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Juul SE, Wood TR. Pipeline to Neonatal Clinical Transformation: The Importance of Preclinical Data. Clin Perinatol 2024; 51:735-748. [PMID: 39095107 DOI: 10.1016/j.clp.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Historically, neonatal neuroscience boasted a robust and successful preclinical pipeline for therapeutic interventions, in particular for the treatment of hypoxic-ischemic encephalopathy (HIE). However, since the successful translation of therapeutic hypothermia (TH), several high-profile failures of promising adjunctive therapies, in addition to the lack of benefit of TH in lower resource settings, have brought to light critical issues in that same pipeline. Using recent data from clinical trials of erythropoietin as an example, the authors highlight several key challenges facing preclinical neonatal neuroscience for HIE therapeutic development and propose key areas where model development and collaboration across the field in general can ensure ongoing success in treatment development for HIE worldwide.
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Affiliation(s)
- Sandra E Juul
- Institute on Human Development and Disability, University of Washington, Box 357920, 1701 Northeast Columbia Road, Seattle, WA 98195-7920, USA; Division of Neonatology, Department of Pediatrics, University of Washington, Box 356320, 1959 Northeast Pacific Street, RR451 HSB, Seattle, WA 98195-6320, USA
| | - Thomas R Wood
- Institute on Human Development and Disability, University of Washington, Box 357920, 1701 Northeast Columbia Road, Seattle, WA 98195-7920, USA; Division of Neonatology, Department of Pediatrics, University of Washington, Box 356320, 1959 Northeast Pacific Street, RR451 HSB, Seattle, WA 98195-6320, USA.
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2
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Gaston-Breton R, Maïza Letrou A, Hamoudi R, Stonestreet BS, Mabondzo A. Brain organoids for hypoxic-ischemic studies: from bench to bedside. Cell Mol Life Sci 2023; 80:318. [PMID: 37804439 PMCID: PMC10560197 DOI: 10.1007/s00018-023-04951-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 10/09/2023]
Abstract
Our current knowledge regarding the development of the human brain mostly derives from experimental studies on non-human primates, sheep, and rodents. However, these studies may not completely simulate all the features of human brain development as a result of species differences and variations in pre- and postnatal brain maturation. Therefore, it is important to supplement the in vivo animal models to increase the possibility that preclinical studies have appropriate relevance for potential future human trials. Three-dimensional brain organoid culture technology could complement in vivo animal studies to enhance the translatability of the preclinical animal studies and the understanding of brain-related disorders. In this review, we focus on the development of a model of hypoxic-ischemic (HI) brain injury using human brain organoids to complement the translation from animal experiments to human pathophysiology. We also discuss how the development of these tools provides potential opportunities to study fundamental aspects of the pathophysiology of HI-related brain injury including differences in the responses between males and females.
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Affiliation(s)
- Romane Gaston-Breton
- Université Paris Saclay, CEA, INRAE, Médicaments et Technologies pour la Santé (DMTS), Laboratoire d'Etude de l'Unité Neurovasculaire & Innovation Thérapeutique, 91191, Gif-sur-Yvette Cedex, France
| | - Auriane Maïza Letrou
- Université Paris Saclay, CEA, INRAE, Médicaments et Technologies pour la Santé (DMTS), Laboratoire d'Etude de l'Unité Neurovasculaire & Innovation Thérapeutique, 91191, Gif-sur-Yvette Cedex, France
| | - Rifat Hamoudi
- Research Institute for Medical and Health Sciences, University of Sharjah, P. O. 27272, Sharjah, United Arab Emirates
- College of Medicine, University of Sharjah, P. O. 27272, Sharjah, United Arab Emirates
- Division of Surgery and Interventional Science, University College London, London, UK
- ASPIRE Precision Medicine Research Institute Abu Dhabi, University of Sharjah, Sharjah, United Arab Emirates
| | - Barbara S Stonestreet
- Departments of Molecular Biology, Cell Biology and Biochemistry and Department of Pediatrics, Women & Infants Hospital of Rhode Island, The Alpert Medical School of Brown University, 101 Dudley Street, Providence, RI, 02905, USA
| | - Aloïse Mabondzo
- Université Paris Saclay, CEA, INRAE, Médicaments et Technologies pour la Santé (DMTS), Laboratoire d'Etude de l'Unité Neurovasculaire & Innovation Thérapeutique, 91191, Gif-sur-Yvette Cedex, France.
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3
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She HQ, Sun YF, Chen L, Xiao QX, Luo BY, Zhou HS, Zhou D, Chang QY, Xiong LL. Current analysis of hypoxic-ischemic encephalopathy research issues and future treatment modalities. Front Neurosci 2023; 17:1136500. [PMID: 37360183 PMCID: PMC10288156 DOI: 10.3389/fnins.2023.1136500] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/09/2023] [Indexed: 06/28/2023] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) is the leading cause of long-term neurological disability in neonates and adults. Through bibliometric analysis, we analyzed the current research on HIE in various countries, institutions, and authors. At the same time, we extensively summarized the animal HIE models and modeling methods. There are various opinions on the neuroprotective treatment of HIE, and the main therapy in clinical is therapeutic hypothermia, although its efficacy remains to be investigated. Therefore, in this study, we discussed the progress of neural circuits, injured brain tissue, and neural circuits-related technologies, providing new ideas for the treatment and prognosis management of HIE with the combination of neuroendocrine and neuroprotection.
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Affiliation(s)
- Hong-Qing She
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Translational Neurology Laboratory, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- WANG TINGHUA Translation Institute, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Yi-Fei Sun
- Institute of Neurological Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Li Chen
- Institute of Neurological Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Qiu-Xia Xiao
- Institute of Neurological Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Bo-Yan Luo
- WANG TINGHUA Translation Institute, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Hong-Su Zhou
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Translational Neurology Laboratory, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- WANG TINGHUA Translation Institute, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Di Zhou
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Quan-Yuan Chang
- Department of Anesthesiology, Southwest Medical University, Luzhou, China
| | - Liu-Lin Xiong
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Translational Neurology Laboratory, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- WANG TINGHUA Translation Institute, Affiliated Hospital of Zunyi Medical University, Zunyi, China
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Kratimenos P, Vij A, Vidva R, Koutroulis I, Delivoria-Papadopoulos M, Gallo V, Sathyanesan A. Computational analysis of cortical neuronal excitotoxicity in a large animal model of neonatal brain injury. J Neurodev Disord 2022; 14:26. [PMID: 35351004 PMCID: PMC8966144 DOI: 10.1186/s11689-022-09431-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/23/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Neonatal hypoxic brain injury is a major cause of intellectual and developmental disability. Hypoxia causes neuronal dysfunction and death in the developing cerebral cortex due to excitotoxic Ca2+-influx. In the translational piglet model of hypoxic encephalopathy, we have previously shown that hypoxia overactivates Ca2+/Calmodulin (CaM) signaling via Sarcoma (Src) kinase in cortical neurons, resulting in overexpression of proapoptotic genes. However, identifying the exact relationship between alterations in neuronal Ca2+-influx, molecular determinants of cell death, and the degree of hypoxia in a dynamic system represents a significant challenge. METHODS We used experimental and computational methods to identify molecular events critical to the onset of excitotoxicity-induced apoptosis in the cerebral cortex of newborn piglets. We used 2-3-day-old piglets (normoxic [Nx], hypoxic [Hx], and hypoxic + Src-inhibitor-treatment [Hx+PP2] groups) for biochemical analysis of ATP production, Ca2+-influx, and Ca2+/CaM-dependent protein kinase kinase 2 (CaMKK2) expression. We then used SimBiology to build a computational model of the Ca2+/CaM-Src-kinase signaling cascade, simulating Nx, Hx, and Hx+PP2 conditions. To evaluate our model, we used Sobol variance decomposition, multiparametric global sensitivity analysis, and parameter scanning. RESULTS Our model captures important molecular trends caused by hypoxia in the piglet brain. Incorporating the action of Src kinase inhibitor PP2 further validated our model and enabled predictive analysis of the effect of hypoxia on CaMKK2. We determined the impact of a feedback loop related to Src phosphorylation of NMDA receptors and activation kinetics of CaMKII. We also identified distinct modes of signaling wherein Ca2+ level alterations following Src kinase inhibition may not be a linear predictor of changes in Bax expression. Importantly, our model indicates that while pharmacological pre-treatment significantly reduces the onset of abnormal Ca2+-influx, there exists a window of intervention after hypoxia during which targeted modulation of Src-NMDAR interaction kinetics in combination with PP2 administration can reduce Ca2+-influx and Bax expression to similar levels as pre-treatment. CONCLUSIONS Our model identifies new dynamics of critical components in the Ca2+/CaM-Src signaling pathway leading to neuronal injury and provides a feasible framework for drug efficacy studies in translational models of neonatal brain injury for the prevention of intellectual and developmental disabilities.
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Affiliation(s)
- Panagiotis Kratimenos
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, 111 Michigan Avenue, Washington, DC, 20010, USA. .,Department of Pediatrics, Division of Neonatology, Children's National Hospital, Washington DC, USA. .,George Washington University School of Medicine and Health Sciences, Washington DC, USA.
| | - Abhya Vij
- George Washington University School of Medicine and Health Sciences, Washington DC, USA
| | | | - Ioannis Koutroulis
- George Washington University School of Medicine and Health Sciences, Washington DC, USA.,Department of Pediatrics, Division of Emergency Medicine, Children's National Hospital, Washington, DC, USA.,Center for Genetic Medicine Research, Children's National Research Institute and Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | | | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, 111 Michigan Avenue, Washington, DC, 20010, USA.,George Washington University School of Medicine and Health Sciences, Washington DC, USA
| | - Aaron Sathyanesan
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, 111 Michigan Avenue, Washington, DC, 20010, USA. .,George Washington University School of Medicine and Health Sciences, Washington DC, USA.
