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Olmos-Pastoresa CA, Vázquez-Mendoza E, López-Meraz ML, Pérez-Estudillo CA, Beltran-Parrazal L, Morgado-Valle C. Transgenic rodents as dynamic models for the study of respiratory rhythm generation and modulation: a scoping review and a bibliometric analysis. Front Physiol 2023; 14:1295632. [PMID: 38179140 PMCID: PMC10764557 DOI: 10.3389/fphys.2023.1295632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/20/2023] [Indexed: 01/06/2024] Open
Abstract
The pre-Bötzinger complex, situated in the ventrolateral medulla, serves as the central generator for the inspiratory phase of the respiratory rhythm. Evidence strongly supports its pivotal role in generating, and, in conjunction with the post-inspiratory complex and the lateral parafacial nucleus, in shaping the respiratory rhythm. While there remains an ongoing debate concerning the mechanisms underlying these nuclei's ability to generate and modulate breathing, transgenic rodent models have significantly contributed to our understanding of these processes. However, there is a significant knowledge gap regarding the spectrum of transgenic rodent lines developed for studying respiratory rhythm, and the methodologies employed in these models. In this study, we conducted a scoping review to identify commonly used transgenic rodent lines and techniques for studying respiratory rhythm generation and modulation. Following PRISMA guidelines, we identified relevant papers in PubMed and EBSCO on 29 March 2023, and transgenic lines in Mouse Genome Informatics and the International Mouse Phenotyping Consortium. With strict inclusion and exclusion criteria, we identified 80 publications spanning 1997-2022 using 107 rodent lines. Our findings revealed 30 lines focusing on rhythm generation, 61 on modulation, and 16 on both. The primary in vivo method was whole-body plethysmography. The main in vitro method was hypoglossal/phrenic nerve recordings using the en bloc preparation. Additionally, we identified 119 transgenic lines with the potential for investigating the intricate mechanisms underlying respiratory rhythm. Through this review, we provide insights needed to design more effective experiments with transgenic animals to unravel the mechanisms governing respiratory rhythm. The identified transgenic rodent lines and methodological approaches compile current knowledge and guide future research towards filling knowledge gaps in respiratory rhythm generation and modulation.
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Affiliation(s)
| | | | | | | | - Luis Beltran-Parrazal
- Laboratorio de Neurofisiología, Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| | - Consuelo Morgado-Valle
- Laboratorio de Neurofisiología, Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Xalapa, Veracruz, Mexico
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2
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Jampolska M, Andrzejewski K, Boguszewski PM, Kaczyńska K. L-DOPA Improves Ventilation but Not the Ventilatory Response to Hypercapnia in a Reserpine Model of Parkinson's Disease. Brain Sci 2023; 13:brainsci13050775. [PMID: 37239247 DOI: 10.3390/brainsci13050775] [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: 04/04/2023] [Revised: 04/27/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Parkinson's disease (PD) is a neurological disorder characterized by progressive degeneration of the substantia nigra that affects mainly movement control. However, pathological changes associated with the development of PD may also alter respiration and can lead to chronic episodes of hypoxia and hypercapnia. The mechanism behind impaired ventilation in PD is unclear. Therefore, in this study, we explore the hypercapnic ventilatory response in a reproducible reserpine-induced (RES) model of PD and parkinsonism. We also investigated how dopamine supplementation with L-DOPA, a classic drug used to treat PD, would affect the breathing and respiratory response to hypercapnia. Reserpine treatment resulted in decreased normocapnic ventilation and behavioral changes manifested as low physical activity and exploratory behavior. The respiratory rate and the minute ventilation response to hypercapnia were significantly higher in sham rats compared to the RES group, while the tidal volume response was lower. All of this appears to be due to reduced baseline ventilation values produced by reserpine. L-DOPA reversed reduced ventilation, indicating a stimulatory effect of DA on breathing, and showed the potency of DA supplementation in restoring normal respiratory activity.
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Affiliation(s)
- Monika Jampolska
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland
| | - Kryspin Andrzejewski
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland
| | - Paweł M Boguszewski
- Laboratory of Animal Models, Neurobiology Centre, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Ludwika Pasteura 3 St., 02-093 Warsaw, Poland
| | - Katarzyna Kaczyńska
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland
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Cáceres D, Ochoa M, González-Ortiz M, Bravo K, Eugenín J. Effects of Prenatal Cannabinoids Exposure upon Placenta and Development of Respiratory Neural Circuits. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1428:199-232. [PMID: 37466775 DOI: 10.1007/978-3-031-32554-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Cannabis use has risen dangerously during pregnancy in the face of incipient therapeutic use and a growing perception of safety. The main psychoactive compound of the Cannabis sativa plant is the phytocannabinoid delta-9-tetrahydrocannabinol (A-9 THC), and its status as a teratogen is controversial. THC and its endogenous analogues, anandamide (AEA) and 2-AG, exert their actions through specific receptors (eCBr) that activate intracellular signaling pathways. CB1r and CB2r, also called classic cannabinoid receptors, together with their endogenous ligands and the enzymes that synthesize and degrade them, constitute the endocannabinoid system. This system is distributed ubiquitously in various central and peripheral tissues. Although the endocannabinoid system's most studied role is controlling the release of neurotransmitters in the central nervous system, the study of long-term exposure to cannabinoids on fetal development is not well known and is vital for understanding environmental or pathological embryo-fetal or postnatal conditions. Prenatal exposure to cannabinoids in animal models has induced changes in placental and embryo-fetal organs. Particularly, cannabinoids could influence both neural and nonneural tissues and induce embryo-fetal pathological conditions in critical processes such as neural respiratory control. This review aims at the acute and chronic effects of prenatal exposure to cannabinoids on placental function and the embryo-fetal neurodevelopment of the respiratory pattern. The information provided here will serve as a theoretical framework to critically evaluate the teratogen effects of the consumption of cannabis during pregnancy.
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Affiliation(s)
- Daniela Cáceres
- Laboratorio de Sistemas Neurales, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Martín Ochoa
- Laboratorio de Sistemas Neurales, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Marcelo González-Ortiz
- Laboratorio de Investigación Materno-Fetal (LIMaF), Departamento de Obstetricia y Ginecología, Facultad de Medicina, Universidad de Concepción, Concepción, Chile
| | - Karina Bravo
- Laboratorio de Sistemas Neurales, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
- Facultad de Ingeniería, Universidad Autónoma de Chile, Providencia, Chile
| | - Jaime Eugenín
- Laboratorio de Sistemas Neurales, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
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4
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Willems S, Merk D. Medicinal Chemistry and Chemical Biology of Nurr1 Modulators: An Emerging Strategy in Neurodegeneration. J Med Chem 2022; 65:9548-9563. [PMID: 35797147 DOI: 10.1021/acs.jmedchem.2c00585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nuclear receptor related 1 (Nurr1) is a transcription factor with neuroprotective and antineuroinflammatory properties. Observations from genetic studies and human patients support potential of Nurr1 as a therapeutic target in neurodegeneration, but due to a lack of high-quality chemical tools for pharmacological control of Nurr1, its target validation is pending. Nevertheless, considerable progress has recently been made in elucidating structural and functional characteristics of Nurr1, and several ligand scaffolds have been discovered. Here, we analyze Nurr1's structure and mechanisms compared to other nuclear receptors, summarize the known small molecule Nurr1 ligands, and discuss the available evidence for the therapeutic potential of Nurr1 in neurodegeneration.
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Affiliation(s)
- Sabine Willems
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, 60438 Frankfurt, Germany.,Department of Pharmacy, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Daniel Merk
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, 60438 Frankfurt, Germany.,Department of Pharmacy, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
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Mouradian GC, Kilby M, Alvarez S, Kaplan K, Hodges MR. Mortality and ventilatory effects of central serotonin deficiency during postnatal development depend on age but not sex. Physiol Rep 2021; 9:e14946. [PMID: 34228894 PMCID: PMC8259800 DOI: 10.14814/phy2.14946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 11/24/2022] Open
Abstract
Serotonin (5-HT) influences brain development and has predominantly excitatory neuromodulatory effects on the neural respiratory control circuitry. Infants that succumb to sudden infant death syndrome (SIDS) have reduced brainstem 5-HT levels and Tryptophan hydroxylase 2 (Tph2). Furthermore, there are age- and sex-dependent risk factors associated with SIDS. Here we utilized our established Dark Agouti transgenic rat lacking central serotonin KO to test the hypotheses that CNS 5-HT deficiency leads to: (1) high mortality in a sex-independent manner, (2) age-dependent alterations in other CNS aminergic systems, and (3) age-dependent impairment of chemoreflexes during post-natal development. KO rat pups showed high neonatal mortality but not in a sex-dependent manner and did not show altered hypoxic or hypercapnic ventilatory chemoreflexes. However, KO rat pups had increased apnea-related metrics during a specific developmental age (P12-16), which were preceded by transient increases in dopaminergic system activity (P7-8). These results support and extend the concept that 5-HT per se is a critical factor in supporting respiratory control during post-natal development.
