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Kondo T, Yamanishi T, Nishio T, Yokota Y, Seikai T, Enomoto A, Harada T, Tsuji T, Tanaka S. Swallowing-like activity elicited in neonatal rat medullary slice preparation. Brain Res 2024; 1837:148955. [PMID: 38679314 DOI: 10.1016/j.brainres.2024.148955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/30/2024] [Accepted: 04/20/2024] [Indexed: 05/01/2024]
Abstract
Swallowing is induced by a central pattern generator in the nucleus tractus solitarius (NTS). We aimed to create a medullary slice preparation to elucidate the neural architecture of the central pattern generator of swallowing (Sw-CPG) and record its neural activities. Experiments were conducted on 2-day-old Sprague-Dawley rats (n = 46). The brainstem-spinal cord was transected at the pontomedullary and cervicothoracic junctions; the medulla was sliced transversely at thicknesses of 600, 700, or 800 μm. The rostral end of the slice was 100 μm rostral to the vagus nerve. We recorded hypoglossal nerve activity and electrically stimulated the vagus nerve or microinjected bicuculline methiodide (BIC) into the NTS. The 800-μm slices generated both rhythmic respiratory activity and electrically elicited neural activity. The 700-μm slices generated only respiratory activity, while the 600-μm slices did not generate any neural activity. BIC microinjection into the NTS in 800-μm slices resulted in the typical activity that closely resembled the swallowing activity reported in other experiments. This swallowing-like activity consistently lengthened the respiratory interval. Despite complete inhibition of respiratory activity, weak swallowing-like activity was observed under bath application of a non-NMDA receptor antagonist. Contrastingly, bath application of NMDA receptor antagonists resulted in a complete loss of swallowing-like activity and no change in respiratory activity. These results suggest that the 800-μm medullary slice preparation contains both afferent and efferent neural circuits and pattern generators of swallowing activity. Additionally, NMDA receptors may be necessary for generating swallowing activity. This medullary slice preparation can therefore elucidate Sw-CPG neural networks.
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Affiliation(s)
- Takahide Kondo
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan.
| | - Tadashi Yamanishi
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan; Department of Oral and Maxillofacial Surgery, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Takahiro Nishio
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan; Department of Oral and Maxillofacial Surgery, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Yusuke Yokota
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan
| | - Tetsuya Seikai
- Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Hokkaido, Japan
| | - Akifumi Enomoto
- Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Takeshi Harada
- Department of Oral and Maxillofacial Surgery, Kansai Rosai Hospital, Osaka, Japan
| | - Tadataka Tsuji
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan
| | - Susumu Tanaka
- First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan
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Behrens R, Dutschmann M, Trewella M, Mazzone SB, Moe AAK. Regulation of vagally-evoked respiratory responses by the lateral parabrachial nucleus in the mouse. Respir Physiol Neurobiol 2023; 316:104141. [PMID: 37597796 DOI: 10.1016/j.resp.2023.104141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/04/2023] [Accepted: 08/14/2023] [Indexed: 08/21/2023]
Abstract
Vagal sensory inputs to the brainstem can alter breathing through the modulation of pontomedullary respiratory circuits. In this study, we set out to investigate the localised effects of modulating lateral parabrachial nucleus (LPB) activity on vagally-evoked changes in breathing pattern. In isoflurane-anaesthetised and instrumented mice, electrical stimulation of the vagus nerve (eVNS) produced stimulation frequency-dependent changes in diaphragm electromyograph (dEMG) activity with an evoked tachypnoea and apnoea at low and high stimulation frequencies, respectively. Muscimol microinjections into the LPB significantly attenuated eVNS-evoked respiratory rate responses. Notably, muscimol injections reaching the caudal LPB, previously unrecognised for respiratory modulation, potently modulated eVNS-evoked apnoea, whilst muscimol injections reaching the intermediate LPB selectively modulated the eVNS-evoked tachypnoea. The effects of muscimol on eVNS-evoked breathing rate changes occurred without altering basal eupneic breathing. These results highlight novel roles for the LPB in regulating vagally-evoked respiratory reflexes.
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Affiliation(s)
- Robert Behrens
- Department of Anatomy and Physiology, University of Melbourne, VIC, Australia
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Matthew Trewella
- Department of Anatomy and Physiology, University of Melbourne, VIC, Australia
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, University of Melbourne, VIC, Australia.
