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Kato T, Okawa G, Tanaka KF, Mitsukura Y. Dexamethasone induces sleep disturbance in a dose-dependent manner in mice. PLoS One 2023; 18:e0296028. [PMID: 38117835 PMCID: PMC10732373 DOI: 10.1371/journal.pone.0296028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 12/05/2023] [Indexed: 12/22/2023] Open
Abstract
Synthetic corticosteroids, the most well-known anti-inflammatory drugs globally, are effective against inflammatory diseases despite their adverse effects that decrease a patient's quality of life (QOL). One of these effects is sleep disturbance, which causes other health issues and further diminishes the QOL. However, the acute effects of steroid drugs on sleep-wake issues are not fully understood and must be clarified in detail using experimental animals. Therefore, this study examines the dose-dependent effect of dexamethasone (DXM), one of the strongest steroid drugs, on the sleep-wake architecture of mice. We conducted acute DXM administration at multiple doses and 24-hour EEG/EMG recordings. Our results revealed that DXM increased the time spent in arousal and decreased that of NREM sleep, even at very low doses. These results imply that steroid-induced sleep disturbance must be addressed at any dosage.
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Affiliation(s)
- Tomonobu Kato
- Faculty of Science and Technology of Keio University, Yokohama, Kanagawa, Japan
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Gento Okawa
- Faculty of Science and Technology of Keio University, Yokohama, Kanagawa, Japan
| | - Kenji F. Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Yasue Mitsukura
- Faculty of Science and Technology of Keio University, Yokohama, Kanagawa, Japan
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2
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Dhillon SK, Gunn ER, Pedersen MV, Lear CA, Wassink G, Davidson JO, Gunn AJ, Bennet L. Alpha-adrenergic receptor activation after fetal hypoxia-ischaemia suppresses transient epileptiform activity and limits loss of oligodendrocytes and hippocampal neurons. J Cereb Blood Flow Metab 2023; 43:947-961. [PMID: 36703575 DOI: 10.1177/0271678x231153723] [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] [Indexed: 01/28/2023]
Abstract
Exposure to hypoxic-ischaemia (HI) is consistently followed by a delayed fall in cerebral perfusion. In preterm fetal sheep this is associated with impaired cerebral oxygenation, consistent with mismatch between perfusion and metabolism. In the present study we tested the hypothesis that alpha-adrenergic inhibition after HI would improve cerebral perfusion, and so attenuate mismatch and reduce neural injury. Chronically instrumented preterm (0.7 gestation) fetal sheep received sham-HI (n = 10) or HI induced by complete umbilical cord occlusion for 25 minutes. From 15 minutes to 8 hours after HI, fetuses received either an intravenous infusion of a non-selective alpha-adrenergic antagonist, phentolamine (10 mg bolus, 10 mg/h infusion, n = 10), or saline (n = 10). Fetal brains were processed for histology 72 hours post-HI. Phentolamine infusion was associated with increased epileptiform transient activity and a greater fall in cerebral oxygenation in the early post-HI recovery phase. Histologically, phentolamine was associated with greater loss of oligodendrocytes and hippocampal neurons. In summary, contrary to our hypothesis, alpha-adrenergic inhibition increased epileptiform transient activity with an exaggerated fall in cerebral oxygenation, and increased neural injury, suggesting that alpha-adrenergic receptor activation after HI is an important endogenous neuroprotective mechanism.
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Affiliation(s)
| | - Eleanor R Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Mette V Pedersen
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | - Christopher A Lear
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Guido Wassink
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
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3
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Laptook AR, Chalak L, Pappas A, Davis A, Sanchez PJ, Van Meurs KP, Oh W, Sommers R, Shankaran S, Hensman AM, Rouse DJ, McDonald S, Das A, Goldberg RN, Ambalavanan N, Gyamfi-Bannerman C, Thom EA, Higgins RD. The effects of betamethasone on the amplitude integrated EEG of infants born at 34- or 35-weeks gestation. J Perinatol 2022; 42:1615-1621. [PMID: 35618748 PMCID: PMC9699898 DOI: 10.1038/s41372-022-01415-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/21/2022] [Accepted: 05/13/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Assess if maternal betamethasone administration at 34-35 weeks accelerated neonatal amplitude integrated EEG (aEEG) maturation. STUDY DESIGN Nested, observational cohort in 7 centers participating in the Antenatal Late Preterm Steroid randomized trial. Up to 2 aEEGs were obtained in neonates born from 340-356 weeks gestation before 72 h (aEEG 1) and at 5-7 days (aEEG 2) if hospitalized. Personnel and aEEG central readers were masked to the intervention. The primary outcome was maturation reflected by cycle frequency; secondary outcomes were border voltage, span, and discontinuity. RESULTS 58 neonates were enrolled (betamethasone, 28, placebo, 30). On aEEG 1, cycle frequency did not differ, but betamethasone exposed infants had a greater lower border voltage and a broader span. On aEEG 2, both groups displayed increases in lower border voltage. CONCLUSIONS Betamethasone associated changes in lower border voltage support accelerated electrical activity. Further investigation is needed to understand the broader span.
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Affiliation(s)
- Abbot R Laptook
- Department of Pediatrics, Women and Infants Hospital, Brown University, Providence, RI, USA.
| | - Lina Chalak
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Athina Pappas
- Department of Pediatrics, Wayne State University, Detroit, MI, USA
| | - Alexis Davis
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA, USA
| | - Pablo J Sanchez
- Department of Pediatrics, Nationwide Children's Hospital, The Ohio State College of Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Krisa P Van Meurs
- Department of Pediatrics, Division of Neonatal and Developmental Medicine, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA, USA
| | - William Oh
- Department of Pediatrics, Women and Infants Hospital, Brown University, Providence, RI, USA
| | - Ross Sommers
- Neonatology, Wellington Medical Center, Boca Raton, FL, USA
| | - Seetha Shankaran
- Department of Pediatrics, Wayne State University, Detroit, MI, USA
| | - Angelita M Hensman
- Department of Pediatrics, Women and Infants Hospital, Brown University, Providence, RI, USA
| | - Dwight J Rouse
- Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Women and Infants Hospital, Brown University, Providence, RI, USA
| | - Scott McDonald
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle, NC, USA
| | - Abhik Das
- Social, Statistical and Environmental Sciences Unit, RTI International, Rockville, MD, USA
| | | | | | - Cynthia Gyamfi-Bannerman
- Department of Obstetrics and Gynecology, Columbia University Irving Medical Center, New York, NY, USA
| | - Elizabeth A Thom
- Department of Biostatistics and Bioinformatics, George Washington University, Washington, DC, USA
| | - Rosemary D Higgins
- Department of Global and Community Health, George Mason University, Fairfax, VA, USA
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4
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Miller SL, Bennet L, Sutherland AE, Pham Y, McDonald C, Castillo‐Melendez M, Allison BJ, Mihelakis J, Nitsos I, Boyd BJ, Hirst JJ, Walker DW, Hunt RW, Jenkin G, Wong F, Malhotra A, Fahey MC, Yawno T. Ganaxolone versus Phenobarbital for Neonatal Seizure Management. Ann Neurol 2022; 92:1066-1079. [PMID: 36054160 PMCID: PMC9828769 DOI: 10.1002/ana.26493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Seizures are more common in the neonatal period than at any other stage of life. Phenobarbital is the first-line treatment for neonatal seizures and is at best effective in approximately 50% of babies, but may contribute to neuronal injury. Here, we assessed the efficacy of phenobarbital versus the synthetic neurosteroid, ganaxolone, to moderate seizure activity and neuropathology in neonatal lambs exposed to perinatal asphyxia. METHODS Asphyxia was induced via umbilical cord occlusion in term lambs at birth. Lambs were treated with ganaxolone (5mg/kg/bolus then 5mg/kg/day for 2 days) or phenobarbital (20mg/kg/bolus then 5mg/kg/day for 2 days) at 6 hours. Abnormal brain activity was classified as stereotypic evolving (SE) seizures, epileptiform discharges (EDs), and epileptiform transients (ETs) using continuous amplitude-integrated electroencephalographic recordings. At 48 hours, lambs were euthanized for brain pathology. RESULTS Asphyxia caused abnormal brain activity, including SE seizures that peaked at 18 to 20 hours, EDs, and ETs, and induced neuronal degeneration and neuroinflammation. Ganaxolone treatment was associated with an 86.4% reduction in the number of seizures compared to the asphyxia group. The total seizure duration in the asphyxia+ganaxolone group was less than the untreated asphyxia group. There was no difference in the number of SE seizures between the asphyxia and asphyxia+phenobarbital groups or duration of SE seizures. Ganaxolone treatment, but not phenobarbital, reduced neuronal degeneration within hippocampal CA1 and CA3 regions, and cortical neurons, and ganaxolone reduced neuroinflammation within the thalamus. INTERPRETATION Ganaxolone provided better seizure control than phenobarbital in this perinatal asphyxia model and was neuroprotective for the newborn brain, affording a new therapeutic opportunity for treatment of neonatal seizures. ANN NEUROL 2022;92:1066-1079.
