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Abstract
The cerebral microcirculation undergoes dynamic changes in parallel with the development of neurons, glia, and their energy metabolism throughout gestation and postnatally. Cerebral blood flow (CBF), oxygen consumption, and glucose consumption are as low as 20% of adult levels in humans born prematurely but eventually exceed adult levels at ages 3 to 11 years, which coincide with the period of continued brain growth, synapse formation, synapse pruning, and myelination. Neurovascular coupling to sensory activation is present but attenuated at birth. By 2 postnatal months, the increase in CBF often is disproportionately smaller than the increase in oxygen consumption, in contrast to the relative hyperemia seen in adults. Vascular smooth muscle myogenic tone increases in parallel with developmental increases in arterial pressure. CBF autoregulatory response to increased arterial pressure is intact at birth but has a more limited range with arterial hypotension. Hypoxia-induced vasodilation in preterm fetal sheep with low oxygen consumption does not sustain cerebral oxygen transport, but the response becomes better developed for sustaining oxygen transport by term. Nitric oxide tonically inhibits vasomotor tone, and glutamate receptor activation can evoke its release in lambs and piglets. In piglets, astrocyte-derived carbon monoxide plays a central role in vasodilation evoked by glutamate, ADP, and seizures, and prostanoids play a large role in endothelial-dependent and hypercapnic vasodilation. Overall, homeostatic mechanisms of CBF regulation in response to arterial pressure, neuronal activity, carbon dioxide, and oxygenation are present at birth but continue to develop postnatally as neurovascular signaling pathways are dynamically altered and integrated. © 2021 American Physiological Society. Compr Physiol 11:1-62, 2021.
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Dupré N, Derambure C, Le Dieu-Lugon B, Hauchecorne M, Detroussel Y, Gonzalez BJ, Marret S, Leroux P. Hypoxia-Ischemia Induced Age-Dependent Gene Transcription Effects at Two Development Stages in the Neonate Mouse Brain. Front Mol Neurosci 2020; 13:587815. [PMID: 33343297 PMCID: PMC7738628 DOI: 10.3389/fnmol.2020.587815] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
Human brain lesions in the perinatal period result in life-long neuro-disabilities impairing sensory-motor, cognitive, and behavior functions for years. Topographical aspects of brain lesions depend on gestational age at the time of insult in preterm or term infants and impaired subsequent steps of brain development and maturation. In mice, the Rice-Vannucci procedure of neonate hypoxia-ischemia (HI) was used at 5 days (P5) or P10, mimicking the development of 30 week-gestation fetus/preterm newborn, or full-term infant, respectively. Transcription response to HI was assessed at 3, 6, 12, and 24 h after insult, using micro-array technology. Statistical Pathway and Gene Ontology terms enrichments were investigated using DAVID®, Revigo® and Ingenuity Pathway Analysis (IPA®) to identify a core of transcription response to HI, age-specific regulations, and interactions with spontaneous development. Investigations were based on direction, amplitude, and duration of responses, basal expression, and annotation. Five major points deserve attention; (i) inductions exceeded repressions (60/40%) at both ages, (ii) only 20.3% (393/1938 records) were common to P5 and P10 mice, (iii) at P5, HI effects occurred early and decreased 24 h after insult whereas they were delayed at P10 and increased 24 h after insult, (iv) common responses at P5 and P10 involved inflammation, immunity, apoptosis, and angiogenesis. (v) age-specific effects occurred with higher statistical significance at P5 than at P10. Transient repression of 12 genes encoding cholesterol biosynthesis enzymes was transiently observed 12 h after HI at P5. Synaptogenesis appeared inhibited at P5 while induced at P10, showing reciprocal effects on glutamate receptors. Specific involvement of Il-1 (interleukin-1) implicated in the firing of inflammation was observed at P10. This study pointed out age-differences in HI responses kinetics, e.g., a long-lasting inflammatory response at P10 compared to P5. Whether the specific strong depression of cholesterol biosynthesis genes that could account for white matter-specific vulnerability at P5 or prevent delayed inflammation needs further investigation. Determination of putative involvement of Il-1 and the identification of upstream regulators involved in the delayed inflammation firing at P10 appears promising routes of research in the understandings of age-dependent vulnerabilities in the neonatal brain.
