up to Hypercapnia. Front Neurosci 2019; 13:401. [PMID: 31080401 PMCID: PMC6497806 DOI: 10.3389/fnins.2019.00401] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/08/2019] [Indexed: 12/13/2022] Open
Abstract
Obstructive sleep apnea is a sleep and breathing disorder, in which, patients suffer from cycles of atonia of airway dilator muscles during sleep, resulting in airway collapse, followed by brief arousals that help re-establish the airway patency. These repetitive arousals which can occur hundreds of times during the course of a night are the cause of the sleep-disruption, which in turn causes cognitive impairment as well as cardiovascular and metabolic morbidities. To prevent this potential outcome, it is important to target preventing the arousal from sleep while preserving or augmenting the increase in respiratory drive that reinitiates breathing, but will require understanding of the neural circuits that regulate the cortical and respiratory responses to apnea. The parabrachial nucleus (PB) is located in rostral pons. It receives chemosensory information from medullary nuclei that sense increase in CO2 (hypercapnia), decrease in O2 (hypoxia) and mechanosensory inputs from airway negative pressure during apneas. The PB area also exerts powerful control over cortical arousal and respiration, and therefore, is an excellent candidate for mediating the EEG arousal and restoration of the airway during sleep apneas. Using various genetic tools, we dissected the neuronal sub-types responsible for relaying the stimulus for cortical arousal to forebrain arousal circuits. The present review will focus on the circuitries that regulate waking-up from sleep in response to hypercapnia.
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Affiliation(s)
- Satvinder Kaur
- Department of Neurology, Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Clifford B Saper
- Department of Neurology, Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
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3
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Geerling JC, Yokota S, Rukhadze I, Roe D, Chamberlin NL. Kölliker-Fuse GABAergic and glutamatergic neurons project to distinct targets. J Comp Neurol 2017; 525:1844-1860. [PMID: 28032634 DOI: 10.1002/cne.24164] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/16/2016] [Accepted: 10/31/2016] [Indexed: 01/01/2023]
Abstract
The Kölliker-Fuse nucleus (KF) is known primarily for its respiratory function as the "pneumotaxic center" or "pontine respiratory group." Considered part of the parabrachial (PB) complex, KF contains glutamatergic neurons that project to respiratory-related targets in the medulla and spinal cord (Yokota, Oka, Tsumori, Nakamura, & Yasui, 2007). Here we describe an unexpected population of neurons in the caudal KF and adjacent lateral crescent subnucleus (PBlc), which are γ-aminobutyric acid (GABA)ergic and have an entirely different pattern of projections than glutamatergic KF neurons. First, immunofluorescence, in situ hybridization, and Cre-reporter labeling revealed that many of these GABAergic neurons express FoxP2 in both rats and mice. Next, using Cre-dependent axonal tracing in Vgat-IRES-Cre and Vglut2-IRES-Cre mice, we identified different projection patterns from GABAergic and glutamatergic neurons in this region. GABAergic neurons in KF and PBlc project heavily and almost exclusively to trigeminal sensory nuclei, with minimal projections to cardiorespiratory nuclei in the brainstem, and none to the spinal cord. In contrast, glutamatergic KF neurons project heavily to the autonomic, respiratory, and motor regions of the medulla and spinal cord previously identified as efferent targets mediating KF cardiorespiratory effects. These findings identify a novel, GABAergic subpopulation of KF/PB neurons with a distinct efferent projection pattern targeting the brainstem trigeminal sensory system. Rather than regulating breathing, we propose that these neurons influence vibrissal sensorimotor function.