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Affiliation(s)
- Suzanne L. Miller
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Laura Bennet
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
| | - Amy E. Sutherland
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Yen Pham
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Courtney McDonald
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Margie Castillo‐Melendez
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Beth J. Allison
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Jamie Mihelakis
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Ilias Nitsos
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Ben J. Boyd
- Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Jonathan J. Hirst
- School of Biomedical Sciences and Pharmacy, University of NewcastleNewcastleNew South WalesAustralia
| | - David W. Walker
- School of Health and Biomedical Sciences, RMIT UniversityBundooraVictoriaAustralia
| | - Rodney W. Hunt
- Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
| | - Graham Jenkin
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Flora Wong
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,School of Health and Biomedical Sciences, RMIT UniversityBundooraVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
| | - Atul Malhotra
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia,Monash Children's HospitalClaytonVictoriaAustralia
| | - Michael C. Fahey
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia,Monash Children's HospitalClaytonVictoriaAustralia
| | - Tamara Yawno
- Ritchie Centre, Department of Obstetrics and GynaecologyMonash University and Hudson Institute of Medical ResearchClaytonVictoriaAustralia,Department of PaediatricsMonash UniversityClaytonVictoriaAustralia
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Rakers F, Schleußner E, Muth I, Hoyer D, Rupprecht S, Schiecke K, Groten T, Dreiling M, Kozik V, Schwab M, Hoyer H, Ligges C. Association between antenatal glucocorticoid exposure and the activity of the stress system, cognition, and behavior in 8- to 9-year-old children: A prospective observational study. Acta Obstet Gynecol Scand 2022; 101:996-1006. [PMID: 35652410 DOI: 10.1111/aogs.14386] [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: 02/17/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Glucocorticoid (GC) -induced fetal programming of the activity of the hypothalamus-pituitary-adrenal axis (HPAA) and its associated cognitive and behavioral consequences in later life have been well characterized in several animal species. However, information on humans is scarce. In this study, we examined HPAA activity markers and associated outcomes at 8 to 9 years of age among children prenatally exposed to GC for suspected preterm birth. Our hypothesis was that antenatal exposure to the betamethasone (BM) is associated with exacerbation of HPAA activity in childhood. MATERIAL AND METHODS Prospective observational study in 31 children whose mothers received single (n = 19) or multiple (n = 12) courses of BM for threatened preterm birth but born with normal weight appropriate for the gestational age (median 37+6 weeks of gestation) compared with 38 non-exposed, age-matched children. Primary end point was the activity of the HPAA in response to the Trier Social Stress Test. Secondary end points were changes in autonomic nervous system (ANS) activity, cognitive performance (IQ), attention-deficit/hyperactivity disorder (ADHD) symptoms, and electrocortical activity (EEG). RESULTS There was no statistically significant difference in HPAA activity markers between antenatal BM exposed and unexposed groups. ANS activity in BM-exposed children shifted towards a higher parasympathetic tone reflected by a higher overall high-frequency band power of heart rate variability. IQ scores were within normal limits for both groups; however, BM-exposed children had lower IQ scores than the unexposed group. BM-exposed group had marginally more ADHD core symptoms and increased electrocortical activity in the occipital brain region compared with controls. A monotonic dose-response relationship between BM exposure and activity of the ANS and IQ was estimated in post-hoc analyses. CONCLUSIONS Antenatal exposure to BM in the context of threatened preterm birth was not associated with changes in HPAA activity in childhood. However, BM exposure may be associated with changes in ANS activity. Antenatal GC prophylaxis is a valuable and often life-saving therapy, but its prescription may warrant a well-balanced risk-benefit assessment.
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Affiliation(s)
- Florian Rakers
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | | | - Isabel Muth
- Department of Obstetrics, Jena University Hospital, Jena, Germany
| | - Dirk Hoyer
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Sven Rupprecht
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Karin Schiecke
- Institute of Medical Statistics, Computer and Data Sciences, Jena University Hospital, Jena, Germany
| | - Tanja Groten
- Department of Obstetrics, Jena University Hospital, Jena, Germany
| | - Michelle Dreiling
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Valeska Kozik
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Matthias Schwab
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Heike Hoyer
- Institute of Medical Statistics, Computer and Data Sciences, Jena University Hospital, Jena, Germany
| | - Carolin Ligges
- Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Jena University Hospital, Jena, Germany
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6
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Tournier A, Beacom M, Westgate JA, Bennet L, Garabedian C, Ugwumadu A, Gunn AJ, Lear CA. Physiological control of fetal heart rate variability during labour: Implications and controversies. J Physiol 2021; 600:431-450. [PMID: 34951476 DOI: 10.1113/jp282276] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/25/2021] [Indexed: 11/08/2022] Open
Abstract
The interpretation of fetal heart rate (FHR) patterns is the only available method to continuously monitor fetal wellbeing during labour. One of the most important yet contentious aspects of the FHR pattern is changes in FHR variability (FHRV). Some clinical studies suggest that loss of FHRV during labour is a sign of fetal compromise so this is reflected in practice guidelines. Surprisingly, there is little systematic evidence to support this observation. In this review we methodically dissect the potential pathways controlling FHRV during labour-like hypoxaemia. Before labour, FHRV is controlled by the combined activity of the parasympathetic and sympathetic nervous systems, in part regulated by a complex interplay between fetal sleep state and behaviour. By contrast, preclinical studies using multiple autonomic blockades have now shown that sympathetic neural control of FHRV was potently suppressed between periods of labour-like hypoxaemia, and thus, that the parasympathetic system is the sole neural regulator of FHRV once FHR decelerations are present during labour. We further discuss the pattern of changes in FHRV during progressive fetal compromise and highlight potential biochemical, behavioural and clinical factors that may regulate parasympathetic-mediated FHRV during labour. Further studies are needed to investigate the regulators of parasympathetic activity to better understand the dynamic changes in FHRV and their true utility during labour. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Alexane Tournier
- Department of Obstetrics, Universite de Lille, CHU Lille, ULR 2694 - METRICS, Lille, F 59000, France
| | - Michael Beacom
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Jenny A Westgate
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Charles Garabedian
- Department of Obstetrics, Universite de Lille, CHU Lille, ULR 2694 - METRICS, Lille, F 59000, France
| | - Austin Ugwumadu
- Department of Obstetrics and Gynaecology, St George's Hospital, St George's University of London, London, SW17 0RE, UK
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Christopher A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
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7
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Yates N, Gunn AJ, Bennet L, Dhillon SK, Davidson JO. Preventing Brain Injury in the Preterm Infant-Current Controversies and Potential Therapies. Int J Mol Sci 2021; 22:1671. [PMID: 33562339 PMCID: PMC7915709 DOI: 10.3390/ijms22041671] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/12/2022] Open
Abstract
Preterm birth is associated with a high risk of morbidity and mortality including brain damage and cerebral palsy. The development of brain injury in the preterm infant may be influenced by many factors including perinatal asphyxia, infection/inflammation, chronic hypoxia and exposure to treatments such as mechanical ventilation and corticosteroids. There are currently very limited treatment options available. In clinical trials, magnesium sulfate has been associated with a small, significant reduction in the risk of cerebral palsy and gross motor dysfunction in early childhood but no effect on the combined outcome of death or disability, and longer-term follow up to date has not shown improved neurological outcomes in school-age children. Recombinant erythropoietin has shown neuroprotective potential in preclinical studies but two large randomized trials, in extremely preterm infants, of treatment started within 24 or 48 h of birth showed no effect on the risk of severe neurodevelopmental impairment or death at 2 years of age. Preclinical studies have highlighted a number of promising neuroprotective treatments, such as therapeutic hypothermia, melatonin, human amnion epithelial cells, umbilical cord blood and vitamin D supplementation, which may be useful at reducing brain damage in preterm infants. Moreover, refinements of clinical care of preterm infants have the potential to influence later neurological outcomes, including the administration of antenatal and postnatal corticosteroids and more accurate identification and targeted treatment of seizures.
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Affiliation(s)
- Nathanael Yates
- The Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia;
- School of Human Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Alistair J. Gunn
- The Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.); (S.K.D.)
| | - Laura Bennet
- The Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.); (S.K.D.)
| | - Simerdeep K. Dhillon
- The Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.); (S.K.D.)
| | - Joanne O. Davidson
- The Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.); (S.K.D.)
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8
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Abbasi H, Gunn AJ, Unsworth CP, Bennet L. Deep Convolutional Neural Networks for the Accurate Identification of High-Amplitude Stereotypic Epileptiform Seizures in the Post-Hypoxic-Ischemic EEG of Preterm Fetal Sheep. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:1-4. [PMID: 33136538 DOI: 10.1109/embc44109.2020.9237753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Neonatal seizures after birth may contribute to brain injury after an hypoxic-ischemic (HI) event, impaired brain development and a later life risk for epilepsy. Despite neural immaturity, seizures can also occur in preterm infants. However, surprisingly little is known about their evolution after an HI insult or patterns of expression. An improved understanding of preterm seizures will help facilitate diagnosis and prognosis and the implementation of treatments. This requires improved detection of seizures, including electrographic seizures. We have established a stable preterm fetal sheep model of HI that results in different types of post-HI seizures. These including the expression of epileptiform transients during the latent phase (0-6 h) of cerebral energy recovery, and bursts of high amplitude stereotypic evolving seizures (HAS) during the secondary phase of cerebral energy failure (∼6-72 h). We have previously developed successful automated machine-learning strategies for accurate identification and quantification of the evolving micro-scale EEG patterns (e.g. gamma spikes and sharp waves), during the latent phase. The current paper introduces, for the first time, a real-time approach that employs a 15-layer deep convolutional neural network (CNN) classifier, directly fed with the raw EEG time-series, to identify HAS in the 1024Hz and 256Hz down-sampled data in our preterm fetuses post-HI. The classifier was trained and tested using EEG segments during ∼6 to 48 hours post-HI recordings. The classifier accurately identified HAS with 98.52% accuracy in the 1024Hz and 97.78% in the 256Hz data. Clinical relevance-Results highlight the promising ability of the proposed CNN classifier for accurate identification of HI related seizures in the neonatal preterm brain, if further applied to the current 256Hz clinical recordings, in real-world.