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Affiliation(s)
- Gary C. Mouradian
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
- Neuroscience Research CenterMedical College of WisconsinMilwaukeeWIUSA
| | - Madeline Kilby
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
| | - Santiago Alvarez
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
| | - Kara Kaplan
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
| | - Matthew R. Hodges
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
- Neuroscience Research CenterMedical College of WisconsinMilwaukeeWIUSA
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O'Connor KM, Lucking EF, Bastiaanssen TFS, Peterson VL, Crispie F, Cotter PD, Clarke G, Cryan JF, O'Halloran KD. Prebiotic administration modulates gut microbiota and faecal short-chain fatty acid concentrations but does not prevent chronic intermittent hypoxia-induced apnoea and hypertension in adult rats. EBioMedicine 2020; 59:102968. [PMID: 32861200 PMCID: PMC7475129 DOI: 10.1016/j.ebiom.2020.102968] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/22/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Evidence is accruing to suggest that microbiota-gut-brain signalling plays a regulatory role in cardiorespiratory physiology. Chronic intermittent hypoxia (CIH), modelling human sleep apnoea, affects gut microbiota composition and elicits cardiorespiratory morbidity. We investigated if treatment with prebiotics ameliorates cardiorespiratory dysfunction in CIH-exposed rats. METHODS Adult male rats were exposed to CIH (96 cycles/day, 6.0% O2 at nadir) for 14 consecutive days with and without prebiotic supplementation (fructo- and galacto-oligosaccharides) beginning two weeks prior to gas exposures. FINDINGS CIH increased apnoea index and caused hypertension. CIH exposure had modest effects on the gut microbiota, decreasing the relative abundance of Lactobacilli species, but had no effect on microbial functional characteristics. Faecal short-chain fatty acid (SCFA) concentrations, plasma and brainstem pro-inflammatory cytokine concentrations and brainstem neurochemistry were unaffected by exposure to CIH. Prebiotic administration modulated gut microbiota composition and diversity, altering gut-metabolic (GMMs) and gut-brain (GBMs) modules and increased faecal acetic and propionic acid concentrations, but did not prevent adverse CIH-induced cardiorespiratory phenotypes. INTERPRETATION CIH-induced cardiorespiratory dysfunction is not dependant upon changes in microbial functional characteristics and decreased faecal SCFA concentrations. Prebiotic-related modulation of microbial function and resultant increases in faecal SCFAs were not sufficient to prevent CIH-induced apnoea and hypertension in our model. Our results do not exclude the potential for microbiota-gut-brain axis involvement in OSA-related cardiorespiratory morbidity, but they demonstrate that in a relatively mild model of CIH, sufficient to evoke classic cardiorespiratory dysfunction, such changes are not obligatory for the development of morbidity, but may become relevant in the elaboration and maintenance of cardiorespiratory morbidity with progressive disease. FUNDING Department of Physiology and APC Microbiome Ireland, University College Cork, Ireland. APC Microbiome Ireland is funded by Science Foundation Ireland, through the Government's National Development Plan.
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Affiliation(s)
- Karen M O'Connor
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Eric F Lucking
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Thomaz F S Bastiaanssen
- Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | | | - Fiona Crispie
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - Paul D Cotter
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland.
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Ghali MGZ, Beshay S. Role of fast inhibitory synaptic transmission in neonatal respiratory rhythmogenesis and pattern formation. Mol Cell Neurosci 2019; 100:103400. [PMID: 31472222 DOI: 10.1016/j.mcn.2019.103400] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/31/2019] [Accepted: 08/25/2019] [Indexed: 10/26/2022] Open
Abstract
Several studies have investigated the general role of chloride-based neurotransmission (GABAA and glycinergic signaling) in respiratory rhythmogenesis and pattern formation. In several brain regions, developmental alterations in these signaling pathways have been shown to be mediated by changes in cation-chloride cotransporter (CC) expression. For instance, CC expression changes during the course of neonatal development in medullary respiratory nuclei and other brain/spinal cord regions in a manner which decreases the cellular import, and increases the export, of chloride ions, shifting reversal potentials for chloride to progressively more negative values with maturation. In slice preparations of the same, this is related to an excitatory-to-inhibitory shift of GABAA- and glycinergic signaling. In medullary slices, GABAA-/glycinergic signaling in the early neonatal period is excitatory, becoming inhibitory over time. Additionally, blockade of the Na+/K+/2Cl- cotransporter, which imports these ions via secondary active transport, converts excitatory response to inhibitory ones. These effects have not yet been demonstrated at the individual respiratory-related neuron level to occur in intact (in vivo or in situ) animal preparations, which in contrast to slices, possess normal network connectivity and natural sources of tonic drive. Developmental changes in respiratory rhythm generating and pattern forming pontomedullary respiratory circuitry may contribute to critical periods, during which there exist increased risk for perinatal respiratory disturbances of central, obstructive, or hypoxia/hypercapnia-induced origin, including the sudden infant death syndrome. Thus, better characterizing the neurochemical maturation of the central respiratory network will enhance our understanding of these conditions, which will facilitate development of targeted therapies for respiratory disturbances in neonates and infants.
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Affiliation(s)
- Michael George Zaki Ghali
- Department of Neurological Surgery, Houston Methodist Hospital, Houston, TX 77030, United States of America.
| | - Sarah Beshay
- Department of Pulmonology and Critical Care Medicine, Houston Methodist Hospital, Houston, TX 77030, United States of America
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8
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Ikeda K, Onimaru H, Inada H, Tien Lin S, Arata S, Osumi N. Structural and functional defects of the respiratory neural system in the medulla and spinal cord of Pax6 mutant rats. Brain Res Bull 2019; 152:107-116. [PMID: 31301380 DOI: 10.1016/j.brainresbull.2019.07.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/26/2019] [Accepted: 07/08/2019] [Indexed: 11/24/2022]
Abstract
Pax6 is an important transcription factor expressed in several discrete domains of the developing central nervous system. It has been reported that Pax6 is involved in the specification of subtypes of hindbrain motor neurons. Pax6 homozygous mutant (rSey2/rSey2) rats die soon after birth, probably due to impaired respiratory movement. To determine whether the respiratory center in the medulla functions normally, we analyzed the histological and neurophysiological properties of the medulla and spinal cord in fetal rats with this mutation. First, the medulla of rSey2/rSey2 at embryonic (E) 21.5-E22.5 tended to be smaller than those from heterozygous mutant (rSey2/+) and wild-type (+/+) littermates. Through immunohistochemical analysis, we confirmed normal distribution of Phox2b-expressing cells in the parafacial respiratory group (pFRG) of rSey2/rSey2 rats. Expression of neurokinin-1 receptor (NK-1R) was weak and dispersed in rSey2/rSey2 rats. In addition, rSey2/rSey2 rats have a defect of the hypoglossal nerve root. Electrophysiological analysis using brainstem-spinal cord preparations (E21.5-E22.5) revealed that rSey2/rSey2 rats showed larger fluctuation of the amplitude of inspiratory activity monitored from the fourth cervical root although there was no significant difference in the respiratory rate among rSey2/rSey2, rSey2/+, and +/+ littermates. The response of respiratory rhythm to high CO2 was similar among all genotypes. Optical recordings of neuronal activity revealed that the activity of the pFRG tended to be weaker and inspiratory activity appeared in more scattered areas in the caudal ventral medulla in the rSey2/rSey2 rats. These results suggest that the basal activity of the respiratory system was preserved with mild impairment of the inspiratory activity in the rSey2/rSey2 rats and that the Pax6 gene is involved in the functional development of the neuronal system producing effective inspiratory motor outputs for survival.