| | - Aung Aung Kywe Moe
- Department of Anatomy and Physiology, University of Melbourne, VIC, Australia; Department of Medical Imaging and Radiation Sciences, Monash University, Clayton, Australia
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Takemura A, Sugiyama Y, Yamamoto R, Kinoshita S, Kaneko M, Fuse S, Hashimoto K, Mukudai S, Umezaki T, Dutschmann M, Hirano S. Effect of pharmacological inhibition of the pontine respiratory group on swallowing interneurons in the dorsal medulla oblongata. Brain Res 2022; 1797:148101. [PMID: 36183794 DOI: 10.1016/j.brainres.2022.148101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/31/2022] [Accepted: 09/26/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES To examine the role of neurons of the pontine respiratory group (PRG) overlapping with the Kölliker-Fuse nucleus in the regulation of swallowing, we compared the activity of swallowing motor activities and interneuron discharge in the dorsal swallowing group in the medulla before and after pharmacological inhibition of the PRG. METHODS In 23 in situ perfused brainstem preparation of rats, we recorded the activities of the vagus (VNA), hypoglossal (HNA), and phrenic nerves (PNA), and swallowing interneurons of the dorsal medulla during fictive swallowing elicited by electrical stimulation of the superior laryngeal nerve or oral water injection. Subsequently, respiratory- and swallow-related motor activities and single unit cell discharge were assessed before and after local microinjection of the GABA-receptor agonist muscimol into the area of PRG ipsilateral to the recording sites of swallowing interneurons. RESULTS After muscimol injection, the amplitude and duration of swallow-related VNA bursts decreased to 71.3 ± 2.84 and 68.1 ± 2.76 % during electrically induced swallowing and VNA interburst intervals during repetitive swallowing decreased. Similar effects were observed for swallowing-related HNA. The swallowing motor activity was similarly qualitatively altered during physiologically induced swallowing. All 23 neurons were changed in either discharge duration or frequency after PRG inhibition, however, the general discharge patterns in relation to the motor output remained unchanged. CONCLUSION Descending synaptic inputs from PRG provide control of the primary laryngeal sensory gate and synaptic activity of the PRG partially determine medullary cell and cranial motor nerve activities that govern the pharyngeal stage of swallowing.
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Affiliation(s)
- Akiyo Takemura
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Yoichiro Sugiyama
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
| | - Ryota Yamamoto
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan; Department of Otolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-5852, Japan
| | - Shota Kinoshita
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Mami Kaneko
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Shinya Fuse
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Keiko Hashimoto
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Shigeyuki Mukudai
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Toshiro Umezaki
- Department of Speech and Hearing Sciences, International University of Health and Welfare, and the Voice and Swallowing Center, Fukuoka Sanno Hospital, Fukuoka 814-0001, Japan
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria 3052, Australia
| | - Shigeru Hirano
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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Tsujimura T, Nakajima Y, Chotirungsan T, Kawada S, Tsutsui Y, Yoshihara M, Suzuki T, Nagoya K, Magara J, Inoue M. Inhibition of Water-Evoked Swallowing During Noxious Mechanical Stimulation of Tongue in Anesthetized Rats. Dysphagia 2022; 38:965-972. [PMID: 36127446 DOI: 10.1007/s00455-022-10522-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 09/11/2022] [Indexed: 11/30/2022]
Abstract
Dysphagia is sometimes accompanied by pain. Because orofacial structures subserve mastication and swallowing, orofacial pain might impair both functions. Tongue biting can occur not only accidentally while eating but also in some pathological conditions. However, it remains unclear whether noxious mechanical stimulation of the tongue affects swallowing. To explore this question, we evaluated the effects of lingual pinch stimulation on the initiation of swallowing evoked by distilled water (DW) infusion with a flow rate of 5.0 µL/s for 20 s into the pharyngolaryngeal region in anesthetized rats. The swallowing reflex was identified by electromyographic (EMG) bursts in the suprahyoid muscles which include the anterior belly of the digastric muscle, mylohyoid and geniohyoid muscles, and laryngeal elevation by visual inspection. The number of DW-evoked swallows during pinch stimulation was significantly smaller than that in a control condition or during pressure stimulation. The onset latency of the first swallow during pinch stimulation was significantly longer than that in the control condition. DW-evoked swallowing was almost abolished following bilateral transection of the superior laryngeal nerve (SLN) compared with the control condition, suggesting that the SLN plays a crucial role in the initiation of DW-evoked swallowing. Finally, electrophysiological data indicated that some SLN-responsive neurons in the nucleus tractus solitarii (nTS) exhibited delayed latency from a single SLN stimulation during lingual pinch stimulation. These results suggest that noxious mechanical stimulation of the tongue inhibits the initiation of swallowing and modulates neuronal activity in the nTS.
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Affiliation(s)
- Takanori Tsujimura
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan.
| | - Yuta Nakajima
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Titi Chotirungsan
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Satomi Kawada
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Yuhei Tsutsui
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Midori Yoshihara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Taku Suzuki
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Kouta Nagoya
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Jin Magara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
| | - Makoto Inoue
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8514, Japan
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5
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Oku Y. Temporal variations in the pattern of breathing: techniques, sources, and applications to translational sciences. J Physiol Sci 2022; 72:22. [PMID: 36038825 DOI: 10.1186/s12576-022-00847-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/12/2022] [Indexed: 11/10/2022]
Abstract
The breathing process possesses a complex variability caused in part by the respiratory central pattern generator in the brainstem; however, it also arises from chemical and mechanical feedback control loops, network reorganization and network sharing with nonrespiratory motor acts, as well as inputs from cortical and subcortical systems. The notion that respiratory fluctuations contain hidden information has prompted scientists to decipher respiratory signals to better understand the fundamental mechanisms of respiratory pattern generation, interactions with emotion, influences on the cortical neuronal networks associated with cognition, and changes in variability in healthy and disease-carrying individuals. Respiration can be used to express and control emotion. Furthermore, respiration appears to organize brain-wide network oscillations via cross-frequency coupling, optimizing cognitive performance. With the aid of information theory-based techniques and machine learning, the hidden information can be translated into a form usable in clinical practice for diagnosis, emotion recognition, and mental conditioning.