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9
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Sutherland AE, Yawno T, Castillo-Melendez M, Allison BJ, Malhotra A, Polglase GR, Cooper LJ, Jenkin G, Miller SL. Does Antenatal Betamethasone Alter White Matter Brain Development in Growth Restricted Fetal Sheep? Front Cell Neurosci 2020; 14:100. [PMID: 32425758 PMCID: PMC7203345 DOI: 10.3389/fncel.2020.00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/01/2020] [Indexed: 11/13/2022] Open
Abstract
Fetal growth restriction (FGR) is a common complication of pregnancy often associated with neurological impairments. Currently, there is no treatment for FGR, hence it is likely these babies will be delivered prematurely, thus being exposed to antenatal glucocorticoids. While there is no doubt that antenatal glucocorticoids reduce neonatal mortality and morbidities, their effects on the fetal brain, particularly in FGR babies, are less well recognized. We investigated the effects of both short- and long-term exposure to antenatal betamethasone treatment in both FGR and appropriately grown fetal sheep brains. Surgery was performed on pregnant Border-Leicester Merino crossbred ewes at 105-110 days gestation (term ~150 days) to induce FGR by single umbilical artery ligation (SUAL) or sham surgery. Ewes were then treated with a clinical dose of betamethasone (11.4 mg intramuscularly) or saline at 113 and 114 days gestation. Animals were euthanized at 115 days (48 h following the initial betamethasone administration) or 125 days (10 days following the initial dose of betamethasone) and fetal brains collected for analysis. FGR fetuses were significantly smaller than controls (115 days: 1.68 ± 0.11 kg vs. 1.99 ± 0.11 kg, 125 days: 2.70 ± 0.15 kg vs. 3.31 ± 0.20 kg, P < 0.001) and betamethasone treatment reduced body weight in both control (115 days: 1.64 ± 0.10 kg, 125 days: 2.53 ± 0.10 kg) and FGR fetuses (115 days: 1.41 ± 0.10 kg, 125 days: 2.16 ± 0.17 kg, P < 0.001). Brain: body weight ratios were significantly increased with FGR (P < 0.001) and betamethasone treatment (P = 0.002). Within the fetal brain, FGR reduced CNPase-positive myelin staining in the subcortical white matter (SCWM; P = 0.01) and corpus callosum (CC; P = 0.01), increased GFAP staining in the SCWM (P = 0.02) and reduced the number of Olig2 cells in the periventricular white matter (PVWM; P = 0.04). Betamethasone treatment significantly increased CNPase staining in the external capsule (EC; P = 0.02), reduced GFAP staining in the CC (P = 0.03) and increased Olig2 staining in the SCWM (P = 0.04). Here we show that FGR has progressive adverse effects on the fetal brain, particularly within the white matter. Betamethasone exacerbated growth restriction in the FGR offspring, but betamethasone did not worsen white matter brain injury.
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Affiliation(s)
- Amy E Sutherland
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Tamara Yawno
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Margie Castillo-Melendez
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Beth J Allison
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Atul Malhotra
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia.,Department of Paediatrics, Monash University, Clayton, VIC, Australia
| | - Graeme R Polglase
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Leo J Cooper
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Graham Jenkin
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
| | - Suzanne L Miller
- Department of Obstetrics and Gynaecology, The Ritchie Centre, Hudson Institute of Medical Research, Monash University, Clayton, VIC, Australia
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10
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Abbasi H, Gunn AJ, Bennet L, Unsworth CP. Latent Phase Identification of High-Frequency Micro-Scale Gamma Spike Transients in the Hypoxic Ischemic EEG of Preterm Fetal Sheep Using Spectral Analysis and Fuzzy Classifiers. SENSORS 2020; 20:s20051424. [PMID: 32150987 PMCID: PMC7085637 DOI: 10.3390/s20051424] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/27/2020] [Accepted: 03/03/2020] [Indexed: 12/12/2022]
Abstract
Premature babies are at high risk of serious neurodevelopmental disabilities, which in many cases are related to perinatal hypoxic–ischemic encephalopathy (HIE). Studies of neuroprotection in animal models consistently suggest that treatment must be started as early as possible in the first 6 h after hypoxia–ischemia (HI), the so-called latent phase before secondary deterioration, to improve outcomes. We have shown in preterm sheep that EEG biomarkers of injury, in the form of high-frequency micro-scale spike transients, develop and evolve in this critical latent phase after severe asphyxia. Real-time automatic identification of such events is important for the early and accurate detection of HI injury, so that the right treatment can be implemented at the right time. We have previously reported successful strategies for accurate identification of EEG patterns after HI. In this study, we report an alternative high-performance approach based on the fusion of spectral Fourier analysis and Type-I fuzzy classifiers (FFT-Type-I-FLC). We assessed its performance in over 2520 min of latent phase EEG recordings from seven asphyxiated in utero preterm fetal sheep exposed to a range of different occlusion periods. The FFT-Type-I-FLC classifier demonstrated 98.9 ± 1.0% accuracy for identification of high-frequency spike transients in the gamma frequency band (namely 80–120 Hz) post-HI. The spectral-based approach (FFT-Type-I-FLC classifier) has similar accuracy to our previous reverse biorthogonal wavelets rbio2.8 basis function and type-1 fuzzy classifier (rbio-WT-Type-1-FLC), providing competitive performance (within the margin of error: 0.89%), but it is computationally simpler and would be readily adapted to identify other potentially relevant EEG waveforms.
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Affiliation(s)
- Hamid Abbasi
- Department of Engineering Science, Faculty of Engineering, University of Auckland, Auckland 1142, New Zealand;
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.)
- Correspondence:
| | - Alistair J. Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.)
| | - Laura Bennet
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland 1023, New Zealand; (A.J.G.); (L.B.)
| | - Charles P. Unsworth
- Department of Engineering Science, Faculty of Engineering, University of Auckland, Auckland 1142, New Zealand;
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11
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Abbasi H, Unsworth CP. Electroencephalogram studies of hypoxic ischemia in fetal and neonatal animal models. Neural Regen Res 2020; 15:828-837. [PMID: 31719243 PMCID: PMC6990791 DOI: 10.4103/1673-5374.268892] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Alongside clinical achievements, experiments conducted on animal models (including primate or non-primate) have been effective in the understanding of various pathophysiological aspects of perinatal hypoxic/ischemic encephalopathy (HIE). Due to the reasonably fair degree of flexibility with experiments, most of the research around HIE in the literature has been largely concerned with the neurodevelopmental outcome or how the frequency and duration of HI seizures could relate to the severity of perinatal brain injury, following HI insult. This survey concentrates on how EEG experimental studies using asphyxiated animal models (in rodents, piglets, sheep and non-human primate monkeys) provide a unique opportunity to examine from the exact time of HI event to help gain insights into HIE where human studies become difficult.
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Affiliation(s)
- Hamid Abbasi
- Department of Engineering Science, the University of Auckland, Auckland, New Zealand
| | - Charles P Unsworth
- Department of Engineering Science, the University of Auckland, Auckland, New Zealand
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12
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Abbasi H, Bennet L, Gunn AJ, Unsworth CP. Latent Phase Detection of Hypoxic-Ischemic Spike Transients in the EEG of Preterm Fetal Sheep Using Reverse Biorthogonal Wavelets & Fuzzy Classifier. Int J Neural Syst 2019; 29:1950013. [PMID: 31184228 DOI: 10.1142/s0129065719500138] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hypoxic-ischemic (HI) studies in preterms lack reliable prognostic biomarkers for diagnostic tests of HI encephalopathy (HIE). Our group's observations from in utero fetal sheep models suggest that potential biomarkers of HIE in the form of developing HI micro-scale epileptiform transients emerge along suppressed EEG/ECoG background during a latent phase of 6-7h post-insult. However, having to observe for the whole of the latent phase disqualifies any chance of clinical intervention. A precise automatic identification of these transients can help for a well-timed diagnosis of the HIE and to stop the spread of the injury before it becomes irreversible. This paper reports fusion of Reverse-Biorthogonal Wavelets with Type-1 Fuzzy classifiers, for the accurate real-time automatic identification and quantification of high-frequency HI spike transients in the latent phase, tested over seven in utero preterm sheep. Considerable high performance of 99.78 ± 0.10% was obtained from the Rbio-Wavelet Type-1 Fuzzy classifier for automatic identification of HI spikes tested over 42h of high-resolution recordings (sampling-freq:1024Hz). Data from post-insult automatic time-localization of high-frequency HI spikes reveals a promising trend in the average rate of the HI spikes, even in the animals with shorter occlusion periods, which highlights considerable higher number of transients within the first 2h post-insult.
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Affiliation(s)
- Hamid Abbasi
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Charles P Unsworth
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
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13
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Stojanovska V, Barton SK, Tolcos M, Gill AW, Kluckow M, Miller SL, Zahra V, Hooper SB, Galinsky R, Polglase GR. The Effect of Antenatal Betamethasone on White Matter Inflammation and Injury in Fetal Sheep and Ventilated Preterm Lambs. Dev Neurosci 2019; 40:497-507. [PMID: 30840951 DOI: 10.1159/000496466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/20/2018] [Indexed: 11/19/2022] Open
Abstract
Antenatal administration of betamethasone (BM) is a common antecedent of preterm birth, but there is limited information about its impact on the acute evolution of preterm neonatal brain injury. We aimed to compare the effects of maternal BM in combination with mechanical ventilation on the white matter (WM) of late preterm sheep. At 0.85 of gestation, pregnant ewes were randomly assigned to receive intra-muscular (i.m.) saline (n = 9) or i.m. BM (n = 13). Lambs were delivered and unventilated controls (UVCSal, n = 4; UVCBM, n = 6) were humanely killed without intervention; ventilated lambs (VentSal, n = 5; VentBM, n = 7) were injuriously ventilated for 15 min, followed by conventional ventilation for 75 min. Cardiovascular and cerebral haemodynamics and oxygenation were measured continuously. The cerebral WM underwent assessment of inflammation and injury, and oxidative stress was measured in the cerebrospinal fluid (CSF). In the periventricular and subcortical WM tracts, the proportion of amoeboid (activated) microglia, the density of astrocytes, and the number of blood vessels with protein extravasation were higher in UVCBM than in UVCSal (p < 0.05 for all). During ventilation, tidal volume, mean arterial pressure, carotid blood flow, and oxygen delivery were higher in -VentBM lambs (p < 0.05 vs. VentSal). In the subcortical WM, microglial infiltration was increased in the VentSal group compared to UVCSal. The proportion of activated microglia and protein extravasation was higher in the VentBM group compared to VentSal within the periventricular and subcortical WM tracts (p < 0.05). CSF oxidative stress was increased in the VentBM group compared to UVCSal, UVCBM, and VentSal groups (p < 0.05). Antenatal BM was associated with inflammation and vascular permeability in the WM of late preterm fetal sheep. During the immediate neonatal period, the increased carotid perfusion and oxygen delivery in BM-treated lambs was associated with increased oxidative stress, microglial activation and microvascular injury.