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Affiliation(s)
- Nicolas Dupré
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
| | - Céline Derambure
- INSERM-UMR 1245, Team 1, Genetic Predisposition to Cancer, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
| | - Bérénice Le Dieu-Lugon
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
| | - Michelle Hauchecorne
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
| | - Yannick Detroussel
- CURIB, Faculté des Sciences et Techniques, Normandie Université, Mont-Saint-Aignan, France
| | - Bruno J Gonzalez
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
| | - Stéphane Marret
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France.,Neonatal Pediatrics, Intensive Care Unit and Neuropediatrics, Rouen University Hospital, Rouen, France
| | - Philippe Leroux
- INSERM-UMR 1245, Team 4, Epigenetics and Physiopathology of Neurodevelopmental Brain Lesions, Faculté de Médecine et de Pharmacie, Normandie Université, Rouen, France
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Kobuch S, Macefield VG, Henderson LA. Resting regional brain activity and connectivity vary with resting blood pressure but not muscle sympathetic nerve activity in normotensive humans: An exploratory study. J Cereb Blood Flow Metab 2019; 39:2433-2444. [PMID: 30182800 PMCID: PMC6893974 DOI: 10.1177/0271678x18798442] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Blood pressure is tightly controlled by the central nervous system, particularly the brainstem. The aim of this study was to investigate the relationship between mean blood pressure (MBP), muscle sympathetic nerve activity (MSNA) and resting regional brain activity in healthy human subjects. Pseudocontinuous arterial spin labeling and functional magnetic resonance imaging of the brain were performed immediately following a laboratory microneurography recording of MSNA and BP measurement in 31 young, healthy normotensive subjects. Regional cerebral blood flow (CBF) correlated significantly with resting MBP levels in the region encompassing the rostroventrolateral medulla (RVLM), dorsolateral pons, and insular, prefrontal and cingulate cortices. Functional connectivity analysis revealed that the ventrolateral prefrontal cortex displayed greater resting connectivity strength within the RVLM in the lower compared with the higher MBP group. No significant differences in CBF were found when subjects were divided based on their MSNA levels. These results suggest that even subtle differences in resting MBP are associated with significant differences in resting activity in brain regions, which are well known to play a role in cardiovascular function. These data raise the question of the potential long-term consequences of differences in regional brain activity levels and their relationship with systemic blood pressure.
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Affiliation(s)
- Sophie Kobuch
- School of Medicine, Western Sydney University, Sydney, Australia
| | - Vaughan G Macefield
- School of Medicine, Western Sydney University, Sydney, Australia.,Neuroscience Research Australia, Sydney, Australia.,Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Luke A Henderson
- Department of Anatomy and Histology, University of Sydney, Sydney, Australia
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Hefter D, Marti HH, Gass P, Inta D. Perinatal Hypoxia and Ischemia in Animal Models of Schizophrenia. Front Psychiatry 2018; 9:106. [PMID: 29651259 PMCID: PMC5884869 DOI: 10.3389/fpsyt.2018.00106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/16/2018] [Indexed: 12/12/2022] Open
Abstract
Intrauterine or perinatal complications constitute a major risk for psychiatric diseases. Infants who suffered from hypoxia-ischemia (HI) are at twofold risk to develop schizophrenia in later life. Several animal models attempt to reproduce these complications to study the yet unknown steps between an insult in early life and outbreak of the disease decades later. However, it is very challenging to find the right type and severity of insult leading to a disease-like phenotype in the animal, but not causing necrosis and focal neurological deficits. By contrast, too mild, repetitive insults may even be protective via conditioning effects. Thus, it is not surprising that animal models of hypoxia lead to mixed results. To achieve clinically translatable findings, better protocols are urgently needed. Therefore, we compare widely used models of hypoxia and HI and propose future directions for the field.
