Este trabalho é financiado pelo New Jersey Comissão de Pesquisa em Lesão Cerebral.

<ol>
	<li>Cernak, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+head+trauma.">Animal models of head trauma.</a> NeuroRx. 2, 410-422 (2005).</li><li>Reilly, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+injury:+the+pathophysiology+of+the+first+hours.'Talk+and+Die+revisited'.">Brain injury: the pathophysiology of the first hours.'Talk and Die revisited'.</a> J Clin Neurosci. 8, 398-403 (2001).</li><li>Hovda, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+increase+in+local+cerebral+glucose+utilization+following+fluid+percussion+brain+injury+is+prevented+with+kynurenic+acid+and+is+associated+with+an+increase+in+calcium.">The increase in local cerebral glucose utilization following fluid percussion brain injury is prevented with kynurenic acid and is associated with an increase in calcium.</a> Acta neurochir. 51, 331-333 (1990).</li><li>Whiting, M. D., Baranova, A. I., Hamm, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Cognitive Impairment following Traumatic Brain Injury, Animal Models of Cognitive Impairment. , (2006).</li><li>McIntosh, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Traumatic+brain+injury+in+the+rat:+characterization+of+a+lateral+fluid-percussion+model.">Traumatic brain injury in the rat: characterization of a lateral fluid-percussion model.</a> Neuroscience. 28, 233-244 (1989).</li><li>Adams, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffuse+axonal+injury+in+head+injury:+definition,+diagnosis+and+grading.">Diffuse axonal injury in head injury: definition, diagnosis and grading.</a> Histopathology. 15, 49-59 (1989).</li><li>Cordobes, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-traumatic+diffuse+axonal+brain+injury.+Analysis+of+78+patients+studied+with+computed+tomography.">Post-traumatic diffuse axonal brain injury. Analysis of 78 patients studied with computed tomography.</a> Acta Neurochir. 81, 27-35 (1986).</li><li>Maxwell, W. L., Povlishock, J. T., Graham, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mechanistic+analysis+of+nondisruptive+axonal+injury:+a+review.">A mechanistic analysis of nondisruptive axonal injury: a review.</a> J Neurotrauma. 14, 419-440 (1997).</li><li>Lighthall, J. W., Anderson, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The neurobiology of cenral nervous system trauma. , 3-12 (1994).</li><li>Marcoux, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+metabolic+crisis+as+measured+by+elevated+cerebral+microdialysis+lactate-pyruvate+ratio+predicts+chronic+frontal+lobe+brain+atrophy+after+traumatic+brain+injury.">Persistent metabolic crisis as measured by elevated cerebral microdialysis lactate-pyruvate ratio predicts chronic frontal lobe brain atrophy after traumatic brain injury.</a> Crit Care Med. 36, 2871-2877 (2008).</li><li>McIntosh, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropathological+sequelae+of+traumatic+brain+injury:+relationship+to+neurochemical+and+biomechanical+mechanisms.">Neuropathological sequelae of traumatic brain injury: relationship to neurochemical and biomechanical mechanisms.</a> Lab Invest. 74, 315-342 (1996).</li><li>Morganti-Kossmann, M. C., Satgunaseelan, L., Bye, N., Kossmann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+immune+response+by+head+injury.">Modulation of immune response by head injury.</a> Injury. 38, 1392-1400 (2007).</li><li>Capruso, D. X., Levin, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+impairment+following+closed+head+injury.">Cognitive impairment following closed head injury.</a> Neurol Clin. 10, 879-893 (1992).</li><li>Levin, H. S., Goldstein, F. C., High, W. M., Eisenberg, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disproportionately+severe+memory+deficit+in+relation+to+normal+intellectual+functioning+after+closed+head+injury.">Disproportionately severe memory deficit in relation to normal intellectual functioning after closed head injury.</a> J Neurol Neurosurg Psychiatry. 51, 1294-1301 (1988).</li><li>Kabadi, S. V., Hilton, G. D., Stoica, B. A., Zapple, D. N., Faden, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid-percussion-induced+traumatic+brain+injury+model+in+rats.">Fluid-percussion-induced traumatic brain injury model in rats.</a> Nat Protoc. 5, 1552-1563 (2010).</li><li>Cherian, L., Robertson, C. S., Contant, C. F., Bryan, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lateral+cortical+impact+injury+in+rats:+cerebrovascular+effects+of+varying+depth+of+cortical+deformation+and+impact+velocity.">Lateral cortical impact injury in rats: cerebrovascular effects of varying depth of cortical deformation and impact velocity.