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Affiliation(s)
- Vanesa Stojanovska
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Samantha K Barton
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Mary Tolcos
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Andrew W Gill
- Centre for Neonatal Research and Education, The University of Western Australia, Crawley, Washington, Australia
| | - Martin Kluckow
- Department of Neonatal Medicine, Royal North Shore Hospital and University of Sydney, Sydney, New South Wales, Australia
| | - Suzanne L Miller
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Valerie Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia, .,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia,
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14
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Morrison JL, Berry MJ, Botting KJ, Darby JRT, Frasch MG, Gatford KL, Giussani DA, Gray CL, Harding R, Herrera EA, Kemp MW, Lock MC, McMillen IC, Moss TJ, Musk GC, Oliver MH, Regnault TRH, Roberts CT, Soo JY, Tellam RL. Improving pregnancy outcomes in humans through studies in sheep. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1123-R1153. [PMID: 30325659 DOI: 10.1152/ajpregu.00391.2017] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Experimental studies that are relevant to human pregnancy rely on the selection of appropriate animal models as an important element in experimental design. Consideration of the strengths and weaknesses of any animal model of human disease is fundamental to effective and meaningful translation of preclinical research. Studies in sheep have made significant contributions to our understanding of the normal and abnormal development of the fetus. As a model of human pregnancy, studies in sheep have enabled scientists and clinicians to answer questions about the etiology and treatment of poor maternal, placental, and fetal health and to provide an evidence base for translation of interventions to the clinic. The aim of this review is to highlight the advances in perinatal human medicine that have been achieved following translation of research using the pregnant sheep and fetus.
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Affiliation(s)
- Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mary J Berry
- Department of Paediatrics and Child Health, University of Otago , Wellington , New Zealand
| | - Kimberley J Botting
- Department of Physiology, Development, and Neuroscience, University of Cambridge , Cambridge , United Kingdom
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Martin G Frasch
- Department of Obstetrics and Gynecology, University of Washington , Seattle, Washington
| | - Kathryn L Gatford
- Robinson Research Institute and Adelaide Medical School, University of Adelaide , Adelaide, South Australia , Australia
| | - Dino A Giussani
- Department of Physiology, Development, and Neuroscience, University of Cambridge , Cambridge , United Kingdom
| | - Clint L Gray
- Department of Paediatrics and Child Health, University of Otago , Wellington , New Zealand
| | - Richard Harding
- Department of Anatomy and Developmental Biology, Monash University , Clayton, Victoria , Australia
| | - Emilio A Herrera
- Pathophysiology Program, Biomedical Sciences Institute (ICBM), Faculty of Medicine, University of Chile , Santiago , Chile
| | - Matthew W Kemp
- Division of Obstetrics and Gynecology, University of Western Australia , Perth, Western Australia , Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Timothy J Moss
- The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics and Gynaecology, Monash University , Clayton, Victoria , Australia
| | - Gabrielle C Musk
- Animal Care Services, University of Western Australia , Perth, Western Australia , Australia
| | - Mark H Oliver
- Liggins Institute, University of Auckland , Auckland , New Zealand
| | - Timothy R H Regnault
- Department of Obstetrics and Gynecology and Department of Physiology and Pharmacology, Western University, and Children's Health Research Institute , London, Ontario , Canada
| | - Claire T Roberts
- Robinson Research Institute and Adelaide Medical School, University of Adelaide , Adelaide, South Australia , Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Ross L Tellam
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
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15
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Aswathy B, Kumar VM, Gulia KK. Immature sleep pattern in newborn rats when dams encountered sleep restriction during pregnancy. Int J Dev Neurosci 2018; 69:60-67. [DOI: 10.1016/j.ijdevneu.2018.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/09/2018] [Accepted: 06/24/2018] [Indexed: 01/06/2023] Open
Affiliation(s)
- B.S. Aswathy
- Division of Sleep ResearchBiomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and TechnologyTrivandrum695012KeralaIndia
| | - Velayudhan M. Kumar
- Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and TechnologyTrivandrum695012KeralaIndia
| | - Kamalesh K. Gulia
- Division of Sleep ResearchBiomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and TechnologyTrivandrum695012KeralaIndia
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16
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Dhillon SK, Lear CA, Galinsky R, Wassink G, Davidson JO, Juul S, Robertson NJ, Gunn AJ, Bennet L. The fetus at the tipping point: modifying the outcome of fetal asphyxia. J Physiol 2018; 596:5571-5592. [PMID: 29774532 DOI: 10.1113/jp274949] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 04/13/2018] [Indexed: 12/13/2022] Open
Abstract
Brain injury around birth is associated with nearly half of all cases of cerebral palsy. Although brain injury is multifactorial, particularly after preterm birth, acute hypoxia-ischaemia is a major contributor to injury. It is now well established that the severity of injury after hypoxia-ischaemia is determined by a dynamic balance between injurious and protective processes. In addition, mothers who are at risk of premature delivery have high rates of diabetes and antepartum infection/inflammation and are almost universally given treatments such as antenatal glucocorticoids and magnesium sulphate to reduce the risk of death and complications after preterm birth. We review evidence that these common factors affect responses to fetal asphyxia, often in unexpected ways. For example, glucocorticoid exposure dramatically increases delayed cell loss after acute hypoxia-ischaemia, largely through secondary hyperglycaemia. This critical new information is important to understand the effects of clinical treatments of women whose fetuses are at risk of perinatal asphyxia.
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Affiliation(s)
| | - Christopher A Lear
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Robert Galinsky
- The Department of Physiology, University of Auckland, Auckland, New Zealand.,The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
| | - Guido Wassink
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Sandra Juul
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Alistair J Gunn
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Department of Physiology, University of Auckland, Auckland, New Zealand
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17
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Bennet L, Walker DW, Horne RSC. Waking up too early - the consequences of preterm birth on sleep development. J Physiol 2018; 596:5687-5708. [PMID: 29691876 DOI: 10.1113/jp274950] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 03/16/2017] [Indexed: 12/12/2022] Open
Abstract
Good quality sleep of sufficient duration is vital for optimal physiological function and our health. Sleep deprivation is associated with impaired neurocognitive function and emotional control, and increases the risk for cardiometabolic diseases, obesity and cancer. Sleep develops during fetal life with the emergence of a recognisable pattern of sleep states in the preterm fetus associated with the development, maturation and connectivity within neural networks in the brain. Despite the physiological importance of sleep, surprisingly little is known about how sleep develops in individuals born preterm. Globally, an estimated 15 million babies are born preterm (<37 weeks gestation) each year, and these babies are at significant risk of neural injury and impaired brain development. This review discusses how sleep develops during fetal and neonatal life, how preterm birth impacts on sleep development to adulthood, and the factors which may contribute to impaired brain and sleep development, leading to altered neurocognitive, behavioural and motor capabilities in the infant and child. Going forward, the challenge is to identify specific risk factors for impaired sleep development in preterm babies to allow for the design of interventions that will improve the quality and quantity of sleep throughout life.
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Affiliation(s)
- Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - David W Walker
- School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Rosemary S C Horne
- The Ritchie Centre, Department of Paediatrics, Monash University and Hudson Institute of Medical Research, Melbourne, Victoria, Australia
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18
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Bennet L, Galinsky R, Draghi V, Lear CA, Davidson JO, Unsworth CP, Gunn AJ. Time and sex dependent effects of magnesium sulphate on post-asphyxial seizures in preterm fetal sheep. J Physiol 2018; 596:6079-6092. [PMID: 29572829 DOI: 10.1113/jp275627] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/12/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We evaluated the effect of magnesium sulphate (MgSO4 ) on seizures induced by asphyxia in preterm fetal sheep. MgSO4 did not prevent seizures, but significantly reduced the total duration, number of seizures, seizure amplitude and average seizure burden. Saline-asphyxia male fetuses had significantly more seizures than female fetuses, but male fetuses showed significantly greater reduction in seizures during MgSO4 infusion than female fetuses. A circadian profile of seizure activity was observed in all fetuses, with peak seizures seen around 04.00-06.00 h on the first and second days after the end of asphyxia. This study is the first to demonstrate that MgSO4 has utility as an anti-seizure agent after hypoxia-ischaemia. More information is needed about the mechanisms mediating the effect of MgSO4 on seizures and sexual dimorphism, and the influence of circadian rhythms on seizure expression. ABSTRACT Seizures are common in newborns after asphyxia at birth and are often refractory to anti-seizure agents. Magnesium sulphate (MgSO4 ) has anticonvulsant effects and is increasingly given to women in preterm labour for potential neuroprotection. There is limited information on its effects on perinatal seizures. We examined the hypothesis that MgSO4 infusion would reduce fetal seizures after asphyxia in utero. Preterm fetal sheep at 0.7 gestation (104 days, term = 147 days) were given intravenous infusions of either saline (n = 14) or MgSO4 (n = 12, 160 mg bolus + 48 mg h-1 infusion over 48 h). Fetuses underwent umbilical cord occlusion (UCO) for 25 min, 24 h after the start of infusion. The start time for seizures did not differ between groups, but MgSO4 significantly reduced the total number of seizures (P < 0.001), peak seizure amplitude (P < 0.05) and seizure burden (P < 0.005). Within the saline-asphyxia group, male fetuses had significantly more seizures than females (P < 0.05). Within the MgSO4 -asphyxia group, although both sexes had fewer seizures than the saline-asphyxia group, the greatest effect of MgSO4 was on male fetuses, with reduced numbers of seizures (P < 0.001) and seizure burden (P < 0.005). Only 1 out of 6 MgSO4 males had seizures on the second day post-UCO compared to 5 out of 6 MgSO4 female fetuses (P = 0.08). Finally, seizures showed a circadian profile with peak seizures between 04.00 and 06.00 h on the first and second day post-UCO. Collectively, these results suggest that MgSO4 may have utility in treating perinatal seizures and has sexually dimorphic effects.
