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Andrzejewski K, Orłowska ME, Zaremba M, Joniec-Maciejak I, Kaczyńska K. Impact of Serotonergic 5HT 1A and 5HT 2A Receptor Activation on the Respiratory Response to Hypercapnia in a Rat Model of Parkinson's Disease. Int J Mol Sci 2024; 25:4403. [PMID: 38673988 PMCID: PMC11050428 DOI: 10.3390/ijms25084403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/09/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
In Parkinson's disease (PD), along with typical motor dysfunction, abnormal breathing is present; the cause of which is not well understood. The study aimed to analyze the effects of stimulation of the serotonergic system with 5-HT1A and 5-HT2A agonists in a model of PD induced by injection of 6-hydroxydopamine (6-OHDA). To model PD, bilateral injection of 6-OHDA into both striata was performed in male Wistar rats. Respiratory disturbances in response to 7% hypercapnia (CO2 in O2) in the plethysmographic chamber before and after stimulation of the serotonergic system and the incidence of apnea were studied in awake rats 5 weeks after 6-OHDA or vehicle injection. Administration of 6-OHDA reduced the concentration of serotonin (5-HT), dopamine (DA) and norepinephrine (NA) in the striatum and the level of 5-HT in the brainstem of treated rats, which have been associated with decreased basal ventilation, impaired respiratory response to 7% CO2 and increased incidence of apnea compared to Sham-operated rats. Intraperitoneal (i.p.) injection of the 5-HT1AR agonist 8-OH-DPAT and 5-HT2AR agonist NBOH-2C-CN increased breathing during normocapnia and hypercapnia in both groups of rats. However, it restored reactivity to hypercapnia in 6-OHDA group to the level present in Sham rats. Another 5-HT2AR agonist TCB-2 was only effective in increasing normocapnic ventilation in 6-OHDA rats. Both the serotonergic agonists 8-OH-DPAT and NBOH-2C-CN had stronger stimulatory effects on respiration in PD rats, compensating for deficits in basal ventilation and hypercapnic respiration. We conclude that serotonergic stimulation may have a positive effect on respiratory impairments that occur in PD.
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Affiliation(s)
- Kryspin Andrzejewski
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland; (K.A.); (M.E.O.)
| | - Magdalena E. Orłowska
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland; (K.A.); (M.E.O.)
| | - Małgorzata Zaremba
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research (CePT), Medical University of Warsaw, 02-091 Warsaw, Poland; (M.Z.), (I.J.-M.)
| | - Ilona Joniec-Maciejak
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research (CePT), Medical University of Warsaw, 02-091 Warsaw, Poland; (M.Z.), (I.J.-M.)
| | - Katarzyna Kaczyńska
- Department of Respiration Physiology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 St., 02-106 Warsaw, Poland; (K.A.); (M.E.O.)
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2
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Cummings KJ, Leiter JC, Trachtenberg FL, Okaty BW, Darnall RA, Haas EA, Harper RM, Nattie EE, Krous HF, Mena OJ, Richerson GB, Dymecki SM, Kinney HC, Haynes RL. Altered 5-HT2A/C receptor binding in the medulla oblongata in the sudden infant death syndrome (SIDS): Part II. Age-associated alterations in serotonin receptor binding profiles within medullary nuclei supporting cardiorespiratory homeostasis. J Neuropathol Exp Neurol 2024; 83:144-160. [PMID: 38323418 PMCID: PMC10880067 DOI: 10.1093/jnen/nlae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024] Open
Abstract
The failure of chemoreflexes, arousal, and/or autoresuscitation to asphyxia may underlie some sudden infant death syndrome (SIDS) cases. In Part I, we showed that some SIDS infants had altered 5-hydroxytryptamine (5-HT)2A/C receptor binding in medullary nuclei supporting chemoreflexes, arousal, and autoresuscitation. Here, using the same dataset, we tested the hypotheses that the prevalence of low 5-HT1A and/or 5-HT2A/C receptor binding (defined as levels below the 95% confidence interval of controls-a new approach), and the percentages of nuclei affected are greater in SIDS versus controls, and that the distribution of low binding varied with age of death. The prevalence and percentage of nuclei with low 5-HT1A and 5-HT2A/C binding in SIDS were twice that of controls. The percentage of nuclei with low 5-HT2A/C binding was greater in older SIDS infants. In >80% of older SIDS infants, low 5-HT2A/C binding characterized the hypoglossal nucleus, vagal dorsal nucleus, nucleus of solitary tract, and nuclei of the olivocerebellar subnetwork (important for blood pressure regulation). Together, our findings from SIDS infants and from animal models of serotonergic dysfunction suggest that some SIDS cases represent a serotonopathy. We present new hypotheses, yet to be tested, about how defects within serotonergic subnetworks may lead to SIDS.
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - James C Leiter
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | | | - Benjamin W Okaty
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Robert A Darnall
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Elisabeth A Haas
- Department of Research, Rady’s Children’s Hospital, San Diego, California, USA
| | - Ronald M Harper
- Department of Neurobiology and the Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Eugene E Nattie
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Henry F Krous
- Department of Pediatrics, University of California San Diego, San Diego, California, USA
- Departments of Pathology and Pediatrics, Rady Children’s Hospital, San Diego, California, USA
| | - Othon J Mena
- San Diego County Medical Examiner Office, San Diego, California, USA
| | - George B Richerson
- Departments of Neurology and Molecular Physiology & Biophysics, University of Iowa, Iowa City, Iowa, USA
| | - Susan M Dymecki
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Hannah C Kinney
- Department of Pathology, CJ Murphy Laboratory for SIDS Research, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Robin L Haynes
- Department of Pathology, CJ Murphy Laboratory for SIDS Research, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
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3
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Boulain M, Morin D, Juvin L. Multigenerational inheritance of breathing deficits following perinatal exposure to titanium dioxide nanoparticles in the offspring of mice. DISCOVER NANO 2024; 19:16. [PMID: 38261116 PMCID: PMC10805760 DOI: 10.1186/s11671-023-03927-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/14/2023] [Indexed: 01/24/2024]
Abstract
BACKGROUND The utilization of titanium dioxide nanoparticles (TIO2NPs) has experienced a significant surge in recent decades, and these particles are now commonly found in various everyday consumer products. Due to their small size, TIO2NPs can penetrate biological barriers and elicit adverse interactions with biological tissues. Notably, exposure of pregnant females to TIO2NPs during the perinatal period has been shown to disrupt the growth of offspring. Furthermore, this exposure induces epigenetic modifications in the DNA of newborns, suggesting the possibility of multigenerational effects. Thus, perinatal exposure to TIO2NPs may induce immediate metabolic impairments in neonates, which could be transmitted to subsequent generations in the long term. RESULTS In this study, we utilized perinatal exposure of female mice to TIO2NPs through voluntary food intake and observed impaired metabolism in newborn male and female F1 offspring. The exposed newborn mice exhibited reduced body weight gain and a slower breathing rate compared to non-exposed animals. Additionally, a higher proportion of exposed F1 newborns experienced apneas. Similar observations were made when the exposure was limited to the postnatal period, highlighting lactation as a critical period for the adverse effects of TIO2NPs on postnatal metabolism. Importantly, the breathing deficits induced by TIO2NPs were transmitted from F1 females to the subsequent F2 generation. Moreover, re-exposure of adult F1 females to TIO2NPs exacerbated the breathing deficits in newborn F2 males. CONCLUSIONS Our findings demonstrate that perinatal exposure to TIO2NPs disrupts postnatal body weight gain and respiration in the offspring, and these deficits are transmissible to future generations.
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Affiliation(s)
- Marie Boulain
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, 33000, Bordeaux, France
| | - Didier Morin
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, 33000, Bordeaux, France
| | - Laurent Juvin
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, 33000, Bordeaux, France.
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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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MacFarlane PM, Martin RJ, Di Fiore JM, Raffay TM, Tatsuoka C, Chen Z, Minich N, Quintas G, Sánchez-Illana Á, Kuligowski J, Piñeiro-Ramos JD, Vento M, Hibbs AM. Plasma serotonergic biomarkers are associated with hypoxemia events in preterm neonates. Pediatr Res 2023; 94:1436-1443. [PMID: 37188799 DOI: 10.1038/s41390-023-02620-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/15/2023] [Accepted: 04/07/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Hypoxemia is a physiological manifestation of immature respiratory control in preterm neonates, which is likely impacted by neurotransmitter imbalances. We investigated relationships between plasma levels of the neurotransmitter serotonin (5-HT), metabolites of tryptophan (TRP), and parameters of hypoxemia in preterm neonates. METHODS TRP, 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), and kynurenic acid (KA) were analyzed in platelet-poor plasma at ~1 week and ~1 month of life from a prospective cohort of 168 preterm neonates <31 weeks gestational age (GA). Frequency of intermittent hypoxemia (IH) events and percent time hypoxemic (<80%) were analyzed in a 6 h window after the blood draw. RESULTS At 1 week, infants with detectable plasma 5-HT had fewer IH events (OR (95% CI) = 0.52 (0.29, 0.31)) and less percent time <80% (OR (95% CI) = 0.54 (0.31, 0.95)) compared to infants with undetectable 5-HT. A similar relationship occurred at 1 month. At 1 week, infants with higher KA showed greater percent time <80% (OR (95% CI) = 1.90 (1.03, 3.50)). TRP, 5-HIAA or KA were not associated with IH frequency at either postnatal age. IH frequency and percent time <80% were positively associated with GA < 29 weeks. CONCLUSIONS Circulating neuromodulators 5-HT and KA might represent biomarkers of immature respiratory control contributing to hypoxemia in preterm neonates. IMPACT Hypoxemia events are frequent in preterm infants and are associated with poor outcomes. Mechanisms driving hypoxemia such as immature respiratory control may include central and peripheral imbalances in modulatory neurotransmitters. This study found associations between the plasma neuromodulators serotonin and kynurenic acid and parameters of hypoxemia in preterm neonates. Imbalances in plasma biomarkers affecting respiratory control may help identify neonates at risk of short- and long-term adverse outcomes.
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Affiliation(s)
- Peter Mathew MacFarlane
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA.
| | - Richard John Martin
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Juliann Marie Di Fiore
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Thomas Michael Raffay
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Curtis Tatsuoka
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Zhengyi Chen
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Nori Minich
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Guillermo Quintas
- Health and Biomedicine, Leitat Technological Center, Carrer de la Innovació, 2, 08225, Terrassa, Spain
- Analytical Unit, Health Research Institute La Fe, Avda Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Ángel Sánchez-Illana
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
- Department of Analytical Chemistry, Chemistry Faculty, Universtitat de València, Burjassot, Spain
| | - Julia Kuligowski
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - José David Piñeiro-Ramos
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - Maximo Vento
- Neonatal Research Unit, Health Research Institute La Fe (IISLAFE), University & Polytechnic Hospita La Fe (HULAFE), Valencia, Spain
| | - Anna Maria Hibbs
- Department of Pediatrics, University Hospitals Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
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6
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Turk AZ, Millwater M, SheikhBahaei S. Whole-brain analysis of CO 2 chemosensitive regions and identification of the retrotrapezoid and medullary raphé nuclei in the common marmoset ( Callithrix jacchus). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.558361. [PMID: 37986845 PMCID: PMC10659419 DOI: 10.1101/2023.09.26.558361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Respiratory chemosensitivity is an important mechanism by which the brain senses changes in blood partial pressure of CO2 (PCO2). It is proposed that special neurons (and astrocytes) in various brainstem regions play key roles as CO2 central respiratory chemosensors in rodents. Although common marmosets (Callithrix jacchus), New-World non-human primates, show similar respiratory responses to elevated inspired CO2 as rodents, the chemosensitive regions in marmoset brain have not been defined yet. Here, we used c-fos immunostainings to identify brain-wide CO2-activated brain regions in common marmosets. In addition, we mapped the location of the retrotrapezoid nucleus (RTN) and raphé nuclei in the marmoset brainstem based on colocalization of CO2-induced c-fos immunoreactivity with Phox2b, and TPH immunostaining, respectively. Our data also indicated that, similar to rodents, marmoset RTN astrocytes express Phox2b and have complex processes that create a meshwork structure at the ventral surface of medulla. Our data highlight some cellular and structural regional similarities in brainstem of the common marmosets and rodents.