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Affiliation(s)
- Joel C Geerling
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Division of Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Department of Neurology, University of Iowa Hospital and Clinics, Iowa City, Iowa
| | - Shigefumi Yokota
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo, Japan
| | - Irma Rukhadze
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Division of Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,V.A. Greater Los Angeles Healthcare System, Los Angeles, California.,Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Dan Roe
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Nancy L Chamberlin
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Division of Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
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Villiere SM, Nakase K, Kollmar R, Silverman J, Sundaram K, Stewart M. Seizure-associated central apnea in a rat model: Evidence for resetting the respiratory rhythm and activation of the diving reflex. Neurobiol Dis 2017; 101:8-15. [PMID: 28153424 DOI: 10.1016/j.nbd.2017.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/02/2017] [Accepted: 01/25/2017] [Indexed: 12/18/2022] Open
Abstract
Respiratory derangements, including irregular, tachypnic breathing and central or obstructive apnea can be consequences of seizure activity in epilepsy patients and animal models. Periods of seizure-associated central apnea, defined as periods >1s with rapid onset and offset of no airflow during plethysmography, suggest that seizures spread to brainstem respiratory regions to disrupt breathing. We sought to characterize seizure-associated central apneic episodes as an indicator of seizure impact on the respiratory rhythm in rats anesthetized with urethane and given parenteral kainic acid to induce recurring seizures. We measured central apneic period onsets and offsets to determine if onset-offset relations were a consequence of 1) a reset of the respiratory rhythm, 2) a transient pausing of the respiratory rhythm, resuming from the pause point at the end of the apneic period, 3) a transient suppression of respiratory behavior with apnea offset predicted by a continuation of the breathing pattern preceding apnea, or 4) a random re-entry into the respiratory cycle. Animals were monitored with continuous ECG, EEG, and plethysmography. One hundred ninety central apnea episodes (1.04 to 36.18s, mean: 3.2±3.7s) were recorded during seizure activity from 7 rats with multiple apneic episodes. The majority of apneic period onsets occurred during expiration (125/161 apneic episodes, 78%). In either expiration or inspiration, apneic onsets tended to occur late in the cycle, i.e. between the time of the peak and end of expiration (82/125, 66%) or inspiration (34/36, 94%). Apneic period offsets were more uniformly distributed between early and late expiration (27%, 34%) and inspiration (16%, 23%). Differences between the respiratory phase at the onset of apnea and the corresponding offset phase varied widely, even within individual animals. Each central apneic episode was associated with a high frequency event in EEG or ECG records at onset. High frequency events that were not associated with flatline plethysmographs revealed a constant plethysmograph pattern within each animal, suggesting a clear reset of the respiratory rhythm. The respiratory rhythm became highly variable after about 1s, however, accounting for the unpredictability of the offset phase. The dissociation of respiratory rhythm reset from the cessation of airflow also suggested that central apneic periods involved activation of brainstem regions serving the diving reflex to eliminate the expression of respiratory movements. This conclusion was supported by the decreased heart rate as a function of apnea duration. We conclude that seizure-associated central apnea episodes are associated with 1) a reset of the respiratory rhythm, and 2) activation of brainstem regions serving the diving reflex to suppress respiratory behavior. The significance of these conclusions is that these details of seizure impact on brainstem circuitry represent metrics for assessing seizure spread and potentially subclassifying seizure patterns.
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Affiliation(s)
- S M Villiere
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Research Initiative for Scientific Enhancement (RISE) Program, City University of New York Medgar Evers College, 1638 Bedford Avenue, Brooklyn, NY 11225, United States
| | - K Nakase
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - R Kollmar
- Department of Cell Biology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - J Silverman
- Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - K Sundaram
- Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - M Stewart
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Department of Neurology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States.
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5
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Yokota S, Oka T, Asano H, Yasui Y. Orexinergic fibers are in contact with Kölliker-Fuse nucleus neurons projecting to the respiration-related nuclei in the medulla oblongata and spinal cord of the rat. Brain Res 2016; 1648:512-523. [PMID: 27544422 DOI: 10.1016/j.brainres.2016.08.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/02/2016] [Accepted: 08/16/2016] [Indexed: 01/01/2023]
Abstract
The neural pathways underlying the respiratory variation dependent on vigilance states remain unsettled. In the present study, we examined the orexinergic innervation of Kölliker-Fuse nucleus (KFN) neurons sending their axons to the rostral ventral respiratory group (rVRG) and phrenic nucleus (PhN) as well as to the hypoglossal nucleus (HGN) by using a combined retrograde tracing and immunohistochemistry. After injection of cholera toxin B subunit (CTb) into the KFN, CTb-labeled neurons that are also immunoreactive for orexin (ORX) were found prominently in the perifornical and medial regions and additionally in the lateral region of the hypothalamic ORX field. After injection of fluorogold (FG) into the rVRG, PhN or HGN, we found an overlapping distribution of ORX-immunoreactive axon terminals and FG-labeled neurons in the KFN. Within the neuropil of the KFN, asymmetrical synaptic contacts were made between these terminals and neurons. We further demonstrated that many neurons labeled with FG injected into the rVRG, PhN, or HGN are immunoreactive for ORX receptor 2. Present data suggest that rVRG-, PhN- and HGN-projecting KFN neurons may be under the excitatory influence of the ORXergic neurons for the state-dependent regulation of respiration.
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Affiliation(s)
- Shigefumi Yokota
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Tatsuro Oka
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Hirohiko Asano
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Yukihiko Yasui
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan.