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Affiliation(s)
- Keiko Ikeda
- Department of Physiology, International University of Health and Welfare (IUHW), 4-3 Kozunomori, Narita City, Chiba, 286-8686, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan.
| | - Hitoshi Inada
- Department of Developmental Neuroscience, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Shih Tien Lin
- Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan
| | - Satoru Arata
- Department of Biochemistry, Faculty of Arts and Sciences, Showa University, Fujiyoshida, Yamanashi, 403-0005, Japan
| | - Noriko Osumi
- Department of Developmental Neuroscience, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
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O'Connor KM, Lucking EF, Golubeva AV, Strain CR, Fouhy F, Cenit MC, Dhaliwal P, Bastiaanssen TFS, Burns DP, Stanton C, Clarke G, Cryan JF, O'Halloran KD. Manipulation of gut microbiota blunts the ventilatory response to hypercapnia in adult rats. EBioMedicine 2019; 44:618-638. [PMID: 30898652 PMCID: PMC6606895 DOI: 10.1016/j.ebiom.2019.03.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND It is increasingly evident that perturbations to the diversity and composition of the gut microbiota have significant consequences for the regulation of integrative physiological systems. There is growing interest in the potential contribution of microbiota-gut-brain signalling to cardiorespiratory control in health and disease. METHODS In adult male rats, we sought to determine the cardiorespiratory effects of manipulation of the gut microbiota following a 4-week administration of a cocktail of antibiotics. We subsequently explored the effects of administration of faecal microbiota from pooled control (vehicle) rat faeces, given by gavage to vehicle- and antibiotic-treated rats. FINDINGS Antibiotic intervention depressed the ventilatory response to hypercapnic stress in conscious animals, owing to a reduction in the respiratory frequency response to carbon dioxide. Baseline frequency, respiratory timing variability, and the expression of apnoeas and sighs were normal. Microbiota-depleted rats had decreased systolic blood pressure. Faecal microbiota transfer to vehicle- and antibiotic-treated animals also disrupted the gut microbiota composition, associated with depressed ventilatory responsiveness to hypercapnia. Chronic antibiotic intervention or faecal microbiota transfer both caused significant disruptions to brainstem monoamine neurochemistry, with increased homovanillic acid:dopamine ratio indicative of increased dopamine turnover, which correlated with the abundance of several bacteria of six different phyla. INTERPRETATION Chronic antibiotic administration and faecal microbiota transfer disrupt gut microbiota, brainstem monoamine concentrations and the ventilatory response to hypercapnia. We suggest that aberrant microbiota-gut-brain axis signalling has a modulatory influence on respiratory behaviour during hypercapnic stress. FUND: Department of Physiology and APC Microbiome Ireland, University College Cork, Ireland.
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Affiliation(s)
- Karen M O'Connor
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Eric F Lucking
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Anna V Golubeva
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Conall R Strain
- Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - Fiona Fouhy
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - María C Cenit
- Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; Institute of Agrochemistry and Food Technology (IATA), National Council for Scientific Research (CSIC), Valencia, Spain
| | - Pardeep Dhaliwal
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Thomaz F S Bastiaanssen
- Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - David P Burns
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Catherine Stanton
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland.
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10
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Porzionato A, Macchi V, De Caro R. Central and peripheral chemoreceptors in sudden infant death syndrome. J Physiol 2018; 596:3007-3019. [PMID: 29645275 PMCID: PMC6068209 DOI: 10.1113/jp274355] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 03/20/2018] [Indexed: 11/08/2022] Open
Abstract
The pathogenesis of sudden infant death syndrome (SIDS) has been ascribed to an underlying biological vulnerability to stressors during a critical period of development. This paper reviews the main data in the literature supporting the role of central (e.g. retrotrapezoid nucleus, serotoninergic raphe nuclei, locus coeruleus, orexinergic neurons, ventral medullary surface, solitary tract nucleus) and peripheral (e.g. carotid body) chemoreceptors in the pathogenesis of SIDS. Clinical and experimental studies indicate that central and peripheral chemoreceptors undergo critical development during the initial postnatal period, consistent with the age range of SIDS (<1 year). Most of the risk factors for SIDS (gender, genetic factors, prematurity, hypoxic/hyperoxic stimuli, inflammation, perinatal exposure to cigarette smoke and/or substance abuse) may structurally and functionally affect the developmental plasticity of central and peripheral chemoreceptors, strongly suggesting the involvement of these structures in the pathogenesis of SIDS. Morphometric and neurochemical changes have been found in the carotid body and brainstem respiratory chemoreceptors of SIDS victims, together with functional signs of chemoreception impairment in some clinical studies. However, the methodological problems of SIDS research will have to be addressed in the future, requiring large and highly standardized case series. Up-to-date autopsy protocols should be produced, involving substantial, and exhaustive sampling of all potentially involved structures (including peripheral arterial chemoreceptors). Morphometric approaches should include unbiased stereological methods with three-dimensional probes. Prospective clinical studies addressing functional tests and risk factors (including genetic traits) would probably be the gold standard, allowing markers of intrinsic or acquired vulnerability to be properly identified.
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Affiliation(s)
- Andrea Porzionato
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
| | - Veronica Macchi
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
| | - Raffaele De Caro
- Section of Anatomy, Department of NeuroscienceUniversity of PadovaItaly
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11
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de Campos PS, Kawamura LRSM, Hasegawa K, Kumei Y, Zeredo JL. Analysis of respiratory movements in a mouse model of late Parkinson's disease submitted to stress. Respir Physiol Neurobiol 2018; 251:50-56. [PMID: 29481879 DOI: 10.1016/j.resp.2018.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/08/2018] [Accepted: 02/18/2018] [Indexed: 12/16/2022]
Abstract
Parkinson's disease (PD) is known to cause tremor and rigidity, but other symptoms such as respiratory and autonomic dysfunctions are a major cause of disability and mortality in patients. In this study, we examined respiratory movements by using cineradiography on a murine model of late/advanced PD. Under surgical anesthesia, C57BL/6J mice received an injection of either 6-OHDA or vehicle solution to the right striatum. Two weeks after surgery, the animals had their respiratory movements recorded by video X-ray without any restraint. During recordings the animals were submitted to a mild acute-stress challenge. Behavioral tests were performed to assess the severity of the 6-OHDA lesion. As a result, behavioral tests confirmed severe motor impairments in 6-OHDA mice as compared to controls. 6-OHDA mice showed a predominantly thoracic respiratory pattern with reduced diaphragmatic excursion, and reduced respiratory frequency after stress. These results suggest that advanced nigrostrial degeneration may cause respiratory alterations with the features of obstructive-type respiratory disorders.
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Affiliation(s)
- P S de Campos
- Graduate Program in Health Science and Technology, University of Brasilia, Brasilia, Brazil
| | - L R S M Kawamura
- Graduate Program in Health Science and Technology, University of Brasilia, Brasilia, Brazil
| | - K Hasegawa
- JAXA/Institute of Space and Astronautical Science, Sagamihara, Japan
| | - Y Kumei
- Department of Hard Tissue Engineering, Tokyo Medical and Dental University, Tokyo, Japan
| | - J L Zeredo
- Graduate Program in Health Science and Technology, University of Brasilia, Brasilia, Brazil.
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12
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Erythropoietin-Mediated Regulation of Central Respiratory Command. VITAMINS AND HORMONES 2017. [PMID: 28629514 DOI: 10.1016/bs.vh.2017.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Erythropoietin (Epo) is a cytokine expressed throughout the body, including in the central nervous system where it can act as a breathing modulator in the central respiratory network. In vitro, Epo allows maintaining the activity of respiratory neurons during acute hypoxia, resulting in inhibition of the hypoxia-induced rhythm depression. In vivo, Epo action on the central respiratory command results in enhancement of the acute hypoxic ventilatory response, allowing a better oxygenation of the body by improvement of gases exchanges in the lungs. Importantly, this effect of Epo is age-dependent, being observed at adulthood and at both early and late postnatal ages, but not at middle postnatal ages, when an important setup of the central respiratory command occurs. Epo regulation of the central respiratory command involves at least two intracellular signaling pathways, PI3K-Akt and MEK-ERK pathways. However, the exact mechanism underlying the action of Epo on the central respiratory control remains to be deciphered, as well as the exact cell types and nuclei involved in this control. Epo-mediated effect on the central respiratory command is regulated by several factors, including hypoxia, sex hormones, and an endogen antagonist. Although more knowledge is needed before reaching the clinical trial step, Epo seems to be a promising therapeutic treatment, notably against newborn breathing disorders.
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Lai YT, Huang YS. Modification and Application of a Commercial Whole-body Plethysmograph to Monitor Respiratory Abnormalities in Neonatal Mice. Bio Protoc 2017; 7:e2343. [PMID: 34541095 DOI: 10.21769/bioprotoc.2343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/18/2017] [Accepted: 05/22/2017] [Indexed: 11/02/2022] Open
Abstract
Proper breathing is essential for mammals to acquire oxygen after birth and requires coordinated actions among several tissues, including diaphragm, intercostal muscles, trachea, bronchi, lung and respiration-regulating neurons located in the medulla oblongata. Genetically modified mice that die early postnatally may have respiratory defects caused by maldevelopment of any one of these tissues (Turgeon and Meloche, 2009). Because of the small body size of neonatal pups, whole-body plethysmography can be used to monitor their respiratory activities. In this protocol, we modified the commercial whole-body plethysmograph by increasing metal filters in the pneumotach, connecting an extension tube to the pneumotach and removing the bias flow supply. With these modifications, the sensitivity of this device is significantly increased to enable the detection of rhythmic respiration in neonatal mice as early as postnatal day 1 (P1).