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Affiliation(s)
- Yoshitaka Oku
- Division of Physiome, Department of Physiology, Hyogo Medical University, Nishinomiya, Hyogo, 663-8501, Japan.
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6
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Yuan S, Deng B, Ye Q, Wu Z, Wu J, Wang L, Xu Q, Yao L, Xu N. Excitatory neurons in paraventricular hypothalamus contributed to the mechanism underlying acupuncture regulating the swallowing function. Sci Rep 2022; 12:5797. [PMID: 35388042 PMCID: PMC8987055 DOI: 10.1038/s41598-022-09470-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/11/2022] [Indexed: 11/20/2022] Open
Abstract
Paraventricular hypothalamus (PVH) is demonstrated to regulate stress, feeding behaviors, and other related homeostatic processes. However, no direct evidence has been investigated for the role of PVH in swallowing function. Acupuncture therapy at Lianquan (CV23) acupoint has been reported to improve the swallowing function in clinical trials, but its underlying mechanism still needs to be uncovered. Thus, we aimed to explore whether PVH involved the acupuncture mediated regulating swallowing function. Chemogenetics, electromyography (EMG) recording, and immunofluorescence staining methods were combined to demonstrate that neurons in PVH could be activated by electroacupuncture (EA) stimulation at CV23, and this neuronal cluster was represented as excitatory neurons. Furthermore, we mapped both the inputs and outputs of PVH neurons using viral tracing. The neurons in PVH projected with the brain regions, including parabrachial nucleus (PBN) and the solitary tract nucleus (NTS), which both participated in the swallowing process. The EA function regulating the swallowing was attenuated after inhibiting the neurons in PVH in the post stroke dysphagia. In conclusion, this study suggested that EA at CV23 could regulate swallowing function involving the excitatory neurons in PVH.
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Affiliation(s)
- Si Yuan
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Bing Deng
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Qiuping Ye
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China.,Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, No. 600, Tianhe Road, Guangzhou, 510630, Guangdong, China
| | - Zhennan Wu
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Junshang Wu
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Lin Wang
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Qin Xu
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China
| | - Lulu Yao
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China.
| | - Nenggui Xu
- South China Research Center for Acupuncture and Moxibustion, Guangzhou Higher Education Mega Center, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, 232 East Ring Road, Panyu District, Guangzhou, 510006, People's Republic of China.
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7
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Tenorio-Lopes L, Kinkead R. Sex-Specific Effects of Stress on Respiratory Control: Plasticity, Adaptation, and Dysfunction. Compr Physiol 2021; 11:2097-2134. [PMID: 34107062 DOI: 10.1002/cphy.c200022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
As our understanding of respiratory control evolves, we appreciate how the basic neurobiological principles of plasticity discovered in other systems shape the development and function of the respiratory control system. While breathing is a robust homeostatic function, there is growing evidence that stress disrupts respiratory control in ways that predispose to disease. Neonatal stress (in the form of maternal separation) affects "classical" respiratory control structures such as the peripheral O2 sensors (carotid bodies) and the medulla (e.g., nucleus of the solitary tract). Furthermore, early life stress disrupts the paraventricular nucleus of the hypothalamus (PVH), a structure that has emerged as a primary determinant of the intensity of the ventilatory response to hypoxia. Although underestimated, the PVH's influence on respiratory function is a logical extension of the hypothalamic control of metabolic demand and supply. In this article, we review the functional and anatomical links between the stress neuroendocrine axis and the medullary network regulating breathing. We then present the persistent and sex-specific effects of neonatal stress on respiratory control in adult rats. The similarities between the respiratory phenotype of stressed rats and clinical manifestations of respiratory control disorders such as sleep-disordered breathing and panic attacks are remarkable. These observations are in line with the scientific consensus that the origins of adult disease are often found among developmental and biological disruptions occurring during early life. These observations bring a different perspective on the structural hierarchy of respiratory homeostasis and point to new directions in our understanding of the etiology of respiratory control disorders. © 2021 American Physiological Society. Compr Physiol 11:1-38, 2021.