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Affiliation(s)
- Ariana Z. Turk
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Marissa Millwater
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
| | - Shahriar SheikhBahaei
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, 20892 MD, USA
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Gonye EC, Bayliss DA. Criteria for central respiratory chemoreceptors: experimental evidence supporting current candidate cell groups. Front Physiol 2023; 14:1241662. [PMID: 37719465 PMCID: PMC10502317 DOI: 10.3389/fphys.2023.1241662] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 08/16/2023] [Indexed: 09/19/2023] Open
Abstract
An interoceptive homeostatic system monitors levels of CO2/H+ and provides a proportionate drive to respiratory control networks that adjust lung ventilation to maintain physiologically appropriate levels of CO2 and rapidly regulate tissue acid-base balance. It has long been suspected that the sensory cells responsible for the major CNS contribution to this so-called respiratory CO2/H+ chemoreception are located in the brainstem-but there is still substantial debate in the field as to which specific cells subserve the sensory function. Indeed, at the present time, several cell types have been championed as potential respiratory chemoreceptors, including neurons and astrocytes. In this review, we advance a set of criteria that are necessary and sufficient for definitive acceptance of any cell type as a respiratory chemoreceptor. We examine the extant evidence supporting consideration of the different putative chemoreceptor candidate cell types in the context of these criteria and also note for each where the criteria have not yet been fulfilled. By enumerating these specific criteria we hope to provide a useful heuristic that can be employed both to evaluate the various existing respiratory chemoreceptor candidates, and also to focus effort on specific experimental tests that can satisfy the remaining requirements for definitive acceptance.
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Affiliation(s)
- Elizabeth C. Gonye
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States
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8
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Haynes RL, Trachtenberg F, Darnall R, Haas EA, Goldstein RD, Mena OJ, Krous HF, Kinney HC. Altered 5-HT2A/C receptor binding in the medulla oblongata in the sudden infant death syndrome (SIDS): Part I. Tissue-based evidence for serotonin receptor signaling abnormalities in cardiorespiratory- and arousal-related circuits. J Neuropathol Exp Neurol 2023; 82:467-482. [PMID: 37226597 PMCID: PMC10209647 DOI: 10.1093/jnen/nlad030] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
The sudden infant death syndrome (SIDS), the leading cause of postneonatal infant mortality in the United States, is typically associated with a sleep period. Previously, we showed evidence of serotonergic abnormalities in the medulla (e.g. altered serotonin (5-HT)1A receptor binding), in SIDS cases. In rodents, 5-HT2A/C receptor signaling contributes to arousal and autoresuscitation, protecting brain oxygen status during sleep. Nonetheless, the role of 5-HT2A/C receptors in the pathophysiology of SIDS is unclear. We hypothesize that in SIDS, 5-HT2A/C receptor binding is altered in medullary nuclei that are key for arousal and autoresuscitation. Here, we report altered 5-HT2A/C binding in several key medullary nuclei in SIDS cases (n = 58) compared to controls (n = 12). In some nuclei the reduced 5-HT2A/C and 5-HT1A binding overlapped, suggesting abnormal 5-HT receptor interactions. The data presented here (Part 1) suggest that a subset of SIDS is due in part to abnormal 5-HT2A/C and 5-HT1A signaling across multiple medullary nuclei vital for arousal and autoresuscitation. In Part II to follow, we highlight 8 medullary subnetworks with altered 5-HT receptor binding in SIDS. We propose the existence of an integrative brainstem network that fails to facilitate arousal and/or autoresuscitation in SIDS cases.
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Affiliation(s)
- Robin L Haynes
- CJ Murphy Laboratory for SIDS Research, Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Robert’s Program on Sudden Unexpected Death in Pediatrics, Division of General Pediatrics, Department of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts, USA
| | | | - Ryan Darnall
- CJ Murphy Laboratory for SIDS Research, Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Elisabeth A Haas
- Department of Research, Rady Children’s Hospital, San Diego, California, USA
| | - Richard D Goldstein
- Robert’s Program on Sudden Unexpected Death in Pediatrics, Division of General Pediatrics, Department of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Othon J Mena
- San Diego County Medical Examiner Office, San Diego, California, USA
| | - Henry F Krous
- University of California, San Diego, San Diego, California, USA
- Rady Children’s Hospital, San Diego, California, USA
| | - Hannah C Kinney
- CJ Murphy Laboratory for SIDS Research, Department of Pathology, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Robert’s Program on Sudden Unexpected Death in Pediatrics, Division of General Pediatrics, Department of Pediatrics, Boston Children’s Hospital, Boston, Massachusetts, USA
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9
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Faingold CL, Feng HJ. A unified hypothesis of SUDEP: Seizure-induced respiratory depression induced by adenosine may lead to SUDEP but can be prevented by autoresuscitation and other restorative respiratory response mechanisms mediated by the action of serotonin on the periaqueductal gray. Epilepsia 2023; 64:779-796. [PMID: 36715572 PMCID: PMC10673689 DOI: 10.1111/epi.17521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in people with epilepsy (PWE). Postictal apnea leading to cardiac arrest is the most common sequence of terminal events in witnessed cases of SUDEP, and postconvulsive central apnea has been proposed as a potential biomarker of SUDEP susceptibility. Research in SUDEP animal models has led to the serotonin and adenosine hypotheses of SUDEP. These neurotransmitters influence respiration, seizures, and lethality in animal models of SUDEP, and are implicated in human SUDEP cases. Adenosine released during seizures is proposed to be an important seizure termination mechanism. However, adenosine also depresses respiration, and this effect is mediated, in part, by inhibition of neuronal activity in subcortical structures that modulate respiration, including the periaqueductal gray (PAG). Drugs that enhance the action of adenosine increase postictal death in SUDEP models. Serotonin is also released during seizures, but enhances respiration in response to an elevated carbon dioxide level, which often occurs postictally. This effect of serotonin can potentially compensate, in part, for the adenosine-mediated respiratory depression, acting to facilitate autoresuscitation and other restorative respiratory response mechanisms. A number of drugs that enhance the action of serotonin prevent postictal death in several SUDEP models and reduce postictal respiratory depression in PWE. This effect of serotonergic drugs may be mediated, in part, by actions on brainstem sites that modulate respiration, including the PAG. Enhanced activity in the PAG increases respiration in response to hypoxia and other exigent conditions and can be activated by electrical stimulation. Thus, we propose the unifying hypothesis that seizure-induced adenosine release leads to respiratory depression. This can be reversed by serotonergic action on autoresuscitation and other restorative respiratory responses acting, in part, via the PAG. Therefore, we hypothesize that serotonergic or direct activation of this brainstem site may be a useful approach for SUDEP prevention.
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Affiliation(s)
- Carl L Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts, USA
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10
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Joyal KG, Petrucci AN, Littlepage-Saunders MV, Boodhoo NA, Wendt LH, Buchanan GF. Selective Serotonin Reuptake Inhibitors and 5-HT 2 Receptor Agonists Have Distinct, Sleep-state Dependent Effects on Postictal Breathing in Amygdala Kindled Mice. Neuroscience 2023; 513:76-95. [PMID: 36702372 PMCID: PMC9974756 DOI: 10.1016/j.neuroscience.2023.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 01/11/2023] [Accepted: 01/16/2023] [Indexed: 01/24/2023]
Abstract
Seizures can cause profound breathing disruptions. Seizures arising from sleep cause greater breathing impairment than those emerging from wakefulness and more often result in sudden unexpected death in epilepsy (SUDEP). The neurotransmitter serotonin (5-HT) plays a major role in respiration and sleep-wake regulation. 5-HT modulates seizure susceptibility and severity and is dysregulated by seizures. Thus, the impact of seizures on breathing dysregulation may be due to impaired 5-HT neurotransmission. We examined whether pharmacologically increasing 5-HT neurotransmission prior to seizures improves postictal breathing and how sleep-state during seizure induction contributes to these effects. We assessed breathing with whole-body plethysmography in 84 amygdala-kindled mice pre-treated with selective serotonin reuptake inhibitors (SSRI) or 5-HT2 receptor agonists. SSRIs and 5-HT2 agonists increased postictal breathing frequency (fR), tidal volume (VT), and minute ventilation (VE) at different timepoints following seizures induced during wakefulness. These effects were not observed following seizures induced during NREM sleep. SSRIs suppressed ictal and postictal apnea regardless of sleep state. The SSRI citalopram and the 5-HT2 agonists TCB-2 and MK-212 decreased breathing variability following wake-occurring seizures at different postictal timepoints. Only MK-212 decreased breathing variability when seizures were induced during NREM sleep. The 5-HT2A antagonist MDL-11939 reduced the effect of citalopram on fR, VT, and VE, and enhanced its effect on breathing variability in the initial period following a seizure. These results suggest that 5-HT mechanisms that are dependent on or independent from the 5-HT2 family of receptors impact breathing on different timescales during the recovery of eupnea, and that certain serotonergic treatments may be less effective at facilitating postictal breathing following seizures emerging from sleep.
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Affiliation(s)
- Katelyn G Joyal
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
| | - Alexandra N Petrucci
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
| | - Mydirah V Littlepage-Saunders
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
| | - Nicole A Boodhoo
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
| | - Linder H Wendt
- Institute for Clinical and Translational Science, University of Iowa, Iowa City, IA 52242, USA.
| | - Gordon F Buchanan
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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11
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Yackle K. Transformation of Our Understanding of Breathing Control by Molecular Tools. Annu Rev Physiol 2023; 85:93-113. [PMID: 36323001 PMCID: PMC9918693 DOI: 10.1146/annurev-physiol-021522-094142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The rhythmicity of breath is vital for normal physiology. Even so, breathing is enriched with multifunctionality. External signals constantly change breathing, stopping it when under water or deepening it during exertion. Internal cues utilize breath to express emotions such as sighs of frustration and yawns of boredom. Breathing harmonizes with other actions that use our mouth and throat, including speech, chewing, and swallowing. In addition, our perception of breathing intensity can dictate how we feel, such as during the slow breathing of calming meditation and anxiety-inducing hyperventilation. Heartbeat originates from a peripheral pacemaker in the heart, but the automation of breathing arises from neural clusters within the brainstem, enabling interaction with other brain areas and thus multifunctionality. Here, we document how the recent transformation of cellular and molecular tools has contributed to our appreciation of the diversity of neuronal types in the breathing control circuit and how they confer the multifunctionality of breathing.
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Affiliation(s)
- Kevin Yackle
- Department of Physiology, University of California, San Francisco, California, USA;
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12
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Patrone LGA, Ferrari GD, da Silva RM, Alberici LC, Lopes NP, Stabile AM, Klein W, Bícego KC, Gargaglioni LH. Sex- and age-specific respiratory alterations induced by prenatal exposure to the cannabinoid receptor agonist WIN 55,212-2 in rats. Br J Pharmacol 2023. [PMID: 36710256 DOI: 10.1111/bph.16044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 12/19/2022] [Accepted: 01/10/2023] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE Cannabis legalization has risen in many countries, and its use during pregnancy has increased. The endocannabinoid system is present in the CNS at early stages of embryonic development, and regulates functional brain maturation including areas responsible for respiratory control, data on the influence of external cannabinoids on the development of the respiratory system and possible consequences during postnatal life are limited. EXPERIMENTAL APPROACH We evaluated the effects of prenatal exposure to synthetic cannabinoid (WIN 55,212-2 [WIN], 0.5 mg·kg-1 ·day-1 ) on the respiratory control system in neonatal (P0, P6-7 and P12-13) and juvenile (P27-28) male and female rats. KEY RESULTS WIN administration to pregnant rats interfered sex-specifically with breathing regulation of offspring, promoting a greater sensitivity to CO2 at all ages in males (except P6-7) and in juvenile females. An altered hypoxic chemoreflex was observed in P0 (hyperventilation) and P6-7 (hypoventilation) males, which was absent in females. Along with breathing alterations, brainstem analysis showed an increase in the number of catecholaminergic neurons and cannabinoid receptor type 1 (CB1 ) and changes in tissue respiration in the early males. A reduction in pulmonary compliance was observed in juvenile male rats. Preexposure to WIN enhanced spontaneous apnoea and reduced the number of serotoninergic (5-HT) neurons in the raphe magnus nucleus of P0 females. CONCLUSIONS AND IMPLICATIONS These data demonstrate that excess stimulation of the endocannabinoid system during gestation has prolonged and sex-specific consequences for the respiratory control system.