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Affiliation(s)
- Dimitri Hefter
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany.,RG Neuro- and Sensory Physiology, Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Hugo H Marti
- RG Neurovascular Research, Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Peter Gass
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany
| | - Dragos Inta
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Heidelberg, Germany.,Department of Psychiatry, University of Basel, Basel, Switzerland
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Redistribution of Cerebral Blood Flow during Severe Hypovolemia and Reperfusion in a Sheep Model: Critical Role of α1-Adrenergic Signaling. Int J Mol Sci 2017; 18:ijms18051031. [PMID: 28492488 PMCID: PMC5454943 DOI: 10.3390/ijms18051031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 11/29/2022] Open
Abstract
Background: Maintenance of brain circulation during shock is sufficient to prevent subcortical injury but the cerebral cortex is not spared. This suggests area-specific regulation of cerebral blood flow (CBF) during hemorrhage. Methods: Cortical and subcortical CBF were continuously measured during blood loss (≤50%) and subsequent reperfusion using laser Doppler flowmetry. Blood gases, mean arterial blood pressure (MABP), heart rate and renal blood flow were also monitored. Urapidil was used for α1A-adrenergic receptor blockade in dosages, which did not modify the MABP-response to blood loss. Western blot and quantitative reverse transcription polymerase chain reactions were used to determine adrenergic receptor expression in brain arterioles. Results: During hypovolemia subcortical CBF was maintained at 81 ± 6% of baseline, whereas cortical CBF decreased to 40 ± 4% (p < 0.001). Reperfusion led to peak CBFs of about 70% above baseline in both brain regions. α1A-Adrenergic blockade massively reduced subcortical CBF during hemorrhage and reperfusion, and prevented hyperperfusion during reperfusion in the cortex. α1A-mRNA expression was significantly higher in the cortex, whereas α1D-mRNA expression was higher in the subcortex (p < 0.001). Conclusions: α1-Adrenergic receptors are critical for perfusion redistribution: activity of the α1A-receptor subtype is a prerequisite for redistribution of CBF, whereas the α1D-receptor subtype may determine the magnitude of redistribution responses.
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Porte B, Chatelain C, Hardouin J, Derambure C, Zerdoumi Y, Hauchecorne M, Dupré N, Bekri S, Gonzalez B, Marret S, Cosette P, Leroux P. Proteomic and transcriptomic study of brain microvessels in neonatal and adult mice. PLoS One 2017; 12:e0171048. [PMID: 28141873 PMCID: PMC5283732 DOI: 10.1371/journal.pone.0171048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/13/2017] [Indexed: 12/17/2022] Open
Abstract
Infants born before 29 weeks gestation incur a major risk of preterm encephalopathy and subependymal/intracerebral/intraventricular haemorrhage. In mice, an ontogenic window of haemorrhage risk was recorded up to 5 days after birth in serpine1 knock-out animals. Using proteome and transcriptome approaches in mouse forebrain microvessels, we previously described the remodelling of extracellular matrix and integrins likely strengthening the vascular wall between postnatal day 5 (P5) and P10. Haemorrhage is the ultimate outcome of vessel damage (i.e., during ischaemia), although discreet vessel insults may be involved in the aetiology of preterm encephalopathy. In this study, we examined proteins identified by mass spectrometry and segregating in gene ontology pathways in forebrain microvessels in P5, P10, and adult wild type mice. In parallel, comparative transcript levels were obtained using RNA hybridization microarrays and enriched biological pathways were extracted from genes exhibiting at least a two-fold change in expression. Five major biological functions were observed in those genes detected both as proteins and mRNA expression undergoing at least a two-fold change in expression in one or more age comparisons: energy metabolism, protein metabolism, antioxidant function, ion exchanges, and transport. Adult microvessels exhibited the highest protein and mRNA expression levels for a majority of genes. Energy metabolism-enriched gene ontology pathways pointed to the preferential occurrence of glycolysis in P5 microvessels cells versus P10 and adult preparations enriched in aerobic oxidative enzymes. Age-dependent levels of RNA coding transport proteins at the plasma membrane and mitochondria strengthened our findings based on protein data. The data suggest that immature microvessels have fewer energy supply alternatives to glycolysis than mature structures. In the context of high energy demand, this constraint might account for vascular damage and maintenance of the high bleeding occurrence in specific areas in immature brain.