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Affiliation(s)
- Luana Tenorio-Lopes
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, The University of Calgary, Calgary, Alberta, Canada
| | - Richard Kinkead
- Département de Pédiatrie, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
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8
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Reed MD, English M, English C, Huff A, Poliacek I, Musselwhite MN, Howland DR, Bolser DC, Pitts T. The Role of the Cerebellum in Control of Swallow: Evidence of Inspiratory Activity During Swallow. Lung 2019; 197:235-240. [PMID: 30680516 DOI: 10.1007/s00408-018-00192-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/29/2018] [Indexed: 10/27/2022]
Abstract
Anatomical connections are reported between the cerebellum and brainstem nuclei involved in swallow such as the nucleus tractus solitarius, nucleus ambiguus, and Kölliker-fuse nuclei. Despite these connections, a functional role of the cerebellum during swallow has not been elucidated. Therefore, we examined the effects of cerebellectomy on swallow muscle recruitment and swallow-breathing coordination in anesthetized freely breathing cats. Electromyograms were recorded from upper airway, pharyngeal, laryngeal, diaphragm, and chest wall muscles before and after complete cerebellectomy. Removal of the cerebellum reduced the excitability of swallow (i.e., swallow number), and muscle recruitment of the geniohyoid, thyroarytenoid, parasternal (chestwall), and diaphragm muscles, but did not disrupt swallow-breathing coordination. Additionally, diaphragm and parasternal muscle activity during swallow is reduced after cerebellectomy, while no changes were observed during breathing. These findings suggest the cerebellum modulates muscle excitability during recruitment, but not pattern or coordination of swallow with breathing.
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Affiliation(s)
- Mitchell D Reed
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA
| | - Mason English
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA
| | - Connor English
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA
| | - Alyssa Huff
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA.,Department of Physiology, College of Medicine, University of Louisville, Louisville, KY, USA
| | - Ivan Poliacek
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.,Institute of Medical Biophysics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - M Nicholas Musselwhite
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Dena R Howland
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA.,Research Service, Robley Rex Veterans Affairs Medical Center, Louisville, KY, USA
| | - Donald C Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Teresa Pitts
- Department of Neurological Surgery and Kentucky Spinal Cord Injury Research Center, College of Medicine, University of Louisville, Louisville, KY, USA.
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9
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Horton KK, Segers LS, Nuding SC, O'Connor R, Alencar PA, Davenport PW, Bolser DC, Pitts T, Lindsey BG, Morris KF, Gestreau C. Central Respiration and Mechanical Ventilation in the Gating of Swallow With Breathing. Front Physiol 2018; 9:785. [PMID: 30013484 PMCID: PMC6036260 DOI: 10.3389/fphys.2018.00785] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Swallow-breathing coordination safeguards the lower airways from tracheal aspiration of bolus material as it moves through the pharynx into the esophagus. Impaired movements of the shared muscles or structures of the aerodigestive tract, or disruptions in the interaction of brainstem swallow and respiratory central pattern generators (CPGs) result in dysphagia. To maximize lower airway protection these CPGs integrate respiratory rhythm generation signals and vagal afferent feedback to synchronize swallow with breathing. Despite extensive study, the roles of central respiratory activity and vagal feedback from the lungs as key elements for effective swallow-breathing coordination remain unclear. The effect of altered timing of bronchopulmonary vagal afferent input on swallows triggered during electrical stimulation of the superior laryngeal nerves or by injection of water into the pharyngeal cavity was studied in decerebrate, paralyzed, and artificially ventilated cats. We observed two types of single swallows that produced distinct effects on central respiratory-rhythm across all conditions: post-inspiratory type swallows disrupted central-inspiratory activity without affecting expiration, whereas expiratory type swallows prolonged expiration without affecting central-inspiratory activity. Repetitive swallows observed during apnea reset the E2 phase of central respiration and produced facilitation of swallow motor output nerve burst durations. Moreover, swallow initiation was negatively modulated by vagal feedback and was reset by lung inflation. Collectively, these findings support a novel model of reciprocal inhibition between the swallow CPG and inspiratory or expiratory cells of the respiratory CPG where lung distension and phases of central respiratory activity represent a dual peripheral and central gating mechanism of swallow-breathing coordination.