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Affiliation(s)
- Luis Gustavo A Patrone
- Department of Animal Morphology and Physiology, São Paulo State University - UNESP/FCAV, Jaboticabal, São Paulo, Brazil
| | - Gustavo D Ferrari
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rodrigo Moreira da Silva
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luciane C Alberici
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Norberto Peporine Lopes
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Angelita M Stabile
- Department of General and Specialized Nursing, School of Nursing of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Wilfried Klein
- Department of Biology, School of Philosophy, Sciences and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, São Paulo State University - UNESP/FCAV, Jaboticabal, São Paulo, Brazil
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, São Paulo State University - UNESP/FCAV, Jaboticabal, São Paulo, Brazil
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13
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Genes involved in paediatric apnoea and death based on knockout animal models: Implications for sudden infant death syndrome (SIDS). Paediatr Respir Rev 2022; 44:53-60. [PMID: 34750067 DOI: 10.1016/j.prrv.2021.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022]
Abstract
The mechanism of death in Sudden infant death syndrome (SIDS) remains unknown but it is hypothesised that cardiorespiratory failure of brainstem origin results in early post-natal death. For a subset of SIDS infants, an underlying genetic cause may be present, and genetic abnormalities affecting brainstem respiratory control may result in abnormalities that are detectable before death. Genetic knockout mice models were developed in the 1990s and have since helped to elucidate the physiological roles of a number of genes. This systematic review aimed to identify which genes, when knocked out, result in the phenotypes of abnormal cardiorespiratory control and/or early post-natal death. Three major genes were identified: Pet1- a serotonin transcription factor, the neurotrophin pituitary adenylate cyclase activating polypeptide (PACAP) and its receptor (PAC1). Knockouts targeting these genes had blunted hypercapnic and/or hypoxic responses and early post-natal death. The hypothesis that these genes have a role in SIDS is supported by their being identified as abnormal in SIDS cohorts. Future research in SIDS cohorts will be important to determine whether these genetic abnormalities coexist and their potential applicability as biomarkers.
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14
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Xia Y, Cui K, Alonso A, Lowenstein ED, Hernandez-Miranda LR. Transcription factors regulating the specification of brainstem respiratory neurons. Front Mol Neurosci 2022; 15:1072475. [PMID: 36523603 PMCID: PMC9745097 DOI: 10.3389/fnmol.2022.1072475] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/14/2022] [Indexed: 11/12/2023] Open
Abstract
Breathing (or respiration) is an unconscious and complex motor behavior which neuronal drive emerges from the brainstem. In simplistic terms, respiratory motor activity comprises two phases, inspiration (uptake of oxygen, O2) and expiration (release of carbon dioxide, CO2). Breathing is not rigid, but instead highly adaptable to external and internal physiological demands of the organism. The neurons that generate, monitor, and adjust breathing patterns locate to two major brainstem structures, the pons and medulla oblongata. Extensive research over the last three decades has begun to identify the developmental origins of most brainstem neurons that control different aspects of breathing. This research has also elucidated the transcriptional control that secures the specification of brainstem respiratory neurons. In this review, we aim to summarize our current knowledge on the transcriptional regulation that operates during the specification of respiratory neurons, and we will highlight the cell lineages that contribute to the central respiratory circuit. Lastly, we will discuss on genetic disturbances altering transcription factor regulation and their impact in hypoventilation disorders in humans.
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Affiliation(s)
- Yiling Xia
- The Brainstem Group, Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Ke Cui
- The Brainstem Group, Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Antonia Alonso
- Functional Genoarchitecture and Neurobiology Groups, Biomedical Research Institute of Murcia (IMIB-Arrixaca), Murcia, Spain
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
| | - Elijah D. Lowenstein
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Luis R. Hernandez-Miranda
- The Brainstem Group, Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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15
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Chen HL, Gao JX, Chen YN, Xie JF, Xie YP, Spruyt K, Lin JS, Shao YF, Hou YP. Rapid Eye Movement Sleep during Early Life: A Comprehensive Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:13101. [PMID: 36293678 PMCID: PMC9602694 DOI: 10.3390/ijerph192013101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
The ontogenetic sleep hypothesis suggested that rapid eye movement (REM) sleep is ontogenetically primitive. Namely, REM sleep plays an imperative role in the maturation of the central nervous system. In coincidence with a rapidly developing brain during the early period of life, a remarkably large amount of REM sleep has been identified in numerous behavioral and polysomnographic studies across species. The abundant REM sleep appears to serve to optimize a cerebral state suitable for homeostasis and inherent neuronal activities favorable to brain maturation, ranging from neuronal differentiation, migration, and myelination to synaptic formation and elimination. Progressively more studies in Mammalia have provided the underlying mechanisms involved in some REM sleep-related disorders (e.g., narcolepsy, autism, attention deficit hyperactivity disorder (ADHD)). We summarize the remarkable alterations of polysomnographic, behavioral, and physiological characteristics in humans and Mammalia. Through a comprehensive review, we offer a hybrid of animal and human findings, demonstrating that early-life REM sleep disturbances constitute a common feature of many neurodevelopmental disorders. Our review may assist and promote investigations of the underlying mechanisms, functions, and neurodevelopmental diseases involved in REM sleep during early life.
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Affiliation(s)
- Hai-Lin Chen
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
| | - Jin-Xian Gao
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
- Sleep Medicine Center of Gansu Provincial Hospital, Lanzhou 730000, China
| | - Yu-Nong Chen
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
| | - Jun-Fan Xie
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
| | - Yu-Ping Xie
- Sleep Medicine Center of Gansu Provincial Hospital, Lanzhou 730000, China
| | - Karen Spruyt
- Université de Paris, NeuroDiderot–INSERM, 75019 Paris, France
| | - Jian-Sheng Lin
- Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM U1028-CNRS UMR 5292, University Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier–Neurocampus Michel Jouvet, 95 Boulevard Pinel, CEDEX, 69675 Bron, France
| | - Yu-Feng Shao
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
- Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM U1028-CNRS UMR 5292, University Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier–Neurocampus Michel Jouvet, 95 Boulevard Pinel, CEDEX, 69675 Bron, France
- Key Lab of Neurology of Gansu Province, Lanzhou University, Lanzhou 730000, China
| | - Yi-Ping Hou
- Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, 199 Donggang Xi Road, Lanzhou 730000, China
- Key Lab of Neurology of Gansu Province, Lanzhou University, Lanzhou 730000, China
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16
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Joyal KG, Kreitlow BL, Buchanan GF. The role of sleep state and time of day in modulating breathing in epilepsy: implications for sudden unexpected death in epilepsy. Front Neural Circuits 2022; 16:983211. [PMID: 36082111 PMCID: PMC9445500 DOI: 10.3389/fncir.2022.983211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with refractory epilepsy. While the exact etiology of SUDEP is unknown, mounting evidence implicates respiratory dysfunction as a precipitating factor in cases of seizure-induced death. Dysregulation of breathing can occur in epilepsy patients during and after seizures as well as interictally, with many epilepsy patients exhibiting sleep-disordered breathing (SDB), such as obstructive sleep apnea (OSA). The majority of SUDEP cases occur during the night, with the victim found prone in or near a bed. As breathing is modulated in both a time-of-day and sleep state-dependent manner, it is relevant to examine the added burden of nocturnal seizures on respiratory function. This review explores the current state of understanding of the relationship between respiratory function, sleep state and time of day, and epilepsy. We highlight sleep as a particularly vulnerable period for individuals with epilepsy and press that this topic warrants further investigation in order to develop therapeutic interventions to mitigate the risk of SUDEP.
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Affiliation(s)
- Katelyn G. Joyal
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Benjamin L. Kreitlow
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gordon F. Buchanan
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- *Correspondence: Gordon F. Buchanan
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17
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Colnot E, Cardoit L, Cabirol MJ, Roudier L, Delville MH, Fayoux A, Thoby-Brisson M, Juvin L, Morin D. Chronic maternal exposure to titanium dioxide nanoparticles alters breathing in newborn offspring. Part Fibre Toxicol 2022; 19:57. [PMID: 35982496 PMCID: PMC9386967 DOI: 10.1186/s12989-022-00497-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 08/08/2022] [Indexed: 12/01/2022] Open
Abstract
Background Over the last two decades, nanotechnologies and the use of nanoparticles represent one of the greatest technological advances in many fields of human activity. Particles of titanium dioxide (TiO2) are one of the nanomaterials most frequently found in everyday consumer products. But, due in particular to their extremely small size, TiO2 nanoparticles (NPs) are prone to cross biological barriers and potentially lead to adverse health effects. The presence of TiO2 NPs found in human placentae and in the infant meconium has indicated unequivocally the capacity for a materno-fetal transfer of this nanomaterial. Although chronic exposure to TiO2 NPs during pregnancy is known to induce offspring cognitive deficits associated with neurotoxicity, the impact of a gestational exposure on a vital motor function such as respiration, whose functional emergence occurs during fetal development, remains unknown. Results Using in vivo whole-body plethysmographic recordings from neonatal mice, we show that a chronic exposure to TiO2 NPs during pregnancy alters the respiratory activity of offspring, characterized by an abnormally elevated rate of breathing. Correspondingly, using ex vivo electrophysiological recordings performed on isolated brainstem-spinal cord preparations of newborn mice and medullary slice preparations containing specific nuclei controlling breathing frequency, we show that the spontaneously generated respiratory-related rhythm is significantly and abnormally accelerated in animals prenatally exposed to TiO2 NPs. Moreover, such a chronic prenatal exposure was found to impair the capacity of respiratory neural circuitry to effectively adjust breathing rates in response to excitatory environmental stimuli such as an increase in ambient temperature. Conclusions Our findings thus demonstrate that a maternal exposure to TiO2 NPs during pregnancy affects the normal development and operation of the respiratory centers in progeny. Supplementary Information The online version contains supplementary material available at 10.1186/s12989-022-00497-4.
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Affiliation(s)
- Eloïse Colnot
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | - Laura Cardoit
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | | | - Lydia Roudier
- Univ. Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, F-33608, Pessac, France
| | | | - Anne Fayoux
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | | | - Laurent Juvin
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France
| | - Didier Morin
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France. .,Univ. Bordeaux, Department of Health, Safety and Environment, Bordeaux Institute of Technology, F-33175, Gradignan, France.
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18
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Biancardi V, Patrone LGA, Vicente MC, Marques DA, Bicego KC, Funk GD, Gargaglioni LH. Prenatal fluoxetine has long lasting, differential effects on respiratory control in male and female rats. J Appl Physiol (1985) 2022; 133:371-389. [PMID: 35708704 DOI: 10.1152/japplphysiol.00020.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Serotonin (5-HT) is an important modulator of brain networks that control breathing. The selective serotonin reuptake inhibitor fluoxetine (FLX) is the first-line antidepressant drug prescribed during pregnancy. We investigated the effects of prenatal FLX on baseline breathing, ventilatory and metabolic responses to hypercapnia and hypoxia as well as number of brainstem 5-HT and tyrosine hydroxylase (TH) neurons of rats during postnatal development (P0-82). Prenatal FLX exposure of males showed a lower baseline that appeared in juveniles and remained in adulthood, with no sleep-wake state dependency. Prenatal FLX exposure of females did not affect baseline breathing. Juvenile male FLX rats showed increased CO2 and hypoxic ventilatory responses, normalizing by adulthood. Alterations in juvenile-FLX treated males were associated with greater number of 5-HT neurons in the ROB and RMAG. Adult FLX-exposed males showed greater number of 5-HT neurons in the RPA and TH neurons in the A5, while reduced number of TH neurons in A7. Prenatal FLX exposure of female rats was associated with greater hyperventilation induced by hypercapnia at P0-2 and juveniles whereas P12-14 and adult FLX (NREM sleep) rats showed an attenuation of the hypercapnic hyperventilation.FLX-exposed females had fewer 5-HT neurons in the RPA and reduced TH A6 density at P0-2; and greater number of TH neurons in the A7 at P12-14. These data indicate that prenatal FLX exposure affects the number of neurons of some monoaminergic regions in the brain and results in long lasting, sex specific changes in baseline breathing pattern and ventilatory responses to respiratory challenges.