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5
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Lyu H, Sun DM, Ng CP, Chen JF, He YZ, Lam SY, Zheng ZY, Askarifirouzjaei H, Wang CC, Young W, Poon WS. A new Hypoxic Ischemic Encephalopathy model in neonatal rats. Heliyon 2021; 7:e08646. [PMID: 35024484 PMCID: PMC8723992 DOI: 10.1016/j.heliyon.2021.e08646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/29/2021] [Accepted: 12/16/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Hypoxic-Ischemic Encephalopathy (HIE) occurs when an infant's brain does not receive adequate blood and oxygen supply, resulting in ischemic and hypoxic brain damage during delivery. Currently, supportive care and hypothermia have been the standard treatment for HIE. However, there are still a 20% mortality and most of the survivors are associated with significant neurodevelopmental disability. HIE animal model was first established by Vannucci et al., in 1981, and has been used extensively to explore the mechanisms of brain damage and its potential treatment. The Vannucci model involves the unilateral common carotid artery occlusion followed by 90 min hypoxia (8% oxygen). The purpose of this study is to define and validate a modified HIE model which mimics closely that of the human neonatal HIE. METHOD The classic Vannucci HIE model occludes one common carotid artery followed by 90 min hypoxia. In the new model, common carotid arteries were occluded bilaterally followed by breathing 8% oxygen in a hypoxic chamber for 90, 60 and 30 min, followed by the release of the common carotid artery ligatures, mimicking a reperfusion. RESULT We studied 110 neonatal rats in detail, following the modified in comparison with the classical Vannucci models. The classical Vannucci model has a consistent surgical mortality of 18% and the new modified models have a 20%-46%. While mortality depended on the duration of hypoxia, fifty-two animals survived for behavioral assessments and standard histology. The modified HIE model with 60 min of transient carotid occlusion is associated with a moderate brain damage, and has a 30% surgical mortality. This modified experimental model is regarded closer to the human situation than the classical Vannucci model.
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Affiliation(s)
- Hao Lyu
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Department of Neurosurgery, Shenzhen Key Laboratory of Neurosurgery, The Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Dong Ming Sun
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, State University of New Jersey, Piscataway, NJ, USA
| | - Chi Ping Ng
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Jun Fan Chen
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Yu Zhong He
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Sin Yu Lam
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Zhi Yuan Zheng
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Hadi Askarifirouzjaei
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, State University of New Jersey, Piscataway, NJ, USA
| | - Chi Chiu Wang
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong, China
| | - Wise Young
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, State University of New Jersey, Piscataway, NJ, USA
| | - Wai Sang Poon
- Division of Neurosurgery, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
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Casey S, Goasdoue K, Miller SM, Brennan GP, Cowin G, O'Mahony AG, Burke C, Hallberg B, Boylan GB, Sullivan AM, Henshall DC, O'Keeffe GW, Mooney C, Bjorkman T, Murray DM. Temporally Altered miRNA Expression in a Piglet Model of Hypoxic Ischemic Brain Injury. Mol Neurobiol 2020; 57:4322-4344. [PMID: 32720074 PMCID: PMC7383124 DOI: 10.1007/s12035-020-02018-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/08/2020] [Indexed: 12/21/2022]
Abstract
Hypoxic ischemic encephalopathy (HIE) is the most frequent cause of acquired infant brain injury. Early, clinically relevant biomarkers are required to allow timely application of therapeutic interventions. We previously reported early alterations in several microRNAs (miRNA) in umbilical cord blood at birth in infants with HIE. However, the exact timing of these alterations is unknown. Here, we report serial changes in six circulating, cross-species/bridging biomarkers in a clinically relevant porcine model of neonatal HIE with functional analysis. Six miRNAs—miR-374a, miR-181b, miR-181a, miR-151a, miR-148a and miR-128—were significantly and rapidly upregulated 1-h post-HI. Changes in miR-374a, miR-181b and miR-181a appeared specific to moderate-severe HI. Histopathological injury and five miRNAs displayed positive correlations and were predictive of MRS Lac/Cr ratios. Bioinformatic analysis identified that components of the bone morphogenic protein (BMP) family may be targets of miR-181a. Inhibition of miR-181a increased neurite length in both SH-SY5Y cells at 1 DIV (days in vitro) and in primary cultures of rat neuronal midbrain at 3 DIV. In agreement, inhibition of miR-181a increased expression of BMPR2 in differentiating SH-SY5Y cells. These miRNAs may therefore act as early biomarkers of HIE, thereby allowing for rapid diagnosis and timely therapeutic intervention and may regulate expression of signalling pathways vital to neuronal survival.
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Affiliation(s)
- Sophie Casey
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland. .,Department of Paediatrics and Child Health, University College Cork, Cork, Ireland. .,Department of Anatomy and Neuroscience, University College Cork, Room 2.33, Western Gateway Building, Cork, Ireland.
| | - Kate Goasdoue
- Perinatal Research Centre, UQ Centre for Clinical Research, University of Queensland, Brisbane, Australia
| | - Stephanie M Miller
- Perinatal Research Centre, UQ Centre for Clinical Research, University of Queensland, Brisbane, Australia
| | - Gary P Brennan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gary Cowin
- National Imaging Facility, Centre for Advanced Imaging, University of Queensland, Brisbane, Australia
| | - Adam G O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Room 2.33, Western Gateway Building, Cork, Ireland
| | - Christopher Burke
- Department of Pathology, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Boubou Hallberg
- Neonatology, Karolinska University Hospital, Stockholm, Sweden
| | - Geraldine B Boylan
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
| | - Aideen M Sullivan
- Department of Anatomy and Neuroscience, University College Cork, Room 2.33, Western Gateway Building, Cork, Ireland
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gerard W O'Keeffe
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Room 2.33, Western Gateway Building, Cork, Ireland
| | - Catherine Mooney
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland.,FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland.,School of Computer Science, University College Dublin, Dublin, Ireland
| | - Tracey Bjorkman
- Perinatal Research Centre, UQ Centre for Clinical Research, University of Queensland, Brisbane, Australia
| | - Deirdre M Murray
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland.,Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
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7
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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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8
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Suppression of PDGF induces neuronal apoptosis after neonatal cerebral hypoxia and ischemia by inhibiting P-PI3K and P-AKT signaling pathways. Brain Res 2019; 1719:77-88. [PMID: 31082354 DOI: 10.1016/j.brainres.2019.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 02/05/2023]
Abstract
Neonatal hypoxic-ischemic encephalopathy (HIE) always results in severe neurologic dysfunction, nevertheless effective treatments are limited and the underlying mechanism also remains unclear. In this study, we firstly established the neonatal HIE model in the postnatal day 7 SD rats, Zea-Longa score and TTC staining were employed to assess the neurological behavior and infarct volume of the brain after cerebral hypoxia-ischemia (HI). Afterwards, protein chip was adopted to detect the differential proteins in the right cortex, hippocampus and lung, ultimately, PDGF was noticed. Then, immunohistochemistry, immunofluorescence double staining of NeuN/PDGF, and western blot were used to validate the expression level of PDGF in the cortex and hippocampus at 6 hours (h), 12 h and 24 h after HI. To determine the role of PDGF, the primary cortical neurons were prepared and performed PDGF shRNA administration. The results showed that HIE induced a severe behavioral dysfunction and brain infarction in neonatal rats, and the expression of PDGF in right cortex and hippocampus was remarkably increased after HI. Whereas, suppressing PDGF resulted in a significant loss of neurons and inhibition of neurite growth. Moreover, the protein level of P-PI3K and P-AKT signaling pathways were largely decreased following PDGF-shRNA application in the cortical neurons. In conclusion, PDGF suppression aggravated neuronal dysfunction, and the underlying mechanism is associated with inhibiting the phosphorylation of P-PI3K and P-AKT. Together, PDGF regulating PI3K and AKT may be an important panel in HIE events and therefore may provide possible strategy for the treatment of HIE in future clinic trail.
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Quinn T, Greaves R, Badoer E, Walker D. DHEA in Prenatal and Postnatal Life: Implications for Brain and Behavior. VITAMINS AND HORMONES 2018; 108:145-174. [PMID: 30029725 DOI: 10.1016/bs.vh.2018.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dehydroepiandrosterone (DHEA) and its sulfated congener (DHEAS) are the principal C19 steroid produced by the adrenal gland in many mammals, including humans. It is secreted in high concentrations during fetal life, but synthesis decreases after birth until, in humans and some other primates, there is a prepubertal surge of DHEA production by the adrenal gland-a phenomenon known as adrenarche. There remains considerable uncertainty about the physiological role of DHEA and DHEAS. Moreover, the origin of the trophic drives that determine the waxing and waning of DHEA synthesis are poorly understood. These gaps in knowledge arise in some measure from the difficulty of understanding mechanistic determinants from observations made opportunistically in humans and primates, and have stimulated a search for other suitable species that exhibit adrenarche- and adrenopause-like changes of adrenal function. DHEA and DHEAS are clearly neuroactive steroids with actions at several neurotransmitter receptors; indeed, DHEA is now known to be also synthesized by many parts of the brain, and this capacity undergoes ontogenic changes, but whether this is dependent or independent of the changes in adrenal synthesis is unknown. In this chapter we review key contributions to this field over the last 50+ years, and speculate on the importance of DHEA for the brain, both during development and for maturation and aging of cerebral function and behavior.