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Affiliation(s)
- Kofi-Kermit Horton
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Lauren S Segers
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Sarah C Nuding
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Russell O'Connor
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Pierina A Alencar
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Paul W Davenport
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Donald C Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Teresa Pitts
- Department of Neurological Surgery, Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, United States
| | - Bruce G Lindsey
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Kendall F Morris
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
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10
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Barnett WH, Jenkin SEM, Milsom WK, Paton JFR, Abdala AP, Molkov YI, Zoccal DB. The Kölliker-Fuse nucleus orchestrates the timing of expiratory abdominal nerve bursting. J Neurophysiol 2017; 119:401-412. [PMID: 29070631 DOI: 10.1152/jn.00499.2017] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Coordination of respiratory pump and valve muscle activity is essential for normal breathing. A hallmark respiratory response to hypercapnia and hypoxia is the emergence of active exhalation, characterized by abdominal muscle pumping during the late one-third of expiration (late-E phase). Late-E abdominal activity during hypercapnia has been attributed to the activation of expiratory neurons located within the parafacial respiratory group (pFRG). However, the mechanisms that control emergence of active exhalation, and its silencing in restful breathing, are not completely understood. We hypothesized that inputs from the Kölliker-Fuse nucleus (KF) control the emergence of late-E activity during hypercapnia. Previously, we reported that reversible inhibition of the KF reduced postinspiratory (post-I) motor output to laryngeal adductor muscles and brought forward the onset of hypercapnia-induced late-E abdominal activity. Here we explored the contribution of the KF for late-E abdominal recruitment during hypercapnia by pharmacologically disinhibiting the KF in in situ decerebrate arterially perfused rat preparations. These data were combined with previous results and incorporated into a computational model of the respiratory central pattern generator. Disinhibition of the KF through local parenchymal microinjections of gabazine (GABAA receptor antagonist) prolonged vagal post-I activity and inhibited late-E abdominal output during hypercapnia. In silico, we reproduced this behavior and predicted a mechanism in which the KF provides excitatory drive to post-I inhibitory neurons, which in turn inhibit late-E neurons of the pFRG. Although the exact mechanism proposed by the model requires testing, our data confirm that the KF modulates the formation of late-E abdominal activity during hypercapnia. NEW & NOTEWORTHY The pons is essential for the formation of the three-phase respiratory pattern, controlling the inspiratory-expiratory phase transition. We provide functional evidence of a novel role for the Kölliker-Fuse nucleus (KF) controlling the emergence of abdominal expiratory bursts during active expiration. A computational model of the respiratory central pattern generator predicts a possible mechanism by which the KF interacts indirectly with the parafacial respiratory group and exerts an inhibitory effect on the expiratory conditional oscillator.
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Affiliation(s)
- William H Barnett
- Department of Mathematics and Statistics, Georgia State University , Atlanta, Georgia
| | - Sarah E M Jenkin
- Department of Zoology, University of British Columbia , Vancouver, British Columbia , Canada
| | - William K Milsom
- Department of Zoology, University of British Columbia , Vancouver, British Columbia , Canada
| | - Julian F R Paton
- School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences, University of Bristol , Bristol , United Kingdom.,Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland , Auckland , New Zealand
| | - Ana P Abdala
- School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences, University of Bristol , Bristol , United Kingdom
| | - Yaroslav I Molkov
- Department of Mathematics and Statistics, Georgia State University , Atlanta, Georgia.,Neuroscience Institute, Georgia State University , Atlanta, Georgia
| | - Daniel B Zoccal
- Department of Physiology and Pathology, São Paulo State University , Araraquara , Brazil
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11
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The Kölliker-Fuse nucleus: a review of animal studies and the implications for cranial nerve function in humans. Eur Arch Otorhinolaryngol 2015; 273:3505-3510. [PMID: 26688431 DOI: 10.1007/s00405-015-3861-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022]
Abstract
To review the scientific literature on the relationship between Kölliker-Fuse nucleus (KF) and cranial nerve function in animal models, with view to evaluating the potential role of KF maturation in explaining age-related normal physiologic parameters and developmental and acquired impairment of cranial nerve function in humans. Medical databases (Medline and PubMed). Studies investigating evidence of KF activity responsible for a specific cranial nerve function that were based on manipulation of KF activity or the use of neural markers were included. Twenty studies were identified that involved the trigeminal (6 studies), vagus (9), and hypoglossal nerves (5). These pertained specifically to a role of the KF in mediating the dive reflex, laryngeal adductor control, swallowing function and upper airway tone. The KF acts as a mediator of a number of important functions that relate primarily to laryngeal closure, upper airway tone and swallowing. These areas are characterized by a variety of disorders that may present to the otolaryngologist, and hence the importance of understanding the role played by the KF in maintaining normal function.
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12
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Lavezzi AM, Ottaviani G, Matturri L. Developmental alterations of the auditory brainstem centers--pathogenetic implications in Sudden Infant Death Syndrome. J Neurol Sci 2015; 357:257-63. [PMID: 26254624 DOI: 10.1016/j.jns.2015.07.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 11/18/2022]
Abstract
Sudden Infant Death Syndrome (SIDS), despite the success of campaigns to reduce its risks, is the leading cause of infant death in the Western world. Even though the pathogenesis remains unexplained, brainstem abnormalities of the neuronal network that mediates breathing and protective responses to asphyxia, particularly in the arousal phase from sleep, are believed to play a fundamental role. This is the first study to identify, in SIDS, developmental defects of specific brainstem centers involved in hearing pathways, particularly in the cochlear and vestibular nuclei, in the superior olivary complex and in the inferior colliculus, suggesting a possible influence of the acoustic system on respiratory activity. In 49 SIDS cases and 20 controls an in-depth anatomopathological examination of the autonomic nervous system was performed, with the main aim of detecting developmental alterations of brainstem structures controlling both the respiratory and auditory activities. Overall, a significantly higher incidence of cytoarchitectural alterations of both the auditory and respiratory network components were observed in SIDS victims compared with matched controls. Even if there is not sufficient evidence to presume that developmental defects of brainstem auditory structures can affect breathing, our findings, showing that developmental deficit in the control respiratory areas are frequently accompanied by alterations of auditory structures, highlight an additional important element for the understanding the pathogenetic mechanism of SIDS.