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Affiliation(s)
- Vivian Biancardi
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil.,Department of Physiology, Faculty of Medicine and Dentistry, Women and Children's Health Research Institute, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Luis Gustavo A Patrone
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Mariane C Vicente
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Danuzia A Marques
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil.,Department of Pediatrics, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, QC, Canada
| | - Kênia C Bicego
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
| | - Gregory D Funk
- Department of Physiology, Faculty of Medicine and Dentistry, Women and Children's Health Research Institute, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, Sao Paulo State University, Jaboticabal, Sao Paulo, Brazil
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19
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Current research in pathophysiology of opioid induced respiratory depression. Curr Res Toxicol 2022; 3:100078. [PMID: 35734228 PMCID: PMC9207297 DOI: 10.1016/j.crtox.2022.100078] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/20/2022] [Accepted: 06/01/2022] [Indexed: 01/29/2023] Open
Abstract
In Oprm1-deleted KO mice, both the preBötC and the KF/PBN are major contributors to OIRD but RD is not totally eliminated. PreBötC neurons expressing NK-1R are necessary for breathing. Their deletion results in ataxic breathing and/or apnoea. GIRK channels are involved in inhibiting respiration by mu opioid receptors. KCNQ channels modulate OIRD independent of mu signaling. Morphine depresses normal but not gasping breathing in rats indicating distinct mechanisms for these 2 forms of breathing. Methadone, given to alleviate symptoms of neonatal opioid withdrawal syndrome, desensitizes rats to respiratory depression.
Respiratory depression (RD) is the primary cause of death due to opioids. Opioids bind to mu (µ)-opioid receptors (MORs) encoded by the MOR gene Oprm1, widely expressed in the central and peripheral nervous systems including centers that modulate breathing. Respiratory centers are located throughout the brainstem. Experiments with Oprm1-deleted knockout (KO) mice undertaken to determine which sites are necessary for the induction of opioid-induced respiratory depression (OIRD) showed that the pre-Bötzinger complex (preBötC) and the pontine Kölliker-Fuse nucleus (KF) contribute equally to OIRD but RD was not totally eliminated. Morphine showed a differential influence on preBötC and KF neurons – low doses attenuated RD following deletion of MORs from preBötC neurons and an increase in apneas after high doses whereas deletion of MORs from KF neurons but not the preBötC attenuated RD at both high and low doses. In other KO mice studies, morphine administration after deletion of Oprm1 from both the preBötC and the KF/PBN neurons, led to the conclusion that both respiratory centres contribute to OIRD but the preBötC predominates. MOR-mediated post-synaptic activation of GIRK potassium channels has been implicated as a cause of OIRD. A complementary mechanism in the preBötC involving KCNQ potassium channels independent of MOR signaling has been described. Recent experiments in rats showing that morphine depresses normal, but not gasping breathing, cast doubt on the belief that eupnea, sighs, and gasps, are under the control of preBötC neurons. Methadone, administered to alleviate symptoms of neonatal opioid withdrawal syndrome (NOWES), desensitized rats to OIRD. Protection lost between postnatal days 1 and 2 coincides with the preBötC becoming the dominant generator of respiratory rhythm. Neonatal antidepressant exposure syndrome (NADES) and serotonin toxicity (ST) show similarities including RD. Enzyme CYP2D6 involved in opioid detoxification is polymorphic. Individuals of different CYP2D6 genotype may show increased, decreased, or no enzyme activity, contributing to the variability of patient responses to different opioids and OIRD.
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20
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Smith JC. Respiratory rhythm and pattern generation: Brainstem cellular and circuit mechanisms. HANDBOOK OF CLINICAL NEUROLOGY 2022; 188:1-35. [PMID: 35965022 DOI: 10.1016/b978-0-323-91534-2.00004-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Breathing movements in mammals are driven by rhythmic neural activity automatically generated within spatially and functionally organized brainstem neural circuits comprising the respiratory central pattern generator (CPG). This chapter reviews up-to-date experimental information and theoretical studies of the cellular and circuit mechanisms of respiratory rhythm and pattern generation operating within critical components of this CPG in the lower brainstem. Over the past several decades, there have been substantial advances in delineating the spatial architecture of essential medullary regions and their regional cellular and circuit properties required to understand rhythm and pattern generation mechanisms. A fundamental concept is that the circuits in these regions have rhythm-generating capabilities at multiple cellular and circuit organization levels. The regional cellular properties, circuit organization, and control mechanisms allow flexible expression of neural activity patterns for a repertoire of respiratory behaviors under various physiologic conditions that are dictated by requirements for homeostatic regulation and behavioral integration. Many mechanistic insights have been provided by computational modeling studies driven by experimental results and have advanced understanding in the field. These conceptual and theoretical developments are discussed.
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Affiliation(s)
- Jeffrey C Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.
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21
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Abstract
Breathing (or respiration) is a complex motor behavior that originates in the brainstem. In minimalistic terms, breathing can be divided into two phases: inspiration (uptake of oxygen, O2) and expiration (release of carbon dioxide, CO2). The neurons that discharge in synchrony with these phases are arranged in three major groups along the brainstem: (i) pontine, (ii) dorsal medullary, and (iii) ventral medullary. These groups are formed by diverse neuron types that coalesce into heterogeneous nuclei or complexes, among which the preBötzinger complex in the ventral medullary group contains cells that generate the respiratory rhythm (Chapter 1). The respiratory rhythm is not rigid, but instead highly adaptable to the physic demands of the organism. In order to generate the appropriate respiratory rhythm, the preBötzinger complex receives direct and indirect chemosensory information from other brainstem respiratory nuclei (Chapter 2) and peripheral organs (Chapter 3). Even though breathing is a hard-wired unconscious behavior, it can be temporarily altered at will by other higher-order brain structures (Chapter 6), and by emotional states (Chapter 7). In this chapter, we focus on the development of brainstem respiratory groups and highlight the cell lineages that contribute to central and peripheral chemoreflexes.
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Affiliation(s)
- Eser Göksu Isik
- Brainstem Group, Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Luis R Hernandez-Miranda
- Brainstem Group, Institute for Cell Biology and Neurobiology, Charité Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
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22
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Teran FA, Bravo E, Richerson GB. Sudden unexpected death in epilepsy: Respiratory mechanisms. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:153-176. [PMID: 36031303 PMCID: PMC10191258 DOI: 10.1016/b978-0-323-91532-8.00012-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Epilepsy is one of the most common chronic neurologic diseases, with a prevalence of 1% in the US population. Many people with epilepsy live normal lives, but are at risk of sudden unexpected death in epilepsy (SUDEP). This mysterious comorbidity of epilepsy causes premature death in 17%-50% of those with epilepsy. Most SUDEP occurs after a generalized seizure, and patients are typically found in bed in the prone position. Until recently, it was thought that SUDEP was due to cardiovascular failure, but patients who died while being monitored in hospital epilepsy units revealed that most SUDEP is due to postictal central apnea. Some cases may occur when seizures invade the amygdala and activate projections to the brainstem. Evidence suggests that the pathophysiology is linked to defects in the serotonin system and central CO2 chemoreception, and that there is considerable overlap with mechanisms thought to be involved in sudden infant death syndrome (SIDS). Future work is needed to identify biomarkers for patients at highest risk, improve ascertainment, develop methods to alert caregivers when SUDEP is imminent, and find effective approaches to prevent these fatal events.
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Affiliation(s)
- Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States.
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA, United States
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23
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Spinieli RL, Ben Musa R, Kielhofner J, Cornelius-Green J, Cummings KJ. Orexin contributes to eupnea within a critical period of postnatal development. Am J Physiol Regul Integr Comp Physiol 2021; 321:R558-R571. [PMID: 34405704 PMCID: PMC8560369 DOI: 10.1152/ajpregu.00156.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 02/03/2023]
Abstract
Orexin neurons are active in wakefulness and mostly silent in sleep. In adult rats and humans, orexin facilitates the hypercapnic ventilatory response but has little effect on resting ventilation. The influence of orexin on breathing in the early postnatal period, and across states of vigilance, have not been investigated. This is relevant as the orexin system may be impaired in Sudden Infant Death Syndrome (SIDS) cases. We addressed three hypotheses: 1) orexin provides a drive to breathe in infancy; 2) the effect of orexin depends on stage of postnatal development; and 3) orexin has a greater influence on breathing in wakefulness compared with sleep. Whole body plethysmography was used to monitor breathing of infant rats at three ages: postnatal days (P) 7-8, 12-14, and 17-19. Respiratory variables were analyzed in wakefulness (W), quiet sleep (QS), and active sleep (AS), following suvorexant (5 mg/kg ip), a dual orexin receptor antagonist, or vehicle (DMSO). Effects of suvorexant on ventilatory responses to graded hypercapnia ([Formula: see text] = 0.02, 0.04, 0.06), hypoxia ([Formula: see text] = 0.10), and hyperoxia ([Formula: see text] = 1.0) at P12-14 were also tested. At P12-14, but not at other ages, suvorexant significantly reduced respiratory frequency in all states, reduced the ventilatory equivalent in QW and QS, and increased [Formula: see text] to ∼5 mmHg. Suvorexant had no effect on ventilatory responses to graded hypercapnia or hypoxia. Hyperoxia eliminated the effects of suvorexant on respiratory frequency at P12-14. Our data suggest that orexin preserves eupneic frequency and ventilation in rats, specifically at ∼2 wk of age, perhaps by facilitating tonic peripheral chemoreflex activity.
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Affiliation(s)
- Richard L Spinieli
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Ruwaida Ben Musa
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Jane Kielhofner
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | | | - Kevin J Cummings
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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24
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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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25
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Cummings KJ. Eupnea and gasping in vivo are facilitated by the activation of 5-HT 2A receptors. J Neurophysiol 2021; 125:1543-1551. [PMID: 33760672 DOI: 10.1152/jn.00088.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Eupnea and gasping in infancy depend on central nervous system (CNS) serotonin (5-hydroxytryptamine; 5-HT). Although previous in vitro preparations have provided some evidence that 5-HT acts through type 2 A receptors (5-HT2A) to facilitate eupnea and gasping, here the hypothesis addressed is that 5-HT2A receptor activation is necessary for eupnea and the proper generation of gasping in vivo. To test this, we administered 2,5-dimethoxy-4-iodoamphetamine (DOI; 0.25 mg/kg i.p.), a 5-HT2A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.25 mg/kg i.p.), a 5-HT1A agonist, or vehicle (saline) to 7-9-day-old tryptophan hydroxylase 2 knockout (TPH2-/-) mice. A second experiment assessed the effect of MDL-11,939 (MDL; 10 mg/kg i.p.), the specific 5-HT2A antagonist, or vehicle (DMSO) on the gasping of wild-type (TPH2+/+) animals. Drugs were given 15 min prior to five episodes of severe hypoxia that elicited gasping. TPH2-/- breathed more slowly but had the same V̇e and V̇e/V̇o2 compared with TPH2+/+. As previously reported, the gasping of TPH2-/- was significantly delayed (P < 0.001) and occurred at a significantly lower frequency compared with TPH2+/+ (P = 0.04). For both genotypes, DOI hastened eupneic frequency but had no effect on V̇e or V̇e/V̇o2. The gasping of TPH2-/-, although unaffected by 8-OH-DPAT, was indistinguishable from the gasping of TPH2+/+ following DOI. In TPH2+/+, application of MDL led to hypoventilation (P = 0.01), a delay in the appearance of gasping (P = 0.005), and reduced gasp frequency (P = 0.05). These data show that, in vivo, 5-HT2A receptors facilitate both eupnea and gasping. As has been shown in vitro, 5-HT2A probably promotes gasping by exciting hypoxia-resistant pacemaker neurons.NEW & NOTEWORTHY Previous in vitro studies suggest that 5-HT2A receptors contribute to eupnea and are necessary for fictive gasping. The current study shows that the impaired gasping displayed by neonatal TPH2-/- mice, deficient in CNS serotonin, is restored by 5-HT2A receptor activation. Following 5-HT2A blockade, wild-type mice hypoventilated and their gasping resembled that of TPH2-/- mice. This study shows that both eupnea and gasping in vivo rely on the activation of 5-HT2A receptors.