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Affiliation(s)
- Yen-Ting Lai
- Institute of Biomedical Sciences, Academia Sinica, 11529, Taipei, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica, 11529, Taipei, Taiwan
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14
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Deficiency of CPEB2-Confined Choline Acetyltransferase Expression in the Dorsal Motor Nucleus of Vagus Causes Hyperactivated Parasympathetic Signaling-Associated Bronchoconstriction. J Neurosci 2016; 36:12661-12676. [PMID: 27810937 DOI: 10.1523/jneurosci.0557-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 09/19/2016] [Accepted: 10/27/2016] [Indexed: 11/21/2022] Open
Abstract
Cytoplasmic polyadenylation element binding protein 2 (CPEB2) is an RNA-binding protein and translational regulator. To understand the physiological function of CPEB2, we generated CPEB2 knock-out (KO) mice and found that most died within 3 d after birth. CPEB2 is highly expressed in the brainstem, which controls vital functions, such as breathing. Whole-body plethysmography revealed that KO neonates had aberrant respiration with frequent apnea. Nevertheless, the morphology and function of the respiratory rhythm generator and diaphragm neuromuscular junctions appeared normal. We found that upregulated translation of choline acetyltransferase in the CPEB2 KO dorsal motor nucleus of vagus resulted in hyperactivation of parasympathetic signaling-induced bronchoconstriction, as evidenced by increased pulmonary acetylcholine and phosphorylated myosin light chain 2 in bronchial smooth muscles. Specific deletion of CPEB2 in cholinergic neurons sufficiently caused increased apnea in neonatal pups and airway hyper-reactivity in adult mice. Moreover, inhalation of an anticholinergic bronchodilator reduced apnea episodes in global and cholinergic CPEB2-KO mice. Together, the elevated airway constriction induced by cholinergic transmission in KO neonates may account for the respiratory defect and mortality. SIGNIFICANCE STATEMENT This study first generated and characterized cpeb2 gene-deficient mice. CPEB2-knock-out (KO) mice are born alive but most die within 3 d after birth showing no overt defects in anatomy. We found that the KO neonates showed severe apnea and altered respiratory pattern. Such respiratory defects could be recapitulated in mice with pan-neuron-specific or cholinergic neuron-specific ablation of the cpeb2 gene. Further investigation revealed that cholinergic transmission in the KO dorsal motor nucleus of vagus was overactivated because KO mice lack CPEB2-suppressed translation of the rate-limiting enzyme in the production of acetylcholine (i.e., choline acetyltransferase). Consequently, increased parasympathetic signaling leads to hyperactivated bronchoconstriction and abnormal respiration in the KO neonates.
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15
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Andrzejewski K, Budzińska K, Zaremba M, Kaczyńska K. Hypoxic ventilatory response after dopamine D2 receptor blockade in unilateral rat model of Parkinson’s disease. Neuroscience 2016; 316:192-200. [DOI: 10.1016/j.neuroscience.2015.12.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/08/2015] [Accepted: 12/12/2015] [Indexed: 02/06/2023]
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16
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Siljehav V, Shvarev Y, Herlenius E. Il-1β and prostaglandin E2 attenuate the hypercapnic as well as the hypoxic respiratory response via prostaglandin E receptor type 3 in neonatal mice. J Appl Physiol (1985) 2014; 117:1027-36. [DOI: 10.1152/japplphysiol.00542.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Prostaglandin E2 (PGE2) serves as a critical mediator of hypoxia, infection, and apnea in term and preterm babies. We hypothesized that the prostaglandin E receptor type 3 (EP3R) is the receptor responsible for PGE2-induced apneas. Plethysmographic recordings revealed that IL-1β (ip) attenuated the hypercapnic response in C57BL/6J wild-type (WT) but not in neonatal (P9) EP3R−/− mice ( P < 0.05). The hypercapnic responses in brain stem spinal cord en bloc preparations also differed depending on EP3R expression whereby the response was attenuated in EP3R−/− preparations ( P < 0.05). After severe hypoxic exposure in vivo, IL-1β prolonged time to autoresuscitation in WT but not in EP3R−/− mice. Moreover, during severe hypoxic stress EP3R−/− mice had an increased gasping duration ( P < 0.01) as well as number of gasps ( P < 0.01), irrespective of intraperitoneal treatment, compared with WT mice. Furthermore, EP3R−/− mice exhibited longer hyperpneic breathing efforts when exposed to severe hypoxia ( P < 0.01). This was then followed by a longer period of secondary apnea before autoresuscitation occurred in EP3R−/− mice ( P < 0.05). In vitro, EP3R−/− brain stem spinal cord preparations had a prolonged respiratory burst activity during severe hypoxia accompanied by a prolonged neuronal arrest during recovery in oxygenated medium ( P < 0.05). In conclusion, PGE2 exerts its effects on respiration via EP3R activation that attenuates the respiratory response to hypercapnia as well as severe hypoxia. Modulation of the EP3R may serve as a potential therapeutic target for treatment of inflammatory and hypoxic-induced detrimental apneas and respiratory disorders in neonates.
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Affiliation(s)
- Veronica Siljehav
- Neonatal Research Unit Q2:07, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; and
| | - Yuri Shvarev
- Neonatal Research Unit Q2:07, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; and
- Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Eric Herlenius
- Neonatal Research Unit Q2:07, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; and
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17
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Stergiopoulos A, Politis PK. The role of nuclear receptors in controlling the fine balance between proliferation and differentiation of neural stem cells. Arch Biochem Biophys 2013; 534:27-37. [DOI: 10.1016/j.abb.2012.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/23/2012] [Accepted: 09/20/2012] [Indexed: 12/22/2022]
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18
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Leviton A. Why the term neonatal encephalopathy should be preferred over neonatal hypoxic-ischemic encephalopathy. Am J Obstet Gynecol 2013; 208:176-80. [PMID: 22901708 DOI: 10.1016/j.ajog.2012.07.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/13/2012] [Accepted: 07/19/2012] [Indexed: 02/05/2023]
Abstract
The unresponsiveness of the full-term newborn is sometimes attributed to asphyxia, even when no severe physiologic disturbance occurred during labor and delivery. The controversy about whether to use the name "hypoxic-ischemic encephalopathy" or "newborn encephalopathy" has recently flared in publications directed toward pediatricians and neurologists. In this clinic opinion piece, I discuss the importance to obstetricians of this decision and explain why "newborn encephalopathy" should be the default term.
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Arata S, Nakamachi T, Onimaru H, Hashimoto H, Shioda S. Impaired response to hypoxia in the respiratory center is a major cause of neonatal death of the PACAP-knockout mouse. Eur J Neurosci 2012; 37:407-16. [PMID: 23136967 DOI: 10.1111/ejn.12054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/09/2012] [Accepted: 10/10/2012] [Indexed: 01/19/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide expressed widely in nervous tissues. PACAP-knockout ((-/-)) mice display a sudden infant death syndrome (SIDS)-like phenotype, although the underlying physiological mechanism to explain this remains unclear. Here, we report on the presence of abnormal respiratory activity in PACAP(-/-) mice under hypoxic conditions, which provides a basis for the SIDS-like phenotype. PACAP(-/-) mice display a lowered baseline respiratory activity compared with wild-type animals, and an abnormal response to hypoxia. More specifically, PACAP(-/-) mice at postnatal day 7 showed respiratory arrest in response to hypoxia. In contrast, their response to hypercapnic conditions was the same as that of wild-type mice. Histological and real-time PCR analyses indicated that the catecholaminergic system in the medulla oblongata was impaired in PACAP(-/-) mice, suggesting that endogenous PACAP affects respiratory centers in the medulla oblongata via its action on the catecholaminergic system. We propose that disruption of this system is involved in the SIDS-like phenotype of PACAP(-/-) mice. Thus, disorders of the catecholaminergic system involved with O(2) sensing could be implicated in underlying neuronal mechanisms responsible for SIDS.
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Affiliation(s)
- Satoru Arata
- Center for Biotechnology, Showa University, Shinagawa-ku, Tokyo, Japan
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Abstract
Breathing is an essential behavior that presents a unique opportunity to understand how the nervous system functions normally, how it balances inherent robustness with a highly regulated lability, how it adapts to both rapidly and slowly changing conditions, and how particular dysfunctions result in disease. We focus on recent advancements related to two essential sites for respiratory rhythmogenesis: (a) the preBötzinger Complex (preBötC) as the site for the generation of inspiratory rhythm and (b) the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG) as the site for the generation of active expiration.
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Affiliation(s)
- Jack L Feldman
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095-1763, USA.
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21
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Berner J, Shvarev Y, Zimmer A, Wickstrom R. Hypoxic ventilatory response in Tac1-/- neonatal mice following exposure to opioids. J Appl Physiol (1985) 2012; 113:1718-26. [PMID: 23065762 DOI: 10.1152/japplphysiol.00188.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Morphine is the dominating analgetic drug used in neonates, but opioid-induced respiratory depression limits its therapeutic use. In this study, we examined acute morphine effects on respiration during intermittent hypoxia in newborn Tac1 gene knockout mice (Tac1-/-) lacking substance P and neurokinin A. In vivo, plethysmography revealed a blunted hypoxic ventilatory response (HVR) in Tac1-/- mice. Morphine (10 mg/kg) depressed the HVR in wild-type animals through an effect on respiratory frequency, whereas it increased tidal volumes in Tac1-/- during hypoxia, resulting in increased minute ventilation. Apneas were reduced during the first hypoxic episode in both morphine-exposed groups, but were restored subsequently in Tac1-/- mice. Morphine did not affect ventilation or apnea prevalence during baseline conditions. In vitro, morphine (50 nM) had no impact on anoxic response of brain stem preparations of either strain. In contrast, it suppressed the inspiratory rhythm during normoxia and potentiated development of posthypoxic neuronal arrest, especially in Tac1-/-. Thus this phenotype has a higher sensitivity to the depressive effects of morphine on inspiratory rhythm generation, but morphine does not modify the reactivity to oxygen deprivation. In conclusion, although Tac1-/- mice are similar to wild-type animals during normoxia, they differed by displaying a reversed pattern with an improved HVR during intermittent hypoxia both in vivo and in vitro. These data suggest that opioids and the substance P-ergic system interact in the HVR, and that reducing the activity in the tachykinin system may alter the respiratory effects of opioid treatment in newborns.