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Affiliation(s)
- Tracey Quinn
- The Ritchie Centre, Hudson Institute of Medical Research, Monash Medical Centre, Clayton, VIC, Australia
| | - Ronda Greaves
- School of Health & Biomedical Sciences, RMIT University-Bundoora Campus, Melbourne, VIC, Australia; Murdoch Children's Research Institute, Parkville, Melbourne, VIC, Australia
| | - Emilio Badoer
- School of Health & Biomedical Sciences, RMIT University-Bundoora Campus, Melbourne, VIC, Australia
| | - David Walker
- School of Health & Biomedical Sciences, RMIT University-Bundoora Campus, Melbourne, VIC, Australia.
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10
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Zheng Y, Wang XM. Expression Changes in Lactate and Glucose Metabolism and Associated Transporters in Basal Ganglia following Hypoxic-Ischemic Reperfusion Injury in Piglets. AJNR Am J Neuroradiol 2018; 39:569-576. [PMID: 29326137 DOI: 10.3174/ajnr.a5505] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 10/30/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE The neonatal brain has active energy metabolism, and glucose oxidation is the major energy source of brain tissue. Lactate is produced by astrocytes and released to neurons. In the central nervous system, lactate is transported between neurons and astrocytes via the astrocyte-neuron lactate shuttle. The aim of this study was to investigate the regulatory mechanisms of energy metabolism in neurons and astrocytes in the basal ganglia of a neonatal hypoxic-ischemic brain injury piglet model. MATERIALS AND METHODS A total of 35 healthy piglets (3-5 days of age; 1.0-1.5 kg) were assigned to a control group (n = 5) or a hypoxic-ischemic model group (n = 30). The hypoxic-ischemic model group was further divided into 6 groups according to the 1H-MR spectroscopy and PET/CT scan times after hypoxia-ischemia (0-2, 2-6, 6-12, 12-24, 24-48, and 48-72 hours; n = 5/group). 1H-MR spectroscopy data were processed with LCModel software. Maximum standard uptake values refer to the maximum standard uptake values for glucose (or FDG). The maximum standard uptake values of the basal ganglia-to-occipital cortex ratio were analyzed. The expression levels of glucose transporters and monocarboxylate transporters were detected by immunohistochemical analysis. RESULTS Lactate levels decreased after an initial increase, with the maximal level occurring around 2-6 hours following hypoxia-ischemia. After hypoxia-ischemia, the maximum standard uptake values of the basal ganglia and basal ganglia/occipital cortex initially increased then decreased, with the maximum occurring at approximately 6-12 hours. The lactate and glucose uptake (basal ganglia/occipital cortex maximum standard uptake values) levels were positively correlated. The expression levels of glucose transporter-1 and glucose transporter-3 were positively correlated with the basal ganglia/occipital cortex. The expression levels of monocarboxylic acid transporter-2 and monocarboxylic acid transporter-4 were positively correlated with lactate content. CONCLUSIONS The results indicate that lactate and glucose transporters have a synergistic effect on the energy metabolism of neurons and astrocytes following hypoxic-ischemic reperfusion brain injury.
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Affiliation(s)
- Y Zheng
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China
| | - X-M Wang
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China.
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11
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Millar LJ, Shi L, Hoerder-Suabedissen A, Molnár Z. Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges. Front Cell Neurosci 2017; 11:78. [PMID: 28533743 PMCID: PMC5420571 DOI: 10.3389/fncel.2017.00078] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.
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Affiliation(s)
- Lancelot J. Millar
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
| | - Lei Shi
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan UniversityGuangzhou, China
| | | | - Zoltán Molnár
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
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Zheng Y, Wang XM. Measurement of Lactate Content and Amide Proton Transfer Values in the Basal Ganglia of a Neonatal Piglet Hypoxic-Ischemic Brain Injury Model Using MRI. AJNR Am J Neuroradiol 2017; 38:827-834. [PMID: 28154122 DOI: 10.3174/ajnr.a5066] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/06/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE As amide proton transfer imaging is sensitive to protein content and intracellular pH, it has been widely used in the nervous system, including brain tumors and stroke. This work aimed to measure the lactate content and amide proton transfer values in the basal ganglia of a neonatal piglet hypoxic-ischemic brain injury model by using MR spectroscopy and amide proton transfer imaging. MATERIALS AND METHODS From 58 healthy neonatal piglets (3-5 days after birth; weight, 1-1.5 kg) selected initially, 9 piglets remained in the control group and 43 piglets, in the hypoxic-ischemic brain injury group. Single-section amide proton transfer imaging was performed at the coronal level of the basal ganglia. Amide proton transfer values of the bilateral basal ganglia were measured in all piglets. The ROI of MR spectroscopy imaging was the right basal ganglia, and the postprocessing was completed with LCModel software. RESULTS After hypoxic-ischemic insult, the amide proton transfer values immediately decreased, and at 0-2 hours, they remained at their lowest level. Thereafter, they gradually increased and finally exceeded those of the control group at 48-72 hours. After hypoxic-ischemic insult, the lactate content increased immediately, was maximal at 2-6 hours, and then gradually decreased to the level of the control group. The amide proton transfer values were negatively correlated with lactate content (r = -0.79, P < .05). CONCLUSIONS This observation suggests that after hypoxic-ischemic insult, the recovery of pH was faster than that of lactate homeostasis.
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Affiliation(s)
- Y Zheng
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China
| | - X-M Wang
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China.
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Huang L, Zhao F, Qu Y, Zhang L, Wang Y, Mu D. Animal models of hypoxic-ischemic encephalopathy: optimal choices for the best outcomes. Rev Neurosci 2017; 28:31-43. [PMID: 27559689 DOI: 10.1515/revneuro-2016-0022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/15/2016] [Indexed: 12/21/2022]
Abstract
AbstractHypoxic-ischemic encephalopathy (HIE), a serious disease leading to neonatal death, is becoming a key area of pediatric neurological research. Despite remarkable advances in the understanding of HIE, the explicit pathogenesis of HIE is unclear, and well-established treatments are absent. Animal models are usually considered as the first step in the exploration of the underlying disease and in evaluating promising therapeutic interventions. Various animal models of HIE have been developed with distinct characteristics, and it is important to choose an appropriate animal model according to the experimental objectives. Generally, small animal models may be more suitable for exploring the mechanisms of HIE, whereas large animal models are better for translational studies. This review focuses on the features of commonly used HIE animal models with respect to their modeling strategies, merits, and shortcomings, and associated neuropathological changes, providing a comprehensive reference for improving existing animal models and developing new animal models.
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Affiliation(s)
- Lan Huang
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Fengyan Zhao
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Yi Qu
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Li Zhang
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Yan Wang
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Dezhi Mu
- 1Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, China
- 2Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu 610041, China
- 3Department of Pediatrics, University of California, San Francisco, CA 94143, USA
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Harding B, Conception K, Li Y, Zhang L. Glucocorticoids Protect Neonatal Rat Brain in Model of Hypoxic-Ischemic Encephalopathy (HIE). Int J Mol Sci 2016; 18:ijms18010017. [PMID: 28025500 PMCID: PMC5297652 DOI: 10.3390/ijms18010017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/10/2016] [Accepted: 12/19/2016] [Indexed: 11/27/2022] Open
Abstract
Hypoxic-ischemic encephalopathy (HIE) resulting from asphyxia in the peripartum period is the most common cause of neonatal brain damage and can result in significant neurologic sequelae, including cerebral palsy. Currently therapeutic hypothermia is the only accepted treatment in addition to supportive care for infants with HIE, however, many additional neuroprotective therapies have been investigated. Of these, glucocorticoids have previously been shown to have neuroprotective effects. HIE is also frequently compounded by infectious inflammatory processes (sepsis) and as such, the infants may be more amenable to treatment with an anti-inflammatory agent. Thus, the present study investigated dexamethasone and hydrocortisone treatment given after hypoxic-ischemic (HI) insult in neonatal rats via intracerebroventricular (ICV) injection and intranasal administration. In addition, we examined the effects of hydrocortisone treatment in HIE after lipopolysaccharide (LPS) sensitization in a model of HIE and sepsis. We found that dexamethasone significantly reduced rat brain infarction size when given after HI treatment via ICV injection; however it did not demonstrate any neuroprotective effects when given intranasally. Hydrocortisone after HI insult also significantly reduced brain infarction size when given via ICV injection; and the intranasal administration showed to be protective of brain injury in male rats at a dose of 300 µg. LPS sensitization did significantly increase the brain infarction size compared to controls, and hydrocortisone treatment after LPS sensitization showed a significant decrease in brain infarction size when given via ICV injection, as well as intranasal administration in both genders at a dose of 300 µg. To conclude, these results show that glucocorticoids have significant neuroprotective effects when given after HI injury and that these effects may be even more pronounced when given in circumstances of additional inflammatory injury, such as neonatal sepsis.
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Affiliation(s)
- Benjamin Harding
- Division of Neonatology, Department of Pediatrics, Loma Linda University Children's Hospital, Loma Linda, CA 92354, USA.
| | - Katherine Conception
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Yong Li
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Lubo Zhang
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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Abstract
BACKGROUND Mild hypothermia is an effective neuroprotective strategy for a variety of acute brain injuries. Cooling the nasopharynx may offer the capability to cool the brain selectively due to anatomic proximity of the internal carotid artery to the cavernous sinus. This study investigated the feasibility and efficiency of nasopharyngeal brain cooling by continuously blowing room temperature or cold air at different flow rates into the nostrils of normal newborn piglets. METHODS Experiments were conducted on thirty piglets (n = 30, weight = 2.7 ± 1.5 kg). Piglets were anesthetized with 1–2% isoflurane and were randomized to receive one of four different nasopharyngeal cooling treatments: I. Room temperature at a flow rate of 3–4 L min(−1) (n = 6); II. −1 ± 2 °C at a flow rate of 3–4 L min(−1) (n = 6); III. Room temperature at a flow rate of 14–15 L min(−1) (n = 6); IV. −8 ± 2 °C at a flow rate of 14–15 L min(−1) (n = 6). To control for the normal thermal regulatory response of piglets without nasopharyngeal cooling, a control group of piglets (n = 6) had their brain temperature monitored without nasopharyngeal cooling. The duration of treatment was 60 min, with additional 30 min of observation. RESULTS In group I, median cooling rate was 1.7 ± 0.9 °C/h by setting the flow rate of room temperature air to 3–4 L min(−1). Results of comparing different temperatures and flow rates in the nasopharyngeal cooling approach reveal that the brain temperature could be reduced rapidly at a rate of 5.5 ± 1.1 °C/h by blowing −8 ± 2 °C air at a flow rate of 14–15 L min(−1). CONCLUSIONS Nasopharyngeal cooling via cooled insufflated air can lower the brain temperature, with higher flows and lower temperatures of insufflated air being more effective.