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri and Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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26
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Barrett KT, Hasan SU, Scantlebury MH, Wilson RJA. Impaired cardiorespiratory responses to hypercapnia in neonatal mice lacking PAC1 but not VPAC2 receptors. Am J Physiol Regul Integr Comp Physiol 2021; 320:R116-R128. [PMID: 33146556 DOI: 10.1152/ajpregu.00161.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The evidence is mounting for a role for abnormal signaling of the stress peptide pituitary adenylate cyclase activating polypeptide (PACAP) and its canonical receptor PAC1 in the pathogenesis of sudden infant death syndrome. In this study, we investigated whether the PACAP receptors PAC1 or VPAC2 are involved in the neonatal cardiorespiratory response to hypercapnic stress. We used head-out plethysmography and surface ECG electrodes to assess cardiorespiratory responses to an 8% hypercapnic challenge in unanesthetized and spontaneously breathing 4-day-old PAC1 or VPAC2 knockout (KO) and wild-type mouse pups. We demonstrate that compared with WTs, breathing frequency (RR) and minute ventilation ([Formula: see text]) in PAC1 KO pups were significantly blunted in response to hypercapnia. Although heart rate was unaltered in PAC1 KO pups during hypercapnia, heart rate recovery posthypercapnia was impaired. In contrast, cardiorespiratory impairments in VPAC2 KO pups were limited to only an overall higher tidal volume (VT), independent of treatment. These findings suggest that PACAP signaling through the PAC1 receptor plays a more important role than signaling through the VPAC2 receptor in neonatal respiratory responses to hypercapnia. Thus deficits in PACAP signaling primarily via PAC1 may contribute to the inability of infants to mount an appropriate protective response to homeostatic stressors in childhood disorders such as SIDS.
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Affiliation(s)
- Karlene T Barrett
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Alberta, Canada
| | - Shabih U Hasan
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Alberta, Canada
| | - Morris H Scantlebury
- Department of Pediatrics, Clinical Neuroscience, Alberta Children's Hospital Research Institute, University of Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Alberta, Canada
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27
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Leirão IP, Colombari DSA, da Silva GSF, Zoccal DB. Lesion of Serotonergic Afferents to the Retrotrapezoid Nucleus Impairs the Tachypneic Response to Hypercapnia in Unanesthetized Animals. Neuroscience 2020; 452:63-77. [PMID: 33212216 DOI: 10.1016/j.neuroscience.2020.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/17/2022]
Abstract
Hypercapnia promotes an increase in pulmonary ventilation due to the stimulation of brainstem chemosensory cells that are connected to the respiratory network. Among these cells are the raphe serotonergic neurons which widely send projections to distinct central respiratory compartments. Nevertheless, the physiological role of specific raphe serotonergic projections to other chemosensitive sites on the emergence of hypercapnia ventilatory response in vivo still remains to be elucidated. Here we investigated whether the ventilatory response to hypercapnia requires serotonergic inputs to the chemosensitive cells of the retrotrapezoid nucleus (RTN) in the ventrolateral medulla. To test this, pulmonary ventilation was evaluated under baseline conditions and during hypercapnia (7% CO2) in unanesthetized juvenile Holtzman rats (60-90 g) that received bilateral microinjections of either vehicle (control) or anti-SERT-SAP (0.1 mM, 10 pmol/100 nl) toxin in the RTN to retrogradely destroy serotonergic afferents to this region. Fifteen days after microinjections, baseline ventilation was not different between anti-SERT-SAP (n = 8) and control animals (n = 9). In contrast, the ablation of RTN-projecting serotonergic neurons markedly attenuated the hypercapnia-induced increase in respiratory frequency which was correlated with reduced numbers of serotonergic neurons in the raphe obscurus and magnus, but not in the raphe pallidus. The increase in tidal volume during hypercapnia was not significantly affected by anti-SERT-SAP microinjections in the RTN. Our data indicate that serotoninergic neurons that send projections to the RTN region are required for the processing of ventilatory reflex response during exposure to high CO2 in unanesthetized conditions.
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Affiliation(s)
- Isabela P Leirão
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Glauber S F da Silva
- Department of Physiology and Biophysics. Institute of Biological Sciences, Federal University of Minas Gerais (ICB/UFMG), Belo Horizonte, MG, Brazil
| | - Daniel B Zoccal
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil.
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28
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Magnusson JL, Emter CA, Cummings KJ. Sex- and age-based differences in the effect of central serotonin on arterial blood pressure regulation. J Appl Physiol (1985) 2020; 129:1310-1323. [PMID: 32909922 DOI: 10.1152/japplphysiol.00414.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Medullary serotonin (5-hydroxytryptamine; 5-HT) neurons project to multiple autonomic nuclei in the central nervous system (CNS). Infant rats lacking 5-HT have low arterial blood pressure (ABP) in quiet sleep, but the role of 5-HT in ABP regulation across vigilance states in adults has not been studied. We hypothesized that in adults, CNS 5-HT deficiency leads to hypotension mainly in quiet wakefulness (QW) and non-rapid eye movement (NREM) sleep, when 5-HT neurons are active. We tested male and female tryptophan hydroxylase 2 knockout rats (TPH2-/-), specifically deficient in CNS 5-HT, and wild-type (TPH2+/+) controls at 2-3, 5-8, and 12-13 mo of age. Compared with TPH2+/+, mean arterial pressure of 5-8- and 12-13-mo-old (middle-aged) male TPH2-/- rats was significantly elevated (∼10 mmHg) in QW and rapid eye movement (REM) sleep. Middle-aged male TPH2-/- rats also had more frequent extreme hypertensive events during prolonged episodes of REM sleep. Female TPH2-/- had normal ABP. The low- and very-low-frequency components of systolic ABP variability were significantly higher in middle-aged male, but not female, TPH2-/- rats compared with in TPH2+/+ rats, suggesting elevated sympathetic vascular tone in male TPH2-/- rats. However, the hypertension of male TPH2-/- rats was not ameliorated by ganglionic blockade. Hearts and lungs of middle-aged male TPH2-/- rats were significantly heavier than those of TPH2+/+ rats. We show that a loss of CNS 5-HT leads to high ABP only in middle-aged males during wakefulness and REM sleep, possibly due to increased vascular tone. It should be investigated whether elevated ventricular afterload associated with CNS 5-HT deficiency initiates cardiac remodeling or alters pulmonary hemodynamics.NEW & NOTEWORTHY The role of serotonin in arterial blood pressure (ABP) regulation across states of vigilance is unknown. We hypothesized that adult rats devoid of CNS serotonin (TPH2-/-) have low ABP in wakefulness and NREM sleep, when serotonin neurons are active. However, TPH2-/- rats experience higher ABP than TPH2+/+ rats in wakefulness and REM only, a phenotype present only in older males and not females. CNS serotonin may be critical for preventing high ABP in males with aging.
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Affiliation(s)
- Jennifer L Magnusson
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Craig A Emter
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri
| | - Kevin J Cummings
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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29
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Alzate-Correa D, Mei-Ling Liu J, Jones M, Silva TM, Alves MJ, Burke E, Zuñiga J, Kaya B, Zaza G, Aslan MT, Blackburn J, Shimada MY, Fernandes-Junior SA, Baer LA, Stanford KI, Kempton A, Smith S, Szujewski CC, Silbaugh A, Viemari JC, Takakura AC, Garcia AJ, Moreira TS, Czeisler CM, Otero JJ. Neonatal apneic phenotype in a murine congenital central hypoventilation syndrome model is induced through non-cell autonomous developmental mechanisms. Brain Pathol 2020; 31:84-102. [PMID: 32654284 PMCID: PMC7881415 DOI: 10.1111/bpa.12877] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 05/10/2020] [Accepted: 06/11/2020] [Indexed: 12/19/2022] Open
Abstract
Congenital central hypoventilation syndrome (CCHS) represents a rare genetic disorder usually caused by mutations in the homeodomain transcription factor PHOX2B. Some CCHS patients suffer mainly from deficiencies in CO2 and/or O2 respiratory chemoreflex, whereas other patients present with full apnea shortly after birth. Our goal was to identify the neuropathological mechanisms of apneic presentations in CCHS. In the developing murine neuroepithelium, Phox2b is expressed in three discrete progenitor domains across the dorsal-ventral axis, with different domains responsible for producing unique autonomic or visceral motor neurons. Restricting the expression of mutant Phox2b to the ventral visceral motor neuron domain induces marked newborn apnea together with a significant loss of visceral motor neurons, RTN ablation, and preBötzinger complex dysfunction. This finding suggests that the observed apnea develops through non-cell autonomous developmental mechanisms. Mutant Phox2b expression in dorsal rhombencephalic neurons did not generate significant respiratory dysfunction, but did result in subtle metabolic thermoregulatory deficiencies. We confirm the expression of a novel murine Phox2b splice variant which shares exons 1 and 2 with the more widely studied Phox2b splice variant, but which differs in exon 3 where most CCHS mutations occur. We also show that mutant Phox2b expression in the visceral motor neuron progenitor domain increases cell proliferation at the expense of visceral motor neuron development. We propose that visceral motor neurons may function as organizers of brainstem respiratory neuron development, and that disruptions in their development result in secondary/non-cell autonomous maldevelopment of key brainstem respiratory neurons.
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Affiliation(s)
- Diego Alzate-Correa
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jillian Mei-Ling Liu
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Mikayla Jones
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Talita M Silva
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Michele Joana Alves
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Elizabeth Burke
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jessica Zuñiga
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Behiye Kaya
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Giuliana Zaza
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Mehmet Tahir Aslan
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jessica Blackburn
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Marina Y Shimada
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Silvio A Fernandes-Junior
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Lisa A Baer
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Kristin I Stanford
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Amber Kempton
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Sakima Smith
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Caroline C Szujewski
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Abby Silbaugh
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Jean-Charles Viemari
- P3M Team, Institut de Neurosciences de la Timone, UMR 7289 AMU-CNRS, Marseille, France
| | - Ana C Takakura
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Alfredo J Garcia
- Institute for Integrative Physiology, Grossman Institute for Neuroscience Quantitative Biology and Human Behavior, The Committee on Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Thiago S Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Catherine M Czeisler
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - José J Otero
- Division of Neuropathology, Department of Pathology, The Ohio State University College of Medicine, Columbus, OH, USA
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30
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Kaur S, De Luca R, Khanday MA, Bandaru SS, Thomas RC, Broadhurst RY, Venner A, Todd WD, Fuller PM, Arrigoni E, Saper CB. Role of serotonergic dorsal raphe neurons in hypercapnia-induced arousals. Nat Commun 2020; 11:2769. [PMID: 32488015 PMCID: PMC7265411 DOI: 10.1038/s41467-020-16518-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 05/05/2020] [Indexed: 01/23/2023] Open
Abstract
During obstructive sleep apnea, elevation of CO2 during apneas contributes to awakening and restoring airway patency. We previously found that glutamatergic neurons in the external lateral parabrachial nucleus (PBel) containing calcitonin gene related peptide (PBelCGRP neurons) are critical for causing arousal during hypercapnia. However, others found that genetic deletion of serotonin (5HT) neurons in the brainstem also prevented arousal from hypercapnia. To examine interactions between the two systems, we showed that dorsal raphe (DR) 5HT neurons selectively targeted the PBel. Either genetically directed deletion or acute optogenetic silencing of DRSert neurons dramatically increased the latency of mice to arouse during hypercapnia, as did silencing DRSert terminals in the PBel. This effect was mediated by 5HT2a receptors which are expressed by PBelCGRP neurons. Our results indicate that the serotonergic input from the DR to the PBel via 5HT2a receptors is critical for modulating the sensitivity of the PBelCGRP neurons that cause arousal to rising levels of blood CO2. Dorsal raphe 5HT(DRSert) neurons regulate arousal from hypercapnia by their projections to the neurons in the external lateral parabrachial nucleus (PBel) that are glutamatergic and also express calcitonin gene related peptide (PBelCGRP). The DRSert input to the PBel modulates the arousal system to rising levels of blood CO2, and may be mediated by 5HT2a receptors on the PBelCGRP neurons.