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Affiliation(s)
- J Berner
- Department of Woman and Child Health, Karolinska Institutet, Stockholm, Sweden.
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22
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Khemiri H, Seaborn T, Gestreau C, Soliz J. Erythropoietin and its antagonist regulate hypoxic fictive breathing in newborn mice. Respir Physiol Neurobiol 2012; 183:115-21. [PMID: 22684041 DOI: 10.1016/j.resp.2012.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 05/29/2012] [Accepted: 05/30/2012] [Indexed: 10/28/2022]
Abstract
Clinical use of erythropoietin in adult and newborn patients has revealed its involvement in neuroprotection, neurogenesis, and angiogenesis. More recently, we showed in adult mouse, that brain erythropoietin interacts with the major brainstem centers associated with respiration to enhance the ventilatory response to acute and chronic conditions of physiological hypoxia (e.g., as occurring at high altitude). However, whether brain erythropoietin is involved in breathing regulation in newborns remains unknown. In this study, en bloc brainstem-spinal cord preparations were obtained from mice at postnatal day 4. After various periods (30, 60, or 90 min) of incubation with 0, 25, or 250 U of erythropoietin, preparations were superfused with artificial cerebrospinal fluid bubbled with normoxic or hypoxic gas mixtures. The electrophysiological fictive breathing produced by axons at the C4 ventral root was next recorded. Our results show that erythropoietin attenuates the hypoxia-mediated decrease of the central respiratory activity and improves post-hypoxic recovery. Additional analysis revealed that the soluble erythropoietin receptor (the endogenous erythropoietin antagonist) dramatically decreases neural hypoxic respiratory activity, confirming the specific erythropoietin effect on respiratory drive. These results imply that erythropoietin exerts main modulation and maintenance of respiratory motor output during hypoxic and post-hypoxic challenges in 4-days old mice.
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Affiliation(s)
- Hanan Khemiri
- Départment de Pédiatrie, Centre de Recherche de l'Hôpital St-François d'Assise (CR-SFA), Centre Hospitalier Universitaire de Québec (CHUQ), Faculté de Médecine, Université Laval, Québec, QC, Canada.
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Shirahata M, Kostuk EW, Pichard LE. Carotid chemoreceptor development in mice. Respir Physiol Neurobiol 2012; 185:20-9. [PMID: 22634368 DOI: 10.1016/j.resp.2012.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/17/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
Mice are the most suitable species for understanding genetic aspects of postnatal developments of the carotid body due to the availability of many inbred strains and knockout mice. Our study has shown that the carotid body grows differentially in different mouse strains, indicating the involvement of genes. However, the small size hampers investigating functional development of the carotid body. Hypoxic and/or hyperoxic ventilatory responses have been investigated in newborn mice, but these responses are indirect assessment of the carotid body function. Therefore, we need to develop techniques of measuring carotid chemoreceptor neural activity from young mice. Many studies have taken advantage of the knockout mice to understand chemoreceptor function of the carotid body, but they are not always suitable for addressing postnatal development of the carotid body due to lethality during perinatal periods. Various inbred strains with well-designed experiments will provide useful information regarding genetic mechanisms of the postnatal carotid chemoreceptor development. Also, targeted gene deletion is a critical approach.
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Affiliation(s)
- Machiko Shirahata
- Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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24
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Lalley PM, Mifflin SW. Opposing effects on the phrenic motor pathway attributed to dopamine-D1 and -D3/D2 receptor activation. Respir Physiol Neurobiol 2012; 181:183-93. [PMID: 22465544 DOI: 10.1016/j.resp.2012.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/09/2012] [Accepted: 03/12/2012] [Indexed: 01/11/2023]
Abstract
Previous in vivo studies revealed that dopamine-D1-agonists elevate excitability of ventral respiratory column (VRC) neurons and increase discharge activity in the phrenic motor output through actions in the brainstem. In this in vivo study performed on pentobarbital-anesthetized cats, we show that D1-agonists (SKF-38393, dihydrexidine) given intravenously enhanced discharge activity in VRC inspiratory neurons and the phrenic nerve in two stages; discharge intensity first increased to a peak and then discharge duration increased. Cross-correlation analysis of VRC inspiratory neuron and phrenic nerve discharges showed that both stages increased strength of coupling between medullary inspiratory neurons and the phrenic motoneuron output. Intracellular recording and microiontophoresis experiments indicated that D1-agonists produced their stimulatory effects indirectly through actions on synaptic inputs to VRC inspiratory neurons. Because other laboratories have provided evidence that dopamine acting on other types of receptors depresses respiratory neuron excitability we tested the effects of piribedil, an agonist that activates receptors of the generally depressant D3/D2-dopamine receptor family, on phrenic nerve activity. Piribedil depressed phrenic nerve inspiratory discharge intensity, prolonged discharge duration, slowed burst frequency and slowed rate of action potential augmentation. The effects of piribedil were partially counteracted by intravenous injection of dihydrexidine. We propose that under normal, steady state conditions, D1-receptor-mediated excitatory modulation of phrenic motor output overrides D3/D2-receptor mediated inhibition.
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Affiliation(s)
- Peter M Lalley
- The University of Wisconsin Medical Sciences Center, United States
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25
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Nurr1 regulates Top IIβ and functions in axon genesis of mesencephalic dopaminergic neurons. Mol Neurodegener 2012; 7:4. [PMID: 22296971 PMCID: PMC3359158 DOI: 10.1186/1750-1326-7-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 02/02/2012] [Indexed: 01/28/2023] Open
Abstract
Background NURR1 (also named as NR4A2) is a member of the steroid/thyroid hormone receptor family, which can bind to DNA and modulate expression of target genes. Previous studies have shown that NURR1 is essential for the nigral dopaminergic neuron phenotype and function maintenance, and the defects of the gene are possibly associated with Parkinson's disease (PD). Results In this study, we used new born Nurr1 knock-out mice combined with Affymetrix genechip technology and real time polymerase chain reaction (PCR) to identify Nurr1 regulated genes, which led to the discovery of several transcripts differentially expressed in the nigro-striatal pathway of Nurr1 knock-out mice. We found that an axon genesis gene called Topoisomerase IIβ (Top IIβ) was down-regulated in Nurr1 knock-out mice and we identified two functional NURR1 binding sites in the proximal Top IIβ promoter. While in Top IIβ null mice, we saw a significant loss of dopaminergic neurons in the substantial nigra and lack of neurites along the nigro-striatal pathway. Using specific TOP II antagonist ICRF-193 or Top IIβ siRNA in the primary cultures of ventral mesencephalic (VM) neurons, we documented that suppression of TOP IIβ expression resulted in VM neurites shortening and growth cones collapsing. Furthermore, microinjection of ICRF-193 into the mouse medial forebrain bundle (MFB) led to the loss of nigro-striatal projection. Conclusion Taken together, our findings suggest that Top IIβ might be a down-stream target of Nurr1, which might influence the processes of axon genesis in dopaminergic neurons via the regulation of TOP IIβ expression. The Nurr1-Top IIβ interaction may shed light on the pathologic role of Nurr1 defect in the nigro-striatal pathway deficiency associated with PD.
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26
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Tsuchiya N, Iwase M, Izumizaki M, Homma I. Dopaminergic modulation of exercise hyperpnoea via D2receptors in mice. Exp Physiol 2011; 97:228-38. [DOI: 10.1113/expphysiol.2011.062703] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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27
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Sirin O, Lukov GL, Mao R, Conneely OM, Goodell MA. The orphan nuclear receptor Nurr1 restricts the proliferation of haematopoietic stem cells. Nat Cell Biol 2010; 12:1213-9. [PMID: 21076412 PMCID: PMC3059561 DOI: 10.1038/ncb2125] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 10/18/2010] [Indexed: 12/15/2022]
Abstract
Successful haematopoiesis requires long-term retention of haematopoietic stem cells (HSCs) in a quiescent state. The transcriptional regulation of stem cell quiescence, especially by factors with specific functions in HSCs, is only beginning to be understood. Here, we demonstrate that Nurr1, a nuclear receptor transcription factor, has such a regulatory role. Overexpression of Nurr1 drives early haematopoietic progenitors into quiescence. When stem cells overexpressing Nurr1 are transplanted into lethally irradiated mice, they localize to the bone marrow, but do not contribute to regeneration of the blood system. Furthermore, the loss of only one allele of Nurr1 is sufficient to induce HSCs to enter the cell cycle and proliferate. Molecular analysis revealed an association between Nurr1 overexpression and upregulation of the cell-cycle inhibitor p18 (also known as INK4C), suggesting a mechanism by which Nurr1 could regulate HSC quiescence. Our findings provide critical insight into the transcriptional control mechanisms that determine whether HSCs remain dormant or enter the cell cycle and begin to proliferate.