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Lingam I, Avdic-Belltheus A, Robertson NJ. Using animal models to improve care of neonatal encephalopathy. Arch Dis Child Educ Pract Ed 2016; 101:271-6. [PMID: 27147551 DOI: 10.1136/archdischild-2015-309927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/13/2016] [Indexed: 11/04/2022]
Affiliation(s)
- Ingran Lingam
- Institute for Women's Health, University College London, London, UK
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Kartal Ö, Aydınöz S, Kartal AT, Kelestemur T, Caglayan AB, Beker MC, Karademir F, Süleymanoğlu S, Kul M, Yulug B, Kilic E. Time dependent impact of perinatal hypoxia on growth hormone, insulin-like growth factor 1 and insulin-like growth factor binding protein-3. Metab Brain Dis 2016; 31:827-35. [PMID: 26943480 DOI: 10.1007/s11011-016-9816-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/29/2016] [Indexed: 12/25/2022]
Abstract
Hypoxic-ischemia (HI) is a widely used animal model to mimic the preterm or perinatal sublethal hypoxia, including hypoxic-ischemic encephalopathy. It causes diffuse neurodegeneration in the brain and results in mental retardation, hyperactivity, cerebral palsy, epilepsy and neuroendocrine disturbances. Herein, we examined acute and subacute correlations between neuronal degeneration and serum growth factor changes, including growth hormone (GH), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) after hypoxic-ischemia (HI) in neonatal rats. In the acute phase of hypoxia, brain volume was increased significantly as compared with control animals, which was associated with reduced GH and IGF-1 secretions. Reduced neuronal survival and increased DNA fragmentation were also noticed in these animals. However, in the subacute phase of hypoxia, neuronal survival and brain volume were significantly decreased, accompanied by increased apoptotic cell death in the hippocampus and cortex. Serum GH, IGF-1, and IGFBP-3 levels were significantly reduced in the subacute phase of HI. Significant retardation in the brain and body development were noted in the subacute phase of hypoxia. Here, we provide evidence that serum levels of growth-hormone and factors were decreased in the acute and subacute phase of hypoxia, which was associated with increased DNA fragmentation and decreased neuronal survival.
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Affiliation(s)
- Ömer Kartal
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
- Department of Pediatrics, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
| | - Seçil Aydınöz
- Department of Pediatrics, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
| | - Ayşe Tuğba Kartal
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
- Department of Pediatrics, Marmaris State Hospital, Mugla, Turkey
| | - Taha Kelestemur
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
| | - Ahmet Burak Caglayan
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
| | - Mustafa Caglar Beker
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
| | - Ferhan Karademir
- Department of Pediatrics, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
| | - Selami Süleymanoğlu
- Department of Pediatrics, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
| | - Mustafa Kul
- Department of Pediatrics, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
| | - Burak Yulug
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey
| | - Ertugrul Kilic
- Department of Physiology, Regenerative and Restorative Medical Research Center, Istanbul Medipol University, Ekinciler cad. 19, TR-34810, Istanbul, Turkey.
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Brain Cooling With Ventilation of Cold Air Over Respiratory Tract in Newborn Piglets: An Experimental and Numerical Study. IEEE JOURNAL OF TRANSLATIONAL ENGINEERING IN HEALTH AND MEDICINE 2015; 3:1500108. [PMID: 27170888 PMCID: PMC4848075 DOI: 10.1109/jtehm.2015.2424214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/30/2015] [Accepted: 03/28/2015] [Indexed: 11/20/2022]
Abstract
We investigate thermal effects of pulmonary cooling which was induced by cold air through an endotracheal tube via a ventilator on newborn piglets. A mathematical model was initially employed to compare the thermal impact of two different gas mixtures, O2-medical air (1:2) and O2-Xe (1:2), across the respiratory tract and within the brain. Following mathematical simulations, we examined the theoretical predictions with O2-medical air condition on nine anesthetized piglets which were randomized to two treatment groups: 1) control group (\documentclass[12pt]{minimal}
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}{}$n = 4$
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}{}$n = 5$
\end{document}). Numerical and experimental results using O2-medical air mixture show that brain temperature fell from 38.5 °C and 38.3 °C ± 0.3 °C to 35.7 °C ± 0.9 °C and 36.5 °C ± 0.6 °C during 3 h cooling which corresponded to a mean cooling rate of 0.9 °C/h ± 0.2 °C/h and 0.6 °C/h ± 0.1 °C/h, respectively. According to the numerical results, decreasing the metabolic rate and increasing air velocity are helpful to maximize the cooling effect. We demonstrated that pulmonary cooling by cooling of inhalation gases immediately before they enter the trachea can slowly reduce brain and core body temperature of newborn piglets. Numerical simulations show no significant differences between two different inhaled conditions, i.e., O2-medical air (1:2) and O2-Xe (1:2) with respect to cooling rate.
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19
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Conrad MS, Johnson RW. The domestic piglet: an important model for investigating the neurodevelopmental consequences of early life insults. Annu Rev Anim Biosci 2014; 3:245-64. [PMID: 25387115 DOI: 10.1146/annurev-animal-022114-111049] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Insults in the prenatal and early postnatal period increase the risk for behavioral problems later in life. One hypothesis is that pre- and postnatal stressors influence structural and functional brain plasticity. Understanding the mechanisms is important, but progress has lagged because certain studies in human infants are impossible, while others are extremely difficult. Furthermore, results from popular rodent models are difficult to translate to human infants owing to the substantial differences in brain development and morphology. Because it overcomes some of these obstacles, the domestic piglet has emerged as an important model. Piglets have a gyrencephalic brain that develops similar to the human brain and that can be assessed in vivo by using clinical-grade neuroimaging instruments. Furthermore, owing to their precocial nature, piglets can be weaned at birth and used in behavioral testing paradigms to assess cognitive behavior at an early age. Thus, the domestic piglet represents an important translational model for investigating the neurodevelopmental consequences of early life insults.
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20
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Zhu AH, Hu YR, Liu W, Gao F, Li JX, Zhao LH, Chen G. Systemic Evaluation of Hypoxic-Ischemic Brain Injury in Neonatal Rats. Cell Biochem Biophys 2013; 69:295-301. [DOI: 10.1007/s12013-013-9798-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Subchronic perinatal asphyxia in rats: Embryo–foetal assessment of a new model of oxidative stress during critical period of development. Food Chem Toxicol 2013; 61:233-9. [DOI: 10.1016/j.fct.2013.07.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/10/2013] [Accepted: 07/10/2013] [Indexed: 11/19/2022]
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Nakamura S, Kusaka T, Yasuda S, Ueno M, Miki T, Koyano K, Nakamura M, Okada H, Okazaki K, Isobe K, Itoh S. Cerebral blood volume combined with amplitude-integrated EEG can be a suitable guide to control hypoxic/ischemic insult in a piglet model. Brain Dev 2013. [PMID: 23199679 DOI: 10.1016/j.braindev.2012.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The purposes of this study are to compare two hypoxic/ischemic (H/I) insults using amplitude-integrated EEG (aEEG), alone or combined with cerebral blood volume (CBV), as a guide to control hypoxia and to determine which protocol most effectively produces a consistent degree of survivable neuropathological damage in a newborn piglet model of perinatal asphyxia. METHODS Eighteen piglets were subjected to H/I insult of 20-min low aEEG (LAEEG). After the 20-min, the aEEG group was maintained with low mean arterial blood pressure for 10min. The procedure for the aEEG plus CBV group was stopped if CBV became the rated value after 20min of LAEEG. We measured changes in CBV using a near-infrared time-resolved spectroscopy (TRS) and cerebral electrocortical activity using aEEG until 6h post-insult. At 5days post insult, the piglets' brains were perfusion-fixed and stained with hematoxylin/eosin. Piglets were grouped as undamaged or damaged; piglets that did not survive to 5days were grouped separately as dead. RESULTS Among surviving piglets, CBV combined with aEEG resulted in significantly greater percentage of damaged piglets than aEEG alone. CONCLUSIONS We conclude that combining CBV with aEEG may be a more effective guide to control H/I insult in a newborn piglet model than aEEG alone.
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Affiliation(s)
- Shinji Nakamura
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
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23
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Abstract
Hypoxia-ischemia is a leading cause of morbidity and mortality in the perinatal period with an incidence of 1/4000 live births. Biochemical events such as energy failure, membrane depolarization, brain edema, an increase of neurotransmitter release and inhibition of uptake, an increase of intracellular Ca(2+), production of oxygen-free radicals, lipid peroxidation, and a decrease of blood flow are triggered by hypoxia-ischemia and may lead to brain dysfunction and neuronal death. These abnormalities can result in mental impairments, seizures, and permanent motor deficits, such as cerebral palsy. The physical and emotional strain that is placed on the children affected and their families is enormous. The care that these individuals need is not only confined to childhood, but rather extends throughout their entire life span, so it is very important to understand the pathophysiology that follows a hypoxic-ischemic insult. This review will highlight many of the mechanisms that lead to neuronal death and include the emerging area of white matter injury as well as the role of inflammation and will provide a summary of therapeutic strategies. Hypothermia and oxygen will also be discussed as treatments that currently lack a specific target in the hypoxic/ischemic cascade.