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6
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Silva JN, Lucena EV, Silva TM, Damasceno RS, Takakura AC, Moreira TS. Inhibition of the pontine Kölliker-Fuse nucleus reduces genioglossal activity elicited by stimulation of the retrotrapezoid chemoreceptor neurons. Neuroscience 2016; 328:9-21. [PMID: 27126558 DOI: 10.1016/j.neuroscience.2016.04.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 04/16/2016] [Accepted: 04/18/2016] [Indexed: 01/06/2023]
Abstract
The Kölliker-Fuse (KF) region, located in the dorsolateral pons, projects to several brainstem areas involved in respiratory regulation, including the chemoreceptor neurons within the retrotrapezoid nucleus (RTN). Several lines of evidence indicate that the pontine KF region plays an important role in the control of the upper airways for the maintenance of appropriate airflow to and from the lungs. Specifically, we hypothesized that the KF region is involved in mediating the response of the hypoglossal motor activity to central respiratory chemoreflex activation and to stimulation of the chemoreceptor neurons within the RTN region. To test this hypothesis, we combined immunohistochemistry and physiological experiments. We found that in the KF, the majority of biotinylated dextran amine (BDA)-labeled axonal varicosities contained detectable levels of vesicular glutamate transporter-2 (VGLUT2), but few contained glutamic acid decarboxylase-67 (GAD67). The majority of the RTN neurons that were FluorGold (FG)-immunoreactive (i.e., projected to the KF) contained hypercapnia-induced Fos, but did not express tyrosine hydroxylase. In urethane-anesthetized sino-aortic denervated and vagotomized male Wistar rats, hypercapnia (10% CO2) or N-methyl-d-aspartate (NMDA) injection (0.1mM) in the RTN increased diaphragm (DiaEMG) and genioglossus muscle (GGEMG) activities and elicited abdominal (AbdEMG) activity. Bilateral injection of muscimol (GABA-A agonist; 2mM) into the KF region reduced the increase in DiaEMG and GGEMG produced by hypercapnia or NMDA into the RTN. Our data suggest that activation of chemoreceptor neurons in the RTN produces a significant increase in the genioglossus muscle activity and the excitatory pathway is dependent on the neurons located in the dorsolateral pontine KF region.
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Affiliation(s)
- Josiane N Silva
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil
| | - Elvis V Lucena
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil
| | - Talita M Silva
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil
| | - Rosélia S Damasceno
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo (USP), 05508-000 São Paulo/SP, Brazil.
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7
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Yokota S, Kaur S, VanderHorst VG, Saper CB, Chamberlin NL. Respiratory-related outputs of glutamatergic, hypercapnia-responsive parabrachial neurons in mice. J Comp Neurol 2015; 523:907-20. [PMID: 25424719 DOI: 10.1002/cne.23720] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/20/2014] [Accepted: 11/21/2014] [Indexed: 01/16/2023]
Abstract
In patients with obstructive sleep apnea, airway obstruction during sleep produces hypercapnia, which in turn activates respiratory muscles that pump air into the lungs (e.g., the diaphragm) and that dilate and stabilize the upper airway (e.g., the genioglossus). We hypothesized that these responses are facilitated by glutamatergic neurons in the parabrachial complex (PB) that respond to hypercapnia and project to premotor and motor neurons that innervate the diaphragm and genioglossus muscles. To test this hypothesis, we combined c-Fos immunohistochemistry with in situ hybridization for vGluT2 or GAD67 or with retrograde tracing from the ventrolateral medullary region that contains phrenic premotor neurons, the phrenic motor nucleus in the C3-C5 spinal ventral horn, or the hypoglossal motor nucleus. We found that hypercapnia (10% CO2 for 2 hours) activated c-Fos expression in neurons in the external lateral, lateral crescent (PBcr), and Kölliker-Fuse (KF) PB subnuclei and that most of these neurons were glutamatergic and virtually none γ-aminobutyric acidergic. Numerous CO2 -responsive neurons in the KF and PBcr were labeled after retrograde tracer injection into the ventrolateral medulla or hypoglossal motor nuclei, and in the KF after injections into the spinal cord, making them candidates for mediating respiratory-facilitatory and upper-airway-stabilizing effects of hypercapnia.
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Affiliation(s)
- Shigefumi Yokota
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, 02215; Division of Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, 02215; Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo, 693-8501, Japan
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8
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Koshiya N, Oku Y, Yokota S, Oyamada Y, Yasui Y, Okada Y. Anatomical and functional pathways of rhythmogenic inspiratory premotor information flow originating in the pre-Bötzinger complex in the rat medulla. Neuroscience 2014; 268:194-211. [DOI: 10.1016/j.neuroscience.2014.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 03/02/2014] [Accepted: 03/04/2014] [Indexed: 01/30/2023]
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9
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Holstege G. The periaqueductal gray controls brainstem emotional motor systems including respiration. PROGRESS IN BRAIN RESEARCH 2014; 209:379-405. [PMID: 24746059 DOI: 10.1016/b978-0-444-63274-6.00020-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Respiration is a motor system essential for the survival of the individual and of the species. Because of its vital significance, studies on respiration often assume that breathing takes place independent of other motor systems. However, motor systems generating vocalization, coughing, sneezing, vomiting, as well as parturition, ejaculation, and defecation encompass abdominal pressure control, which involves changes in the respiratory pattern. The mesencephalic periaqueductal gray (PAG) controls all these motor systems. It determines the level setting of the whole body by means of its very strong projections to the ventromedial medullary tegmentum, but it also controls the cell groups that generate vocalization, coughing, sneezing, vomiting, as well as respiration. For this control, the PAG maintains very strong connections with the nucleus retroambiguus, which enables it to control abdominal and intrathoracic pressure. In this same context, the PAG also runs the pelvic organs, bladder, uterus, prostate, seminal vesicles, and the distal colon and rectum via its projections to the pelvic organ stimulating center and the pelvic floor stimulating center. These cell groups, via long descending projections, have direct control of the parasympathetic motoneurons in the sacral cord as well as of the somatic motoneurons in the nucleus of Onuf, innervating the pelvic floor. Respiration, therefore, is not a motor system that functions by itself, but is strongly regulated by the same systems that also control the other motor output systems.