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Affiliation(s)
- Anna M Lavezzi
- "Lino Rossi" Research Center for the study and prevention of unexpected perinatal death and SIDS - Department of Biomedical, Surgical and Dental Sciences, University of Milan, Italy.
| | - Giulia Ottaviani
- "Lino Rossi" Research Center for the study and prevention of unexpected perinatal death and SIDS - Department of Biomedical, Surgical and Dental Sciences, University of Milan, Italy; Department of Clinical Sciences and Community Health, University of Milan, Italy
| | - Luigi Matturri
- "Lino Rossi" Research Center for the study and prevention of unexpected perinatal death and SIDS - Department of Biomedical, Surgical and Dental Sciences, University of Milan, Italy
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13
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Alsahafi Z, Dickson CT, Pagliardini S. Optogenetic excitation of preBötzinger complex neurons potently drives inspiratory activity in vivo. J Physiol 2015; 593:3673-92. [PMID: 26010654 DOI: 10.1113/jp270471] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/15/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS This study investigates the effects on ventilation of an excitatory stimulus delivered in a spatially and temporally precise manner to the inspiratory oscillator, the preBötzinger complex (preBötC). We used an adeno-associated virus expressing channelrhodopsin driven by the synapsin promoter to target the region of the preBötC. Unilateral optogenetic stimulation of preBötC increased respiratory rate, minute ventilation and increased inspiratory modulated genioglossus muscle activity. Unilateral optogenetic stimulation of preBötC consistently entrained respiratory rate up to 180 breaths min(-1) both in presence of ongoing respiratory activity and in absence of inspiratory activity. Unilateral optogenetic stimulation of preBötC induced a strong phase-independent Type 0 respiratory reset, with a short delay in the response of 100 ms. We identified a refractory period of ∼200 ms where unilateral preBötC optogenetic stimulation is not able to initiate the next respiratory event. ABSTRACT Understanding the sites and mechanisms underlying respiratory rhythmogenesis is of fundamental interest in the field of respiratory neurophysiology. Previous studies demonstrated the necessary and sufficient role of preBötzinger complex (preBötC) in generating inspiratory rhythms in vitro and in vivo. However, the influence of timed activation of the preBötC network in vivo is as yet unknown given the experimental approaches previously used. By unilaterally infecting preBötC neurons using an adeno-associated virus expressing channelrhodopsin we photo-activated the network in order to assess how excitation delivered in a spatially and temporally precise manner to the inspiratory oscillator influences ongoing breathing rhythms and related muscular activity in urethane-anaesthetized rats. We hypothesized that if an excitatory drive is necessary for rhythmogenesis and burst initiation, photo-activation of preBötC not only will increase respiratory rate, but also entrain it over a wide range of frequencies with fast onset, and have little effect on ongoing respiratory rhythm if a stimulus is delivered during inspiration. Stimulation of preBötC neurons consistently increased respiratory rate and entrained respiration up to fourfold baseline conditions. Furthermore, brief pulses of photostimulation delivered at random phases between inspiratory events robustly and consistently induced phase-independent (Type 0) respiratory reset and recruited inspiratory muscle activity at very short delays (∼100 ms). A 200 ms refractory period following inspiration was also identified. These data provide strong evidence for a fine control of inspiratory activity in the preBötC and provide further evidence that the preBötC network constitutes the fundamental oscillator of inspiratory rhythms.
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Affiliation(s)
- Zaki Alsahafi
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada
| | - Clayton T Dickson
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,Department of Psychology, Faculty of Science, University of Alberta, Edmonton, Alberta, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Silvia Pagliardini
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada.,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
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14
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Brisebois S, Samson N, Fortier PH, Doueik AA, Carreau AM, Praud JP. Effects of reflux laryngitis on non-nutritive swallowing in newborn lambs. Respir Physiol Neurobiol 2014; 200:57-63. [PMID: 24893350 DOI: 10.1016/j.resp.2014.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/13/2014] [Accepted: 05/27/2014] [Indexed: 11/15/2022]
Abstract
Reflux laryngitis in infants may be involved not only in laryngeal disorders, but also in disorders of cardiorespiratory control through its impact on laryngeal function. Our objective was to study the effect of reflux laryngitis on non-nutritive swallowing (NNS) and NNS-breathing coordination. Two groups of six newborn lambs, randomized into laryngitis and control groups, were surgically instrumented for recording states of alertness, swallowing and cardiorespiratory variables without sedation. A mild to moderate reflux laryngitis was induced in lambs from the experimental group. A significant decrease in the number of NNS bursts and apneas was observed in the laryngitis group in active sleep (p=0.03). In addition, lower heart and respiratory rates, as well as prolonged apnea duration (p<0.0001) were observed. No physiologically significant alterations in NNS-breathing coordination were observed in the laryngitis group. We conclude that a mild to moderate reflux laryngitis alters NNS burst frequency and autonomous control of cardiac activity and respiration in lambs.
