1
|
Amirkhosravi L, Khaksari M, Sheibani V, Shahrokhi N, Ebrahimi MN, Amiresmaili S, Salmani N. Improved spatial memory, neurobehavioral outcomes, and neuroprotective effect after progesterone administration in ovariectomized rats with traumatic brain injury: Role of RU486 progesterone receptor antagonist. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021; 24:349-359. [PMID: 33995946 PMCID: PMC8087858 DOI: 10.22038/ijbms.2021.50973.11591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/22/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES The contribution of classic progesterone receptors (PR) in interceding the neuroprotective efficacy of progesterone (P4) on the prevention of brain edema and long-time behavioral disturbances was assessed in traumatic brain injury (TBI). MATERIALS AND METHODS Female Wistar rats were ovariectomized and apportioned into 6 groups: sham, TBI, oil, P4, vehicle, and RU486. P4 or oil was injected following TBI. The antagonist of PR (RU486) or DMSO was administered before TBI. The brain edema and destruction of the blood-brain barrier (BBB) were determined. Intracranial pressure (ICP), cerebral perfusion pressure (CPP), and beam walk (BW) task were evaluated previously and at various times post-trauma. Long-time locomotor and cognitive consequences were measured one day before and on days 3, 7, 14, and 21 after the trauma. RESULTS RU486 eliminated the inhibitory effects of P4 on brain edema and BBB leakage (P<0.05, P<0.001, respectively). RU486 inhibited the decremental effect of P4 on ICP as well as the increasing effect of P4 on CPP (P<0.001) after TBI. Also, RU486 inhibited the effect of P4 on the increase in traversal time and reduction in vestibulomotor score in the BW task (P<0.001). TBI induced motor, cognitive, and anxiety-like disorders, which lasted for 3 weeks after TBI; but, P4 prevented these cognitive and behavioral abnormalities (P<0.05), and RU486 opposed this P4 effect (P<0.001). CONCLUSION The classic progesterone receptors have neuroprotective effects and prevent long-time behavioral and memory deficiency after brain trauma.
Collapse
Affiliation(s)
- Ladan Amirkhosravi
- Neuroscience Research and Physiology Research Centers, Kerman University of Medical Sciences, Kerman, Iran
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Khaksari
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Vahid Sheibani
- Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Nader Shahrokhi
- Physiology Research Centers, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Navid Ebrahimi
- Neuroscience Research and Physiology Research Centers, Kerman University of Medical Sciences, Kerman, Iran
| | | | - Neda Salmani
- Department of Psychology, Genetic Institute, Islamic Azad University- Zarand Branch, Kerman, Iran
| |
Collapse
|
2
|
Ruiz T, Baldwin AS, Spiegel DP, Hess R, Farivar R. Increased Noise in Cortico-Cortical Integration After Mild TBI Measured With the Equivalent Noise Technique. Front Neurol 2019; 10:767. [PMID: 31428031 PMCID: PMC6689961 DOI: 10.3389/fneur.2019.00767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 07/02/2019] [Indexed: 11/13/2022] Open
Abstract
The bulk of deficits accompanying mild traumatic brain injury (mTBI) is understood in terms of cortical integration—mnemonic, attentional, and cognitive disturbances are believed to involve integrative action across brain regions. Independent of integrative disturbances, mTBI may increase cortical noise, and this has not been previously considered. High-level integrative deficits are exceedingly difficult to measure and model, motivating us to utilize a tightly-controlled task within an established quantitative model to separately estimate internal noise and integration efficiency. First, we utilized a contour integration task modeled as a cortical-integration process involving multiple adjacent cortical columns in early visual areas. Second, we estimated internal noise and integration efficiency using the linear amplifier model (LAM). Fifty-seven mTBI patients and 24 normal controls performed a 4AFC task where they had to identify a valid contour amongst three invalid contours. Thresholds for contour amplitude were measured adaptively across three levels of added external orientation noise. Using the LAM, we found that mTBI increased internal noise without affecting integration efficiency. mTBI also caused hemifield bias differences, and efficiency was related to a change of visual habits. Using a controlled task reflecting cortical integration within the equivalent noise framework empowered us to detect increased computational noise that may be at the heart of mTBI deficits. Our approach is highly sensitive and translatable to rehabilitative efforts for the mTBI population, while also implicating a novel hypothesis of mTBI effects on basic visual processing—namely that cortical integration is maintained at the cost of increased internal noise.