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Affiliation(s)
- Gert Holstege
- UQ Centre for Clinical Research, The University of Queensland, Herston, Queensland, Australia.
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10
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Yokota S, Niu JG, Tsumori T, Oka T, Yasui Y. Glutamatergic Kölliker-Fuse nucleus neurons innervate hypoglossal motoneurons whose axons form the medial (protruder) branch of the hypoglossal nerve in the rat. Brain Res 2011; 1404:10-20. [PMID: 21724177 DOI: 10.1016/j.brainres.2011.06.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/31/2011] [Accepted: 06/09/2011] [Indexed: 10/18/2022]
Abstract
This study was performed to understand the anatomical substrates for Kölliker-Fuse nucleus (KFN) modulation of respiratory-related tongue movement. After application of cholera toxin B subunit (CTb) to the medial branch of the hypoglossal nerve (HGn) and injection of biotinylated dextran amine (BDA) into the KFN ipsilaterally, an overlapping distribution of BDA-labeled axon terminals and CTb-labeled neurons was found in the ventral compartment of the hypoglossal nucleus (HGN) ipsilateral to the application and injection sites. At the electron microscopic level, the BDA-labeled terminals made asymmetrical synaptic contacts predominantly with dendrites of the HGN neurons, some of which were labeled with CTb. Using retrograde tracing combined with in situ hybridization, we demonstrated that almost all the KFN neurons sending their axons to the HGN were positive for vesicular glutamate transporter (VGLUT) 2 mRNA but not glutamic acid decarboxylase 67 mRNA. Using a combination of anterograde and retrograde tracing techniques and immunohistochemistry for VGLUT2, we further demonstrated that the KFN axon terminals with VGLUT2 immunoreactivity established close contact with the HGN motoneurons whose axons constitute the medial branch of the HGn. The present results suggest that glutamatergic KFN fibers may exert excitatory influence upon the HGN motoneurons sending their axons to the medial branch of the HGn for the control of protruder tongue muscles contraction to maintain airway patency during respiration.
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Affiliation(s)
- Shigefumi Yokota
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan
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11
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McKay LC, Critchley HD, Murphy K, Frackowiak RS, Corfield DR. Sub-cortical and brainstem sites associated with chemo-stimulated increases in ventilation in humans. Neuroimage 2010; 49:2526-35. [DOI: 10.1016/j.neuroimage.2009.11.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 11/03/2009] [Accepted: 11/04/2009] [Indexed: 01/29/2023] Open
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12
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Stornetta RL. Identification of neurotransmitters and co-localization of transmitters in brainstem respiratory neurons. Respir Physiol Neurobiol 2009; 164:18-27. [PMID: 18722563 DOI: 10.1016/j.resp.2008.07.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 07/15/2008] [Accepted: 07/17/2008] [Indexed: 11/18/2022]
Abstract
Identifying the major ionotropic neurotransmitter in a respiratory neuron is of critical importance in determining how the neuron fits into the respiratory system, whether in producing or modifying respiratory drive and rhythm. There are now several groups of respiratory neurons whose major neurotransmitters have been identified and in some of these cases, more than one transmitter has been identified in particular neurons. This review will describe the physiologically identified neurons in major respiratory areas that have been phenotyped for major ionotropic transmitters as well as those where more than one transmitter has been identified. Although the purpose of the additional transmitter has not been elucidated for any of the respiratory neurons, some examples from other systems will be discussed.
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Affiliation(s)
- R L Stornetta
- Department of Pharmacology, University of Virginia Health System, P.O. Box 800735, 1300 Jefferson Park Avenue, Charlottesville, VA 22908, USA.
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13
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GABAergic neurons in the ventrolateral subnucleus of the nucleus tractus solitarius are in contact with Kölliker-Fuse nucleus neurons projecting to the rostral ventral respiratory group and phrenic nucleus in the rat. Brain Res 2008; 1228:113-26. [PMID: 18634761 DOI: 10.1016/j.brainres.2008.06.089] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 06/16/2008] [Accepted: 06/18/2008] [Indexed: 12/29/2022]
Abstract
After ipsilateral injections of biotinylated dextran amine (BDA) into the ventrolateral subnucleus of the nucleus tractus solitarius (vlNTS) and Fluoro-gold (FG) into the rostral ventral respiratory group (rVRG) region or into the phrenic nucleus (PhN) region in the rat, an overlapping distribution of BDA-labeled axon terminals and FG-labeled neurons was found in the Kölliker-Fuse (KF) nucleus ipsilateral to the injection sites. Using retrograde tracing combined with immunohistochemistry for glutamic acid decarboxylase isoform 67 (GAD67), we indicated that as many as 40% of the vlNTS neurons projecting to the KF were immunoreactive for GAD67. Using a combination of anterograde and retrograde tracing techniques, and immunohistochemistry for GAD67, we further demonstrated that the vlNTS axon terminals with GAD67 immunoreactivity established close contact to the rVRG- or PhN-projecting KF neurons. The present results suggest that GABAergic vlNTS fibers may exert inhibitory influences on the rVRG- as well as PhN-projecting KF neurons and these circuits may be involved in the respiratory reflexes such as the Hering-Breuer reflex.