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Affiliation(s)
- Simon Brisebois
- Department of Surgery, ENT Division, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4
| | - Nathalie Samson
- Department of Pediatrics, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4; Department of Physiology, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4
| | - Pierre-Hugues Fortier
- Department of Surgery, ENT Division, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4
| | - Alexandre A Doueik
- Department of Pathology, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4
| | - Anne-Marie Carreau
- Department of Pediatrics, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4; Department of Physiology, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4
| | - Jean-Paul Praud
- Department of Pediatrics, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4; Department of Physiology, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4; Department of Surgery, ENT Division, Université de Sherbrooke, 3001 12(e) Avenue Nord, Sherbrooke (QC), Canada J1H 5N4.
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15
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Bautista TG, Fong AY, Dutschmann M. Spontaneous swallowing occurs during autoresuscitation in the in situ brainstem preparation of rat. Respir Physiol Neurobiol 2014; 202:35-43. [PMID: 25086277 DOI: 10.1016/j.resp.2014.07.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 11/18/2022]
Abstract
Previous studies report that upper airway reflexes are operational during autoresuscitation from respiratory arrest. We investigated swallowing/breathing interactions, measured by recording of vagal (VNA) and phrenic nerve activities (PNA), during autoresuscitation in the in situ perfused brainstem preparation of juvenile rats. During the initial surgery, respiratory arrest was induced by exsanguination and cooling. Reperfusion (i.e. re-oxygenation and re-warming) of the brainstem circuits was associated with frequent spontaneous swallowing before resumption of respiration (n=6, 'stage 1 autoresuscitation'). When recovered, the respiratory pattern was transiently apneustic-like ('stage 2 autoresuscitation'). Spontaneous swallowing often occurred at the end of the prolonged PNA (n=9/12). Successful autoresuscitation was characterised by re-establishment of the 3 phase respiratory motor pattern and no spontaneous swallowing. Pharmacological inhibition (isoguvacine, 10 mM, 50-75 nl; n=10) of the Kölliker-Fuse nucleus (KF) mimicked stage 2 autoresuscitation. However, the frequency of spontaneous swallowing after KF inhibition did not correlate with subsequent recovery of the eupneic respiratory motor pattern.
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Affiliation(s)
- Tara G Bautista
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria 3010 Australia.
| | - Angelina Y Fong
- Department of Physiology, University of Melbourne, Victoria 3010, Australia
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria 3010 Australia
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16
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Bautista TG, Dutschmann M. Ponto-medullary nuclei involved in the generation of sequential pharyngeal swallowing and concomitant protective laryngeal adduction in situ. J Physiol 2014; 592:2605-23. [PMID: 24639482 DOI: 10.1113/jphysiol.2014.272468] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Both swallowing and respiration involve postinspiratory laryngeal adduction. Swallowing-related postinspiratory neurons are likely to be located in the nucleus of the solitary tract (NTS) and those involved in respiration are found in the Kölliker-Fuse nucleus (KF). The function of KF and NTS in the generation of swallowing and its coordination with respiration was investigated in perfused brainstem preparations of juvenile rats (n = 41). Orally injected water evoked sequential pharyngeal swallowing (s-PSW) seen as phasic, spindle-shaped bursting of vagal nerve activity (VNA) against tonic postinspiratory discharge. KF inhibition by microinjecting isoguvacine (GABAA receptor agonist) selectively attenuated tonic postinspiratory VNA (n = 10, P < 0.001) but had no effect on frequency or timing of s-PSW. KF disinhibition after bicuculline (GABAA receptor antagonist) microinjections caused an increase of the tonic VNA (n = 8, P < 0.01) resulting in obscured and delayed phasic s-PSW. Occurrence of spontaneous PSW significantly increased after KF inhibition (P < 0.0001) but not after KF disinhibition (P = 0.14). NTS isoguvacine microinjections attenuated the occurrence of all PSW (n = 5, P < 0.01). NTS bicuculline microinjections (n = 6) resulted in spontaneous activation of a disordered PSW pattern and long-lasting suppression of respiratory activity. Pharmacological manipulation of either KF or NTS also triggered profound changes in respiratory postinspiratory VNA. Our results indicate that the s-PSW comprises two functionally distinct components. While the primary s-PSW is generated within the NTS, a KF-mediated laryngeal adductor reflex safeguards the lower airways from aspiration. Synaptic interaction between KF and NTS is required for s-PSW coordination with respiration as well as for proper gating and timing of s-PSW.