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Affiliation(s)
- Baptiste Porte
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Clémence Chatelain
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Julie Hardouin
- Normandie Université, UNIROUEN, UMR-6270, CNRS, IRIB, Mont-Saint-Aignan, France
- Normandie Université, UNIROUEN, Proteomic Facility PISSARO, IRIB, Mont-Saint-Aignan, France
| | - Céline Derambure
- Normandie Université, UNIROUEN, UMR-S905, INSERM, IRIB, Rouen, France
| | - Yasmine Zerdoumi
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Michèle Hauchecorne
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Nicolas Dupré
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Soumeya Bekri
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
- Metabolic Biochemistry Department, Rouen University Hospital, Rouen, France
| | - Bruno Gonzalez
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | - Stéphane Marret
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
- Neonatal Pediatrics and Intensive Care Department, Rouen University Hospital, Rouen, France
| | - Pascal Cosette
- Normandie Université, UNIROUEN, UMR-6270, CNRS, IRIB, Mont-Saint-Aignan, France
- Normandie Université, UNIROUEN, Proteomic Facility PISSARO, IRIB, Mont-Saint-Aignan, France
| | - Philippe Leroux
- Normandie Université, UNIROUEN, U1245, INSERM, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
- * E-mail:
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Siebert E, Bohner G, Endres M, Liman TG. Clinical and radiological spectrum of posterior reversible encephalopathy syndrome: does age make a difference?--A retrospective comparison between adult and pediatric patients. PLoS One 2014; 9:e115073. [PMID: 25514795 PMCID: PMC4267732 DOI: 10.1371/journal.pone.0115073] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/18/2014] [Indexed: 11/19/2022] Open
Abstract
Background Posterior reversible encephalopathy syndrome (PRES) is a serious and increasingly recognized disorder, but data from observational studies on clinicoradiological differences between etiologies and age groups are limited. In this study, we aimed to investigate the clinical and imaging characteristics of PRES in children compared to adults in a large cohort. Methods We retrospectively reviewed the radiological report data bases between January 1999 and August 2012 for patients with PRES (total of 110 patients). Patients fulfilling the criteria for PRES after detailed investigation of clinical charts and imaging studies were separated into children (<18years) and adults (≥18years). Various imaging features at onset of symptoms and on follow-up as well as clinical and paraclinical data were analyzed. Results A total of 19 pediatric and 91 adult patients with PRES were included into the study. In pediatric PRES patients, seizures were significantly more frequent as initial PRES-related symptom (p = 0.01). In addition, in children the superior frontal sulcus topographic lesion pattern occurred as frequent as the parieto-occipital one and was significantly more prevalent than in adults (p = 0.02). In contrast, in adults visual disturbances tended to occur more frequently than in children (p = 0.05). Also, severity of edema tended to be greater in adults than in children (p = 0.07). Conclusion In our PRES cohort, we found relevant clinicoradiological differences between pediatric and adult PRES patients. However, prospective studies are warranted to establish factors that are specifically associated with pediatric PRES.