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Affiliation(s)
- Satvinder Kaur
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Roberto De Luca
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Mudasir A Khanday
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Sathyajit S Bandaru
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Renner C Thomas
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Rebecca Y Broadhurst
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Anne Venner
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - William D Todd
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Patrick M Fuller
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Elda Arrigoni
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA
| | - Clifford B Saper
- Department of Neurology, Division of Sleep Medicine, and Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02215, USA.
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31
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Cummings KJ, Leiter JC. Take a deep breath and wake up: The protean role of serotonin preventing sudden death in infancy. Exp Neurol 2020; 326:113165. [PMID: 31887304 PMCID: PMC6956249 DOI: 10.1016/j.expneurol.2019.113165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/14/2019] [Accepted: 12/26/2019] [Indexed: 01/24/2023]
Abstract
Recordings from infants who died suddenly and unexpectedly demonstrate the occurrence of recurring apneas, ineffective gasping, and finally, failure to restore eupnea and arouse prior to death. Immunohistochemical and autoradiographic data demonstrate a constellation of serotonergic defects in the caudal raphe nuclei in infants who died of Sudden Infant Death Syndrome (SIDS). The purpose of this review is to synthesize what is known about adaptive responses of the infant to severely hypoxic conditions, which unleash a flood of neuromodulators that inhibit cardiorespiratory function, thermogenesis, and arousal and the emerging role of serotonin, which combats this cardiorespiratory inhibition to foster autoresuscitation, eupnea, and arousal to ensure survival following an hypoxic episode. The laryngeal and carotid body chemoreflexes are potent in newborns and infants, and both reflexes can induce apnea and bradycardia, which may be adaptive initially, but must be terminated if an infant is to survive. Serotonin has a unique ability to touch on each of the processes that may be required to recover from hypoxic reflex apnea: gasping, the restoration of heart rate and blood pressure, termination of apneas and, eventually, stimulation of eupnea and arousal. Recurrent apneic events, bradycardia, ineffective gasping and a failure to terminate apneas and restore eupnea are observed in animals harboring defects in the caudal serotonergic system models - all of these phenotypes are reminiscent of and compatible with the cardiorespiratory recordings made in infants who subsequently died of SIDS. The caudal serotonergic system provides an organized, multi-pronged defense against reflex cardiorespiratory inhibition and the hypoxia that accompanies prolonged apnea, bradycardia and hypotension, and any deficiency of caudal serotonergic function will increase the propensity for sudden unexplained infant death.
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, University of Missouri-Columbia, Dalton Cardiovascular Research Center, 134 Research Park Drive, Columbia, MO 65203, USA
| | - James C Leiter
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, One Rope Ferry Road, Hanover, NH 03755, USA.
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Abstract
Neurons that synthesize and release 5-hydroxytryptamine (5-HT; serotonin) express a core set of genes that establish and maintain this neurotransmitter phenotype and distinguish these neurons from other brain cells. Beyond a shared 5-HTergic phenotype, these neurons display divergent cellular properties in relation to anatomy, morphology, hodology, electrophysiology and gene expression, including differential expression of molecules supporting co-transmission of additional neurotransmitters. This diversity suggests that functionally heterogeneous subtypes of 5-HT neurons exist, but linking subsets of these neurons to particular functions has been technically challenging. We discuss recent data from molecular genetic, genomic and functional methods that, when coupled with classical findings, yield a reframing of the 5-HT neuronal system as a conglomeration of diverse subsystems with potential to inspire novel, more targeted therapies for clinically distinct 5-HT-related disorders.
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Chahal CAA, Salloum MN, Alahdab F, Gottwald JA, Tester DJ, Anwer LA, So EL, Murad MH, St Louis EK, Ackerman MJ, Somers VK. Systematic Review of the Genetics of Sudden Unexpected Death in Epilepsy: Potential Overlap With Sudden Cardiac Death and Arrhythmia-Related Genes. J Am Heart Assoc 2020; 9:e012264. [PMID: 31865891 PMCID: PMC6988156 DOI: 10.1161/jaha.119.012264] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022]
Abstract
Background Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death. SUDEP shares many features with sudden cardiac death and sudden unexplained death in the young and may have a similar genetic contribution. We aim to systematically review the literature on the genetics of SUDEP. Methods and Results PubMed, MEDLINE Epub Ahead of Print, Ovid Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Scopus were searched through April 4, 2017. English language human studies analyzing SUDEP for known sudden death, ion channel and arrhythmia-related pathogenic variants, novel variant discovery, and copy number variant analyses were included. Aggregate descriptive statistics were generated; data were insufficient for meta-analysis. A total of 8 studies with 161 unique individuals were included; mean was age 29.0 (±SD 14.2) years; 61% males; ECG data were reported in 7.5% of cases; 50.7% were found prone and 58% of deaths were nocturnal. Cause included all types of epilepsy. Antemortem diagnosis of Dravet syndrome and autism (with duplication of chromosome 15) was associated with 11% and 9% of cases. The most frequently detected known pathogenic variants at postmortem were in Na+ and K+ ion channel subunits, as were novel potentially pathogenic variants (11%). Overall, the majority of variants were of unknown significance. Analysis of copy number variant was insignificant. Conclusions SUDEP case adjudication and evaluation remains limited largely because of crucial missing data such as ECGs. The most frequent pathogenic/likely pathogenic variants identified by molecular autopsy are in ion channel or arrhythmia-related genes, with an ≈11% discovery rate. Comprehensive postmortem examination should include examination of the heart and brain by specialized pathologists and blood storage.
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Affiliation(s)
- C. Anwar A. Chahal
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Mayo Clinic Graduate School of Biomedical SciencesMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
| | - Mohammad N. Salloum
- Internal MedicineIcahn School of Medicine at Mount SinaiQueens Hospital CenterNew YorkNY
| | - Fares Alahdab
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
- Division of Preventive, Occupational and Aerospace MedicineMayo ClinicRochesterMN
| | | | - David J. Tester
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
- Windland Smith Rice Sudden Death Genomics LaboratoryMayo ClinicRochesterMN
| | - Lucman A. Anwer
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular SurgeryMayo ClinicRochesterMN
- General SurgeryUIC/MGHChicagoIL
| | - Elson L. So
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
| | - Mohammad Hassan Murad
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
- Division of Preventive, Occupational and Aerospace MedicineMayo ClinicRochesterMN
| | - Erik K. St Louis
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of NeurologyMayo ClinicRochesterMN
- Mayo Center for Sleep MedicineMayo ClinicRochesterMN
| | - Michael J. Ackerman
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Mayo Clinic Graduate School of Biomedical SciencesMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
- Windland Smith Rice Sudden Death Genomics LaboratoryMayo ClinicRochesterMN
- Department of PediatricsMayo ClinicRochesterMN
| | - Virend K. Somers
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
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5-HT neurons and central CO2 chemoreception. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/b978-0-444-64125-0.00021-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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35
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van der Heijden ME, Zoghbi HY. Development of the brainstem respiratory circuit. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2019; 9:e366. [PMID: 31816185 DOI: 10.1002/wdev.366] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 02/01/2023]
Abstract
The respiratory circuit is comprised of over a dozen functionally and anatomically segregated brainstem nuclei that work together to control respiratory rhythms. These respiratory rhythms emerge prenatally but only acquire vital importance at birth, which is the first time the respiratory circuit faces the sole responsibility for O2 /CO2 homeostasis. Hence, the respiratory circuit has little room for trial-and-error-dependent fine tuning and relies on a detailed genetic blueprint for development. This blueprint is provided by transcription factors that have specific spatiotemporal expression patterns along the rostral-caudal or dorsal-ventral axis of the developing brainstem, in proliferating precursor cells and postmitotic neurons. Studying these transcription factors in mice has provided key insights into the functional segregation of respiratory control and the vital importance of specific respiratory nuclei. Many studies converge on just two respiratory nuclei that each have rhythmogenic properties during the prenatal period: the preBötzinger complex (preBötC) and retrotrapezoid nucleus/parafacial nucleus (RTN/pF). Here, we discuss the transcriptional regulation that guides the development of these nuclei. We also summarize evidence showing that normal preBötC development is necessary for neonatal survival, and that neither the preBötC nor the RTN/pF alone is sufficient to sustain normal postnatal respiratory rhythms. Last, we highlight several studies that use intersectional genetics to assess the necessity of transcription factors only in subregions of their expression domain. These studies independently demonstrate that lack of RTN/pF neurons weakens the respiratory circuit, yet these neurons are not necessary for neonatal survival because developmentally related populations can compensate for abnormal RTN/pF function at birth. This article is categorized under: Nervous System Development > Vertebrates: Regional Development.
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Affiliation(s)
- Meike E van der Heijden
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas
| | - Huda Y Zoghbi
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas
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36
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Donovan LJ, Spencer WC, Kitt MM, Eastman BA, Lobur KJ, Jiao K, Silver J, Deneris ES. Lmx1b is required at multiple stages to build expansive serotonergic axon architectures. eLife 2019; 8:e48788. [PMID: 31355748 PMCID: PMC6685705 DOI: 10.7554/elife.48788] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/27/2019] [Indexed: 01/18/2023] Open
Abstract
Formation of long-range axons occurs over multiple stages of morphological maturation. However, the intrinsic transcriptional mechanisms that temporally control different stages of axon projection development are unknown. Here, we addressed this question by studying the formation of mouse serotonin (5-HT) axons, the exemplar of long-range profusely arborized axon architectures. We report that LIM homeodomain factor 1b (Lmx1b)-deficient 5-HT neurons fail to generate axonal projections to the forebrain and spinal cord. Stage-specific targeting demonstrates that Lmx1b is required at successive stages to control 5-HT axon primary outgrowth, selective routing, and terminal arborization. We show a Lmx1b→Pet1 regulatory cascade is temporally required for 5-HT arborization and upregulation of the 5-HT axon arborization gene, Protocadherin-alphac2, during postnatal development of forebrain 5-HT axons. Our findings identify a temporal regulatory mechanism in which a single continuously expressed transcription factor functions at successive stages to orchestrate the progressive development of long-range axon architectures enabling expansive neuromodulation.
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Affiliation(s)
- Lauren J Donovan
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - William C Spencer
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Meagan M Kitt
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Brent A Eastman
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Katherine J Lobur
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Kexin Jiao
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Jerry Silver
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Evan S Deneris
- Department of NeurosciencesSchool of Medicine, Case Western Reserve UniversityClevelandUnited States
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37
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Garcia AJ, Viemari JC, Khuu MA. Respiratory rhythm generation, hypoxia, and oxidative stress-Implications for development. Respir Physiol Neurobiol 2019; 270:103259. [PMID: 31369874 DOI: 10.1016/j.resp.2019.103259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/15/2019] [Accepted: 07/24/2019] [Indexed: 02/07/2023]
Abstract
Encountered in a number of clinical conditions, repeated hypoxia/reoxygenation during the neonatal period can pose both a threat to immediate survival as well as a diminished quality of living later in life. This review focuses on our current understanding of central respiratory rhythm generation and the role that hypoxia and reoxygenation play in influencing rhythmogenesis. Here, we examine the stereotypical response of the inspiratory rhythm from the preBötzinger complex (preBötC), basic neuronal mechanisms that support rhythm generation during the peri-hypoxic interval, and the physiological consequences of inspiratory network responsivity to hypoxia and reoxygenation, acute and chronic intermittent hypoxia, and oxidative stress. These topics are examined in the context of Sudden Infant Death Syndrome, apneas of prematurity, and neonatal abstinence syndrome.