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14
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McKay LC, Adams L, Frackowiak RS, Corfield DR. A bilateral cortico-bulbar network associated with breath holding in humans, determined by functional magnetic resonance imaging. Neuroimage 2008; 40:1824-32. [DOI: 10.1016/j.neuroimage.2008.01.058] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 12/19/2007] [Accepted: 01/23/2008] [Indexed: 02/05/2023] Open
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15
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Yokota S, Oka T, Tsumori T, Nakamura S, Yasui Y. Glutamatergic neurons in the Kölliker-Fuse nucleus project to the rostral ventral respiratory group and phrenic nucleus: a combined retrograde tracing and in situ hybridization study in the rat. Neurosci Res 2007; 59:341-6. [PMID: 17888537 DOI: 10.1016/j.neures.2007.08.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 08/02/2007] [Accepted: 08/03/2007] [Indexed: 11/15/2022]
Abstract
Kölliker-Fuse nucleus (KF) neurons are considered to excite motoneurons in the phrenic nucleus (PhN) during inspiration through its projection to the PhN and/or to the rostral ventral respiratory group (rVRG), which in turn projects to the PhN, probably by releasing glutamate from their axon terminals. Using a combined retrograde tracing and in situ hybridization technique, here we demonstrate that most of the KF neurons projecting to the PhN and rVRG contain vesicular glutamate transporter 2 (VGLUT2) mRNA but not glutamic acid decarboxylase 67 (GAD67) mRNA, providing definitive evidence that these neurons are glutamatergic. Together with previous data by Stornetta et al. [Stornetta, R.L., Sevigny, C.P., Guyenet, P.G., 2003b. Inspiratory argumenting bulbospinal neurons express both glutamatergic and enkephalinergic phenotypes. J. Comp. Neurol. 455, 113-124], indicating that PhN-projecting rVRG neurons are VGLUT2 mRNA-positive, the present results suggest that the glutamatergic KF-PhN pathway and/or the glutamatergic KF-rVRG-PhN pathway transmit excitatory outputs of KF neurons to the PhN neurons during inspiration.
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Affiliation(s)
- Shigefumi Yokota
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo 693-8501, Japan
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16
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Ezure K, Tanaka I. Distribution and medullary projection of respiratory neurons in the dorsolateral pons of the rat. Neuroscience 2006; 141:1011-1023. [PMID: 16725272 DOI: 10.1016/j.neuroscience.2006.04.020] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/09/2006] [Accepted: 04/14/2006] [Indexed: 10/24/2022]
Abstract
The dorsolateral pons around the parabrachial nucleus including the Kölliker-Fuse nucleus is closely linked with the medullary respiratory center and plays an important role in respiratory control. We aimed to elucidate the firing properties, detailed distributions, and medullary projections of pontine respiratory neurons in pentobarbitone-anesthetized, paralyzed, and artificially ventilated rats with intact vagi. A total of 235 respiratory neurons were recorded from the dorsolateral pons in and around the Kölliker-Fuse nucleus. Six types of firing patterns were identified: inspiratory, expiratory-inspiratory phase spanning, inspiratory-expiratory phase spanning, decrementing expiratory, augmenting expiratory, and whole-phase expiratory patterns. Of these, the inspiratory neurons and the expiratory-inspiratory phase spanning neurons, which constituted the largest population (61%), were characterized most carefully by changing lung inflation levels, since under some conditions both showed similar firing patterns. Many (58%) of the 133 respiratory neurons examined were antidromically activated by electrical stimulation of the medulla. They were activated from the ventrolateral medulla around the ventral respiratory group and the Bötzinger complex and from the dorsomedial medulla around the nucleus tractus solitarii and the hypoglossal nucleus. The projections to the dorsomedial medulla were bilateral in many cases, and those to the ventrolateral medulla were unilateral. Of these medullary projections, two specific projections could be characterized in detail. First, many expiratory-inspiratory phase spanning neurons projected to the hypoglossal nucleus, suggesting that these pontine neurons are important premotor neurons of the hypoglossal motoneurons. This projection explains well the hypoglossal inspiratory activity, which is often dissociated from the phrenic inspiratory activity. Second, most whole-phase expiratory neurons that were distributed medially to the KF nucleus sent their axons toward the spinal cord via the midline medulla. These findings provide a new insight into the pontine control of medullary and spinal respiratory function.