</a> J Neurotrauma. 11, 573-585 (1994).</li><li>Dixon, C. E., Clifton, G. L., Lighthall, J. W., Yaghmai, A. A., Hayes, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+controlled+cortical+impact+model+of+traumatic+brain+injury+in+the+rat.">A controlled cortical impact model of traumatic brain injury in the rat.</a> J Neurosci Methods. 39, 253-262 (1991).</li><li>Flierl, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+closed+head+injury+model+induced+by+a+weight-drop+device.">Mouse closed head injury model induced by a weight-drop device.</a> Nat Protoc. 4, 1328-1337 (2009).</li><li>Lifshitz, J., Chen, J., Xu, Z. C., Xu, X. -. M., Zhang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+32.">Chapter 32.</a> Animal Models of Acute Neurological Injuries. , 369-384 (2008).</li><li>Thompson, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lateral+fluid+percussion+brain+injury:+a+15-year+review+and+evaluation.">Lateral fluid percussion brain injury: a 15-year review and evaluation.</a> J Neurotrauma. 22, 42-75 (2005).</li><li>Hamm, R. J., Pike, B. R., O'Dell, D. M., Lyeth, B. G., Jenkins, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+rotarod+test:+an+evaluation+of+its+effectiveness+in+assessing+motor+deficits+following+traumatic+brain+injury.">The rotarod test: an evaluation of its effectiveness in assessing motor deficits following traumatic brain injury.</a> J Neurotrauma. 11, 187-196 (1994).</li><li>Scherbel, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+acute+and+chronic+responses+of+tumor+necrosis+factor-deficient+mice+to+experimental+brain+injury.">Differential acute and chronic responses of tumor necrosis factor-deficient mice to experimental brain injury.</a> Proc Natl Acad Sci. 96, 8721-8726 (1999).</li><li>Morris, R. G., Garrud, P., Rawlins, J. N., O'Keefe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place+navigation+impaired+in+rats+with+hippocampal+lesions.">Place navigation impaired in rats with hippocampal lesions.</a> Nature. 297, 681-683 (1982).</li><li>Stichel, C. C., Muller, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+CNS+lesion+scar:+new+vistas+on+an+old+regeneration+barrier.">The CNS lesion scar: new vistas on an old regeneration barrier.</a> Cell Tissue Res. 294, 1-9 (1998).</li><li>Brechot, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+macrophage+activation+state+protects+tissue+from+necrosis+during+critical+limb+ischemia+in+thrombospondin-1-deficient+mice.">Modulation of macrophage activation state protects tissue from necrosis during critical limb ischemia in thrombospondin-1-deficient mice.</a> PLoS One. 3, e3950-e3950 (2008).</li><li>Lifshitz, J., Witgen, B. M., Grady, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+cognitive+impairment+after+lateral+fluid+percussion+brain+injury+recovers+by+1+month:+evaluation+by+conditioned+fear+response.">Acute cognitive impairment after lateral fluid percussion brain injury recovers by 1 month: evaluation by conditioned fear response.</a> Behav Brain Res. 177, 347-357 (2007).</li><li>Thompson, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+evaluation+of+traumatically+brain-injured+rats+using+serial+testing+in+the+Morris+water+maze.">Cognitive evaluation of traumatically brain-injured rats using serial testing in the Morris water maze.</a> Restor Neurol Neurosci. 24, 109-114 (2006).</li><li>Doll, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharyngeal+selective+brain+cooling+improves+neurofunctional+and+neurocognitive+outcome+after+fluid+percussion+brain+injury+in+rats.">Pharyngeal selective brain cooling improves neurofunctional and neurocognitive outcome after fluid percussion brain injury in rats.</a> Journal of neurotrauma. 26, 235-242 (2009).</li><li>Fujimoto, S. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+and+cognitive+function+evaluation+following+experimental+traumatic+brain+injury.">Motor and cognitive function evaluation following experimental traumatic brain injury.</a> Neuroscience and biobehavioral reviews. 28, 365-378 (2004).</li><li>Carbonell, W. S., Maris, D. O., McCall, T., Grady, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptation+of+the+fluid+percussion+injury+model+to+the+mouse.">Adaptation of the fluid percussion injury model to the mouse.</a> Journal of neurotrauma. 15, 217-229 (1998).</li></ol>