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Affiliation(s)
- Alfredo J Garcia
- Institute for Integrative Physiology, Section of Emergency Medicine, The University of Chicago, Chicago, 60637, IL, United States
| | - Jean Charles Viemari
- Institut de Neurosciences de la Timone, P3M team, UMR7289 CNRS & AMU, Faculté de Médecine de la Timone, 27 Bd Jean Moulin, Marseille, 13005, France
| | - Maggie A Khuu
- Institute for Integrative Physiology, Section of Emergency Medicine, The University of Chicago, Chicago, 60637, IL, United States
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38
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Cummings KJ, Hodges MR. The serotonergic system and the control of breathing during development. Respir Physiol Neurobiol 2019; 270:103255. [PMID: 31362064 DOI: 10.1016/j.resp.2019.103255] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/28/2019] [Accepted: 07/12/2019] [Indexed: 01/26/2023]
Abstract
Serotonin (5-hydroxytryptamine 5-HT) was first discovered in the late 1940's as an endogenous bioactive amine capable of inducing vasoconstriction, and in the mid-1950's was found in the brain. It was in these early years that some of the first demonstrations were made regarding a role for brain 5-HT in neurological function and behavior, including data implicating reduced brain levels of 5-HT in clinical depression. Since that time, advances in molecular biology and physiological approaches in basic science research have intensely focused on 5-HT in the brain, and the many facets of its role during embryonic development, post-natal maturation, and neural function in adulthood continues to be established. This review focuses on what is known about the developmental roles for the 5-HT system, which we define as the neurons producing 5-HT along with pre-and post-synaptic receptors, in a vital homeostatic motor behavior - the control of breathing. We will cover what is known about the embryonic origins and fate specification of 5-HT neurons, and how the 5-HT system influences pre- and post-natal maturation of the ventilatory control system. In addition, we will focus on the role of the 5-HT system in specific respiratory behaviors during fetal, neonatal and postnatal development, and the relevance of dysfunction in this system in respiratory-related human pathologies including Sudden Infant Death Syndrome (SIDS).
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Affiliation(s)
- Kevin J Cummings
- Department of Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211, USA.
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Mateika JH, Komnenov D, Pop A, Kuhn DM. Genetic depletion of 5-HT increases central apnea frequency and duration and dampens arousal but does not impact the circadian modulation of these variables. J Appl Physiol (1985) 2019; 126:1-10. [DOI: 10.1152/japplphysiol.00724.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We examined the impact of serotonin (5-HT) on the frequency and duration of central apneic events and the frequency of accompanying arousals during nonrapid and rapid eye movement (NREM and REM, respectively) sleep across the light/dark cycle. Electroencephalography, electromyography, core body temperature, and activity were recorded for 24 h following implantation of telemeters in wild-type (Tph2+/+) and tryptophan hydroxylase 2 knockout (Tph2−/−) male mice. The frequency and duration of central apneic events were increased, the number of apneic events coupled to an arousal was decreased, and the ventilatory sensitivity to hypoxia and hypercapnia was decreased in the Tph2−/− compared with the Tph2+/+ mice during NREM sleep. Apnea frequency and duration were similar in the Tph2−/− and Tph2+/+ mice during REM sleep. The duration of apneic events during REM compared with NREM sleep was similar in the Tph2−/− mice. In contrast, the duration was greater during REM sleep in the Tph2+/+ mice. Our results also revealed that apnea frequency was greater during the light compared with the dark cycle. Circadian modulation of this variable was evident in both the Tph2−/− and Tph2+/+ mice during NREM and REM sleep. We conclude that depletion of 5-HT increases the frequency and duration of central apneic events, dampens arousal, and blunts the ventilatory response to hypoxia and hypercapnia during NREM sleep but is not essential for the circadian modulation of these variables. NEW & NOTEWORTHY The presence of serotonin (5-HT) in the central nervous system diminishes the frequency of central apneic events. This neuromodulator also moderates the duration of central apneic events and promotes arousal from central events if they occur during nonrapid eye movement (NREM) sleep. However, 5-HT is not responsible for the circadian modulation of apnea frequency, which we found was greater during NREM sleep in the light compared with the dark cycle.
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Affiliation(s)
- Jason H. Mateika
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, Michigan
| | - Dragana Komnenov
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Alexandru Pop
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Donald M. Kuhn
- John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan
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Hülsmann S, Oke Y, Mesuret G, Latal AT, Fortuna MG, Niebert M, Hirrlinger J, Fischer J, Hammerschmidt K. The postnatal development of ultrasonic vocalization-associated breathing is altered in glycine transporter 2-deficient mice. J Physiol 2018; 597:173-191. [PMID: 30296333 DOI: 10.1113/jp276976] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 10/01/2018] [Indexed: 01/03/2023] Open
Abstract
KEY POINTS Newborn mice produce ultrasonic vocalization to communicate with their mother. The neuronal glycine transporter (GlyT2) is required for efficient loading of synaptic vesicles in glycinergic neurons. Mice lacking GlyT2 develop a phenotype that resembles human hyperekplexia and the mice die in the second postnatal week. In the present study, we show that GlyT2-knockout mice do not acquire adult ultrasonic vocalization-associated breathing patterns. Despite the strong impairment of glycinergic inhibition, they can produce sufficient expiratory airflow to produce ultrasonic vocalization. Because mouse ultrasonic vocalization is a valuable read-out in translational research, these data are highly relevant for a broad range of research fields. ABSTRACT Mouse models are instrumental with respect to determining the genetic basis and neural foundations of breathing regulation. To test the hypothesis that glycinergic synaptic inhibition is required for normal breathing and proper post-inspiratory activity, we analysed breathing and ultrasonic vocalization (USV) patterns in neonatal mice lacking the neuronal glycine transporter (GlyT2). GlyT2-knockout (KO) mice have a profound reduction of glycinergic synaptic currents already at birth, develop a severe motor phenotype and survive only until the second postnatal week. At this stage, GlyT2-KO mice are smaller, have a reduced respiratory rate and still display a neonatal breathing pattern with active expiration for the production of USV. By contrast, wild-type mice acquire different USV-associated breathing patterns that depend on post-inspiratory control of air flow. Nonetheless, USVs per se remain largely indistinguishable between both genotypes. We conclude that GlyT2-KO mice, despite the strong impairment of glycinergic inhibition, can produce sufficient expiratory airflow to produce ultrasonic vocalization.
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Affiliation(s)
- Swen Hülsmann
- Clinic for Anesthesiology, University Medical Center, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Yoshihiko Oke
- Division of Physiome, Department of Physiology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Guillaume Mesuret
- Clinic for Anesthesiology, University Medical Center, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - A Tobias Latal
- Clinic for Anesthesiology, University Medical Center, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Michal G Fortuna
- Clinic for Anesthesiology, University Medical Center, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Marcus Niebert
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University of Leipzig, Leipzig, Germany.,Max Planck Institute of Experimental Medicine, Department of Neurogenetics, Göttingen, Germany
| | - Julia Fischer
- German Primate Center - Leibniz Institute for Primate Research, Cognitive Ethology Laboratory, Göttingen, Germany
| | - Kurt Hammerschmidt
- German Primate Center - Leibniz Institute for Primate Research, Cognitive Ethology Laboratory, Göttingen, Germany
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41
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Watkins L, Shankar R. Reducing the Risk of Sudden Unexpected Death in Epilepsy (SUDEP). Curr Treat Options Neurol 2018; 20:40. [DOI: 10.1007/s11940-018-0527-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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42
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Bright FM, Vink R, Byard RW. The potential role of substance P in brainstem homeostatic control in the pathogenesis of sudden infant death syndrome (SIDS). Neuropeptides 2018; 70:1-8. [PMID: 29908886 DOI: 10.1016/j.npep.2018.02.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/25/2018] [Accepted: 02/25/2018] [Indexed: 12/30/2022]
Abstract
Victims of sudden infant death syndrome (SIDS) are believed to have an underlying dysfunction in medullary homeostatic control that impairs critical responses to life threatening challenges such as hypoxia, hypercarbia and asphyxia, often during a sleep period. This failure is thought to result from abnormalities in a network of neural pathways in the medulla oblongata that control respiration, chemosensitivity, autonomic function and arousal. Studies have mainly focused on the role of serotonin, 5-hydroxytyptamine (5HT), although the neuropeptide substance P (SP) has also been shown to play an integral role in the modulation of medullary homeostatic function, often in conjunction with 5-HT. Actions of SP include regulation of respiratory rhythm generation, integration of cardiovascular control, modulation of the baroreceptor reflex and mediation of the chemoreceptor reflex in response to hypoxia. Abnormalities in SP neurotransmission may, therefore, also play a significant role in homeostatic dysfunction of the neurotransmitter network in SIDS. This review focuses on the pathways within the medulla involving SP and its tachykinin NK1 receptor, their potential relationship with the medullary 5-HT system, and possible involvement in the pathogenesis of SIDS.
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Affiliation(s)
- Fiona M Bright
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, SA, Australia.
| | - Robert Vink
- Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Roger W Byard
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, SA, Australia
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43
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Watkins L, Shankar R, Sander JW. Identifying and mitigating Sudden Unexpected Death in Epilepsy (SUDEP) risk factors. Expert Rev Neurother 2018; 18:265-274. [PMID: 29425076 DOI: 10.1080/14737175.2018.1439738] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Sudden Unexpected Death in Epilepsy (SUDEP) is a significant cause of death for people with chronic epilepsy. Good practice guidance in the UK and the USA expect SUDEP to be discussed with the individual. The event rarity, methodological variance and lack of robust research into the pathological mechanisms, associated risk factors, and management strategies have created a challenge on how and what to discuss. There are some significant associations which allows for risk assessment and mitigation. Areas covered: The current understanding of static and modifiable risk factors for SUDEP and how to manage these more effectively are reviewed. Longitudinal risk may be assessed using standardised risk assessment tools which help in communicating risk. Technological advancement allows measurement of physiological parameters associated with seizures and risk of SUDEP using small wearable devices. Further evidence is needed to demonstrate such technologies are efficacious and safe. Expert commentary: Risk reduction should be an important part of epilepsy management and we suggest a Gold Standard of Care which healthcare professionals and services should aim for when approaching SUDEP risk management. A Minimum Standard of Care is also proposed that is practical to implement, that all people with epilepsy should expect to receive.
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Affiliation(s)
- Lance Watkins
- a Neath Port Talbot CLDT, Mental Health & Learning Disability Delivery Unit , Abertawe Bro Morgannwyg University Health Board , Morriston , Swansea
| | - Rohit Shankar
- b Department of Intellectual Disability Neuropsychiatry , Cornwall Partnership NHS Foundation Trust , Truro , UK.,c Exeter Medical School, Knowledge Spa , Royal Cornwall Hospital Truro , Cornwall , UK
| | - Josemir W Sander
- d UCL Institute of Neurology , NIHR University College London Hospitals Biomedical Research Centre , London , UK.,e Chalfont Centre for Epilepsy , Buckinghamshire , UK.,f Stichting Epilepsie Instellingen Nederland (SEIN) , Heemstede , Netherlands
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44
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Wang G, Zhang YP, Gao Z, Shields LBE, Li F, Chu T, Lv H, Moriarty T, Xu XM, Yang X, Shields CB, Cai J. Pathophysiological and behavioral deficits in developing mice following rotational acceleration-deceleration traumatic brain injury. Dis Model Mech 2018; 11:dmm030387. [PMID: 29208736 PMCID: PMC5818073 DOI: 10.1242/dmm.030387] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 11/16/2017] [Indexed: 01/22/2023] Open
Abstract
Abusive head trauma (AHT) is the leading cause of death from trauma in infants and young children. An AHT animal model was developed on 12-day-old mice subjected to 90° head extension-flexion sagittal shaking repeated 30, 60, 80 and 100 times. The mortality and time until return of consciousness were dependent on the number of repeats and severity of the injury. Following 60 episodes of repeated head shakings, the pups demonstrated apnea and/or bradycardia immediately after injury. Acute oxygen desaturation was observed by pulse oximetry during respiratory and cardiac suppression. The cerebral blood perfusion was assessed by laser speckle contrast analysis (LASCA) using a PeriCam PSI system. There was a severe reduction in cerebral blood perfusion immediately after the trauma that did not significantly improve within 24 h. The injured mice began to experience reversible sensorimotor function at 9 days postinjury (dpi), which had completely recovered at 28 dpi. However, cognitive deficits and anxiety-like behavior remained. Subdural/subarachnoid hemorrhage, damage to the brain-blood barrier and parenchymal edema were found in all pups subjected to 60 insults. Proinflammatory response and reactive gliosis were upregulated at 3 dpi. Degenerated neurons were found in the cerebral cortex and olfactory tubercles at 30 dpi. This mouse model of repetitive brain injury by rotational head acceleration-deceleration partially mimics the major pathophysiological and behavioral events that occur in children with AHT. The resultant hypoxia/ischemia suggests a potential mechanism underlying the secondary rotational acceleration-deceleration-induced brain injury in developing mice.