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Affiliation(s)
- K Ezure
- Department of Neurobiology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan.
| | - I Tanaka
- Department of Neurobiology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan
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17
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Chamberlin NL. Functional organization of the parabrachial complex and intertrigeminal region in the control of breathing. Respir Physiol Neurobiol 2005; 143:115-25. [PMID: 15519549 DOI: 10.1016/j.resp.2004.03.015] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2004] [Indexed: 12/18/2022]
Abstract
Although the medulla oblongata contains the epicenter for respiratory rhythm generation, many other parts of the neuraxis play significant substratal roles in breathing. Accumulating evidence suggests that the pons contains several groups of neurons that may belong to the central respiratory system. This article will review data from microstimulation mapping and tract-tracing studies of the parabrachial complex (PB) and intertrigeminal region (ITR). Chemical activation of neurons in these areas has distinct effects on ventilatory and airway muscle activity. Tract-tracing experiments from functionally identified sites reveal specific respiratory-related sensory inputs and outputs that are likely anatomical substrates for these effects. The data suggest that an important physiological role for the rostral pons may be reflexive respiratory responses to airway stimuli.
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Affiliation(s)
- Nancy L Chamberlin
- Department of Neurology, Room 820, Harvard Institutes of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, 77 Ave. Louis Pasteur, Boston, MA 02115, USA.
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18
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Dutschmann M, Mörschel M, Kron M, Herbert H. Development of adaptive behaviour of the respiratory network: implications for the pontine Kolliker-Fuse nucleus. Respir Physiol Neurobiol 2005; 143:155-65. [PMID: 15519552 DOI: 10.1016/j.resp.2004.04.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2004] [Indexed: 11/30/2022]
Abstract
Breathing is constantly modulated by afferent sensory inputs in order to adapt to changes in behaviour and environment. The pontine respiratory group, in particular the Kolliker-Fuse nucleus, might be a key structure for adaptive behaviours of the respiratory network. Here, we review the anatomical connectivity of the Kolliker-Fuse nucleus with primary sensory structures and with the medullary respiratory centres and focus on the importance of pontine and medullary postinspiratory neurones in the mediation of respiratory reflexes. Furthermore, we will summarise recent findings from our group regarding ontogenetic changes of respiratory reflexes (e.g., the diving response) and provide evidence that immaturity of the Kolliker-Fuse nucleus might account in neonates for a lack of plasticity in sensory evoked modulations of respiratory activity. We propose that a subpopulation of neurones within the Kolliker-Fuse nucleus represent command neurones for sensory processing which are capable of initiating adaptive behaviour in the respiratory network. Recent data from our laboratory suggest that these command neurones undergo substantial postnatal maturation.
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Affiliation(s)
- Mathias Dutschmann
- Department of Physiology, University of Göttingen, Humboldtallee 23, 37073 Göttingen, Germany.
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19
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Jiang M, Alheid GF, Calandriello T, McCrimmon DR. Parabrachial-lateral pontine neurons link nociception and breathing. Respir Physiol Neurobiol 2005; 143:215-33. [PMID: 15519557 DOI: 10.1016/j.resp.2004.07.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2004] [Indexed: 11/17/2022]
Abstract
We investigated the role of the parabrachial complex in cutaneous nociceptor-induced respiratory stimulation in chloralose-urethane anesthetized, vagotomized rats. Noxious stimulation (mustard oil, MO) applied topically to a forelimb or hindlimb enhanced the peak amplitude of the integrated phrenic nerve discharge and, with forelimb application, increased phrenic nerve burst frequency. Bilateral inactivation of neural activity in the parabrachial complex with injection of the GABA agonist muscimol (3nl) markedly attenuated the response to MO application. Injection of the retrograde tracer FluoroGold within the medullary ventral respiratory column labeled neurons in dorsolateral pontine regions known to receive nociceptive inputs (i.e., Kolliker-Fuse, lateral crescent, and superior lateral subnuclei of the parabrachial complex). Extracellular recordings of 65 dorsolateral parabrachial neurons revealed about 15% responded to a noxious cutaneous pinch with either an increase or a decrease in discharge and approximately 40% of these exhibited a phasic respiratory-related component to their discharge. In conclusion, parabrachial pontine neurons contribute to cutaneous nociceptor-induced increases in breathing.
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Affiliation(s)
- Mingchen Jiang
- Department of Physiology and Institute for Neuroscience, Feinberg School of Medicine, Northwestern University, M211, 303 E. Chicago Ave., Chicago, IL 60611-3008, USA
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20
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Alheid GF, Milsom WK, McCrimmon DR. Pontine influences on breathing: an overview. Respir Physiol Neurobiol 2005; 143:105-14. [PMID: 15519548 DOI: 10.1016/j.resp.2004.06.016] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2004] [Indexed: 11/17/2022]
Abstract
Historical and contemporary views of the functional organization of the lateral pontine regions influencing breathing are reviewed. In vertebrates, the rhombencephalon generates a breathing rhythm and detailed motor pattern that persist throughout life. Key to this process is an essentially continuous column of neurons extending from the spino-medullary border through the ventrolateral medulla, continuing through the ventral pons and arcing into the dorsolateral medulla. Comparative neuroanatomy and physiology indicate this is a richly interconnected network divided into serial, functionally distinct compartments. Serial compartmentalization of pontomedullary structures related to breathing also reflects the developmental segmentation of the rhombencephalon. However, with migration of cell groups such as the facial nucleus from the pons to the medulla during ontogeny, the boundaries of the adult pons are sometimes difficult to precisely define. Accordingly, a working definition of rostral and caudal pontine boundaries for adult mammals is depicted.