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Affiliation(s)
- Laura Bennet
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Robert Galinsky
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Vittoria Draghi
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Christopher A Lear
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Charles P Unsworth
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, The Department of Physiology, The University of Auckland, Auckland, New Zealand
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19
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Lear CA, Davidson JO, Mackay GR, Drury PP, Galinsky R, Quaedackers JS, Gunn AJ, Bennet L. Antenatal dexamethasone before asphyxia promotes cystic neural injury in preterm fetal sheep by inducing hyperglycemia. J Cereb Blood Flow Metab 2018; 38:706-718. [PMID: 28387144 PMCID: PMC5888852 DOI: 10.1177/0271678x17703124] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Antenatal glucocorticoid therapy significantly improves the short-term systemic outcomes of prematurely born infants, but there is limited information available on their impact on neurodevelopmental outcomes in at-risk preterm babies exposed to perinatal asphyxia. Preterm fetal sheep (0.7 of gestation) were exposed to a maternal injection of 12 mg dexamethasone or saline followed 4 h later by asphyxia induced by 25 min of complete umbilical cord occlusion. In a subsequent study, fetuses received titrated glucose infusions followed 4 h later by asphyxia to examine the hypothesis that hyperglycemia mediated the effects of dexamethasone. Post-mortems were performed 7 days after asphyxia for cerebral histology. Maternal dexamethasone before asphyxia was associated with severe, cystic brain injury compared to diffuse injury after saline injection, with increased numbers of seizures, worse recovery of brain activity, and increased arterial glucose levels before, during, and after asphyxia. Glucose infusions before asphyxia replicated these adverse outcomes, with a strong correlation between greater increases in glucose before asphyxia and greater neural injury. These findings strongly suggest that dexamethasone exposure and hyperglycemia can transform diffuse injury into cystic brain injury after asphyxia in preterm fetal sheep.
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Affiliation(s)
- Christopher A Lear
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Georgia R Mackay
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Paul P Drury
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Robert Galinsky
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | | | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
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20
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Bennet L, Dhillon S, Lear CA, van den Heuij L, King V, Dean JM, Wassink G, Davidson JO, Gunn AJ. Chronic inflammation and impaired development of the preterm brain. J Reprod Immunol 2018; 125:45-55. [DOI: 10.1016/j.jri.2017.11.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 11/13/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
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21
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Yamaguchi K, Lear CA, Beacom MJ, Ikeda T, Gunn AJ, Bennet L. Evolving changes in fetal heart rate variability and brain injury after hypoxia-ischaemia in preterm fetal sheep. J Physiol 2018; 596:6093-6104. [PMID: 29315570 DOI: 10.1113/jp275434] [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] [Received: 10/13/2017] [Accepted: 12/22/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Fetal heart rate variability is a critical index of fetal wellbeing. Suppression of heart rate variability may provide prognostic information on the risk of hypoxic-ischaemic brain injury after birth. In the present study, we report the evolution of fetal heart rate variability after both mild and severe hypoxia-ischaemia. Both mild and severe hypoxia-ischaemia were associated with an initial, brief suppression of multiple measures of heart rate variability. This was followed by normal or increased levels of heart rate variability during the latent phase of injury. Severe hypoxia-ischaemia was subsequently associated with the prolonged suppression of measures of heart rate variability during the secondary phase of injury, which is the period of time when brain injury is no longer treatable. These findings suggest that a biphasic pattern of heart rate variability may be an early marker of brain injury when treatment or intervention is probably most effective. ABSTRACT Hypoxia-ischaemia (HI) is a major contributor to preterm brain injury, although there are currently no reliable biomarkers for identifying infants who are at risk. We tested the hypothesis that fetal heart rate (FHR) and FHR variability (FHRV) would identify evolving brain injury after HI. Fetal sheep at 0.7 of gestation were subjected to either 15 (n = 10) or 25 min (n = 17) of complete umbilical cord occlusion or sham occlusion (n = 12). FHR and four measures of FHRV [short-term variation, long-term variation, standard deviation of normal to normal R-R intervals (SDNN), root mean square of successive differences) were assessed until 72 h after HI. All measures of FHRV were suppressed for the first 3-4 h in the 15 min group and 1-2 h in the 25 min group. Measures of FHRV recovered to control levels by 4 h in the 15 min group, whereas the 25 min group showed tachycardia and an increase in short-term variation and SDNN from 4 to 6 h after occlusion. The measures of FHRV then progressively declined in the 25 min group and became profoundly suppressed from 18 to 48 h. A partial recovery of FHRV measures towards control levels was observed in the 25 min group from 49 to 72 h. These findings illustrate the complex regulation of FHRV after both mild and severe HI and suggest that the longitudinal analysis of FHR and FHRV after HI may be able to help determine the timing and severity of preterm HI.
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Affiliation(s)
- Kyohei Yamaguchi
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, New Zealand.,The Department of Obstetrics and Gynaecology, Mie University, Mie, Japan
| | - Christopher A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, New Zealand
| | - Michael J Beacom
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, New Zealand
| | - Tomoaki Ikeda
- The Department of Obstetrics and Gynaecology, Mie University, Mie, Japan
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, New Zealand
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22
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Cohen E, Wong FY, Wallace EM, Mockler JC, Odoi A, Hollis S, Horne RSC, Yiallourou SR. EEG power spectrum maturation in preterm fetal growth restricted infants. Brain Res 2017; 1678:180-186. [PMID: 29050860 DOI: 10.1016/j.brainres.2017.10.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 09/03/2017] [Accepted: 10/08/2017] [Indexed: 01/23/2023]
Abstract
Power spectral analysis of the electroencephalogram (EEG) is a non-invasive method to examine infant brain maturation. Preterm fetal growth restricted (p-FGR) neonates display an altered EEG power spectrum compared to appropriate-for-gestational-age (AGA) peers, suggesting delayed brain maturation. Longitudinal studies investigating EEG power spectrum maturation in p-FGR infants are lacking, however. We thus aimed to investigate brain maturation using sleep EEG power spectral analysis in p-FGR infants compared to preterm and term AGA controls (p-AGA and t-AGA, respectively). EEG was recorded during spontaneous sleep in 13 p-FGR, 17 p-AGA and 19 t-AGA infants at 1 and 6 months post-term age. Infant sleep states (active and quiet sleep) were scored using standard criteria. Power spectral analysis of a single-channel EEG (C3-M2/C4-M1) was performed using Fast Fourier Transform. The EEG power spectrum was divided into delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), sigma (12-14 Hz) and beta (14-30 Hz) frequency bands. Relative (%) powers and the spectral edge frequency were calculated. The spectral edge frequency was significantly higher in p-FGR infants compared to p-AGA controls in quiet sleep at 1 month post-term age (p < .01). This was due to significantly reduced %-delta and significantly increased %-theta, %-alpha and %-beta power (p < .01 for all) compared to p-AGA infants. p-FGR infants also showed significantly increased %-beta power compared to t-AGA infants (p < .05). No group differences were observed in active sleep or at 6 months post-term age. In conclusion, p-FGR infants show altered sleep EEG power spectrum maturation compared to AGA peers. However, changes resolved by 6 months post-term age.
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Affiliation(s)
- Emily Cohen
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia; Department of Neonatology, Wilhelmina Children's Hospital/University Medical Center Utrecht and Utrecht University, PO Box 85090, 3508 AB Utrecht, The Netherlands
| | - Flora Y Wong
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia; Monash Newborn, Monash Health, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia
| | - Euan M Wallace
- The Ritchie Centre, Department of Obstetrics and Gynaecology, Monash University, Level 5 Monash Medical Centre, 246 Clayton Road, Clayton, Victoria 3168, Australia
| | - Joanne C Mockler
- Department of Obstetrics and Gynaecology, Monash University and Monash Women's, Monash Health, Level 5 Monash Medical Centre, 246 Clayton Road, Clayton, Victoria 3168, Australia
| | - Alexsandria Odoi
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia
| | - Samantha Hollis
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia
| | - Rosemary S C Horne
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia.
| | - Stephanie R Yiallourou
- The Ritchie Centre, Hudson Institute of Medical Research and Department of Paediatrics, Monash University, Level 5 Monash Children's Hospital, 246 Clayton Road, Clayton, Victoria 3168, Australia
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23
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Anegroaie P, Frasch MG, Rupprecht S, Antonow-Schlorke I, Müller T, Schubert H, Witte OW, Schwab M. Development of somatosensory-evoked potentials in foetal sheep: effects of betamethasone. Acta Physiol (Oxf) 2017; 220:137-149. [PMID: 27580709 DOI: 10.1111/apha.12795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 06/15/2016] [Accepted: 08/30/2016] [Indexed: 11/30/2022]
Abstract
AIM Antenatal glucocorticoids are used to accelerate foetal lung maturation in babies threatened with premature labour. We examined the influence of glucocorticoids on functional and structural maturation of the central somatosensory pathway in foetal sheep. Somatosensory-evoked potentials (SEP) reflect processing of somatosensory stimuli. SEP latencies are determined by afferent stimuli transmission while SEP amplitudes reveal cerebral processing. METHODS After chronic instrumentation of foetal sheep, mothers received saline (n = 9) or three courses of betamethasone (human equivalent dose of 2 × 110 μg kg-1 betamethasone i.m. 24 h apart, n = 12) at 0.7, 0.75 and 0.8 of gestational age. Trigeminal SEP were evoked prior to, 4 and 24 h after each injection and at 0.8 of gestational age before brains were histologically processed. RESULTS Somatosensory-evoked potentials were already detectable at 0.7 of gestation age. The early and late responses N20 and N200 were the only reproducible peaks over the entire study period. With advancing gestational age, SEP latencies decreased but amplitudes remained unchanged. Acutely, betamethasone did not affect SEP latencies and amplitudes 4 and 24 h following administration. Chronically, betamethasone delayed developmental decrease in the N200 but not N20 latency by 2 weeks without affecting amplitudes. In parallel, betamethasone decreased subcortical white matter myelination but did not affect network formation and synaptic density in the somatosensory cortex. CONCLUSION Somatosensory stimuli are already processed by the foetal cerebral cortex at the beginning of the third trimester. Subsequent developmental decrease in SEP latencies suggests ongoing maturation of afferent sensory transmission. Antenatal glucocorticoids affect structural and functional development of the somatosensory system with specific effects at subcortical level.