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Affiliation(s)
- John W Calvert
- Departments of Neurosurgery and Molecular and Cellular Physiology, Loma Linda University Medical Center, 11234 Anderson Street, Loma Linda, CA 92354, USA
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Aleman M, Pickles KJ, Conley AJ, Stanley S, Haggett E, Toth B, Madigan JE. Abnormal plasma neuroactive progestagen derivatives in ill, neonatal foals presented to the neonatal intensive care unit. Equine Vet J 2013; 45:661-5. [PMID: 23600660 DOI: 10.1111/evj.12065] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 01/18/2013] [Indexed: 11/28/2022]
Abstract
REASONS FOR PERFORMING THE STUDY Increased levels of pregnanes have been reported in foals with neonatal maladjustment syndrome (NMS). These steroids may cross the blood-brain barrier and have depressive effects in the central nervous system leading to behavioural abnormalities and altered states of consciousness in affected foals. OBJECTIVES The aim of this study was to determine the pregnane profile of foals with NMS and compare it with that of healthy controls and sick, non-NMS foals. STUDY DESIGN Prospective-clinical study. METHODS Thirty-two foals with a clinical diagnosis of NMS, 12 foals with other neonatal disorders and 10 healthy control foals were selected for the study. Heparinised blood samples were collected from each group of foals and pregnane and androgen concentrations determined using liquid chromatography mass spectrometry at 0, 24 and 48 h of age. RESULTS Healthy foals showed a significant decrease in pregnane concentrations over the first 48 h of life (P<0.01). Foals with NMS and sick, non-NMS foals had significantly increased progesterone, pregnenolone, androstenedione, dehydroepiandrosterone and epitestosterone concentrations compared with healthy foals (P<0.05). Progesterone and pregnenolone concentrations of sick, non-NMS foals decreased significantly over 48 h (P<0.05), whereas concentrations in NMS foals remained increased. CONCLUSIONS AND POTENTIAL RELEVANCE Pregnane concentrations of ill, neonatal foals remain increased following birth, reflecting a delayed, or interrupted, transition from intra- to extra-uterine life. Serial progesterone and pregnenolone measurement may be useful in aiding diagnosis of NMS.
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Affiliation(s)
- M Aleman
- Department of Medicine and Epidemiology, School of Veterinary Medicine University of California, USA
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Moroz T, Banaji M, Robertson NJ, Cooper CE, Tachtsidis I. Computational modelling of the piglet brain to simulate near-infrared spectroscopy and magnetic resonance spectroscopy data collected during oxygen deprivation. J R Soc Interface 2012; 9:1499-509. [PMID: 22279158 PMCID: PMC3367814 DOI: 10.1098/rsif.2011.0766] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We describe a computational model to simulate measurements from near-infrared spectroscopy (NIRS) and magnetic resonance spectroscopy (MRS) in the piglet brain. Piglets are often subjected to anoxic, hypoxic and ischaemic insults, as experimental models for human neonates. The model aims to help interpret measurements and increase understanding of physiological processes occurring during such insults. It is an extension of a previous model of circulation and mitochondrial metabolism. This was developed to predict NIRS measurements in the brains of healthy adults i.e. concentration changes of oxyhaemoglobin and deoxyhaemoglobin and redox state changes of cytochrome c oxidase (CCO). We altered and enhanced the model to apply to the anaesthetized piglet brain. It now includes metabolites measured by 31P-MRS, namely phosphocreatine, inorganic phosphate and adenosine triphosphate (ATP). It also includes simple descriptions of glycolysis, lactate dynamics and the tricarboxylic acid (TCA) cycle. The model is described, and its simulations compared with existing measurements from piglets during anoxia. The NIRS and MRS measurements are predicted well, although this requires a reduction in blood pressure autoregulation. Predictions of the cerebral metabolic rate of oxygen consumption (CMRO2) and lactate concentration, which were not measured, are given. Finally, the model is used to investigate hypotheses regarding changes in CCO redox state during anoxia.
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Affiliation(s)
- Tracy Moroz
- CoMPLEX, University College London, London, UK.
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Scorza CA, Cavalheiro EA. Animal models of intellectual disability: towards a translational approach. Clinics (Sao Paulo) 2011; 66 Suppl 1:55-63. [PMID: 21779723 PMCID: PMC3118438 DOI: 10.1590/s1807-59322011001300007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 01/25/2011] [Indexed: 11/24/2022] Open
Abstract
Intellectual disability is a prevalent form of cognitive impairment, affecting 2-3% of the general population. It is a daunting societal problem characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social and practical adaptive skills. Intellectual disability is a clinically important disorder for which the etiology and pathogenesis are still poorly understood. Moreover, although tremendous progress has been made, pharmacological intervention is still currently non-existent and therapeutic strategies remain limited. Studies in humans have a very limited capacity to explain basic mechanisms of this condition. In this sense, animal models have been invaluable in intellectual disability investigation. Certainly, a great deal of the knowledge that has improved our understanding of several pathologies has derived from appropriate animal models. Moreover, to improve human health, scientific discoveries must be translated into practical applications. Translational research specifically aims at taking basic scientific discoveries and best practices to benefit the lives of people in our communities. In this context, the challenge that basic science research needs to meet is to make use of a comparative approach to benefit the most from what each animal model can tell us. Intellectual disability results from many different genetic and environmental insults. Taken together, the present review will describe several animal models of potential intellectual disability risk factors.
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Affiliation(s)
- Carla A Scorza
- Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
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Lai MC, Yang SN. Perinatal hypoxic-ischemic encephalopathy. J Biomed Biotechnol 2010; 2011:609813. [PMID: 21197402 PMCID: PMC3010686 DOI: 10.1155/2011/609813] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 11/08/2010] [Indexed: 01/12/2023] Open
Abstract
Perinatal hypoxic-ischemic encephalopathy (HIE) is an important cause of brain injury in the newborn and can result in long-term devastating consequences. Perinatal hypoxia is a vital cause of long-term neurologic complications varying from mild behavioural deficits to severe seizure, mental retardation, and/or cerebral palsy in the newborn. In the mammalian developing brain, ongoing research into pathophysiological mechanism of neuronal injury and therapeutic strategy after perinatal hypoxia is still limited. With the advent of promising therapy of hypothermia in HIE, this paper reviews the pathophysiology of HIE and the future potential neuroprotective strategies for clinical potential for hypoxia sufferers.
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Affiliation(s)
- Ming-Chi Lai
- Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan
| | - San-Nan Yang
- Graduate Institute of Medicine, Kaohsiung Medical University, No. 100, Zihyou 1st Road, Sanmin District Kaohsiung City 807, Taiwan
- Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
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Solberg R, Løberg EM, Andresen JH, Wright MS, Charrat E, Khrestchatisky M, Rivera S, Saugstad OD. Resuscitation of newborn piglets. short-term influence of FiO2 on matrix metalloproteinases, caspase-3 and BDNF. PLoS One 2010; 5:e14261. [PMID: 21151608 PMCID: PMC3000320 DOI: 10.1371/journal.pone.0014261] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 11/10/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Perinatal hypoxia-ischemia is a major cause of mortality and cerebral morbidity, and using oxygen during newborn resuscitation may further harm the brain. The aim was to examine how supplementary oxygen used for newborn resuscitation would influence early brain tissue injury, cell death and repair processes and the regulation of genes related to apoptosis, neurodegeneration and neuroprotection. METHODS AND FINDINGS Anesthetized newborn piglets were subjected to global hypoxia and then randomly assigned to resuscitation with 21%, 40% or 100% O(2) for 30 min and followed for 9 h. An additional group received 100% O(2) for 30 min without preceding hypoxia. The left hemisphere was used for histopathology and immunohistochemistry and the right hemisphere was used for in situ zymography in the corpus striatum; gene expression and the activity of various relevant biofactors were measured in the frontal cortex. There was an increase in the net matrix metalloproteinase gelatinolytic activity in the corpus striatum from piglets resuscitated with 100% oxygen vs. 21%. Hematoxylin-eosin (HE) staining revealed no significant changes. Nine hours after oxygen-assisted resuscitation, caspase-3 expression and activity was increased by 30-40% in the 100% O(2) group (n = 9/10) vs. the 21% O(2) group (n = 10; p<0.04), whereas brain-derived neurotrophic factor (BDNF) activity was decreased by 65% p<0.03. CONCLUSIONS The use of 100% oxygen for resuscitation resulted in increased potentially harmful proteolytic activities and attenuated BDNF activity when compared with 21%. Although there were no significant changes in short term cell loss, hyperoxia seems to cause an early imbalance between neuroprotective and neurotoxic mechanisms that might compromise the final pathological outcome.
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Affiliation(s)
- Rønnaug Solberg
- Department of Paediatric Research, University of Oslo and Oslo University Hospital, Rikshospitalet, Oslo, Norway.