Não há conflitos de interesse declarados.

O método apresentado aqui LFP muitos modelos dos resultados neuropathalogical e comportamentais de leve a moderada lesão cerebral traumática é por isso que tornou-se um modelo animal amplamente utilizado do TCE. Existem vários passos críticos a considerar a fim de aumentar a validade ea confiabilidade desta técnica. Por exemplo, é importante que os animais apenas em que a integridade da dura-máter não foi comprometida durante a craniectomia ser submetido a LFP e utilizados no estudo. Além disso, se a craniectomia é obstruída por qualquer cola ou cimento como a parte da dura abaixo da craniectomia não é exposto à força da pressão do fluido, o animal deve ser eliminado do estudo. Finalmente, se o tempo de reflexo de endireitamento ou a taxa de mortalidade não está dentro do intervalo desejado, o animal não deve ser incluído no estudo. A intensidade do pulso de pressão pode ser aumentada para gerar lesões mais graves. Conforme mostrado na Figura 1, a configuração do dispositivo de LFP é relativamente simples e reprodutibilidade do grau de lesão é mantida através do acompanhamento das atmosferas de pressão sobre o osciloscópio. A forma suave da curva no traçado osciloscópio indica que não há bolhas de ar no fluido que possam interferir com a indução da lesão LFP. Um pulso de teste deve ser entregue antes da indução de lesão e se o traço do osciloscópio não apresentam uma curva suave, as bolhas de ar deve ser removido. A duração do pulso é de aproximadamente 20 ms, que representa o tempo de indução medido em simulações de testes de colisão. Lesões de pulsos curtos são susceptíveis de produzir lesões mais focal. Portanto, essa duração de modelos de pulso humano TCE. As alterações morfológicas e celulares seguintes LFP incluem danos físicos para o tecido, assim como aumento do número de astrócitos e macrófagos como demonstrado na Figura 2. É bem estabelecido que um dos sinais de lesão característica é a hiperplasia dos astrócitos ea formação de uma cicatriz glial. A cicatriz glial foi mostrado para ter tanto efeitos benéficos e prejudiciais 24. Da mesma forma, os macrófagos são conhecidos por se acumular em vários tecidos durante a fase seguinte lesão quando o processo de cura começa 25. Assim, o aumento do número de GFAP e MAC1 células positivas nas amostras LFP em relação aos controles sham é um indicativo de indução de lesão. A falta de expressão desses marcadores celulares específicos nos controles sham indica que a manipulações cirúrgicas por si só não tem consequências negativas sobre a saúde do tecido cerebral e que as mudanças na expressão de proteínas são específicos para o paradigma lesão. As conseqüências comportamentais da LFP leve ilustrada na Figura 3 incluem déficits cognitivos e motor. As descobertas indicam que a MWM ratos LFP eventualmente aprender a tarefa, mas a um ritmo mais lento do que os ratos sham e eles não me lembro a tarefa bem um dia após o treinamento. Assim, mesmo os ratos levemente feridos são menos eficientes do que os ratos sham em usar estímulos externos para processar, consolidar e armazenar informações espaciais, que devem ser recuperadas durante os testes subseqüentes. Outros hipocampo-dependente tarefas cognitivas, tais como resposta de medo condicionado foram mostrados para ser prejudicada em camundongos submetidos a LFP 26. Finalmente, quanto menor a latência para queda de ratos LFP relação aos ratos sham no paradigma rotarod até 3 semanas após a lesão leve é ​​um indicador de déficits de vestibulomotor integrado e função sensório-motor. A lesão mais moderado iria revelar mudanças mais marcantes na função cognitiva e motora como tem sido demonstrado por outros grupos 27-30. Em suma, a LFP é um modelo válido para TBI humano, porque cumpre muitos dos critérios que o esperado. LFP fornece validade de construto na medida em que recria os processos etiológicos que induzem TCE em humanos. Especificamente, a magnitude da força e taxa de mortalidade é semelhante ao que ocorre no esporte leve e moderada e as lesões relacionadas a carros com a ressalva de que as intervenções pré-lesão cirúrgica são exclusivas para o modelo animal. LFP também apresenta validade de face, em que recapitula LFP muitos dos anatômicos, bioquímicos, os efeitos neuropatológicos e comportamentais observadas no TCE humana. Há duas alterações focais e difusas detectados após LFP ea lateralização do impacto permite que se compare os danos morfológicos no lado ipsilateral à lesão de que no lado contralateral. Uma ressalva é que os efeitos cognitivos e motor podem ser mais sutis, como resultado de ferir apenas um hemisfério. Finalmente, LFP apresenta validade preditiva ea confiabilidade da técnica LFP permite a avaliação de várias manipulações farmacológicas e genéticas antes ou após a indução da lesão 20. Variáveis ​​fisiológicas como a pressão arterial, o pH do sangue e do sanguegases precisam ser medidos na presença e ausência de uma droga de teste para determinar o mecanismo de ação de um agente terapêutico. No entanto, devido à natureza complexa das conseqüências primária e secundária da TBI, é uma tarefa difícil identificar uma única intervenção que pode mitigar todos os sintomas. Uma consideração futura para a técnica LFP pode ser o uso de micro-percussão líquido que emprega um instrumento controlado por microprocessador, pneumaticamente para eliminar a necessidade de calibrar a força entregue pelo pêndulo e para evitar variáveis ​​operacionais, tais como bolhas de ar no fluido 15 . No entanto, a abordagem LFP padrão tem sido comprovada por muitos pesquisadores de ser uma técnica confiável e simples para explorar os mecanismos moleculares subjacentes à danos e recuperação após o TCE que irá levar a melhor e intervenções terapêuticas.