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Affiliation(s)
- Eberhard Siebert
- Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
| | - Georg Bohner
- Department of Neuroradiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Matthias Endres
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK) Partner Site, Charité - Universitätsmedizin Berlin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE) Partner Site, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas G. Liman
- Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Fernández-López D, Faustino J, Derugin N, Vexler ZS. Acute and chronic vascular responses to experimental focal arterial stroke in the neonate rat. Transl Stroke Res 2014; 4:179-88. [PMID: 23730350 DOI: 10.1007/s12975-012-0214-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The presence of active developmental angiogenesis and vascular outgrowth in the postnatal brain may differentially affect vascular responses to stroke in newborns and adults, but very little is known about the dynamics of vascular injury and re-growth after stroke during the neonatal period. In this study we used a clinically relevant animal model of ischemic arterial stroke in neonate rats, a transient middle cerebral artery occlusion (MCAO) in postnatal day 7 (P7), to characterize the effects of injury on vascular density and angiogenesis from acute through the chronic phase. A marked vessel degeneration and suppressed endothelial cell proliferation occur in the ischemic regions early after neonatal stroke. In contrast to what has been described in adult animals, endothelial cell proliferation and vascular density are not increased in the peri-ischemic regions during the first week after MCAO in neonates. By two weeks after injury, endothelial cell proliferation is increased in the cortical peri-ischemic region but these changes are not accompanied by an increased vascular density. Suppressed angiogenesis in injured postnatal brain that we report may limit recovery after neonatal stroke. Thus, enhancement of angiogenesis after neonatal stroke may be a promising strategy for the long-term recovery of the affected newborns.
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Affiliation(s)
- David Fernández-López
- Neonatal Brain Disorders Center. Department of Neurology. University of California San Francisco, San Francisco, USA
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Mechanisms of perinatal arterial ischemic stroke. J Cereb Blood Flow Metab 2014; 34:921-32. [PMID: 24667913 PMCID: PMC4050239 DOI: 10.1038/jcbfm.2014.41] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 12/30/2013] [Accepted: 01/02/2014] [Indexed: 01/21/2023]
Abstract
The incidence of perinatal stroke is high, similar to that in the elderly, and produces a significant morbidity and severe long-term neurologic and cognitive deficits, including cerebral palsy, epilepsy, neuropsychological impairments, and behavioral disorders. Emerging clinical data and data from experimental models of cerebral ischemia in neonatal rodents have shown that the pathophysiology of perinatal brain damage is multifactorial. These studies have revealed that, far from just being a smaller version of the adult brain, the neonatal brain is unique with a very particular and age-dependent responsiveness to hypoxia-ischemia and focal arterial stroke. In this review, we discuss fundamental clinical aspects of perinatal stroke as well as some of the most recent and relevant findings regarding the susceptibility of specific brain cell populations to injury, the dynamics and the mechanisms of neuronal cell death in injured neonates, the responses of neonatal blood-brain barrier to stroke in relation to systemic and local inflammation, and the long-term effects of stroke on angiogenesis and neurogenesis. Finally, we address translational strategies currently being considered for neonatal stroke as well as treatments that might effectively enhance repair later after injury.
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Age and gender may affect posterior reversible encephalopathy syndrome in renal disease. Pediatr Nephrol 2012; 27:277-83. [PMID: 21822908 DOI: 10.1007/s00467-011-1974-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 07/11/2011] [Accepted: 07/12/2011] [Indexed: 10/17/2022]
Abstract
It remains elusive what factors affect posterior reversible encephalopathy syndrome (PRES). Eleven PRES children, all with acute glomerulonephritis, Alport syndrome, and lupus nephritis, 5 with nephrosis, and 3 renal transplant recipients, were studied. PRES recurred in 1 patient. Neurological symptoms were graded as 1: mild (headache, nausea/vomiting, or tremor), 2: moderate (vision change), and 3: severe (mental dysfunction, cerebellar symptoms, seizures, recurrence of seizures, and coma). Magnetic resonance imaging was graded as 1: subtle change, 2: abnormal large areas, and 3: complete involvement of the regions. The common symptoms were seizures (100%), headache (82%), nausea/vomiting (73%), coma (55%), and vision change (46%). Seizures recurred in 7 (64%). All but one (91%) developed hypertension and 7 (64%) received calcineurin inhibitors (CNI). Edema occurred in 7 (64%) and renal insufficiency/end-stage renal disease (ESRD) in 4 (36%). Seizures recurred frequently in younger patients. Symptoms were severe in girls. Duration or severity of the condition with predisposing factors (hypertension, CNI, nephrosis or renal insufficiency/ERSD) did not make a difference in the symptoms and neuroimaging. Two patients developed chronic epilepsy. Age and gender may affect PRES symptoms. Our results are limited by small sample size and should be determined using larger numbers of patients.