Collapse
Affiliation(s)
- Tatiana Ruiz
- Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Alex S Baldwin
- Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Daniel P Spiegel
- Vision Sciences, Essilor R&D, Center for Innovation and Technology, Singapore, Singapore
| | - Robert Hess
- Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Reza Farivar
- Research Institute of the McGill University Health Center, Montreal, QC, Canada
| |
Collapse
|
3
|
Kinder HA, Baker EW, West FD. The pig as a preclinical traumatic brain injury model: current models, functional outcome measures, and translational detection strategies. Neural Regen Res 2019; 14:413-424. [PMID: 30539807 PMCID: PMC6334610 DOI: 10.4103/1673-5374.245334] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a major contributor of long-term disability and a leading cause of death worldwide. A series of secondary injury cascades can contribute to cell death, tissue loss, and ultimately to the development of functional impairments. However, there are currently no effective therapeutic interventions that improve brain outcomes following TBI. As a result, a number of experimental TBI models have been developed to recapitulate TBI injury mechanisms and to test the efficacy of potential therapeutics. The pig model has recently come to the forefront as the pig brain is closer in size, structure, and composition to the human brain compared to traditional rodent models, making it an ideal large animal model to study TBI pathophysiology and functional outcomes. This review will focus on the shared characteristics between humans and pigs that make them ideal for modeling TBI and will review the three most common pig TBI models-the diffuse axonal injury, the controlled cortical impact, and the fluid percussion models. It will also review current advances in functional outcome assessment measures and other non-invasive, translational TBI detection and measurement tools like biomarker analysis and magnetic resonance imaging. The use of pigs as TBI models and the continued development and improvement of translational assessment modalities have made significant contributions to unraveling the complex cascade of TBI sequela and provide an important means to study potential clinically relevant therapeutic interventions.
Collapse
Affiliation(s)
- Holly A Kinder
- Regenerative Bioscience Center; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA
| | - Emily W Baker
- Regenerative Bioscience Center; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA
| | - Franklin D West
- Regenerative Bioscience Center; Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA
| |
Collapse
|
4
|
Rötering S, Deuther-Conrad W, Cumming P, Donat CK, Scheunemann M, Fischer S, Xiong G, Steinbach J, Peters D, Sabri O, Bucerius J, Brust P. Imaging of α7 nicotinic acetylcholine receptors in brain and cerebral vasculature of juvenile pigs with [(18)F]NS14490. EJNMMI Res 2014; 4:43. [PMID: 25136512 PMCID: PMC4129469 DOI: 10.1186/s13550-014-0043-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 07/17/2014] [Indexed: 11/21/2022] Open
Abstract
Background The α7 nicotinic acetylcholine receptor (nAChR) is an important molecular target in neuropsychiatry and oncology. Development of applicable highly specific radiotracers has been challenging due to comparably low protein expression. To identify novel ligands as candidates for positron emission tomography (PET), a library of diazabicyclononane compounds was screened regarding affinity and specificity towards α7 nAChRs. From these, [18F]NS14490 has been shown to yield reliable results in organ distribution studies; however, the radiosynthesis of [18F]NS14490 required optimization and automation to obtain the radiotracer in quantities allowing dynamic PET studies in piglets. Methods Automated radiosynthesis of [18F]NS14490 has been performed by [18F]fluorination with the tosylate precursor in the TRACERlab™ FX F-N synthesis module (Waukesha, WI, USA). After optimization, the radiochemical yield of [18F]NS14490 was consistently approximately 35%, and the total synthesis time was about 90 min. The radiotracer was prepared with >92% radiochemical purity, and the specific activity at the end of the synthesis was 226 ± 68 GBq μmol−1. PET measurements were performed in young pigs to investigate the metabolic stability and cerebral binding of [18F]NS14490 without and with administration of the α7 nAChR partial agonist NS6740 in baseline and blocking conditions. Results The total distribution volume relative to the metabolite-corrected arterial input was 3.5 to 4.0 mL g−1 throughout the telencephalon and was reduced to 2.6 mL g−1 in animals treated with NS6740. Assuming complete blockade, this displacement indicated a binding potential (BPND) of approximately 0.5 in the brain of living pigs. In addition, evidence for specific binding in major brain arteries has been obtained. Conclusion [18F]NS14490 is not only comparable to other preclinically investigated PET radiotracers for imaging of α7 nAChR in brain but also could be a potential PET radiotracer for imaging of α7 nAChR in vulnerable plaques of diseased vessels.