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Affiliation(s)
- Olga Sirin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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28
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Teppema LJ, Dahan A. The Ventilatory Response to Hypoxia in Mammals: Mechanisms, Measurement, and Analysis. Physiol Rev 2010; 90:675-754. [DOI: 10.1152/physrev.00012.2009] [Citation(s) in RCA: 257] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The respiratory response to hypoxia in mammals develops from an inhibition of breathing movements in utero into a sustained increase in ventilation in the adult. This ventilatory response to hypoxia (HVR) in mammals is the subject of this review. The period immediately after birth contains a critical time window in which environmental factors can cause long-term changes in the structural and functional properties of the respiratory system, resulting in an altered HVR phenotype. Both neonatal chronic and chronic intermittent hypoxia, but also chronic hyperoxia, can induce such plastic changes, the nature of which depends on the time pattern and duration of the exposure (acute or chronic, episodic or not, etc.). At adult age, exposure to chronic hypoxic paradigms induces adjustments in the HVR that seem reversible when the respiratory system is fully matured. These changes are orchestrated by transcription factors of which hypoxia-inducible factor 1 has been identified as the master regulator. We discuss the mechanisms underlying the HVR and its adaptations to chronic changes in ambient oxygen concentration, with emphasis on the carotid bodies that contain oxygen sensors and initiate the response, and on the contribution of central neurotransmitters and brain stem regions. We also briefly summarize the techniques used in small animals and in humans to measure the HVR and discuss the specific difficulties encountered in its measurement and analysis.
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Affiliation(s)
- Luc J. Teppema
- Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Albert Dahan
- Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands
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Lalley PM. D1/D2-dopamine receptor agonist dihydrexidine stimulates inspiratory motor output and depresses medullary expiratory neurons. Am J Physiol Regul Integr Comp Physiol 2009; 296:R1829-36. [PMID: 19279296 DOI: 10.1152/ajpregu.00057.2009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is now accepted that dopamine plays an important neuromodulatory role in the central nervous control of respiration. D1, D2, and D4 subtypes of the receptor seem to be important players, but the assignment of various respiratory tasks to specific subtypes of the dopamine receptor is a work in progress. In the present investigation, dihydrexidine (DHD), a full dopamine receptor agonist with affinity for both D1- and D2-subtypes of receptor, was tested for its effects on inspiratory neurons and motor output and on membrane potential properties of medullary bulbospinal expiratory augmenting expiratory neurons in the pentobarbital anesthetized adult cat. The effects of DHD were compared with those of the highly selective D1-dopamine receptor (D1R) agonists SKF-38393 and 6-chloro-APB. DHD increased the intensity and duration of inspiratory motor output. Phrenic nerve discharge intensity was increased and prolonged, contributing to elevated inspiratory effort and duration when spontaneous breathing was monitored with tracheal pressure measurements. Intracellular recording from rostral medullary inspiratory neurons revealed that DHD, like SKF-38393, increases and prolongs inspiratory phase membrane depolarization, resulting in a longer and more intense discharge of action potentials. Remarkably, DHD had opposite effects on Aug-E neurons. Membrane potential was hyperpolarized, and action potential discharges were suppressed or abolished. In association with reduction of discharge intensity, action potential half width was reduced and after-hyperpolarization increased. The stimulatory action of DHD on inspiratory motor output is attributed to D1R effects, while the depression of Aug-E neurons seems to be linked to D2R actions on the postsynaptic membrane.
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Affiliation(s)
- Peter M Lalley
- Department of Physiology, The University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.
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30
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Lalley PM. Opioidergic and dopaminergic modulation of respiration. Respir Physiol Neurobiol 2008; 164:160-7. [PMID: 18394974 PMCID: PMC2642894 DOI: 10.1016/j.resp.2008.02.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/15/2008] [Accepted: 02/18/2008] [Indexed: 11/24/2022]
Abstract
Opioids, dopamine and their receptors are present in many regions of the bulbar respiratory network. The physiological importance of endogenous opioids to respiratory control has not been explicitly demonstrated. Nonetheless, studies of opioidergic respiratory mechanisms are important because synthetic opiate drugs have respiratory side effects that in some situations pose health risks and limit their therapeutic usefulness. They can depress breathing depth and rate, blunt respiratory responsiveness to CO2 and hypoxia, increase upper airway resistance and reduce pulmonary compliance. The opiate respiratory disturbances are mainly due to agonist activation of mu- and delta-subtypes of receptor and involve specific types of respiratory-related neurons in the ventrolateral medulla and the dorsolateral pons. Endogenous dopaminergic modulation in the CNS and carotid bodies enhances CO2-dependent respiratory drive and depresses hypoxic drive. In the CNS, synthetic agonists with selectivity for D1-and D4-types of receptor slow respiratory rhythm, whereas D2-selective agonists modulate acute and chronic responses to hypoxia. D1-receptor agonists also act centrally to increase respiratory responsiveness to CO2, and counteract opiate blunting of CO2-dependent respiratory drive and depression of breathing. Cellular targets and intracellular mechanisms responsible for opioidergic and dopaminergic respiratory effects for the most part remain to be determined.
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Affiliation(s)
- Peter M Lalley
- Department of Physiology, The University of Wisconsin School of Medicine and Public Health, Medical Sciences Center, 1300 University Avenue, Madison, WI 53706, USA.
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31
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Gaultier C, Gallego J. Neural control of breathing: insights from genetic mouse models. J Appl Physiol (1985) 2008; 104:1522-30. [DOI: 10.1152/japplphysiol.01266.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Recent studies described the in vivo ventilatory phenotype of mutant newborn mice with targeted deletions of genes involved in the organization and development of the respiratory-neuron network. Whole body flow barometric plethysmography is the noninvasive method of choice for studying unrestrained newborn mice. Breathing-pattern abnormalities with apneas occur in mutant newborn mice that lack genes involved in the development and modulation of rhythmogenesis. Studies of deficits in ventilatory responses to hypercapnia and/or hypoxia helped to identify genes involved in chemosensitivity to oxygen and carbon dioxide. Combined studies in mutant newborn mice and in humans have shed light on the pathogenesis of genetically determined respiratory-control abnormalities such as congenital central hypoventilation syndrome, Rett syndrome, and Prader-Willi syndrome. The development of mouse models has opened up the field of research into new treatments for respiratory-control disorders in humans.
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32
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Li QJ, Tang YM, Liu J, Zhou DY, Li XP, Xiao SH, Jian DX, Xing YG. Treatment of Parkinson disease with C17.2 neural stem cells overexpressing NURR1 with a recombined republic-deficit adenovirus containing the NURR1 gene. Synapse 2008; 61:971-7. [PMID: 17879263 DOI: 10.1002/syn.20449] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To study the potential benefit of the NURR1 gene in Parkinson's disease (PD), we constructed a recombinant republic-deficit adenovirus containing the NURR1 gene (Ad-NURR1) and expressed it in transplanted neural stem cells (NSC). Ad-NURR1 was constructed, and NURR1 mRNA and protein expression were identified by in situ hybridization and western blot analysis, respectively. The identified NURR1 protein could directly or indirectly induce NSC differentiation into neurons. To identify a potential therapeutic use for the transfected NSCs, cells were transplanted into 6-hydroxydopamine lesioned rats. Histopathological and behavioral alterations were evaluated via immunohistochemistry and the ration test, respectively, in rats transplanted with NSCs with or without the Ad-NURR1 adenovirus. The Ad-NURR1 construct effectively expressed the NURR1 protein, which could directly or indirectly induce NSC differentiation into neurons. Both histopathological and behavioral alterations were seen in rats treated with NSCs with or without the Ad-NURR1 construct, although in the case of the latter, the benefits were more robust. These results suggest a potential therapeutic benefit for Ad-NURR1-expressing cells in the treatment of PD. The Ad-NURR1 modification induced NSC differentiation and therefore represents a potential therapy for PD.