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29
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Tichauer KM, Elliott JT, Hadway JA, Lee DS, Lee TY, St. Lawrence K. Using near-infrared spectroscopy to measure cerebral metabolic rate of oxygen under multiple levels of arterial oxygenation in piglets. J Appl Physiol (1985) 2010; 109:878-85. [DOI: 10.1152/japplphysiol.01432.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Improving neurological care of neonates has been impeded by the absence of suitable techniques for measuring cerebral hemodynamics and energy metabolism at the bedside. Currently, near-infrared spectroscopy (NIRS) appears to be the technology best suited to fill this gap, and techniques have been proposed to measure both cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2). We have developed a fast and reliable bolus-tracking method of determining CMRO2 that combines measurements of CBF and cerebral venous oxygenation [venous oxygen saturation (CSvO2)]. However, this method has never been validated at different levels of arterial oxygenation [arterial oxygen saturation (SaO2)], which can be highly variable in the clinical setting. In this study, NIRS measurements of CBF, CSvO2, and CMRO2 were obtained over a range of SaO2 in newborn piglets ( n = 12); CSvO2 values measured directly from sagittal sinus blood samples were collected for validation. Two alternative NIRS methods that measure CSvO2 by manipulating venous oxygenation (i.e., head tilt and partial venous occlusion methods) were also employed for comparison. Statistically significant correlations were found between each NIRS technique and sagittal sinus blood oxygenation ( P < 0.05). Correlation slopes were 1.03 ( r = 0.91), 0.73 ( r = 0.73), and 0.73 ( r = 0.81) for the bolus-tracking, head tilt, and partial venous occlusion methods, respectively. The bolus-tracking technique displayed the best correlation under hyperoxic (SaO2 = 99.9 ± 0.03%) and normoxic (SaO2 = 86.9 ± 6.6%) conditions and was comparable to the other techniques under hypoxic conditions (SaO2 = 40.7 ± 9.9%). The reduced precision of the bolus-tracking method under hypoxia was attributed to errors in CSvO2 measurement that were magnified at low SaO2 levels. In conclusion, the bolus-tracking technique of measuring CSvO2, and therefore CMRO2, is accurate and robust for an SaO2 > 50% but provides reduced accuracy under more severe hypoxic levels.
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Affiliation(s)
- Kenneth M. Tichauer
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jonathan T. Elliott
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
| | - Jennifer A. Hadway
- Imaging Division, Lawson Health Research Institute,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - David S. Lee
- Department of Paediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Ting-Yim Lee
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
- Imaging Research Laboratories, Robarts Research Institute, and
| | - Keith St. Lawrence
- Imaging Division, Lawson Health Research Institute,
- Department of Medical Biophysics, University of Western Ontario,
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31
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32
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Scafidi J, Fagel DM, Ment LR, Vaccarino FM. Modeling premature brain injury and recovery. Int J Dev Neurosci 2009; 27:863-71. [PMID: 19482072 DOI: 10.1016/j.ijdevneu.2009.05.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Accepted: 05/20/2009] [Indexed: 10/20/2022] Open
Abstract
Premature birth is a growing and significant public health problem because of the large number of infants that survive with neurodevelopmental sequelae from brain injury. Recent advances in neuroimaging have shown that although some neuroanatomical structures are altered, others improve over time. This review outlines recent insights into brain structure and function in these preterm infants at school age and relevant animal models. These animal models have provided scientists with an opportunity to explore in depth the molecular and cellular mechanisms of injury as well as the potential of the brain for recovery. The endogenous potential that the brain has for neurogenesis and gliogenesis, and how environment contributes to recovery, are also outlined. These preclinical models will provide important insights into the genetic and epigenetic mechanisms responsible for variable degrees of injury and recovery, permitting the exploration of targeted therapies to facilitate recovery in the developing preterm brain.
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Affiliation(s)
- Joey Scafidi
- Center for Neuroscience Research, Children's National Medical Center, Washington, DC 20010, USA
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33
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Abstract
This article summarizes recent insights into perinatal hypoxic-ischemic brain injury in the neonate. Before effective treatments can be offered, diagnosis, timing, and an understanding of the pathogenesis are imperative. The analysis of appropriate animal models is also summarized in this review. These models have provided interesting evidence that after hypoxia ischemia, progenitor cells in the postnatal brain are stimulated to generate new neurons and oligodendrocytes. The role of these newly generated cells is unclear, and mechanisms of migration and survival are currently being elucidated. A discussion of more recent imaging techniques, such as diffusion tensor imaging, is provided. This allows for improved understanding of the microstructural organization of white matter and how this is altered by hypoxic-ischemic injury. Neuroprotection with hypothermia is now occurring in full-term neonates that meet clinical criteria; however, specific therapies such as inhibition of non-N-methyl-D-aspartate receptors may offer improved outcomes by targeting specific pathways and populations of cells.
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Affiliation(s)
- Joseph Scafidi
- Department of Neurology, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA.
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34
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van Dijk A, van Loon J, Taverne M, Jonker F. Umbilical cord clamping in term piglets: A useful model to study perinatal asphyxia? Theriogenology 2008; 70:662-74. [DOI: 10.1016/j.theriogenology.2008.04.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 04/06/2008] [Accepted: 04/21/2008] [Indexed: 10/21/2022]
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Abstract
Classical conditioning of eyeblink responses has been one of the most important models for studying the neurobiology of learning, with many comparative, ontogenetic, and clinical applications. The current study reports the development of procedures to conduct eyeblink conditioning in preweanling lambs and demonstrates successful conditioning using these procedures. These methods will permit application of eyeblink conditioning procedures in the analysis of functional correlates of cerebellar damage in a sheep model of fetal alcohol spectrum disorders, which has significant advantages over more common laboratory rodent models. Because sheep have been widely used for studies of pathogenesis and mechanisms of injury with many different prenatal or perinatal physiological insults, eyeblink conditioning can provide a well-studied method to assess postnatal behavioral outcomes, which heretofore have not typically been pursued with ovine models of developmental insults.
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Affiliation(s)
- Timothy B Johnson
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA.
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36
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Hobbs CE, Oorschot DE. Neonatal rat hypoxia-ischemia: long-term rescue of striatal neurons and motor skills by combined antioxidant-hypothermia treatment. Brain Pathol 2008; 18:443-54. [PMID: 18371175 DOI: 10.1111/j.1750-3639.2008.00146.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Perinatal hypoxia-ischemia can cause long-term neurological and behavioral disability. Recent multicenter clinical trials suggest that moderate hypothermia, within 6 h of birth, offers significant yet incomplete protection. We investigated the effect of combined treatment with the antioxidant N-tert-butyl-(2-sulfophenyl)-nitrone (S-PBN) and moderate hypothermia on long-term neuronal injury and behavioral disability. S-PBN or its diluent was administered 12-hourly to rats from postnatal day (PN) 7 to 10. On PN8, hypoxia-ischemia was induced. Immediately post-hypoxia, additional S-PBN and 6 h of moderate hypothermia or additional diluent and 6 h of normothermia were administered. At 1 week, and at 11 weeks, after hypoxia-ischemia, the absolute number of surviving medium-spiny neurons was measured in the coded right striatum. In a separate experiment, skilled forepaw ability was investigated in coded 9- to 11-week-old rats. Normal, uninjured animals were also tested for motor skills at 9- to 11-weeks-of-age. The combination of S-PBN and moderate hypothermia provided statistically significant short- and long-term protection of the striatal medium-spiny neurons to normal control levels. This combinatorial treatment also preserved fine motor skills to normal control levels. The impressive histological and functional preservation suggests that S-PBN and moderate hypothermia is a safe and attractive combination therapy for perinatal hypoxia-ischemia.
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Affiliation(s)
- Catherine E Hobbs
- Department of Anatomy and Structural Biology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
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37
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Kuluz J, Huang T, Watson B, Vannucci S. Stroke in the immature brain: review of pathophysiology and animal models of pediatric stroke. FUTURE NEUROLOGY 2008. [DOI: 10.2217/14796708.3.2.199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pediatric stroke research presents many challenges. Relatively low incidence, need for age stratification, diverse etiologies, delays in diagnosis, lack of an established age-based stroke severity scale and outcome measures are only some of the issues that have prevented the implementation of clinical trials in infants and children with stroke. Experimental animal models of pediatric stroke, therefore, are critical to understanding the pathophysiology and management of ischemic brain damage in the immature brain, and provide the necessary platform for future clinical trials. In this review we discuss the pertinent clinical aspects of pediatric stroke, the pathophysiology of stroke in the developing brain and the animal models established to study basic mechanisms as well as translational issues in pediatric stroke.
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Affiliation(s)
- John Kuluz
- Associate Professor of Pediatrics, University of Miami, Department of Pediatrics (R-131), Miller School of Medicine, PO Box 016960, Miami, FL 33101, USA
| | - Tingting Huang
- Post-Doctoral Research Associate, University of Miami, Department of Pediatrics (R-131), Miller School of Medicine, PO Box 016960 Miami, FL 33101, USA
| | - Brant Watson
- Professor of Neurology, University of Miami, Department of Neurology (D4–5), Miller School of Medicine, PO Box 016960, Miami, FL 33136, USA
| | - Susan Vannucci
- Research Professor of Neuroscience in Pediatrics/Newborn Medicine, Weill Cornell Medical College, 525 East 68th Street, N-506, NY 10065, USA
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Carloni S, Balduini W. Experimental models of hypoxic-ischemic encephalopathy: hypoxia-ischemia in the immature rat. ACTA ACUST UNITED AC 2008; Chapter 11:Unit11.15. [PMID: 23045002 DOI: 10.1002/0471140856.tx1115s35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The development of experimental models to study the mechanisms of perinatal hypoxic-ischemic encephalopathy and stroke and effective therapies represents an important goal in perinatal medicine. However, due to the complexity of this pathological condition in humans, to date there is no ideal animal model that completely reproduces this condition. This unit describes the most widely used rodent animal model for the study of hypoxic-ischemic encephalopathy during development. The model consists of 7-day-old pup rats subjected to unilateral carotid artery ligation followed by timed hypoxia exposure, and incorporates both focal cerebral ischemia and reperfusion. Its strength lies in the relative ease of the surgical procedure, the low mortality rate, and the possibility of performing long-term experiments, a necessity for preclinical therapeutic trials. Over the years, this model has been extensively characterized, and most information on the mechanisms responsible for neurodegeneration and possible therapeutic approaches following hypoxia-ischemia during brain development derives from studies performed using this model.