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Affiliation(s)
- Tara G Bautista
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria, 3052, Australia
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria, 3052, Australia
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17
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Bautista TG, Dutschmann M. Inhibition of the pontine Kölliker-Fuse nucleus abolishes eupneic inspiratory hypoglossal motor discharge in rat. Neuroscience 2014; 267:22-9. [PMID: 24603053 DOI: 10.1016/j.neuroscience.2014.02.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/17/2014] [Accepted: 02/19/2014] [Indexed: 11/28/2022]
Abstract
The pontine Kölliker-Fuse nucleus (KF) has established functions in the regulation of inspiratory-expiratory phase transition and the regulation of upper airway patency via laryngeal valving mechanisms. Here we studied the role of the KF in the gating and modulation of eupneic hypoglossal motor activity (HNA) using the in situ perfused brainstem preparation, which displays robust inspiratory HNA. Microinjection of glutamate into the KF area triggered complex and often biphasic modulation (excitation/inhibition or inhibition/excitation) of HNA. Subsequent transient pharmacological inhibition of KF by unilateral microinjection of GABA-A receptor agonist isoguvacine reduced HNA and while bilateral microinjections completely abolished HNA. Our results indicate that mixed and overlapping KF pre-motor neurons provide eupneic drive for inspiratory HNA and postinspiratory vagal nerve activity. Both motor activities have important functions in the regulation of upper airway patency during eupnea but also during various oro-pharyngeal behaviors. These results have potential implications in the contribution of state-dependent modulation of KF hypoglossal pre-motor neurons during sleep-wake cycle to obstructive sleep apnea.
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Affiliation(s)
- T G Bautista
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria 3052, Australia
| | - M Dutschmann
- Florey Institute of Neuroscience and Mental Health, Gate 11, Royal Parade, University of Melbourne, Victoria 3052, Australia.
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18
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Forster H, Bonis J, Krause K, Wenninger J, Neumueller S, Hodges M, Pan L. Contributions of the pre-Bötzinger complex and the Kölliker-fuse nuclei to respiratory rhythm and pattern generation in awake and sleeping goats. PROGRESS IN BRAIN RESEARCH 2014; 209:73-89. [PMID: 24746044 DOI: 10.1016/b978-0-444-63274-6.00005-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We investigated in three groups of awake and sleeping goats whether there are differences in ventilatory responses after injections of Ibotenic acid (IA, glutamate receptor agonist and neurotoxin) into the pre-Bötzinger complex (preBötC), lateral parabrachial (LPBN), medial (MPBN) parabrachial, or Kölliker-Fuse nuclei (KFN). In one group, within minutes after bilateral injection of 10μl IA (50mM) into the preBötC, there was a 10-fold increase in breathing frequency, but 1.5h later, the goats succumbed to terminal apnea. These data are consistent with findings in reduced preparations that the preBötC is critical to sustaining normal breathing. In a second group, increasing volumes (0.5-10μl) of IA injected at weekly intervals into the preBötC elicited a near-dose-dependent tachypnea and irregular breathing that lasted at least 5h. There were apneas restricted to wakefulness, but none were terminal. Postmortem histology revealed that the preBötC was 90% destroyed, but there was a 25-40% above normal number of neurons in the presumed parafacial respiratory group that may have contributed to maintenance of arterial blood gas homeostasis. In a third group, bilateral injections (1 and 10μl) of IA into the LPBN, MPBN, or KFN did not significantly increase breathing in any group, and there were no terminal apneas. However, 3-5h after the injections into the KFN, breathing frequency was decreased and the three-phase eupneic breathing pattern was eliminated. Between 10 and 15h after the injections, the eupneic breathing pattern was not consistently restored to normal, breathing frequency remained attenuated, and there were apneas during wakefulness. Our findings during wakefulness and NREM sleep warrant concluding that (a) the preBötC is a primary site of respiratory rhythm generation; (b) the preBötC and the KFN are determinants of respiratory pattern generation; (c) after IA-induced lesions, there is time-dependent plasticity within the respiratory control network; and (d) ventilatory control mechanisms are state dependent.
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Affiliation(s)
- Hubert Forster
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA.
| | - Josh Bonis
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | - Katie Krause
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | - Julie Wenninger
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | - Suzanne Neumueller
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | - Matthew Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | - Lawrence Pan
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physical Therapy, Marquette University, Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
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19
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Bautista TG, Sun QJ, Pilowsky PM. The generation of pharyngeal phase of swallow and its coordination with breathing: interaction between the swallow and respiratory central pattern generators. PROGRESS IN BRAIN RESEARCH 2014; 212:253-75. [PMID: 25194202 DOI: 10.1016/b978-0-444-63488-7.00013-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Swallowing and breathing utilize common muscles and an anatomical passage: the pharynx. The risk of aspiration of ingested material is minimized not only by the laryngeal adduction of the vocal folds and laryngeal elevation but also by the precise coordination of swallows with breathing. Namely, swallows: (1) are preferentially initiated in the postinspiratory/expiratory phase, (2) are accompanied by a brief apnea, and (3) are often followed by an expiration and delay of the next breath. This review summarizes the expiratory evidence on the brainstem regions comprising the central pattern generator (CPG) that produces the pharyngeal stage of swallow, how the motor acts of swallowing and breathing are coordinated, and lastly, brainstem regions where the swallowing and respiratory CPGs may interact in order to ensure "safe" swallows.
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Affiliation(s)
- Tara G Bautista
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia; Australian School of Advanced Medicine, Macquarie University, North Ryde, New South Wales, Australia.
| | - Qi-Jian Sun
- Australian School of Advanced Medicine, Macquarie University, North Ryde, New South Wales, Australia
| | - Paul M Pilowsky
- Heart Research Institute, Newtown, New South Wales, Australia
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