Collapse
Affiliation(s)
- Sven Rötering
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Winnie Deuther-Conrad
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Paul Cumming
- Department of Nuclear Medicine, Friedrich-Alexander-Universität, Ulmenweg 18, Erlangen 91054, Germany ; Department of Pharmacology and Neuroscience, Copenhagen University, Blegdamsvej 3B, Copenhagen 2200, Denmark
| | - Cornelius K Donat
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Matthias Scheunemann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Steffen Fischer
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Guoming Xiong
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität, Marchioninistr. 15, Munich 83177, Germany
| | - Jörg Steinbach
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| | - Dan Peters
- DanPET AB, Rosenstigen 7, Malmö SE-21619, Sweden
| | - Osama Sabri
- Department of Nuclear Medicine, Universität Leipzig, Liebigstr. 18, Leipzig 04103, Germany
| | - Jan Bucerius
- Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, Maastricht 6229, The Netherlands ; Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, P. Debeylaan 25, Maastricht 6229, The Netherlands ; Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelstr. 30, Aachen 52074, Germany
| | - Peter Brust
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstr. 15, Leipzig 04318, Germany
| |
Collapse
|
5
|
Juvenile traumatic brain injury evolves into a chronic brain disorder: behavioral and histological changes over 6months. Exp Neurol 2013; 250:8-19. [PMID: 24076005 DOI: 10.1016/j.expneurol.2013.09.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 11/22/2022]
Abstract
Traumatic brain injury (TBI) refers to physical trauma to the brain that can lead to motor and cognitive dysfunctions. TBI is particularly serious in infants and young children, often leading to long-term functional impairments. Although clinical research is useful for quantifying and observing the effects of these injuries, few studies have empirically assessed the long-term effects of juvenile TBI (jTBI) on behavior and histology. After a controlled cortical impact delivered to postnatal 17day old rats, functional abilities were measured after 3, 5, and 6months using open field (activity levels), zero maze (anxiety-like behaviors), rotarod (sensorimotor abilities, coordination, and balance), and water maze (spatial learning and memory, swim speed, turn bias). Sensorimotor function was impaired for up to 6months in jTBI animals, which showed no improvement from repeated test exposure. Although spatial learning was not impaired, spatial memory deficits were observed in jTBI animals starting at 3months after injury. Magnetic resonance imaging and histological data revealed that the effects of jTBI were evolving for up to 6months post-injury, with reduced cortical thickness, decreased corpus callosum area and CA1 neuronal cell death in jTBI animals distant to the impact site. These findings suggest that this model of jTBI produces long-term impairments comparable to those reported clinically. Although some deficits were stable over time, the variable nature of other deficits (e.g., memory) as well as changing properties of the lesion itself, suggest that the effects of a single jTBI produce a chronic brain disorder with long-term complications.