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Affiliation(s)
- George F Alheid
- Department of Physiology and Institute for Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL 60611-3008, USA.
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21
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Song G, Poon CS. Functional and structural models of pontine modulation of mechanoreceptor and chemoreceptor reflexes. Respir Physiol Neurobiol 2005; 143:281-92. [PMID: 15519561 DOI: 10.1016/j.resp.2004.05.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2004] [Indexed: 11/30/2022]
Abstract
The dorsolateral and ventrolateral pons (dl-pons, vl-pons) are critical brainstem structures mediating the plasticity of the Hering-Breuer mechanoreflex (HBR) and carotid chemoreflex (CCR). Review of anatomical evidence indicates that dl-pons and vl-pons are connected reciprocally with one another and with medullary nucleus tractus solitarius (NTS) and ventral respiratory group (VRG). With this structural map, functional models of HBR and CCR are proposed in which the respiratory rhythm is modulated by short-term depression (STD) or potentiation (STP) of corresponding primary NTS-VRG and auxiliary pons-VRG excitatory or inhibitory pathways. Behaviorally, STD and STP of respiratory reflexes are akin to non-associative learning such as habituation, sensitization or desensitization to afferent inputs. Computationally, the STD and STP effects amount to signal differentiation and integration in the time domain, or high-pass and low-pass filtering in the frequency domain, respectively. These functional and structural models of pontomedullary signal processing provide a novel conceptual framework that unifies a wealth of experimental observations regarding mechanoreceptor and chemoreceptor reflex control of breathing.
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Affiliation(s)
- Gang Song
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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22
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Hayakawa T, Takanaga A, Tanaka K, Maeda S, Seki M. Ultrastructure of the rostral ventral respiratory group neurons in the ventrolateral medulla of the rat. Brain Res 2004; 1027:94-102. [PMID: 15494161 DOI: 10.1016/j.brainres.2004.08.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2004] [Indexed: 02/02/2023]
Abstract
The neurons in the ventrolateral medulla that project to the spinal cord are called the rostral ventral respiratory group (rVRG) because they activate spinal respiratory motor neurons. We retrogradely labeled rVRG neurons with Fluoro-Gold (FG) injections into the fourth cervical spinal cord segment to determine their distribution. The rostral half of the rVRG was located in the area ventral to the semicompact formation of the nucleus ambiguus (AmS). A cluster of the neurons moved dorsally and intermingled with the palatopharyngeal motor neurons at the caudal end of the AmS. The caudal half of the rVRG was located in the area including the loose formation of the nucleus ambiguus caudal to the AmS. We also labeled the rVRG neurons retrogradely with wheat germ agglutinin-horseradish peroxidase (WGA-HRP) to determine their ultrastructural characteristics. The neurons of the rVRG were medium to large (38.1 x 22.1 microm), oval or ellipsoid in shape, and had a dark cytoplasm containing numerous free ribosomes, rough endoplasmic reticulum (rER), mitochondria, Golgi apparatuses, lipofuscin granules and a round nucleus with an invaginated nuclear membrane. The average number of axosomatic terminals in a profile was 33.2. The number of axosomatic terminals containing round vesicles and making asymmetric synaptic contacts (Gray's type I) was almost equal to those containing pleomorphic vesicles and making symmetric synaptic contacts (Gray's type II). The axodendritic terminals were large (1.55 microm), and about 60% of them were Gray's type I. The rVRG neurons have ultrastructural characteristics, which are different from the palatopharyngeal motor neurons or the prorpiobulbar neurons.
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Affiliation(s)
- Tetsu Hayakawa
- Department of Anatomy, Hyogo College of Medicine, Mukogawa, Nishinomiya, Hyogo 663-8501, Japan.