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Cerebral blood flow and cerebrovascular autoregulation in a swine model of pediatric cardiac arrest and hypothermia. Crit Care Med 2011; 39:2337-45. [PMID: 21705904 DOI: 10.1097/ccm.0b013e318223b910] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Knowledge remains limited regarding cerebral blood flow autoregulation after cardiac arrest and during postresuscitation hypothermia. We determined the relationship of cerebral blood flow to cerebral perfusion pressure in a swine model of pediatric hypoxic-asphyxic cardiac arrest during normothermia and hypothermia and tested novel measures of autoregulation derived from near-infrared spectroscopy. DESIGN Prospective, balanced animal study. SETTING Basic physiology laboratory at an academic institution. SUBJECTS Eighty-four neonatal swine. INTERVENTIONS Piglets underwent hypoxic-asphyxic cardiac arrest or sham surgery and recovered for 2 hrs with normothermia followed by 4 hrs of either moderate hypothermia or normothermia. In half of the groups, blood pressure was slowly decreased through inflation of a balloon catheter in the inferior vena cava to identify the lower limit of cerebral autoregulation at 6 hrs postresuscitation. In the remaining groups, blood pressure was gradually increased by inflation of a balloon catheter in the aorta to determine the autoregulatory response to hypertension. Measures of autoregulation obtained from standard laser-Doppler flowmetry and indices derived from near-infrared spectroscopy were compared. MEASUREMENTS AND MAIN RESULTS Laser-Doppler flux was lower in postarrest animals compared to sham-operated controls during the 2-hr normothermic period after resuscitation. During the subsequent 4-hr recovery, hypothermia decreased laser-Doppler flux in both the sham surgery and postarrest groups. Autoregulation was intact during hypertension in all groups. With arterial hypotension, postarrest, hypothermic piglets had a significant decrease in the perfusion pressure lower limit of autoregulation compared to postarrest, normothermic piglets. The near-infrared spectroscopy-derived measures of autoregulation accurately detected loss of autoregulation during hypotension. CONCLUSIONS In a pediatric model of cardiac arrest and resuscitation, delayed induction of hypothermia decreased cerebral perfusion and decreased the lower limit of autoregulation. Metrics derived from noninvasive near-infrared spectroscopy accurately identified the lower limit of autoregulation during normothermia and hypothermia in piglets resuscitated from arrest.
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Abstract
The visual system is one of the most energetically demanding systems in the brain. The currency of energy is ATP, which is generated most efficiently from oxidative metabolism in the mitochondria. ATP supports multiple neuronal functions. Foremost is repolarization of the membrane potential after depolarization. Neuronal activity, ATP generation, blood flow, oxygen consumption, glucose utilization, and mitochondrial oxidative metabolism are all interrelated. In the retina, phototransduction, neurotransmitter utilization, and protein/organelle transport are energy-dependent, yet repolarization-after-depolarization consumes the bulk of the energy. Repolarization in photoreceptor inner segments maintains the dark current. Repolarization by all neurons along the visual pathway following depolarizing excitatory glutamatergic neurotransmission preserves cellular integrity and permits reactivation. The higher metabolic activity in the magno- versus the parvo-cellular pathway, the ON- versus the OFF-pathway in some (and the reverse in other) species, and in specialized functional representations in the visual cortex all reflect a greater emphasis on the processing of specific visual attributes. Neuronal activity and energy metabolism are tightly coupled processes at the cellular and even at the molecular levels. Deficiencies in energy metabolism, such as in diabetes, mitochondrial DNA mutation, mitochondrial protein malfunction, and oxidative stress can lead to retinopathy, visual deficits, neuronal degeneration, and eventual blindness.