Collapse
|
6
|
Baykara B, Aksu I, Buyuk E, Kiray M, Sisman AR, Baykara B, Dayi A, Tas A, Ozdemir D, Arda MN, Uysal N. Progesterone treatment decreases traumatic brain injury induced anxiety and is correlated with increased serum IGF-1 levels; prefrontal cortex, amygdala, hippocampus neuron density; and reduced serum corticosterone levels in immature rats. Biotech Histochem 2013; 88:250-7. [DOI: 10.3109/10520295.2013.769630] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
7
|
Walter B, Eiselt M, Cumming P, Xiong G, Hinz R, Uthe S, Brust P, Bauer R. Resistance of brain glucose metabolism to thiopental-induced CNS depression in newborn piglets. Int J Dev Neurosci 2013; 31:157-64. [PMID: 23305916 DOI: 10.1016/j.ijdevneu.2012.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Accepted: 12/30/2012] [Indexed: 10/27/2022] Open
Abstract
The transition from mild sedation to deep anaesthesia is marked by the phenomenon of burst suppression (BS). FDG-PET studies show that the cerebral metabolic rate for glucose (CMRglc) declines dramatically with onset of BS in the adult brain. Global CMRglc increases substantially in the post-natal period and achieves its maximum in preadolescence. However, the impact of post-natal brain development on the vulnerability of CMRglc to the onset of BS has not been documented. Therefore, cerebral blood flow and metabolism were measured using a variant of the Kety-Schmidt method, in conjunction with quantitative regional estimation of brain glucose uptake by FDG-PET in groups of neonate and juvenile pigs, under a condition of light sedation or after induction of deep anaesthesia with thiopental. Quantification of simultaneous ECoG recordings was used to establish the correlation between anaesthesia-related changes in brain electrical activity and the observed cerebrometabolic changes. In the condition of light sedation the magnitude of CMRglc was approximately 20% higher in the older pigs, with the greatest developmental increase evident in the cerebral cortex and basal ganglia (P<0.05). Onset of BS was associated with 20-40% declines in CMRglc. Subtraction of the mean parametric maps for CMRglc showed the absolute reductions in CMRglc evoked by thiopental anaesthesia to be two-fold greater in the pre-adolescent pigs than in the neonates (P<0.05). Thus, the lesser suppression of brain energy demand of neonate brain during deep anaesthesia represents a reduced part of thiopental suppressing brain metabolism in neonates.
Collapse
Affiliation(s)
- Bernd Walter
- Institute of Molecular Cell Biology, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Traumatic Brain Injury Elicits Similar Alterations in α7 Nicotinic Receptor Density in Two Different Experimental Models. Neuromolecular Med 2010; 13:44-53. [DOI: 10.1007/s12017-010-8136-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 08/20/2010] [Indexed: 10/19/2022]
|
9
|
Donat CK, Walter B, Deuther-Conrad W, Wenzel B, Nieber K, Bauer R, Brust P. Alterations of cholinergic receptors and the vesicular acetylcholine transporter after lateral fluid percussion injury in newborn piglets. Neuropathol Appl Neurobiol 2010; 36:225-36. [DOI: 10.1111/j.1365-2990.2009.01050.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
10
|
Effects of lateral fluid percussion injury on cholinergic markers in the newborn piglet brain. Int J Dev Neurosci 2009; 28:31-8. [DOI: 10.1016/j.ijdevneu.2009.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 09/03/2009] [Accepted: 10/04/2009] [Indexed: 11/18/2022] Open
|
11
|
Jagannathan P, Jagannathan J. Molecular mechanisms of traumatic brain injury in children. A review. Neurosurg Focus 2009; 25:E6. [PMID: 18828704 DOI: 10.3171/foc.2008.25.10.e6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Despite advances in molecular biology and genetics, the precise pathophysiology of traumatic brain injury (TBI) in children is unknown. In this paper the authors review what is currently known about intra- and extracellular responses to pediatric TBI and relate these factors to future investigations. Although hyperemia and vascular congestion have long been thought to be the hallmarks of pediatric TBI, on a cellular level, calcium influx as well as modulation of local neurotransmitters appears to play a major role in its onset. Recent genetic and proteomic research has identified specific neurotrophic factors as well as apoptotic and antiapoptotic genes that appear to control the progression of inflammation and neuronal damage. The search for a therapeutic target will ultimately require a thorough understanding of these factors and their interplay on a proteomic, genomic, and neuromic level.
Collapse
|
12
|
Lind NM, Moustgaard A, Jelsing J, Vajta G, Cumming P, Hansen AK. The use of pigs in neuroscience: Modeling brain disorders. Neurosci Biobehav Rev 2007; 31:728-51. [PMID: 17445892 DOI: 10.1016/j.neubiorev.2007.02.003] [Citation(s) in RCA: 365] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 02/05/2007] [Accepted: 02/18/2007] [Indexed: 11/22/2022]
Abstract
The use of pigs in neuroscience research has increased in the past decade, which has seen broader recognition of the potential of pigs as an animal for experimental modeling of human brain disorders. The volume of available background data concerning pig brain anatomy and neurochemistry has increased considerably in recent years. The pig brain, which is gyrencephalic, resembles the human brain more in anatomy, growth and development than do the brains of commonly used small laboratory animals. The size of the pig brain permits the identification of cortical and subcortical structures by imaging techniques. Furthermore, the pig is an increasingly popular laboratory animal for transgenic manipulations of neural genes. The present paper focuses on evaluating the potential for modeling symptoms, phenomena or constructs of human brain diseases in pigs, the neuropsychiatric disorders in particular. Important practical and ethical aspects of the use of pigs as an experimental animal as pertaining to relevant in vivo experimental brain techniques are reviewed. Finally, current knowledge of aspects of behavioral processes including learning and memory are reviewed so as to complete the summary of the status of pigs as a species suitable for experimental models of diverse human brain disorders.