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Affiliation(s)
- P. Anegroaie
- Department of Neurology; Jena University Hospital; Jena Germany
- Department of Pediatric Surgery; Jena University Hospital; Jena Germany
| | - M. G. Frasch
- Department of Obstetrics and Gynecology; University of Washington; Seattle WA USA
| | - S. Rupprecht
- Department of Neurology; Jena University Hospital; Jena Germany
| | | | - T. Müller
- Institute of Laboratory Animal Science; Jena University Hospital; Jena Germany
| | - H. Schubert
- Institute of Laboratory Animal Science; Jena University Hospital; Jena Germany
| | - O. W. Witte
- Department of Neurology; Jena University Hospital; Jena Germany
| | - M. Schwab
- Department of Neurology; Jena University Hospital; Jena Germany
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24
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Shany E, Berger I, Goldberg O, Karplus M, Gilat S, Benzaquen O, Yogev H, Shalev R. Do Prenatal Corticosteroids Affect Brain Maturation of the Premature Infant? An Electroencephalography Study. Clin EEG Neurosci 2017; 48:79-87. [PMID: 27090506 DOI: 10.1177/1550059416643202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To assess whether prenatal treatment with betamethasone has a significant influence on cerebral maturation indices as measured by electroencephalographic (EEG) indices. STUDY DESIGN Infants born less than 35 weeks postmenstrual age (PMA) were prospectively enrolled if their mother received a full course of bethametasone prior to delivery (study group) or not (control group); infants with major intracranial abnormalities were excluded as well as those who were sedated or needed assisted ventilation. EEG was recorded during the first 10 days of life. Interburst intervals and maximal amplitudes of theta and delta bandwidths were calculated by a signal processing software. A multivariate general linear model was used to analyze the relationship between the 2 groups and the different electrophysiologic parameters, adjusting for PMA and mode of delivery. RESULTS Thirty-eight infants were included in the study group and 36 in the control group. Univariate analysis demonstrated a negative correlation between PMA at test and EEG indices (interburst interval and delta and theta frequencies). Multivariate analysis demonstrated a less robust correlation of PMA and EEG indices and a positive correlation of prenatal betamethasone treatment with Theta frequencies. Repeating the data analysis separately for each study group, the above results remained significant mainly in the study group. CONCLUSIONS Our findings suggest a possible stabilization effect of corticosteroids on the central nervous system and a possible delay of the maturation of cerebral activity related to prenatal corticosteroids use. These findings may relate to a better neurodevelopmental outcome of infants treated prenatally with corticosteroids.
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Affiliation(s)
- Eilon Shany
- 1 Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,2 Neonatal Department, Soroka Medical Center, Beer Sheva, Israel
| | - Itai Berger
- 3 Neuro-Cognitive Center, Pediatric Wing, Hadassah-Hebrew University Medical Center (Mt. Scopus Campus), Jerusalem, Israel
| | - Ori Goldberg
- 4 Pediatric Department, Shneider Children Hospital, Petah Tikwa, Israel
| | - Michael Karplus
- 1 Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Shlomo Gilat
- 5 S. Gilat Medical Research & Equipment Ltd, Karkur, Israel
| | - Oshra Benzaquen
- 6 Radiology Department, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel
| | - Hagai Yogev
- 7 Tel Aviv-Yaffo Academic College, Tel Aviv-Yaffo, Israel
| | - Ruth Shalev
- 8 Neuropaediatric Unit, Shaare Zedek Medical Centre, Jerusalem, Israel
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25
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Yates NJ, Robertson D, Rodger J, Martin-Iverson MT. Effects of Neonatal Dexamethasone Exposure on Adult Neuropsychiatric Traits in Rats. PLoS One 2016; 11:e0167220. [PMID: 27936175 PMCID: PMC5147874 DOI: 10.1371/journal.pone.0167220] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 11/10/2016] [Indexed: 11/18/2022] Open
Abstract
The effects of early life stress in utero or in neonates has long-term consequences on hypothalamic-pituitary-adrenal (HPA) stress axis function and neurodevelopment. These effects extend into adulthood and may underpin a variety of mental illnesses and be related to various developmental and cognitive changes. We examined the potential role of neonatal HPA axis activation on adult psychopathology and dopamine sensitivity in the mature rat using neonatal exposure to the synthetic glucocorticoid receptor agonist and stress hormone, dexamethasone. We utilized a comprehensive battery of assessments for behaviour, brain function and gene expression to determine if elevated early life HPA activation is associated with adult-onset neuropsychiatric traits. Dexamethasone exposure increased startle reactivity under all conditions tested, but decreased sensitivity of sensorimotor gating to dopaminergic disruption–contrasting with what is observed in several neuropsychiatric diseases. Under certain conditions there also appeared to be mild long-term changes in stress and anxiety-related behaviours with neonatal dexamethasone exposure. Electrophysiology revealed that there were no consistent neuropsychiatric abnormalities in auditory processing or resting state brain function with dexamethasone exposure. However, neonatal dexamethasone altered auditory cortex glucocorticoid activation, and auditory cortex synchronization. Our results indicate that neonatal HPA axis activation by dexamethasone alters several aspects of adult brain function and behaviour and may induce long-term changes in emotional stress-reactivity. However, neonatal dexamethasone exposure is not specifically related to any particular neuropsychiatric disease.
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Affiliation(s)
- Nathanael J. Yates
- School of Animal Biology, Faculty of Science, The University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
| | - Donald Robertson
- School of Anatomy, Physiology, and Human Biology, Faculty of Science, The University of Western Australia, Crawley, Western Australia, Australia
| | - Jennifer Rodger
- School of Animal Biology, Faculty of Science, The University of Western Australia, Crawley, Western Australia, Australia
| | - Mathew T. Martin-Iverson
- School of Medicine and Pharmacology, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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26
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Abbasi H, Bennet L, Gunn AJ, Unsworth CP. Robust Wavelet Stabilized 'Footprints of Uncertainty' for Fuzzy System Classifiers to Automatically Detect Sharp Waves in the EEG after Hypoxia Ischemia. Int J Neural Syst 2016; 27:1650051. [PMID: 27760476 DOI: 10.1142/s0129065716500519] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Currently, there are no developed methods to detect sharp wave transients that exist in the latent phase after hypoxia-ischemia (HI) in the electroencephalogram (EEG) in order to determine if these micro-scale transients are potential biomarkers of HI. A major issue with sharp waves in the HI-EEG is that they possess a large variability in their sharp wave profile making it difficult to build a compact 'footprint of uncertainty' (FOU) required for ideal performance of a Type-2 fuzzy logic system (FLS) classifier. In this paper, we develop a novel computational EEG analysis method to robustly detect sharp waves using over 30[Formula: see text]h of post occlusion HI-EEG from an equivalent, in utero, preterm fetal sheep model cohort. We demonstrate that initial wavelet transform (WT) of the sharp waves stabilizes the variation in their profile and thus permits a highly compact FOU to be built, hence, optimizing the performance of a Type-2 FLS. We demonstrate that this method leads to higher overall performance of [Formula: see text] for the clinical [Formula: see text] sampled EEG and [Formula: see text] for the high resolution [Formula: see text] sampled EEG that is improved upon over conventional standard wavelet [Formula: see text] and [Formula: see text], respectively, and fuzzy approaches [Formula: see text] and [Formula: see text], respectively, when performed in isolation.
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Affiliation(s)
- Hamid Abbasi
- 1 Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- 2 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- 2 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Charles P Unsworth
- 1 Department of Engineering Science, The University of Auckland, Auckland, New Zealand
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27
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Zwanenburg A, Andriessen P, Jellema RK, Niemarkt HJ, Wolfs TGAM, Kramer BW, Delhaas T. Using trend templates in a neonatal seizure algorithm improves detection of short seizures in a foetal ovine model. Physiol Meas 2015; 36:369-84. [DOI: 10.1088/0967-3334/36/3/369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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28
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Neonatal dexamethasone accelerates spreading depression in the rat, and antioxidant vitamins counteract this effect. Brain Res 2014; 1591:93-101. [DOI: 10.1016/j.brainres.2014.09.075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 12/27/2022]
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29
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Lear CA, Koome ME, Davidson JO, Drury PP, Quaedackers JS, Galinsky R, Gunn AJ, Bennet L. The effects of dexamethasone on post-asphyxial cerebral oxygenation in the preterm fetal sheep. J Physiol 2014; 592:5493-505. [PMID: 25384775 DOI: 10.1113/jphysiol.2014.281253] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Exposure to clinical doses of the glucocorticoid dexamethasone increases brain activity and causes seizures in normoxic preterm fetal sheep without causing brain injury. In contrast, the same treatment after asphyxia increased brain injury. We hypothesised that increased injury was in part mediated by a mismatch between oxygen demand and oxygen supply. In preterm fetal sheep at 0.7 gestation we measured cerebral oxygenation using near-infrared spectroscopy, electroencephalographic (EEG) activity, and carotid blood flow (CaBF) from 24 h before until 72 h after asphyxia induced by 25 min of umbilical cord occlusion. Ewes received dexamethasone intramuscularly (12 mg 3 ml(-1)) or saline 15 min after the end of asphyxia. Fetuses were studied for 3 days after occlusion. During the first 6 h of recovery after asphyxia, dexamethasone treatment was associated with a significantly greater fall in CaBF (P < 0.05), increased carotid vascular resistance (P < 0.001) and a greater fall in cerebral oxygenation as measured by the difference between oxygenated and deoxygenated haemoglobin (delta haemoglobin; P < 0.05). EEG activity was similarly suppressed in both groups. From 6 to 10 h onward, dexamethasone treatment was associated with a return of CaBF to saline control levels, increased EEG power (P < 0.005), greater epileptiform transient activity (P < 0.001), increased oxidised cytochrome oxidase (P < 0.05) and an attenuated increase in [delta haemoglobin] (P < 0.05). In conclusion, dexamethasone treatment after asphyxia is associated with greater hypoperfusion in the critical latent phase, leading to impaired intracerebral oxygenation that may exacerbate neural injury after asphyxia.