<ul><li> Instrumento de alinhamento estereotáxico para ratos (Instrumentos Kopf) </li><li> Gás do mouse titular cabeça anestesia (Instruments Kopf) </li><li> Aparelho de anestesia com O 2 flush (Parkland Científica) </li><li> Aparelho de anestesia com O2 flush (Parkland Científica) </li><li> Buprenorphrine (Webster Abastecimento Animal) </li><li> Atualizar Lacri pomada Lube (Fisher) </li><li> Bupivacaína / Marcaine (Webster Abastecimento Animal) </li><li> Iodopovidona solução (Fisher) </li><li> 20 g 1 ½ &quot;agulhas (Becton Dickinson) </li><li> Lâmina de bisturi (# 15) e titular (Becton Dickinson) </li><li> Grampos Bulldog (Ferramentas Ciência Fine) </li><li> Ferramenta dental ou raspador de osso (Ferramentas Ciência Fine) </li><li> Lado segurando uma pinça Dumont n º 6 (Ferramentas Ciência Fine) </li><li> 3 milímetros de diâmetro exterior trefina (Investigação Loja Instrumentation, University of Pennsylvania) </li><li> Cabo de nylon sólido (1,7 mm de diâmetro, por exemplo, linha de trimmer erva daninha) </li><li> Super cola gel </li><li> Loctite cola de cianoacrilato (Loctite 444 Tak Pak) (Henkel Corporation) </li><li> Jet Líquido Acrílico (Butler Schein) </li><li> Resina Perm reembasamento / Reparação (Butler Schein) </li><li> Armazenamento osciloscópio TDS 1001B, 40 mHz, 500MS / s (Tektronix) </li><li> Trauma Indutor Amplificador transdutor de pressão (Custom Design e Fabricação, Virginia Commonwealth University) </li><li> LFP dispositivo (Design personalizado e Fabricação, Virginia Commonwealth University) </li><li> Tubulação de alta pressão, 41 centímetros de comprimento, 2 ml de volume (Baxter) </li><li> 3M Adesivo Vetbond Tissue (Fisher) </li></ul>