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Affiliation(s)
- Silvia Carloni
- Istituto di Farmacologia e Farmacognosia, Università di Urbino Carlo Bo, Urbino, Italy
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39
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Berman RF, Pessah IN, Mouton PR, Mav D, Harry J. Low-level neonatal thimerosal exposure: further evaluation of altered neurotoxic potential in SJL mice. Toxicol Sci 2007; 101:294-309. [PMID: 17977901 DOI: 10.1093/toxsci/kfm265] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ethylmercury in thimerosal-preserved childhood vaccines has been suggested to be neurotoxic and to contribute to the etiology of neurodevelopmental disorders, including autism. Immune system function may be an important factor influencing vulnerability of the developing nervous system to thimerosal. This possibility is based in part on a report by Hornig et al. (2004, Mol. Psychiatry 9, 833-845) of neurodevelomental toxicity in SJL/J mice that develop autoantibodies when exposed to organic mercury. The present study reexamined this possibility by injecting neonatal SJL/J mice with thimerosal, with and without combined HiB and DTP vaccines. Injections modeled childhood vaccination schedules, with mice injected on postnatal days 7, 9, 11, and 15 with 14.2, 10.8, 9.2, and 5.6 mug/kg mercury from thimerosal, respectively, or vehicle. Additional groups received vaccine only or a 10 times higher thimerosal + vaccine dose. Low levels of mercury were found in blood, brain, and kidneys 24 h following the last thimerosal injection. Survival, body weight, indices of early development (negative geotaxis, righting) and hippocampal morphology were not affected. Performance was unaffected in behavioral tests selected to assess behavioral domains relevant to core deficits in neurodevelopmental disorders such as autism (i.e., social interaction, sensory gating, anxiety). In an open-field test the majority of behaviors were unaffected by thimerosal injection, although thimerosal-injected female mice showed increased time in the margin of an open field at 4 weeks of age. Considered together the present results do not indicate pervasive developmental neurotoxicity following vaccine-level thimerosal injections in SJL mice, and provide little if any support for the hypothesis that thimerosal exposure contributes to the etiology of neurodevelopmental disorders.
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Affiliation(s)
- Robert F Berman
- Department of Neurological Surgery and the Center for Children's Environmental Health, University of California Davis, CA 95616, USA.
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40
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Dutra F, Quintans G, Banchero G. Lesions in the central nervous system associated with perinatal lamb mortality. Aust Vet J 2007; 85:405-13. [PMID: 17903128 DOI: 10.1111/j.1751-0813.2007.00205.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To identify and describe the occurrence of neurological lesions that could have an effect on lamb mortality. PROCEDURE The central nervous system was investigated macroscopically (n = 92) and microscopically (n = 72) in lambs dying in the perinatal period during 3 years in flocks of adult Corriedale ewes. The central nervous system was removed intact and samples of cerebral cortex, basal ganglia, thalamus, hippocampus, mesencephalon, cerebellar cortex, medulla oblongata, and cervical spinal cord were scored microscopically for the severity of neuronal dead, cytotoxic and perivascular oedema, and haemorrhage. RESULTS Neurologic findings between birth and 6 days included haemorrhages in meninges, brain congestion and oedema, neuronal ischemic necrosis, intraparenchymal haemorrhages in medulla oblongata and cervical spinal cord, parasagittal cerebral necrosis, and periventricular leukomalacia. No significant lesions were found in anteparturient deaths or in those aged between 7 and 16 days. Oedema was more severe in the brain than in other regions of the central nervous system. Ischaemic neurons first appeared 24 hours post partum, increased linearly in number between 48 hours and 5 days post partum, and had a laminar distribution in the cerebral cortex, indicating a hypoxic-ischemic encephalopathy. Haemorrhages were most severe in the gray matter of medulla oblongata and cervical spinal cord, suggesting trauma due to instability of atlantoaxialis joint. CONCLUSION Lesions in the central nervous system can explain most deaths at birth and within 6 days of birth. The lesions were hypoxic-ischemic and appeared to be related to birth injury.
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Affiliation(s)
- F Dutra
- DILAVE Miguel C Rubino, Laboratorio Regional Este, Avelino Miranda 2045, CP 33000, Treinta y Tres, Uruguay.
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41
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Lodygensky GA, Inder TE, Neil JJ. Application of magnetic resonance imaging in animal models of perinatal hypoxic-ischemic cerebral injury. Int J Dev Neurosci 2007; 26:13-25. [PMID: 17977687 DOI: 10.1016/j.ijdevneu.2007.08.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 08/29/2007] [Accepted: 08/29/2007] [Indexed: 11/30/2022] Open
Abstract
Brain injury occurring in the perinatal period is an important etiology of subsequent neurodevelopmental disabilities. Magnetic resonance imaging (MRI) is a tool that is used to evaluate the nature of brain injury in the human infant. MRI techniques have also been applied to various animal models of perinatal injury. The most commonly used model is the immature rat, but there have also been imaging studies in mice, rabbit kits and piglets. The studies have been carried out using MR systems of various magnetic field strengths, ranging from 1.5 to 11.7tesla (T), with applications for quantification of infarct volume, T1 measurements, T2 measurements, proton and phosphorus spectroscopy and diffusion imaging. The MR findings are then related to histopathology and, in a few cases, behavioral evaluations. There is also a growing number of studies utilizing MRI in evaluating the efficacy of neuroprotective treatments, such as hypothermia.
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Affiliation(s)
- Gregory A Lodygensky
- Departments of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
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Munkeby BH, Smith HJ, Winther-Larssen EH, Bjørnerud A, Bjerkås I. Magnetic resonance imaging of the Harderian gland in piglets. J Anat 2007; 209:699-705. [PMID: 17062026 PMCID: PMC2100344 DOI: 10.1111/j.1469-7580.2006.00642.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The main purpose of the present study was to investigate the value and effectiveness of functional and morphological magnetic resonance imaging (MRI), in order to assess the extent of brain injury in a hypoxic-ischaemic piglet model, and further to validate that the ischaemic injury was successfully induced. In this way, we also characterized the Harderian gland. MRI was performed at 1.5 T in anaesthetized piglets (n = 10, 12-36 h of age). Magnetic resonance perfusion and diffusion imaging were performed at different time points, before, during and after the induction of hypoxia-ischaemia. The effects following bilateral clamping of the carotid arteries were also assessed by contrast-enhanced magnetic resonance angiography. Morphological assessment included T1- and T2-weighted imaging, and fat-suppressed T1-weighted imaging before and after contrast medium enhancement. Morphological MRI revealed a prominent, well-defined structure located at the eyeball. Magnetic resonance angiography reconstructed with volume rendering showed this structure to be partially enclosed by large venous sinuses. At dissection, when compared with the magnetic resonance images, the deep gland of the third eyelid, the Harderian gland, corresponded to this structure both in topography and in size. By contrast, the lacrimal gland proper presented as a small, soft and pale structure that was difficult to distinguish from the surrounding connective tissue. At histological examination, the Harderian gland consisted mainly of compact areas of tubuloacinar glands with abundant eosinophilic granules. The present MRI demonstration of the Harderian gland was an accidental finding during an investigation to assess the extent of brain injury in a hypoxic-ischaemic piglet model. The combination of MRI and histology made it possible to detect and describe the Harderian gland in pig. It has generally been studied in rodents and lower vertebrates and is reported to possess various endocrine and exocrine functions.
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Affiliation(s)
- Berit H Munkeby
- Department of Pediatric Research, Rikshospitalet-Radiumhospitalet Medical Cneter, University of Oslo, Norway.
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43
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Duhaime AC. Large animal models of traumatic injury to the immature brain. Dev Neurosci 2006; 28:380-7. [PMID: 16943661 DOI: 10.1159/000094164] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 05/09/2006] [Indexed: 11/19/2022] Open
Abstract
Large animal models have been used much less frequently than rodent models to study traumatic brain injury. However, large animal models offer distinct advantages in replicating specific mechanisms, morphology and maturational stages relevant to age-dependent injury responses. This paper reviews how each of these features is relevant in matching a model to a particular scientific question and discusses various scaling strategies, advantages and disadvantages of large animal models for studying traumatic brain injury in infants and children. Progress to date and future directions are outlined.
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Affiliation(s)
- Ann-Christine Duhaime
- Pediatric Neurosurgery, Children's Hospital at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, NH 03756, USA.
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44
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Northington FJ. Brief update on animal models of hypoxic-ischemic encephalopathy and neonatal stroke. ILAR J 2006; 47:32-8. [PMID: 16391429 DOI: 10.1093/ilar.47.1.32] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The discovery of safe and effective therapies for perinatal hypoxia ischemia (HI) and stroke remains an unmet goal of neonatal-perinatal medicine. Because of the many developmental and functional differences between the neonatal brain and the adult brain, the ability to extrapolate adult data to the neonatal condition is very limited. For this reason, it is incumbent on scientists in the field of neonatal brain injury to address the questions of therapeutic efficacy of an array of potential therapies in a developmentally appropriate model. Toward that end, a number of new models of neonatal HI and stroke have been introduced recently. Additionally, some of the established models have been adapted to different species and different ages, giving scientists a greater choice of models for the study of neonatal HI and stroke. Many of these models are now also being used for functional and behavioral testing, an absolute necessity for preclinical therapeutic trials. This review focuses primarily on the newly developed models, recent adaptations to established models, and the studies of functional outcome that have been published since 2000.