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Affiliation(s)
- Qing-Jun Li
- Department of Neurology, Dong Guan People Hospital, Dong Guan 523018, China
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33
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Berner J, Shvarev Y, Lagercrantz H, Bilkei-Gorzo A, Hökfelt T, Wickström R. Altered respiratory pattern and hypoxic response in transgenic newborn mice lacking the tachykinin-1 gene. J Appl Physiol (1985) 2007; 103:552-9. [PMID: 17525292 DOI: 10.1152/japplphysiol.01389.2006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Substance P is known to be involved in respiratory rhythm and central pattern-generating mechanisms, especially during early development. We therefore studied respiratory responses in transgenic newborn mice (Tac1(-/-)) lacking substance P and neurokinin A (NKA). In vivo, the effects of intermittent isocapnic hypoxia (IH) and hypercapnia were studied using whole body flow plethysmography at P2-3 and P8-10. In vitro, anoxic responses and the effects of hypocapnic and hypercapnic conditions were studied in brain stem-spinal cord preparations (C4 activity) at P2. Hypoxic challenge considerably modified the respiratory activity in transgenic mice displayed in vivo as an attenuated increase in tidal volume during IH. Transgenic mice also showed a more prominent posthypoxic frequency decline in vivo, and posthypoxic neuronal arrests appeared more often in vitro. We recognized two types of sigh activity: with or without a following pause. During IH, the amount of sighs with a pause decreased and those without increased, a redistribution that became stronger with age only in controls. Intermittent anoxia induced long-term facilitation effects in controls, but not in Tac1(-/-) animals, manifested as an increase in burst frequency in vitro and by an augmentation of ventilation during posthypoxic periods in vivo. Thus our data demonstrate that a functional substance P/NKA system is of great importance for the generation of an adequate respiratory response to hypoxic provocation in newborn mice and during early maturation. It also indicates that substance P (and/or NKA) is involved in the development of the plasticity of the respiratory system.
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Affiliation(s)
- J Berner
- Department of Woman and Child Health, Karolinska Institutet, Stockholm, Sweden.
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34
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Abstract
Natural behaviors such as eating, drinking, reproduction and exercise activate brain reward pathways and consequently the individual engages in these behaviors to receive the reward. However, drugs of abuse are even more potent in activating the reward pathways. Rewarding behaviors and addictive drugs also affect other parts of the brain not directly involved in the mediation of reward. For instance, running increases neurogenesis in hippocampus and is beneficial as an antidepressant in a genetic animal model of depression and in depressed humans. Here we discuss and compare neurochemical and functional changes in the brain after addictive drugs and exercise with a focus on brain reward pathways and hippocampus.
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Affiliation(s)
- Stefan Brené
- Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Karolinska University Hospital, Huddinge, S-141 86 Stockholm, Sweden.
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35
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Fujii M, Arata A, Kanbara-Kume N, Saito K, Yanagawa Y, Obata K. Respiratory activity in brainstem of fetal mice lacking glutamate decarboxylase 65/67 and vesicular GABA transporter. Neuroscience 2007; 146:1044-52. [PMID: 17418495 DOI: 10.1016/j.neuroscience.2007.02.050] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 02/27/2007] [Accepted: 02/28/2007] [Indexed: 10/23/2022]
Abstract
The respiratory neural network in the mammalian medulla oblongata shows rhythmic activity before birth. GABA and glycine are considered to be involved in control of respiratory rhythm. Recently we have demonstrated respiratory failure in glutamic acid decarboxylase (GAD) 67-deficient mice [Tsunekawa N, Arata A, Obata K (2005) Development of spontaneous mouth/tongue movement and related neural activity, and their repression in mouse fetus lacking glutamate decarboxylase 67. Eur J Neurosci 21:173-178]. To further evaluate the involvement of GABA and glycine in fetal respiratory function, we studied neural activities in brainstem-spinal cord blocks prepared from GAD65-/-:67-/- and vesicular GABA transporter (VGAT)-/-mice on embryonic day 14 (E14)-E15 and E18. In these knockout mice, the synthesis of GABA and the vesicular release of GABA and glycine are completely absent, respectively. Spontaneous respiratory discharges were observed in the ventral roots at the cervical cord (C) 4 level from wild-type mice but not from the knockout mice on E18. Administration of substance P induced C4 discharges in GAD65-/-:67-/- preparations but not in VGAT-/- preparations. C4 discharges were observed in the knockout mice on E14-E15, although the frequency was lower than that in the wild-type. Neuronal activities in the respiratory network of the E18 brainstem were recorded using a "blind" patch-clamp technique. Expiratory and inspiratory neurons with their characteristic firing patterns were observed in the wild-type fetuses. Strychnine reversed inspiratory-phase hyperpolarization to large depolarization in expiratory neurons. On the other hand, neurons in the same area of the knockout mice fired spontaneously without any rhythm. Substance P induced hyperpolarizing potentials in medullary neurons of GAD65-/-:67-/- mice. Further administration of strychnine induced large depolarizing potentials. Rhythmic activities were not observed in VGAT-/- mice even in the presence of substance P and strychnine. These results indicate that the lack of GABA and glycine impairs the function of the respiratory network in mouse fetuses and the impairment progresses with fetal age.
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Affiliation(s)
- M Fujii
- Laboratory for Memory and Learning, RIKEN Brain Science Institute, Wako 351-0198, Japan
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36
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Benoit G, Cooney A, Giguere V, Ingraham H, Lazar M, Muscat G, Perlmann T, Renaud JP, Schwabe J, Sladek F, Tsai MJ, Laudet V. International Union of Pharmacology. LXVI. Orphan nuclear receptors. Pharmacol Rev 2007; 58:798-836. [PMID: 17132856 DOI: 10.1124/pr.58.4.10] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Half of the members of the nuclear receptors superfamily are so-called "orphan" receptors because the identity of their ligand, if any, is unknown. Because of their important biological roles, the study of orphan receptors has attracted much attention recently and has resulted in rapid advances that have helped in the discovery of novel signaling pathways. In this review we present the main features of orphan receptors, discuss the structure of their ligand-binding domains and their biological functions. The paradoxical existence of a pharmacology of orphan receptors, a rapidly growing and innovative field, is highlighted.
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Affiliation(s)
- Gérard Benoit
- Unité Mixte de Recherche 5161 du Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique 1237, Institut Fédératif de Recherche 128 BioSciences Lyon-Gerland, Ecole Normale Supérieure de Lyon, Lyon, France
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37
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Hermanson E, Borgius L, Bergsland M, Joodmardi E, Perlmann T. Neuropilin1 is a direct downstream target of Nurr1 in the developing brain stem. J Neurochem 2006; 97:1403-11. [PMID: 16638018 DOI: 10.1111/j.1471-4159.2006.03829.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The orphan nuclear receptor Nurr1 is expressed in the developing and adult central nervous system. Previous studies have shown that Nurr1 is essential for the generation of midbrain dopamine neurons. Furthermore, Nurr1 is critical for respiratory functions associated with the brain stem. Very few Nurr1 regulated genes have been identified and it remains unclear how Nurr1 influences the function and development of neurons. To identify novel Nurr1 target genes we have searched for regulated genes in the dopaminergic MN9D cell line. These experiments identified Neuropilin-1 (Nrp1), a receptor protein involved in axon guidance and angiogenesis, as a novel Nurr1 target gene. Nrp1 expression was rapidly up-regulated by Nurr1 in MN9D cells and in situ hybridization analysis showed that Nrp1 was coexpressed with Nurr1 in the brain stem dorsal motor nucleus. Importantly, Nrp1 expression was down-regulated in this area in Nurr1 null mice. Moreover, two functional Nurr1 binding sites were identified in the Nrp1 promoter and Nurr1 was found to be recruited to these sites in MN9D cells, further supporting that Nrp1 is a direct downstream target of Nurr1. Taken together, our findings suggest that Nurr1 might influence the processes of axon guidance and/or angiogenesis via the regulation of Nrp1 expression.
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Affiliation(s)
- Elisabet Hermanson
- Ludwig Institute for Cancer Research, Stockholm Branch, Stockholm, Sweden
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38
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Schmidt-Kastner R, van Os J, W M Steinbusch H, Schmitz C. Gene regulation by hypoxia and the neurodevelopmental origin of schizophrenia. Schizophr Res 2006; 84:253-71. [PMID: 16632332 DOI: 10.1016/j.schres.2006.02.022] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 02/27/2006] [Accepted: 02/28/2006] [Indexed: 01/11/2023]
Abstract
Neurodevelopmental changes may underlie the brain dysfunction seen in schizophrenia. While advances have been made in our understanding of the genetics of schizophrenia, little is known about how non-genetic factors interact with genes for schizophrenia. The present analysis of genes potentially associated with schizophrenia is based on the observation that hypoxia prevails in the embryonic and fetal brain, and that interactions between neuronal genes, molecular regulators of hypoxia, such as hypoxia-inducible factor 1 (HIF-1), and intrinsic hypoxia occur in the developing brain and may create the conditions for complex changes in neurodevelopment. Consequently, we searched the literature for currently hypothesized candidate genes for susceptibility to schizophrenia that may be subject to ischemia-hypoxia regulation and/or associated with vascular expression. Genes were considered when at least two independent reports of a significant association with schizophrenia had appeared in the literature. The analysis showed that more than 50% of these genes, particularly AKT1, BDNF, CAPON, CCKAR, CHRNA7, CNR1, COMT, DNTBP1, GAD1, GRM3, IL10, MLC1, NOTCH4, NRG1, NR4A2/NURR1, PRODH, RELN, RGS4, RTN4/NOGO and TNF, are subject to regulation by hypoxia and/or are expressed in the vasculature. Future studies of genes proposed as candidates for susceptibility to schizophrenia should include their possible regulation by physiological or pathological hypoxia during development as well as their potential role in cerebral vascular function.