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Affiliation(s)
- Christopher A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Miriam E Koome
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Paul P Drury
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Josine S Quaedackers
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Robert Galinsky
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
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30
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Jones NC, O'Brien TJ, Carmant L. Interaction between sex and early-life stress: influence on epileptogenesis and epilepsy comorbidities. Neurobiol Dis 2014; 72 Pt B:233-41. [PMID: 25266701 DOI: 10.1016/j.nbd.2014.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/08/2014] [Accepted: 09/12/2014] [Indexed: 12/22/2022] Open
Abstract
Epilepsy is a common brain disorder which is characterised by recurring seizures. In addition to suffering from the constant stress of living with this neurological condition, patients also frequently experience comorbid psychiatric and cognitive disorders which significantly impact their quality of life. There is growing appreciation that stress, in particular occurring in early life, can negatively impact brain development, creating an enduring vulnerability to develop epilepsy. This aligns with the solid connections between early life environments and the development of psychiatric conditions, promoting the possibility that adverse early life events could represent a common risk factor for the later development of both epilepsy and comorbid psychiatric disorders. The influence of sex has been little studied, but recent research points to potential important interactions, particularly with regard to effects mediated by HPA axis programming. Understanding these interactions, and the underlying molecular mechanisms, will provide important new insights into the causation of both epilepsy and of psychiatric disorders, and potentially open up novel avenues for treatment.
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Affiliation(s)
- Nigel C Jones
- Department of Medicine (Royal Melbourne Hospital), Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia.
| | - Terence J O'Brien
- Department of Medicine (Royal Melbourne Hospital), Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Lionel Carmant
- Centre de Recherche du Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
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31
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van Campen JS, Jansen FE, de Graan PNE, Braun KPJ, Joels M. Early life stress in epilepsy: a seizure precipitant and risk factor for epileptogenesis. Epilepsy Behav 2014; 38:160-71. [PMID: 24144618 DOI: 10.1016/j.yebeh.2013.09.029] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 09/17/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
Abstract
Stress can influence epilepsy in multiple ways. A relation between stress and seizures is often experienced by patients with epilepsy. Numerous questionnaire and diary studies have shown that stress is the most often reported seizure-precipitating factor in epilepsy. Acute stress can provoke epileptic seizures, and chronic stress increases seizure frequency. In addition to its effects on seizure susceptibility in patients with epilepsy, stress might also increase the risk of epilepsy development, especially when the stressors are severe, prolonged, or experienced early in life. Although the latter has not been fully resolved in humans, various preclinical epilepsy models have shown increased seizure susceptibility in naïve rodents after prenatal and early postnatal stress exposure. In the current review, we first provide an overview of the effects of stress on the brain. Thereafter, we discuss human as well as preclinical studies evaluating the relation between stress, epileptic seizures, and epileptogenesis, focusing on the epileptogenic effects of early life stress. Increased knowledge on the interaction between early life stress, seizures, and epileptogenesis could improve patient care and provide a basis for new treatment strategies for epilepsy.
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Affiliation(s)
- Jolien S van Campen
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands; Department of Neuroscience & Pharmacology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
| | - Floor E Jansen
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Pierre N E de Graan
- Department of Neuroscience & Pharmacology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Kees P J Braun
- Department of Pediatric Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Marian Joels
- Department of Neuroscience & Pharmacology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
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32
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Maternal treatment with glucocorticoids modulates gap junction protein expression in the ovine fetal brain. Neuroscience 2014; 275:248-58. [PMID: 24929069 DOI: 10.1016/j.neuroscience.2014.05.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 04/28/2014] [Accepted: 05/14/2014] [Indexed: 12/31/2022]
Abstract
Gap junctions facilitate intercellular communication and are important in brain development. Connexins (Cx) comprise a transmembrane protein family that forms gap junctions. Cx-32 is expressed in oligodendrocytes and neurons, Cx-36 in neurons, and Cx-43 in astrocytes. Although single antenatal steroid courses are recommended for fetal lung maturation, multiple courses can be given to women at recurrent risk for premature delivery. We examined the effects of single and multiple glucocorticoid courses on Cx-32, Cx-36, and Cx-43 protein expressions in the fetal cerebral cortex, cerebellum, and spinal cord, and differences in Cx expression among brain regions under basal conditions. In the single-course groups, the ewes received dexamethasone (6 mg) or placebo as four intramuscular injections every 12h over 48 h. In the multiple-course groups, the ewes received the same treatment, once a week for 5 weeks starting at 76-78 days of gestation. Cx were measured by Western immunoblot on brain samples from 105 to 108-day gestation fetuses. A single dexamethasone course was associated with increases (P<0.05) in cerebral cortical and spinal cord Cx-36 and Cx-43 and multiple courses with increases in cerebellar and spinal cord Cx-36, and cerebral cortical and cerebellar Cx-43. Cx-32 did not change. Cx-32 was higher in the cerebellum than cerebral cortex and spinal cord, Cx-36 higher in the spinal cord than cerebellum, and Cx-43 higher in the cerebellum and spinal cord than cerebral cortex during basal conditions. In conclusion, maternal glucocorticoid therapy increases specific Cx, responses to different maternal courses vary among Cx and brain regions, and Cx expression differs among brain regions under basal conditions. Maternal treatment with glucocorticoids differentially modulates Cx in the fetal brain.
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33
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Yerushalmy-Feler A, Marom R, Peylan T, Korn A, Haham A, Mandel D, Yarkoni I, Bassan H. Electroencephalographic characteristics in preterm infants born with intrauterine growth restriction. J Pediatr 2014; 164:756-761.e1. [PMID: 24485822 DOI: 10.1016/j.jpeds.2013.12.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/29/2013] [Accepted: 12/13/2013] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine the impact of fetal growth on postnatal amplitude-integrated electroencephalography (aEEG) and power spectrum electroencephalography (EEG) data in preterm infants born with intrauterine growth restriction (IUGR). STUDY DESIGN We defined IUGR as birth weight <10th percentile, and control as birth weight appropriate for gestational age (GA). We performed single-channel (C3-C4) EEG during the first 48 hours of life and measured the upper and lower margins of the aEEG trace width. EEG readings were analyzed by spectral analysis, and the relative power of the frequency bands was calculated. The Lacey Assessment of the Preterm Infant was administered before discharge. RESULTS We enrolled 14 infants with IUGR (mean GA, 34.3 ± 1.8 weeks; mean birth weight 1486 ± 304 g) and 16 appropriate for GA controls (mean GA, 33.7 ± 2 weeks; mean birth weight, 1978 ± 488 g). There were no significant between-group differences in perinatal complications. The mean aEEG trace width was 20.8 ± 1.4 μv in the infants with IUGR versus 17.3 ± 1.6 μv in controls (P < .001). The infants with IUGR also had significantly greater delta frequency activity and decreased theta, alpha, and beta frequency activities compared with controls. Delta frequency activity decreased with increasing GA (r = -0.8; P = .001 for infants with IUGR and r = -0.9; P < .001 for controls). The Lacey Assessment of the Preterm Infant developmental score was significantly lower in the infants with IUGR (P < .02) and was correlated with aEEG trace width (r = -0.6; P = .002) and with delta activity (r = -0.5; P = .02). CONCLUSION Preterm infants with IUGR have delayed EEG maturation associated with delayed neuromotor development. The predictive value of these alterations regarding developmental deficits associated with IUGR remains undetermined, however.
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Affiliation(s)
- Anat Yerushalmy-Feler
- Department of Neonatology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Child Neurology and Development Unit, Department of Pediatric Neurosurgery, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Ronella Marom
- Department of Neonatology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Tali Peylan
- Child Neurology and Development Unit, Department of Pediatric Neurosurgery, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Akiva Korn
- Division of Neurophysiology, Department of Pediatric Neurosurgery, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Alon Haham
- Department of Neonatology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Dror Mandel
- Department of Neonatology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Inbal Yarkoni
- Department of Neonatology, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Haim Bassan
- Child Neurology and Development Unit, Department of Pediatric Neurosurgery, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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34
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Bennet L, Van Den Heuij L, M Dean J, Drury P, Wassink G, Jan Gunn A. Neural plasticity and the Kennard principle: does it work for the preterm brain? Clin Exp Pharmacol Physiol 2013; 40:774-84. [DOI: 10.1111/1440-1681.12135] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/29/2013] [Accepted: 05/31/2013] [Indexed: 12/27/2022]
Affiliation(s)
- Laura Bennet
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
| | - Lotte Van Den Heuij
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
| | - Justin M Dean
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
| | - Paul Drury
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
| | - Guido Wassink
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
| | - Alistair Jan Gunn
- Fetal Physiology and Neuroscience Groups; Department of Physiology; University of Auckland; Auckland New Zealand
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Koome ME, Davidson JO, Drury PP, Mathai S, Booth LC, Gunn AJ, Bennet L. Antenatal dexamethasone after asphyxia increases neural injury in preterm fetal sheep. PLoS One 2013; 8:e77480. [PMID: 24204840 PMCID: PMC3799621 DOI: 10.1371/journal.pone.0077480] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 09/02/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Maternal glucocorticoid treatment for threatened premature delivery dramatically improves neonatal survival and short-term morbidity; however, its effects on neurodevelopmental outcome are variable. We investigated the effect of maternal glucocorticoid exposure after acute asphyxia on injury in the preterm brain. METHODS Chronically instrumented singleton fetal sheep at 0.7 of gestation received asphyxia induced by complete umbilical cord occlusion for 25 minutes. 15 minutes after release of occlusion, ewes received a 3 ml i.m. injection of either dexamethasone (12 mg, n = 10) or saline (n = 10). Sheep were killed after 7 days recovery; survival of neurons in the hippocampus and basal ganglia, and oligodendrocytes in periventricular white matter were assessed using an unbiased stereological approach. RESULTS Maternal dexamethasone after asphyxia was associated with more severe loss of neurons in the hippocampus (CA3 regions, 290 ± 76 vs 484 ± 98 neurons/mm(2), mean ± SEM, P<0.05) and basal ganglia (putamen, 538 ± 112 vs 814 ± 34 neurons/mm(2), P<0.05) compared to asphyxia-saline, and with greater loss of both total (913 ± 77 vs 1201 ± 75/mm(2), P<0.05) and immature/mature myelinating oligodendrocytes in periventricular white matter (66 ± 8 vs 114 ± 12/mm(2), P<0.05, vs sham controls 165 ± 10/mm(2), P<0.001). This was associated with transient hyperglycemia (peak 3.5 ± 0.2 vs. 1.4 ± 0.2 mmol/L at 6 h, P<0.05) and reduced suppression of EEG power in the first 24 h after occlusion (maximum -1.5 ± 1.2 dB vs. -5.0 ± 1.4 dB in saline controls, P<0.01), but later onset and fewer overt seizures. CONCLUSIONS In preterm fetal sheep, exposure to maternal dexamethasone during recovery from asphyxia exacerbated brain damage.