lateral fluid percussion: model of traumatic brain injury in mice

Traumatismo crânio-encefálico (TCE) investigação tem atingido impulso renovado devido à consciência crescente de lesões na cabeça, o que resulta em morbidade e mortalidade. Com base na natureza da lesão primária seguintes TBI, resultado conseqüências complexa e heterogênea secundário, que são seguidos por 1,2 processos regenerativos. Lesão primária pode ser induzida por uma contusão direto para o cérebro de fratura de crânio ou de cisalhamento e alongamento dos tecidos causando deslocamento do cérebro devido ao movimento de 3,4. Os hematomas e lacerações resultantes causar uma resposta vascular 3,5, e os danos morfológicos e funcionais da substância branca leva a lesão axonal difusa 6-8. Adicional alterações secundárias comumente observadas no cérebro são edema e aumento da pressão intracraniana 9. Seguintes TCE existem alterações microscópicas em vias bioquímicas e fisiológicas que envolvem a liberação de neurotransmissores excitotoxic, mediadores imunes e radicais de oxigênio 10-12, o que acaba resultado em longo prazo neurológicas 13,14. Assim, escolhendo modelos animais apropriados de TCE que apresentam semelhante eventos celulares e moleculares no TCE humanos e roedores é fundamental para estudar os mecanismos subjacentes lesão e reparo. Vários modelos experimentais de TCE foram desenvolvidos para reproduzir aspectos do TCE observados em humanos, entre eles três modelos específicos são amplamente adaptados para roedores: percussão fluido, o impacto cortical e aceleração de queda de peso / impacto 1. O dispositivo de percussão fluido produz uma lesão através de uma craniectomia pela aplicação de um pulso de pressão de fluido em breve para a dura-máter intacta. O pulso é criado por um pêndulo impressionante o pistão de um reservatório de fluido. A percussão produz deslocamento breve e deformação do tecido neural 1,15. Por outro lado, lesões impacto cortical fornece energia mecânica para a dura-máter intacta através de um pêndulo rígido sob pressão pneumática 16,17. O peso do modelo queda / impacto é caracterizada pela queda de uma haste com uma massa específica no crânio fechado 18. Entre os modelos de TCE, LFP é o modelo mais estabelecidos e comumente utilizada para avaliar lesão cerebral mista focal e difusa 19. É reprodutível e é padronizado para permitir a manipulação de parâmetros de lesão. Lesões recapitula LFP observada em seres humanos, tornando-la clinicamente relevantes, e permite a exploração de novas terapêuticas para a tradução clínica 20. Descrevemos o protocolo detalhado para realizar procedimento de LFP em camundongos. A contusão é leve a moderada, com regiões do cérebro como o córtex, hipocampo e corpo caloso sendo mais vulneráveis. Hipocampo e motor tarefas de aprendizagem são explorados seguintes LFP.

Watch this Scientific Journal Video about Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice at JoVE.com

Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice

Lateral fluido percussão (LFP), um modelo estabelecido de lesão cerebral traumática em camundongos, é demonstrada. LFP preenche três critérios principais para modelos animais: relevância, fiabilidade, validade e clínicos. O procedimento, que consiste em craniotomia cirúrgico, a fixação do cubo seguida de indução de lesão, resultando em lesões focais e difusas, é descrito.