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Affiliation(s)
- Frances J Northington
- Department of Pediatrics, Eudowood Neonatal Pulmonary Division, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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van Os S, Ruitenbeek W, Hopman J, Klaessens J, van de Bor M. Cortical Excitatory Amino Acid Release and Cell Function during Hypotension in Near-Term Born Lambs. Neonatology 2006; 90:128-34. [PMID: 16582537 DOI: 10.1159/000092450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2005] [Accepted: 10/04/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND Energy failure due to insufficient cerebral O2-supply leads to excess accumulation of calcium ions in presynaptic neurons, followed by excess release of excitatory amino acids, which are potent neurotoxins, into the synaptic cleft. AIM To investigate whether electrocortical brain activity (ECBA) can provide an adequate measure for excitatory amino acid release due to hemorrhagic hypotension. METHODS Ten near-term lambs were delivered at 127 days of gestation (term: 147 days). After a stabilization period, hypotension was induced by stepwise withdrawal of blood. Cerebral microdialysis was used to measure the concentrations of glutamate and aspartate. RESULTS During hypotension, mean arterial blood pressure, cerebral O2-supply and ECBA decreased and the extracellular concentration of glutamate increased significantly. ECBA was significantly related to glutamate (R2: 0.67, p < 0.001) and aspartate (R2: 0.57, p < 0.001) concentrations. CONCLUSION The extracellular release of glutamate and aspartate in the cerebral cortex increases after hemorrhagic hypotension in near-term born lambs. The extracellular overflow of glutamate and aspartate were significantly inversely related to ECBA.
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Affiliation(s)
- Sandra van Os
- Department of Pediatrics, University Medical Center Nijmegen, Nijmegen, The Netherlands
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Björkman ST, Foster KA, O'driscoll SM, Healy GN, Lingwood BE, Burke C, Colditz PB. Hypoxic/Ischemic models in newborn piglet: Comparison of constant FiO2 versus variable FiO2 delivery. Brain Res 2006; 1100:110-7. [PMID: 16765329 DOI: 10.1016/j.brainres.2006.04.119] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 04/27/2006] [Accepted: 04/29/2006] [Indexed: 10/24/2022]
Abstract
A comparison of a constant (continuous delivery of 4% FiO2) and a variable (initial 5% FiO2 with adjustments to induce low amplitude EEG (LAEEG) and hypotension) hypoxic/ischemic insult was performed to determine which insult was more effective in producing a consistent degree of survivable neuropathological damage in a newborn piglet model of perinatal asphyxia. We also examined which physiological responses contributed to this outcome. Thirty-nine 1-day-old piglets were subjected to either a constant hypoxic/ischemic insult of 30- to 37-min duration or a variable hypoxic/ischemic insult of 30-min low peak amplitude EEG (LAEEG <5 microV) including 10 min of low mean arterial blood pressure (MABP <70% of baseline). Control animals (n = 6) received 21% FiO2 for the duration of the experiment. At 72 h, the piglets were euthanased, their brains removed and fixed in 4% paraformaldehyde and assessed for hypoxic/ischemic injury by histological analysis. Based on neuropathology scores, piglets were grouped as undamaged or damaged; piglets that did not survive to 72 h were grouped separately as dead. The variable insult resulted in a greater number of piglets with neuropathological damage (undamaged = 12.5%, damaged = 68.75%, dead = 18.75%) while the constant insult resulted in a large proportion of undamaged piglets (undamaged = 50%, damaged = 22.2%, dead = 27.8%). A hypoxic insult varied to maintain peak amplitude EEG <5 microV results in a greater number of survivors with a consistent degree of neuropathological damage than a constant hypoxic insult. Physiological variables MABP, LAEEG, pH and arterial base excess were found to be significantly associated with neuropathological outcome.
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Affiliation(s)
- S Tracey Björkman
- Perinatal Research Centre, Royal Brisbane and Women's Hospital, University of Queensland, Brisbane 4029, Australia.
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van Os S, Ruitenbeek W, Hopman J, van de Bor M. Excitatory amino acid release and electrocortical brain activity after hypoxemia in near-term lambs. Brain Dev 2006; 28:380-8. [PMID: 16504443 DOI: 10.1016/j.braindev.2005.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 09/05/2005] [Accepted: 12/05/2005] [Indexed: 11/26/2022]
Abstract
BACKGROUND Energy failure due to insufficient cerebral O(2)-supply leads to excess accumulation of calcium ions in presynaptic neurons, followed by excess release of excitatory amino acids (EAAs), which are potent neurotoxins, into the synaptic cleft. AIM The aim of the present study was to determine whether extracellular EAAs release after prolonged hypoxemia affects electrocortical brain activity (ECBA), as a measure of brain cell function, in near-term born lambs. METHODS Ten near-term lambs (term: 147 days) were delivered at 131 days of gestation. After a stabilization period, prolonged hypoxemia (FiO(2): 0.10; duration 2.5h) was induced. Mean values of physiologic variables, including ECBA, were calculated over the last 3 min of normoxemia as well as of hypoxemia. Cerebral arterial and venous blood gases were determined at the end of the normoxemic and hypoxemic periods. Cerebrospinal fluid (CSF) was obtained at the end of the hypoxemic period. CSF from six normoxemic sibs was used for comparison. HPLC was used to measure EAAs in the CSF. RESULTS During hypoxemia, aspartate and glutamate concentration increased significantly (4.8 and 6.0 times, respectively), while asparagine and glutamine did not. ECBA decreased to 30% of the normoxemic value. Glutamate was significantly higher in lambs with a flat cerebral function monitor (CFM) tracing than in lambs with a burst-suppression pattern. CONCLUSIONS After prolonged hypoxemia aspartate and glutamate accumulated excessively in the CSF of near-term born lambs. Especially glutamate concentrations in CSF were related to the decline in brain cell function.
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Affiliation(s)
- Sandra van Os
- Division of Neonatology, Department of Pediatrics 435, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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Vexler ZS, Sharp FR, Feuerstein GZ, Ashwal S, Thoresen M, Yager JY, Ferriero DM. Translational stroke research in the developing brain. Pediatr Neurol 2006; 34:459-63. [PMID: 16765824 DOI: 10.1016/j.pediatrneurol.2005.10.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Revised: 08/15/2005] [Accepted: 10/06/2005] [Indexed: 11/26/2022]
Abstract
Preclinical animal models can help guide the development of clinical pediatric and newborn stroke trials. Data obtained using currently available models of hypoxia-ischemia and focal stroke have demonstrated the need for age-appropriate models. There are age-related differences in susceptibility of the immature brain to oxidative stress and inflammation, as well as in the rate and degree of apoptotic neuronal death. These issues need to be carefully addressed in designing future clinical trials.
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Affiliation(s)
- Zinaida S Vexler
- Department of Neurology, University of California San Francisco, San Francisco, California 94143-0663, USA.
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Makarewicz D, Duszczyk M, Gadamski R, Danysz W, Łazarewicz JW. Neuroprotective potential of group I metabotropic glutamate receptor antagonists in two ischemic models. Neurochem Int 2006; 48:485-90. [PMID: 16513218 DOI: 10.1016/j.neuint.2005.12.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 12/19/2005] [Accepted: 12/22/2005] [Indexed: 11/28/2022]
Abstract
The neuroprotective potential of mGluR1 and mGluR5 antagonists (group I), EMQMCM and MTEP, respectively was studied using the 3 min forebrain ischemia model in Mongolian gerbils and the hypoxia-ischemia model in 7-day-old rats. Hypoxia-ischemia was induced by unilateral carotid occlusion followed by 75 min exposure to hypoxia (7.3% O(2) in N(2)), forebrain ischemia in gerbils was evoked by bilateral common carotid artery occlusion. The postischemic rectal body temperature in rat pups or brain temperature of gerbils was measured. The drugs were administered i.p. three times every 2 h after the insult, each time in equal doses of 1.25, 2.5 or 5.0 mg/kg. After 2 weeks brain damage was evaluated as weight decrease of the ipsilateral hemisphere in the rat pups or damage to CA1 pyramids in the gerbil hippocampus. The results demonstrated a dose dependent neuroprotection in both ischemic models by EMQMCM, while MTEP was neuroprotective only in the gerbil model of forebrain ischemia. EMQMCM reduced postischemic hyperthermia in gerbils. Thus, the antagonists of mGluR1 and mGluR5 show differential neuroprotective ability in two models of brain ischemia. Postischemic hypothermia may be partially involved in the mechanism of neuroprotection following EMQMCM in gerbils.
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Affiliation(s)
- Dorota Makarewicz
- Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Street, 02-106 Warsaw, Poland
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50
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Abstract
Germinal matrix hemorrhage refers to bleeding that arises from the subependymal (or periventricular) germinal region of the immature brain. Clinical studies have shown that infants who experience germinal matrix hemorrhage can develop hydrocephalus or suffer from long-term neurologic dysfunction, including cerebral palsy, seizures, and learning disabilities. Understanding the causative factors and the pathogenesis of subsequent brain damage is important if germinal matrix hemorrhage is to be prevented or treated. Appropriate animal models are necessary to achieve this understanding. A number of animal species, including mice, rats, rabbits, sheep, pigs, dogs, cats, and primates, have been used to model germinal matrix hemorrhage. This literature review critically evaluates the animal models of germinal matrix hemorrhage. Each model has its own advantages and disadvantages; no single model is suitable for the study of all aspects of brain damage.
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Affiliation(s)
- Janani Balasubramaniam
- Department of Pathology, University of Manitoba and Manitoba Instititute of Child Health, Winnipeg, MB, Canada
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