Collapse
Affiliation(s)
- Nanna Marie Lind
- Department of Experimental Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, Copenhagen N, Denmark.
| | | | | | | | | | | |
Collapse
|
13
|
Giza CC, Prins ML. Is being plastic fantastic? Mechanisms of altered plasticity after developmental traumatic brain injury. Dev Neurosci 2006; 28:364-79. [PMID: 16943660 PMCID: PMC4297630 DOI: 10.1159/000094163] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Accepted: 03/10/2006] [Indexed: 11/19/2022] Open
Abstract
Traumatic brain injury (TBI) is predominantly a clinical problem of young persons, resulting in chronic cognitive and behavioral deficits. Specifically, the physiological response to a diffuse biomechanical injury in a maturing brain can clearly alter normal neuroplasticity. To properly evaluate and investigate developmental TBI requires an understanding of normal principles of cerebral maturation, as well as a consideration of experience-dependent changes. Changes in neuroplasticity may occur through many age-specific processes, and our understanding of these responses at a basic neuroscience level is only beginning. In this article, we will particularly discuss mechanisms of TBI-induced altered developmental plasticity such as altered neurotransmission, distinct molecular responses, cell death, perturbations in neuronal connectivity, experience-dependent 'good plasticity' enhancements and chronic 'bad plasticity' sequelae. From this summary, we can conclude that 'young is not always better' and that the developing brain manifests several crucial vulnerabilities to TBI.
Collapse
Affiliation(s)
- Christopher C Giza
- Division of Pediatric Neurology, Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
| | | |
Collapse
|
14
|
Bauer R, Fritz H. Pathophysiology of traumatic injury in the developing brain: an introduction and short update. ACTA ACUST UNITED AC 2005; 56:65-73. [PMID: 15581277 DOI: 10.1016/j.etp.2004.04.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Current understanding about the main peculiarities in pathophysiology of immature brain traumatic injury involves marked developmental discrepancy of biomechanical properties, aspects of altered features in water and electrolyte homeostasis as well as maturation dependent differences in structural and functional responses of major transmitter systems. Based on the fact that traumatic brain injury (TBI) is one of the major causes of morbidity and mortality in infants and children, the currently available epidemiological data are reviewed in order to gain insights about scope and dimension of health care engagement and derive the requirements for reinforced pathogenetic research. To this end, the main aspects of peculiarities in primary and secondary TBI mechanisms in the immature/developing brain are discussed, including structural and functional conditions resulting in a markedly diminished shear resistance of the immature brain tissue. As such, the immature brain tissue appears to be more susceptible to mechanical alterations, because similar mechanical load induces a more intense brain tissue displacement. Furthermore, available indications for increased incidence of brain swelling in the immature brain after TBI are reviewed, focusing on the interrelationship between the age-dependent differences in extracellular space and aquaporin-4 expression during brain maturation. The developmental differences of TBI induced cerebrovascular response as well as some relevant aspects of altered neurotransmission following TBI of the immature brain in regard to the glutamatergic and dopaminergic transmitter system are assessed. Thus, this mini-review highlights some progress but also an increased necessity for expanded pathogenetic research on a clinical scale in order to develop a solid foundation for adequate therapeutic strategies for the different life-threatening consequences of TBI in infancy and childhood, which mainly have failed up to now.
Collapse
Affiliation(s)
- Reinhard Bauer
- Institute of Pathophysiology and Pathobiochemistry, Universitätsklinikum Jena, Friedrich Schiller University, 07740 Jena, Germany.
| | | |
Collapse
|