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Affiliation(s)
- Margaret T T Wong-Riley
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Qiao M, Latta P, Foniok T, Buist R, Meng S, Tomanek B, Tuor UI. Cerebral blood flow response to a hypoxic-ischemic insult differs in neonatal and juvenile rats. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 17:117-24. [PMID: 15538659 DOI: 10.1007/s10334-004-0058-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Accepted: 07/29/2004] [Indexed: 01/07/2023]
Abstract
To compare the cerebral blood flow (CBF) response to a transient episode of hypoxia-ischemia producing damage in neonatal and juvenile rats. One- and four-week-old rats were subjected to unilateral carotid artery occlusion plus hypoxia (8% oxygen). Perfusion MR images were acquired either in sham controls or in hypoxic-ischemic rats before, during, 1 h and 24 h after hypoxia-ischemia. At 24 h post hypoxia-ischemia, T2 maps and histology were used to assess damage. In sham controls, CBF increased twofold between the age of one and four weeks. Reductions in CBF ipsilateral to the occlusion occurred during hypoxia-ischemia followed by a substantial recovery at 1 h post in both age groups. However, contralaterally, hyperemia occurred during hypoxia-ischemia in four-week but not one-week-old rats. Similarly, hyperemia occurred ipsilaterally at 24 h post hypoxia-ischemia in four-week but not one-week-olds, corresponding to the distribution of elevations in T2. Despite CBF differences, extensive cell death occurred ipsilaterally in both age groups. The CBF responses to hypoxia-ischemia and reperfusion differ depending on postnatal age, with hyperemia occurring in juvenile but not neonatal rats. The results suggest a greater CBF responsiveness and differential relationship between post-ischemic vascular perfusion and tissue injury in older compared with immature animals.
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Affiliation(s)
- M Qiao
- Institute for Biodiagnostics (West), National Research Council of Canada, B153, 3330 Hospital Dr. NW, Calgary, AB, Canada, T2N 4N1
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14
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Williams JM, Hull AD, Pearce WJ. Maturational modulation of endothelium-dependent vasodilatation in ovine cerebral arteries. Am J Physiol Regul Integr Comp Physiol 2004; 288:R149-57. [PMID: 15358604 DOI: 10.1152/ajpregu.00427.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To address the hypothesis that maturation enhances endothelial vasodilator function in cerebral arteries, relaxant responses to ADP and A-23187 were determined in ovine carotid and cerebral arteries harvested from 25 newborn lambs (3-7 days) and 23 adult sheep. Maturation significantly increased pD(2) values for A-23187 (newborn range: 4.9 +/- 0.3 to 5.4 +/- 0.3; adult range: 6.0 +/- 0.2 to 7.1 +/- 0.2) and the maximal vasodilator response to A-23187 by 10-18%. In contrast, maturation decreased maximum responses to ADP by 5-25% with no change in pD(2). The magnitudes of endothelium-dependent relaxation were not affected by 10 microM indomethacin but were virtually abolished by 100 microM N(G)-nitro-L-arginine methyl ester/L-nitro arginine, indicating that nitric oxide (NO) is the primary endothelium-dependent vasodilator in these arteries. Maturation also modestly decreased endothelial NO synthase (eNOS) abundance in both carotid (32%) and cerebral (26%) arteries. Together, these findings reinforce the view that receptor coupling to endothelial activation is tightly regulated and may offset underlying changes in maximal endothelial vasodilator capacity. This capacity, in turn, appears to increase with postnatal age despite major growth and expansion of endothelial cell size and vascular wall volume. In ovine cerebral arteries, endothelial vasodilator capacity appears completely dependent on eNOS activity but not on cyclooxygenase activity. In turn, eNOS activity appears to be postnatally regulated by mechanisms independent of changes in eNOS abundance alone.