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Affiliation(s)
- Miriam E. Koome
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Joanne O. Davidson
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Paul P. Drury
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Sam Mathai
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Lindsea C. Booth
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Alistair Jan Gunn
- Department of Physiology, the University of Auckland, Auckland New Zealand
| | - Laura Bennet
- Department of Physiology, the University of Auckland, Auckland New Zealand
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Jellema RK, Wolfs TGAM, Lima Passos V, Zwanenburg A, Ophelders DRMG, Kuypers E, Hopman AHN, Dudink J, Steinbusch HW, Andriessen P, Germeraad WTV, Vanderlocht J, Kramer BW. Mesenchymal stem cells induce T-cell tolerance and protect the preterm brain after global hypoxia-ischemia. PLoS One 2013; 8:e73031. [PMID: 23991170 PMCID: PMC3753351 DOI: 10.1371/journal.pone.0073031] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/23/2013] [Indexed: 12/11/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) in preterm infants is a severe disease for which no curative treatment is available. Cerebral inflammation and invasion of activated peripheral immune cells have been shown to play a pivotal role in the etiology of white matter injury, which is the clinical hallmark of HIE in preterm infants. The objective of this study was to assess the neuroprotective and anti-inflammatory effects of intravenously delivered mesenchymal stem cells (MSC) in an ovine model of HIE. In this translational animal model, global hypoxia-ischemia (HI) was induced in instrumented preterm sheep by transient umbilical cord occlusion, which closely mimics the clinical insult. Intravenous administration of 2 x 10(6) MSC/kg reduced microglial proliferation, diminished loss of oligodendrocytes and reduced demyelination, as determined by histology and Diffusion Tensor Imaging (DTI), in the preterm brain after global HI. These anti-inflammatory and neuroprotective effects of MSC were paralleled by reduced electrographic seizure activity in the ischemic preterm brain. Furthermore, we showed that MSC induced persistent peripheral T-cell tolerance in vivo and reduced invasion of T-cells into the preterm brain following global HI. These findings show in a preclinical animal model that intravenously administered MSC reduced cerebral inflammation, protected against white matter injury and established functional improvement in the preterm brain following global HI. Moreover, we provide evidence that induction of T-cell tolerance by MSC might play an important role in the neuroprotective effects of MSC in HIE. This is the first study to describe a marked neuroprotective effect of MSC in a translational animal model of HIE.
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Affiliation(s)
- Reint K. Jellema
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Tim G. A. M. Wolfs
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
- School of Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Valéria Lima Passos
- Department of Methodology & Statistics, Maastricht University, Maastricht, The Netherlands
| | - Alex Zwanenburg
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | - Daan R. M. G. Ophelders
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Elke Kuypers
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Anton H. N. Hopman
- School of Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
- Department of Molecular Cell Biology, Maastricht University, Maastricht, The Netherlands
| | - Jeroen Dudink
- Department of Neonatology and Neuroscience, Sophia Children’s Hospital, Rotterdam, The Netherlands
| | - Harry W. Steinbusch
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Peter Andriessen
- Department of Pediatrics, Máxima Medical Centre, Veldhoven, The Netherlands
| | - Wilfred T. V. Germeraad
- School of Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
- Department of Internal Medicine, Division of Haematology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joris Vanderlocht
- School of Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
- Department of Transplantation Immunology, Tissue Typing Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Boris W. Kramer
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
- School of Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
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Bennet L, Booth LC, Drury PP, Quaedackers JSL, Gunn AJ. Preterm neonatal cardiovascular instability: Does understanding the fetus help evaluate the newborn? Clin Exp Pharmacol Physiol 2012; 39:965-72. [DOI: 10.1111/j.1440-1681.2012.05744.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Laura Bennet
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Lindsea C Booth
- Neurobiology Division; Florey Neuroscience Institutes; University of Melbourne; Melbourne; Victoria; Australia
| | - Paul P Drury
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Josine SL Quaedackers
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
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Bennet L, Davidson JO, Koome M, Gunn AJ. Glucocorticoids and preterm hypoxic-ischemic brain injury: the good and the bad. J Pregnancy 2012; 2012:751694. [PMID: 22970371 PMCID: PMC3431094 DOI: 10.1155/2012/751694] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/13/2012] [Indexed: 12/20/2022] Open
Abstract
Fetuses at risk of premature delivery are now routinely exposed to maternal treatment with synthetic glucocorticoids. In randomized clinical trials, these substantially reduce acute neonatal systemic morbidity, and mortality, after premature birth and reduce intraventricular hemorrhage. However, the overall neurodevelopmental impact is surprisingly unclear; worryingly, postnatal glucocorticoids are consistently associated with impaired brain development. We review the clinical and experimental evidence on how glucocorticoids may affect the developing brain and highlight the need for systematic research.
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Affiliation(s)
- Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland 1142, New Zealand.
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Keogh MJ, Bennet L, Drury PP, Booth LC, Mathai S, Naylor AS, Fraser M, Gunn AJ. Subclinical exposure to low-dose endotoxin impairs EEG maturation in preterm fetal sheep. Am J Physiol Regul Integr Comp Physiol 2012; 303:R270-8. [PMID: 22696578 DOI: 10.1152/ajpregu.00216.2012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure to chorioamnionitis is strongly associated with neurodevelopmental disability after premature birth; however, it remains unclear whether subclinical infection affects functional EEG maturation. Chronically instrumented 103-104-day-old (0.7 gestational age: term 147 days) fetal sheep in utero were randomized to receive either gram-negative LPS by continuous low-dose infusion (100 ng iv over 24 h, followed by 250 ng/24 h for 4 days; n = 6) or the same volume of normal saline (n = 9). Arterial plasma cortisol, ACTH, and IL-6 were measured. The delta (0-3.9 Hz), theta (4-7.9 Hz), alpha (8-12.9 Hz), and beta (13-22 Hz) components of the EEG were determined by power spectral analysis. Brains were taken after 10 days for histopathology. There were no changes in blood gases, cardiovascular variables, or EEG power during LPS infusion, but a transient rise in plasma cortisol and IL-6 (P < 0.05). LPS infusion was associated with loss of the maturational increase to higher frequency activity, with reduced alpha and beta power, and greater delta power than saline controls from 6 to 10 days (P < 0.05). Histologically, LPS was associated with increased numbers of microglia and TNF-α-positive cells in the periventricular white matter and frontoparietal cortex, increased caspase-3-positive cells in white matter, but no loss of CNPase-positive oligodendrocytes, Nurr-1 subplate cells, or gyral complexity. These data suggest that low-dose endotoxin exposure can impair EEG maturation in preterm fetal sheep in association with neural inflammation but without hemodynamic disturbances or cortical injury.
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Affiliation(s)
- Michael J Keogh
- Department of Physiology, University of Auckland, New Zealand
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Keogh MJ, Drury PP, Bennet L, Davidson JO, Mathai S, Gunn ER, Booth LC, Gunn AJ. Limited predictive value of early changes in EEG spectral power for neural injury after asphyxia in preterm fetal sheep. Pediatr Res 2012; 71:345-53. [PMID: 22391634 DOI: 10.1038/pr.2011.80] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION This study examined whether spectral analysis of the electroencephalogram (EEG) can discriminate between mild and severe hypoxic-ischemic injury in the immature brain. RESULTS Total EEG power was profoundly suppressed after umbilical cord occlusion and recovered to baseline by 5 h after 15-min of occlusion, in contrast with transient recovery in the 25-min (P < 0.05). Power spectra were not different between groups in the first 3 h; α and β power were significantly higher in the 15-min group from 4 h, and Δ and θ power from 5 h (P < 0.05). The 25-min group showed severe neuronal loss in hippocampal regions and basal ganglia at 3 days, in contrast with no/minimal injury in the 15-min group. DISCUSSION EEG power after asphyxia did not discriminate between mild and severe injury in the first 3 h in preterm fetal sheep. Severe subcortical neural injury was associated with persistent loss of high-frequency activity. METHODS Chronically instrumented fetal sheep at 0.7 gestation (101-104 days; term is 147 days) received either 15-min (n = 13) or 25-min (n = 13) of complete umbilical cord occlusion. The Δ (0-3.9 Hz), θ (4-7.9 Hz), α (8-12.9 Hz), and β (13-22 Hz) components of the EEG were determined by power spectral analysis. Brains were taken at 3 days for histopathology.
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Affiliation(s)
- Michael J Keogh
- Fetal Physiology and Neuroscience Group, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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