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23
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Roda F, Pio J, Bianchi AL, Gestreau C. Effects of anesthetics on hypoglossal nerve discharge and c-Fos expression in brainstem hypoglossal premotor neurons. J Comp Neurol 2004; 468:571-86. [PMID: 14689487 DOI: 10.1002/cne.10974] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study examined the effects of anesthesia on the hypoglossal nerve and diaphragm activities and on c-Fos expression in brainstem hypoglossal premotor neurons (pmXII). Experiments were performed in 71 rats by using halothane inhalation, pentobarbital sodium, or mixtures of alpha-chloralose and urethane or ketamine and xylazine. First, various cardiorespiratory parameters were measured in the rats (n = 31) during both awake and anesthetized conditions. The volatile anesthetic halothane, but not the other anesthetics, was always associated with a strong phasic inspiratory activity in the hypoglossal nerve. Second, a double-immunohistochemical study was performed in awake and anesthetized rats (n = 40) to gauge the level of activity of pmXII neurons. Brainstem pmXII neurons were identified after microiontophoresis of the retrograde tracer Fluoro-Gold in the right hypoglossal motor nucleus. Patterns of c-Fos expression at different brainstem levels were compared in five groups of rats (i.e., awake or anesthetized with halothane, pentobarbital, chloralose-urethane, and ketamine-xylazine). Sections were processed for double detection of c-Fos protein and Fluoro-Gold by using the standard ABC method and a two-color peroxidase technique. Anesthesia with halothane induced the strongest c-Fos expression in a restricted pool of pmXII located in the pons at the level of the Kölliker-Fuse nucleus and the intertrigeminal region. The results demonstrated a major effect of halothane in inducing changes in hypoglossal activity and revealed a differential expression of c-Fos protein in pmXII neurons among groups of anesthetized rats. We suggest that halothane mediates changes in respiratory hypoglossal nerve discharge by altering activity of premotor neurons in the Kölliker-Fuse and intertrigeminal region.
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Affiliation(s)
- Fabrice Roda
- Laboratoire de Physiologie Neurovégétative, UMR Centre National de la Recherche Scientifique 6153, Institut National de la Recherche Agronomique 1147, Faculté des Sciences et Techniques Saint Jérôme, 13397 Marseille 20, France
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24
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Yokota S, Tsumori T, Ono K, Yasui Y. Glutamatergic pathways from the Kölliker-Fuse nucleus to the phrenic nucleus in the rat. Brain Res 2004; 995:118-30. [PMID: 14644477 DOI: 10.1016/j.brainres.2003.09.067] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
After ipsilateral injections of biotinylated dextran amine (BDA) into the Kölliker-Fuse (KF) nucleus and cholera toxin B subunit (CTb) into the ventral horn in C4 to C5 segments of the spinal cord, an overlapping distribution of BDA-labeled axon terminals and CTb-labeled neurons was found in the rostral ventral respiratory group (rVRG) region ipsilateral to the injection sites. After ipsilateral injections of BDA into the KF and Fluoro-Gold (FG) into the ventral horn in C4 to C5 segments of the spinal cord, BDA-labeled axons were found to make asymmetrical synapses with the somata and dendrites of FG-labeled neurons within the neuropil of the rVRG region. Using retrograde tracing combined with immunohistochemistry for phosphate-activated glutaminase (PAG), we observed that as many as 72% of the rVRG neurons projecting to the PhN were immunoreactive for PAG and that approximately 62% and 75% of the KF neurons projecting respectively to the rVRG region and PhN contain PAG immunoreactivity. Using anterograde tracing combined with immunohistochemistry for vesicular glutamate transporter 2 (VGluT2), we further demonstrated that the KF axon terminals in the rVRG and PhN regions as well as the rVRG axon terminals in the PhN region contain VGluT2 immunoreactivity. The present results suggest that the glutamatergic pathways from the KF to the PhN directly and indirectly via the rVRG region may exist and underlie the inspiratory responses that are elicited by activation of the KF neurons.
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Affiliation(s)
- Shigefumi Yokota
- Department of Anatomy and Morphological Neuroscience, Shimane Medical University, Izumo 693-8501, Japan
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25
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Joseph V, Pequignot JM, Van Reeth O. Neurochemical perspectives on the control of breathing during sleep. Respir Physiol Neurobiol 2002; 130:253-63. [PMID: 12093622 DOI: 10.1016/s0034-5687(02)00012-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A specific depression of minute ventilation occurs during sleep in normal subjects. This sleep-related ventilatory depression is partially related to mechanical events and upper airway atonia but some data also indicate that it is likely to be centrally mediated. This paper reviews the anatomical and neurochemical connections between sleep/wake- and respiratory-related areas in an attempt to identify the potential implication of sleep-related neurochemicals (serotonin, catecholamines, GABA, acetylcholine) in the sleep-related hypoventilation. The review of available data suggests that the sleep-related ventilatory depression depends upon the enhanced GABAergic activity together with a loss of suprapontine influence depending on the cessation of activity of the reticular formation. During REM sleep, an additional inhibitory activity emerges from the pontine cholinergic neurons, which contributes to the breathing irregularities and the associated depression of minute ventilation and ventilatory response to chemical stimuli. This model may contribute to a better understanding of the neurochemical environment of respiratory neurons during sleep, which remains a question of importance regarding the numerous pathological states that are linked to specific perturbations of breathing control during sleep.
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Affiliation(s)
- Vincent Joseph
- Centre d'Etudes des Rythmes Biologiques, ULB Hôpital Erasme, 808 Route de Lennik, 1070, Brussels, Belgium.
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