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Affiliation(s)
- James M Williams
- Department of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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15
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Müller T, Löhle M, Schubert H, Bauer R, Wicher C, Antonow-Schlorke I, Sliwka U, Nathanielsz PW, Schwab M. Developmental changes in cerebral autoregulatory capacity in the fetal sheep parietal cortex. J Physiol 2002; 539:957-67. [PMID: 11897864 PMCID: PMC2290182 DOI: 10.1113/jphysiol.2001.012590] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We validated laser Doppler flowmetry (LDF) for long-term monitoring and detection of acute changes of local cerebral blood flow (lCBF) in chronically instrumented fetal sheep. Using LDF, we estimated developmental changes of cerebral autoregulation. Single fibre laser probes (0.4 mm in diameter) were implanted in and surface probes were placed on the parietal cerebral cortex at 105 +/- 2 (n = 7) and 120 +/- 2 days gestational age (dGA, n = 7). Basal lCBF was monitored over 5 days followed by a hypercapnic challenge (fetal arterial partial pressure of CO(2), P(a,CO2): 83 +/- 3 mmHg) during which lCBF changes obtained by LDF were compared to those obtained with coloured microspheres (CMSs). Mean arterial blood pressure (MABP) was increased and decreased using phenylephrine and sodium nitroprusside at 110 +/- 2 and 128 +/- 2 dGA. Intracortical and cortical surface laser probes gave stable measurements over 5 days. The lCBF increase during hypercapnia obtained by LDF correlated well with flows obtained using CMS (r = 0.89, P < 0.01). The signals of intracortical and surface laser probes also correlated well (r = 0.91, P < 0.01). Gliosis of 0.35 +/- 0.06 mm around the tip of intracortical probes did not affect the measurements. The range of MABP over which cerebral autoregulation was observed increased from 20-48 mmHg at 110 dGA to 35 to > 95 mmHg at 128 dGA (P < 0.05). Since MABP increased from 33 to 54 mmHg over this period (P < 0.01), the range between the lower limit of cerebral autoregulation and the MABP increased from 13 mmHg at 110 dGA to 19 mmHg at 128 dGA (P < 0.01). LDF is a reliable tool to assess dynamic changes in cerebral perfusion continuously in fetal sheep.
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Affiliation(s)
- Thomas Müller
- Institute of Laboratory Animal Science, Friedrich Schiller University, D-07740 Jena, Germany
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16
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Cooper CE, Delpy DT, Nemoto EM. The relationship of oxygen delivery to absolute haemoglobin oxygenation and mitochondrial cytochrome oxidase redox state in the adult brain: a near-infrared spectroscopy study. Biochem J 1998; 332 ( Pt 3):627-32. [PMID: 9620863 PMCID: PMC1219521 DOI: 10.1042/bj3320627] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Near-infrared spectroscopy was used to determine the effect of changes in the rate of oxygen delivery to the adult rat brain on the absolute concentrations of oxyhaemoglobin, deoxyhaemoglobin and the redox state of the CuA centre in mitochondrial cytochrome oxidase. The cytochrome oxidase detection algorithm was determined to be robust to large changes in haemoglobin oxygenation and concentration. By assuming complete haemoglobin deoxygenation and CuA reduction following mechanical ventilation on 100% N2O, the absolute concentration of oxyhaemoglobin (35 microM), deoxyhaemoglobin (27 microM) and the redox state of CuA (82% oxidized) were calculated in the normal adult brain. The mean arterial blood pressure was decreased by exsanguination. When the pressure reached 100 mmHg, haemoglobin oxygenation started to fall, but the total haemoglobin concentration and oxidized CuA levels only fell when cerebral blood volume autoregulation mechanisms failed at 50 mmHg. Haemoglobin oxygenation fell linearly with decreases in the rate of oxygen delivery to the brain, but the oxidized CuA concentration did not start to fall until this rate was 50% of normal. The results suggest that the brain maintains more than adequate oxygen delivery to mitochondria and that near-infrared spectroscopy may be a good measure of oxygen insufficiency in vivo.
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Affiliation(s)
- C E Cooper
- Department of Biological Sciences, Central Campus, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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