Percussão Fluid lateral: Modelo de Lesão em Ratos

Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and ...

lateral-fluid-percussion-model-of-traumatic-brain-injury-in-mice

Research

JoVE Journal

Neuroscience

40.3K visualizações.  University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School. Lateral fluido percussão (LFP), um modelo estabelecido de lesão cerebral traumática em camundongos, é demonstrada. LFP preenche três critérios principais para modelos animais: relevância, fiabilidade, validade e clínicos. O procedimento, que consiste em craniotomia cirúrgico, a fixação do cubo seguida de indução de lesão, resultando em lesões focais e difusas, é descrito.

Vídeo: Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice

A Novel In Vitro Model of Blast Traumatic Brain Injury

Traumatic brain injury is a leading cause of death and disability in military and civilian populations. Blast traumatic brain injury results from the detonation of explosive devices, however, the mechanisms that underlie the brain damage resulting from blast overpressure exposure are not entirely understood and are believed to be unique to this type of brain injury. Preclinical models are crucial tools that contribute to better understand blast-induced brain injury. A novel in vitro blast TBI model was developed using an open-ended shock tube to simulate real-life open-field blast waves modelled by the Friedlander waveform. C57BL/6N mouse organotypic hippocampal slice cultures were exposed to single shock waves and the development of injury was characterized up to 72 h using propidium iodide, a well-established fluorescent marker of cell damage that only penetrates cells with compromised cellular membranes. Propidium iodide fluorescence was significantly higher in the slices exposed to a blast wave when compared with sham slices throughout the duration of the protocol. The brain tissue injury is very reproducible and proportional to the peak overpressure of the shock wave applied.

A Novel In Vitro Model of Blast Traumatic Brain Injury

This paper describes a novel model of primary blast traumatic brain injury. A compressed-air driven shock tube is used to expose in vitro mouse hippocampal slice cultures to a single shock wave. This is a simple and rapid protocol generating a reproducible brain tissue injury with a high throughput.

Um modelo de romance In Vitro de explosão traumatismo crânio-encefálico

Traumatic brain injury is a leading cause of death and disability in military and civilian populations. Blast traumatic brain injury results from the ...

Neurociência

Effects of Blast-induced Neurotrauma on Pressurized Rodent Middle Cerebral Arteries

Though there have been studies on the histopathological and behavioral effects of blast exposure, fewer have been dedicated to blast&#39;s cerebral vascular effects. Impact (i.e., non-blast) traumatic brain injury (TBI) is known to decrease pressure autoregulation in the cerebral vasculature in both humans and experimental animals. The hypothesis that blast-induced traumatic brain injury (bTBI), like impact TBI, results in impaired cerebral vascular reactivity was tested by measuring myogenic dilatory responses to reduced intravascular pressure in rodent middle cerebral arterial (MCA) segments from rats subjected to mild bTBI using an Advanced Blast Simulator (ABS) shock tube. Adult, male Sprague-Dawley rats were anesthetized, intubated, ventilated and prepared for Sham bTBI (identical manipulation and anesthesia except for blast injury) or mild bTBI. Rats were randomly assigned to receive Sham bTBI or mild bTBI followed by sacrifice 30 or 60 min post-injury. Immediately after bTBI, righting reflex (RR) suppression times were assessed, euthanasia at the time points post-injury was completed, the brain was harvested and the individual MCA segments were collected, mounted and pressurized. As the intraluminal pressure perfused through the arterial segments was reduced in 20 mmHg increments from 100 to 20 mmHg, MCA diameters were measured and recorded. With decreasing intraluminal pressure, MCA diameters steadily increased significantly above baseline in the Sham bTBI groups while MCA dilator responses were significantly reduced (p &#60; 0.05) in both bTBI groups as evidenced by the impaired, smaller MCA diameters recorded for the bTBI groups. In addition, RR suppression in the bTBI groups was significantly (p &#60; 0.05) higher than in the Sham bTBI groups. MCA&#39;s collected from the Sham bTBI groups exhibited typical vasodilatory properties to decreases in intraluminal pressure while MCA&#39;s collected following bTBI exhibited significantly impaired myogenic vasodilatory responses to reduced pressure that persisted for at least 60 min after bTBI.