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Affiliation(s)
- Guoxiang Wang
- Department of Spine Surgery, Orthopedics Hospital affiliated to the Second Bethune Hospital, Jilin University, Changchun 130041, China
- Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Yi Ping Zhang
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
| | - Zhongwen Gao
- Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Lisa B E Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
| | - Fang Li
- Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Neurological Surgery, China-Japan Friendship Hospital, Beijing 100029, China
| | - Tianci Chu
- Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Huayi Lv
- Eye Center of the Second Bethune Hospital, Jilin University, Changchun 130041, China
| | - Thomas Moriarty
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
| | - Xiao-Ming Xu
- Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Xiaoyu Yang
- Department of Spine Surgery, Orthopedics Hospital affiliated to the Second Bethune Hospital, Jilin University, Changchun 130041, China
| | - Christopher B Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Jun Cai
- Department of Spine Surgery, Orthopedics Hospital affiliated to the Second Bethune Hospital, Jilin University, Changchun 130041, China
- Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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Santin JM. How important is the CO 2 chemoreflex for the control of breathing? Environmental and evolutionary considerations. Comp Biochem Physiol A Mol Integr Physiol 2017; 215:6-19. [PMID: 28966145 DOI: 10.1016/j.cbpa.2017.09.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/19/2017] [Accepted: 09/19/2017] [Indexed: 12/27/2022]
Abstract
Haldane and Priestley (1905) discovered that the ventilatory control system is highly sensitive to CO2. This "CO2 chemoreflex" has been interpreted to dominate control of resting arterial PCO2/pH (PaCO2/pHa) by monitoring PaCO2/pHa and altering ventilation through negative feedback. However, PaCO2/pHa varies little in mammals as ventilation tightly couples to metabolic demands, which may minimize chemoreflex control of PaCO2. The purpose of this synthesis is to (1) interpret data from experimental models with meager CO2 chemoreflexes to infer their role in ventilatory control of steady-state PaCO2, and (2) identify physiological causes of respiratory acidosis occurring normally across vertebrate classes. Interestingly, multiple rodent and amphibian models with minimal/absent CO2 chemoreflexes exhibit normal ventilation, gas exchange, and PaCO2/pHa. The chemoreflex, therefore, plays at most a minor role in ventilatory control at rest; however, the chemoreflex may be critical for recovering PaCO2 following acute respiratory acidosis induced by breath-holding and activity in many ectothermic vertebrates. An apparently small role for CO2 feedback in the genesis of normal breathing contradicts the prevailing view that central CO2/pH chemoreceptors increased in importance throughout vertebrate evolution. Since the CO2 chemoreflex contributes minimally to resting ventilation, these CO2 chemoreceptors may have instead decreased importance throughout tetrapod evolution, particularly with the onset and refinement of neural innovations that improved the matching of ventilation to tissue metabolic demands. This distinct and elusive "metabolic ventilatory drive" likely underlies steady-state PaCO2 in air-breathers. Uncovering the mechanisms and evolution of the metabolic ventilatory drive presents a challenge to clinically-oriented and comparative respiratory physiologists alike.
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Yeh SY, Huang WH, Wang W, Ward CS, Chao ES, Wu Z, Tang B, Tang J, Sun JJ, Esther van der Heijden M, Gray PA, Xue M, Ray RS, Ren D, Zoghbi HY. Respiratory Network Stability and Modulatory Response to Substance P Require Nalcn. Neuron 2017; 94:294-303.e4. [PMID: 28392070 DOI: 10.1016/j.neuron.2017.03.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 01/26/2017] [Accepted: 03/17/2017] [Indexed: 12/25/2022]
Abstract
Respiration is a rhythmic activity as well as one that requires responsiveness to internal and external circumstances; both the rhythm and neuromodulatory responses of breathing are controlled by brainstem neurons in the preBötzinger complex (preBötC) and the retrotrapezoid nucleus (RTN), but the specific ion channels essential to these activities remain to be identified. Because deficiency of sodium leak channel, non-selective (Nalcn) causes lethal apnea in humans and mice, we investigated Nalcn function in these neuronal groups. We found that one-third of mice lacking Nalcn in excitatory preBötC neurons died soon after birth; surviving mice developed apneas in adulthood. Interestingly, in both preBötC and RTN neurons, the Nalcn current influences the resting membrane potential, contributes to maintenance of stable network activity, and mediates modulatory responses to the neuropeptide substance P. These findings reveal Nalcn's specific role in both rhythmic stability and responsiveness to neuropeptides within the respiratory network.
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Affiliation(s)
- Szu-Ying Yeh
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Wei-Hsiang Huang
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Wei Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher S Ward
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Eugene S Chao
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA; The Cain Foundation Laboratories at Texas Children's Hospital, Houston, TX 77030, USA
| | - Zhenyu Wu
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Bin Tang
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jianrong Tang
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jenny J Sun
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meike Esther van der Heijden
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA
| | - Paul A Gray
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Mingshan Xue
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA; The Cain Foundation Laboratories at Texas Children's Hospital, Houston, TX 77030, USA
| | - Russell S Ray
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, 415 South University Avenue, Philadelphia, PA 19104, USA
| | - Huda Y Zoghbi
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
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Andrzejewski K, Kaczyńska K, Zaremba M. Serotonergic system in hypoxic ventilatory response in unilateral rat model of Parkinson's disease. J Biomed Sci 2017; 24:24. [PMID: 28347345 PMCID: PMC5368902 DOI: 10.1186/s12929-017-0331-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/21/2017] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Malfunctioning of the serotonergic system in Parkinson's disease may contribute to non-motor symptoms such as respiratory complications. Thus the aim of our study was to investigate the role of serotonin 5-HT2 receptors in the modulation of normoxic breathing and the hypoxic ventilatory response (HVR) in rat model of Parkinson's disease. METHODS Wistar rats were lesioned unilaterally with double 6-hydroxydopamine (6-OHDA) injection to the right medial forebrain bundle (MFB). Before lesion and two weeks later animals were put in whole body plethysmography chamber and exposed to hypoxia (8% O2). Before hypoxic tests animals received intraperitoneal injections of DOI and ketanserin. Efficacy of lesion was confirmed by cylinder test, assessing limb use asymmetry. RESULTS Degeneration of the nigrostriatal pathway augmented response of tidal volume and minute ventilation to hypoxia. DOI administration in control and lesion state caused a significant rise in normoxic respiratory rate and minute ventilation. Yet, ventilatory response of these parameters to hypoxia was attenuated. Post-DOI magnitude of HVR in lesioned state was decreased in compare to pre-lesion control. Subsequent ketanserin injection reverted DOI-induced respiratory effects. We demonstrated that 6-OHDA treatment decreased the content of serotonin in the injured striatum and on both sides of the brainstem, leaving the concentration of noradrenaline on unchanged level. CONCLUSIONS These observations showed that damage of the nigrostriatal system initiates changes in the serotonergic system, confirmed by reduced concentration of serotonin in the striatum and brainstem, which affects the magnitude of respiratory response to hypoxia after activation of 5-HT2 receptors.
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Affiliation(s)
- Kryspin Andrzejewski
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland
| | - Katarzyna Kaczyńska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland
| | - Małgorzata Zaremba
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research (CePT), Medical University of Warsaw, Warsaw, Poland
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Kraus C, Castrén E, Kasper S, Lanzenberger R. Serotonin and neuroplasticity - Links between molecular, functional and structural pathophysiology in depression. Neurosci Biobehav Rev 2017; 77:317-326. [PMID: 28342763 DOI: 10.1016/j.neubiorev.2017.03.007] [Citation(s) in RCA: 254] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 02/23/2017] [Accepted: 03/12/2017] [Indexed: 12/26/2022]
Abstract
Serotonin modulates neuroplasticity, especially during early life, and dysfunctions in both systems likewise contribute to pathophysiology of depression. Recent findings demonstrate that serotonin reuptake inhibitors trigger reactivation of juvenile-like neuroplasticity. How these findings translate to clinical antidepressant treatment in major depressive disorder remains unclear. With this review, we link preclinical with clinical work on serotonin and neuroplasticity to bring two pathophysiologic models in clinical depression closer together. Dysfunctional developmental plasticity impacts on later-life cognitive and emotional functions, changes of synaptic serotonin levels and receptor levels are coupled with altered synaptic plasticity and neurogenesis. Structural magnetic resonance imaging in patients reveals disease-state-specific reductions of gray matter, a marker of neuroplasticity, and reversibility upon selective serotonin reuptake inhibitor treatment. Translational evidence from magnetic resonance imaging in animals support that reduced densities and sizes of neurons and reduced hippocampal volumes in depressive patients could be attributable to changes of serotonergic neuroplasticity. Since ketamine, physical exercise or learning enhance neuroplasticity, combinatory paradigms with selective serotonin reuptake inhibitors could enhance clinical treatment of depression.
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Affiliation(s)
- Christoph Kraus
- NEUROIMAGING LABs (NIL) - PET & MRI & EEG & Chemical Lab Department of Psychiatry and Psychotherapy Medical University of Vienna
| | - Eero Castrén
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria(1)
| | - Rupert Lanzenberger
- NEUROIMAGING LABs (NIL) - PET & MRI & EEG & Chemical Lab Department of Psychiatry and Psychotherapy Medical University of Vienna.
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Vogelgesang S, Niebert S, Renner U, Möbius W, Hülsmann S, Manzke T, Niebert M. Analysis of the Serotonergic System in a Mouse Model of Rett Syndrome Reveals Unusual Upregulation of Serotonin Receptor 5b. Front Mol Neurosci 2017; 10:61. [PMID: 28337123 PMCID: PMC5340760 DOI: 10.3389/fnmol.2017.00061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/23/2017] [Indexed: 12/03/2022] Open
Abstract
Mutations in the transcription factor methyl-CpG-binding-protein 2 (MeCP2) cause a delayed-onset neurodevelopmental disorder known as Rett syndrome (RTT). Although alteration in serotonin levels have been reported in RTT patients, the molecular mechanisms underlying these defects are not well understood. Therefore, we chose to investigate the serotonergic system in hippocampus and brainstem of male Mecp2-/y knock-out mice in the B6.129P2(C)-Mecp2(tm1.1Bird) mouse model of RTT. The serotonergic system in mouse is comprised of 16 genes, whose mRNA expression profile was analyzed by quantitative RT-PCR. Mecp2-/y mice are an established animal model for RTT displaying most of the cognitive and physical impairments of human patients and the selected areas receive significant modulation through serotonin. Using anatomically and functional characterized areas, we found region-specific differential expression between wild type and Mecp2-/y mice at post-natal day 40. In brainstem, we found five genes to be dysregulated, while in hippocampus, two genes were dysregulated. The one gene dysregulated in both brain regions was dopamine decarboxylase, but of special interest is the serotonin receptor 5b (5-ht5b), which showed 75-fold dysregulation in brainstem of Mecp2-/y mice. This dysregulation was not due to upregulation, but due to failure of down-regulation in Mecp2-/y mice during development. Detailed analysis of 5-ht5b revealed a receptor that localizes to endosomes and interacts with Gαi proteins.
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Affiliation(s)
- Steffen Vogelgesang
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the Brain Göttingen, Germany
| | - Sabine Niebert
- Department of Maxillofacial Surgery, University Medical Center Göttingen, Germany
| | - Ute Renner
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the Brain Göttingen, Germany
| | - Wiebke Möbius
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the BrainGöttingen, Germany; Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingen, Germany
| | - Swen Hülsmann
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the BrainGöttingen, Germany; Clinic for Anesthesiology, University Medical CenterGöttingen, Germany
| | - Till Manzke
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the Brain Göttingen, Germany
| | - Marcus Niebert
- DFG Research Center and Excellence Cluster Microscopy at the Nanometer Range and Molecular Physiology of the BrainGöttingen, Germany; Institute of Neuro- and Sensory Physiology, University Medical CenterGöttingen, Germany
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Neurodevelopmental Effects of Serotonin on the Brainstem Respiratory Network. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:193-216. [DOI: 10.1007/978-3-319-62817-2_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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