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Affiliation(s)
- Rainald Schmidt-Kastner
- Department of Psychiatry and Neuropsychology, Division of Cellular Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands.
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39
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Maxwell MA, Muscat GEO. The NR4A subgroup: immediate early response genes with pleiotropic physiological roles. NUCLEAR RECEPTOR SIGNALING 2006; 4:e002. [PMID: 16604165 PMCID: PMC1402209 DOI: 10.1621/nrs.04002] [Citation(s) in RCA: 327] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 12/20/2005] [Indexed: 12/20/2022]
Abstract
The nuclear hormone receptor (NR) superfamily includes the orphan NR4A subgroup, comprised of Nur77 (NR4A1), Nurr1 (NR4A2) and NOR-1 (NR4A3). These NRs are classified as early response genes, are induced by a diverse range of signals, including fatty acids, stress, growth factors, cytokines, peptide hormones, phorbol esters, neurotransmitters, and physical stimuli (for example magnetic fields, shear stress). The ability to sense and rapidly respond to changes in the cellular environment thus appears to be a hallmark of this subfamily. The members of the NR4A subgroup are well conserved in the DNA binding domain (~91-95%) and the C-terminal ligand-binding domain (~60%), but are divergent in the N-terminal AB region. These receptors bind as monomers, homodimers and heterodimers with RXRs (to mediate retinoid signaling) to different permutations of the canonical NR binding motif. The NR4A subgroup activates gene expression in a constitutive ligand-independent manner. NR4A-mediated trans-activation (LBD) involves unusually active N-terminal AF-1 domains that mediate coactivator recruitment. Moreover, the NR4A receptors encode atypical LBDs and AF-2 domains. For example, the LBDs contain no cavity due to bulky hydrophobic residue side chains, and lack the classical coactivator-binding cleft constituted by helices 3, 4 and 12. However, a hydrophobic patch exists between helices 11 and 12, that encodes a novel cofactor interface that modulates transcriptional activity. In line with the pleiotropic physiological stimuli that induce the NR4A subgroup, these orphan NRs have been implicated in cell cycle regulation (and apoptosis), neurological disease, steroidogenesis, inflammation, carcinogenesis and atherogenesis.
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Affiliation(s)
- Megan A Maxwell
- Institute for Molecular Bioscience, Division of Molecular Genetics and Development, The University of Queensland, St. Lucia, QLD 4072, Australia.
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40
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Gaultier C, Matrot B, Gallego J. Transgenic Models to Study Disorders of Respiratory Control in Newborn Mice. ILAR J 2006; 47:15-21. [PMID: 16391427 DOI: 10.1093/ilar.47.1.15] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent studies described the in vivo respiratory phenotype of mutant newborn mice with targeted deletions of genes involved in respiratory control development. Whole-body flow barometric plethysmography is the noninvasive method of choice for studying unrestrained newborn mice. The main characteristics of the early postnatal development of respiratory control in mice are reviewed, including available data on breathing patterns and on hypoxic and hypercapnic ventilatory responses. Mice are very immature at birth, and their instable breathing is similar to that of preterm infants. Breathing pattern abnormalities with prolonged apneas occur in newborn mice that lack genes involved in the development of rhythmogenesis. Some mutant newborn mice have blunted hypoxic and hypercapnic ventilatory responses whereas others exhibit impairments in responses to hypoxia or hypercapnia. Furthermore, combined studies in mutant newborn mice and in humans have helped to provide pathogenic information on genetically determined developmental disorders of respiratory control in humans.
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Affiliation(s)
- Claude Gaultier
- Service de Physiologie and INSERM U676, Hôpital Robert Debré, Paris, France
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41
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Gaultier C, Gallego J. Development of respiratory control: Evolving concepts and perspectives. Respir Physiol Neurobiol 2005; 149:3-15. [PMID: 15941676 DOI: 10.1016/j.resp.2005.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/22/2005] [Accepted: 04/25/2005] [Indexed: 10/25/2022]
Abstract
The mechanisms underlying respiratory system immaturity in newborns have been investigated, both in vivo and in vitro, in humans and in animals. Immaturity affects breathing rhythmicity and its modulation by suprapontine influences and by afferents from central and peripheral chemoreceptors. Recent research has moved from bedside tools to sophisticated technologies, bringing new insights into the plasticity and genetics of respiratory control development. Genetic research has benefited from investigations of newborn mice having targeted deletions of genes involved in respiratory control. Genetic variability may govern the normal programming of development and the processes underlying adaptation to homeostasis disturbances induced by prenatal and postnatal insults. Studies of plasticity have emphasized the role of neurotrophic factors. Improvements in our understanding of the mechanistic effects of these factors should lead to new neuroprotective strategies for infants at risk for early respiratory control disturbances, such as apnoeas of prematurity, sudden infant death syndrome and congenital central hypoventilation syndrome.
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Affiliation(s)
- Claude Gaultier
- Service de Physiologie, Hôpital Robert Debré, 48 Boulevard Serurier, 75019 Paris, France.
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42
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Matrot B, Durand E, Dauger S, Vardon G, Gaultier C, Gallego J. Automatic classification of activity and apneas using whole body plethysmography in newborn mice. J Appl Physiol (1985) 2005; 98:365-70. [PMID: 15591306 DOI: 10.1152/japplphysiol.00803.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An increasing number of studies in newborn mice are being performed to determine the mechanisms of sleep apnea, which is the hallmark of early breathing disorders. Whole body plethysmography is the method of choice, as it does not require immobilization, which affects behavioral states and breathing. However, activity inside the plethysmograph may disturb the respiratory signal. Visual classification of the respiratory signal into ventilatory activity, activity-related disturbances, or apneas is so time-consuming as to considerably hamper the phenotyping of large pup samples. We propose an automatic classification of activity based on respiratory disturbances and of apneas based on spectral analysis. This method was validated in newborn mice on the day of birth and on postnatal days 2, 5, and 10, under normoxic and hypoxic (5% O2) conditions. For both activity and apneas, visual and automatic scores showed high Pearson's correlation coefficients (0.92 and 0.98, respectively) and high intraclass correlation coefficients (0.96–0.99), supporting strong agreement between the two methods. The present results suggest that breathing disturbances may provide a valid indirect index of activity in freely moving newborn mice and that automatic apnea classification based on spectral analysis may be efficient in terms of precision and of time saved.
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Affiliation(s)
- B Matrot
- Laboratoire de Neurologie et Physiologie du Développement, INSERM-E9935, Hôpital Robert-Debré, 48 Boulevard Sérurier, 75010 Paris, France
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43
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Perlmann T, Wallén-Mackenzie A. Nurr1, an orphan nuclear receptor with essential functions in developing dopamine cells. Cell Tissue Res 2004; 318:45-52. [PMID: 15340833 DOI: 10.1007/s00441-004-0974-7] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2004] [Accepted: 08/02/2004] [Indexed: 01/05/2023]
Abstract
Nurr1 is a transcription factor that is expressed in the embryonic ventral midbrain and is critical for the development of dopamine (DA) neurons. It belongs to the conserved family of nuclear receptors but lacks an identified ligand and is therefore referred to as an orphan receptor. Recent structural studies have indicated that Nurr1 belongs to a class of ligand-independent nuclear receptors that are unable to bind cognate ligands. However, Nurr1 can promote signaling via its heterodimerization partner, the retinoid X receptor (RXR). RXR ligands can promote the survival of DA neurons via a process that depends on Nurr1-RXR heterodimers. In developing DA cells, Nurr1 is required for the expression of several genes important for DA synthesis and function. However, Nurr1 is probably also important for the maintenance of adult DA neurons and plays additional less-well-elucidated roles in other regions of the central nervous system and in peripheral tissues.
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44
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Abstract
The genetic approach to respiratory control is opening up new paths for research into developmental respiratory control disorders. Despite the identification of numerous genes involved in respiratory control, none of the genetically engineered mice developed to date fully replicate the human respiratory phenotype of human developmental respiratory disorders. However, combining studies in humans and studies in mouse models has proved useful in identifying candidate genes for human developmental respiratory control disorders and providing pathogenic information. In clinical practice, the development of databases that incorporate clinical phenotypes and genetic samples from patients would facilitate further genetic studies. International multicentre studies would advance the area of respiratory control research.
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Affiliation(s)
- Claude Gaultier
- Department of Physiology, INSERM 9935, Hôpital Robert, Faculté de Médecine Lariboisière, Université Paris VII, France.
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