Here, we present a protocol to describe methods for ex vivo vascular reactivity determination following a primary blast traumatic brain injury (bTBI) using isolated, pressurized, rodent middle cerebral arterial (MCA) segments. bTBI induction is accomplished using a shock tube, also known as an Advanced Blast Simulator (ABS) device.

Efeitos de Neurotrauma induzida por explosão em roedores pressurizado artérias cerebrais de médio

Though there have been studies on the histopathological and behavioral effects of blast exposure, fewer have been dedicated to blast&#39;s cerebral ...

Investigating Alterations in Caecum Microbiota After Traumatic Brain Injury in Mice

Increasing evidence shows that the microbiota-gut-brain axis plays an important role in the pathogenesis of brain diseases. Several studies also demonstrate that traumatic brain injuries cause changes to the gut microbiota. However, mechanisms underlying the bidirectional regulation of the brain-gut axis remain unknown. Currently, few models exist for studying the changes in gut microbiota after traumatic brain injury. Therefore, the presented study combines protocols for inducing traumatic brain injury using a lateral fluid percussion device and analysis of caecum samples following injury for investigating alterations in the gut microbiome. Alterations of the gut microbiota composition after traumatic brain injury are determined using 16S-rDNA sequencing. This protocol provides an effective method for studying the relationships between enteric microorganisms and traumatic brain injury.

Presented here is a protocol to induce diffuse traumatic brain injury using a lateral fluid percussion device followed by the collection of the caecum content for gut microbiome analysis.

Investigando alterações na microbiota de caecum após traumatismo cranioencefálico em camundongos

Increasing evidence shows that the microbiota-gut-brain axis plays an important role in the pathogenesis of brain diseases. Several studies also ...

Murine Model of Controlled Cortical Impact for the Induction of Traumatic Brain Injury

The Centers for Disease Control and Injury Prevention estimate that almost 2 million people sustain a traumatic brain injury (TBI) every year in the United States. In fact, TBI is a contributing factor to over a third of all injury-related mortality. Nonetheless, the cellular and molecular mechanisms underlying the pathophysiology of TBI are poorly understood. Thus, preclinical models of TBI capable of replicating the injury mechanisms pertinent to TBI in human patients are a critical research need. The controlled cortical impact (CCI) model of TBI utilizes a mechanical device to directly impact the exposed cortex. While no model can full recapitulate the disparate injury patterns and heterogeneous nature of TBI in human patients, CCI is capable of inducing a wide range of clinically applicable TBI. Furthermore, CCI is easily standardized allowing investigators to compare results across experiments as well as across investigative groups. The following protocol is a detailed description of applying a severe CCI with a commercially available impacting device in a murine model of TBI.

Here we describe a protocol for the induction of murine traumatic brain injury via an open-head controlled cortical impact.

Modelo murino de impacto cortical controlado para a indução de traumatismo cranioencefálico

The Centers for Disease Control and Injury Prevention estimate that almost 2 million people sustain a traumatic brain injury (TBI) every year in the ...

Electromagnetic Controlled Closed-Head Model of Mild Traumatic Brain Injury in Mice

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and understanding the mechanisms of how a TBI alters brain function. The availability of multiple animal models of TBI is necessary to model the different aspects and severities of TBI seen in people. This manuscript describes the use of a midline closed head injury (CHI) to develop a mouse model of mild TBI. The model is considered mild because it does not produce structural brain lesions based on neuroimaging or gross neuronal loss. However, a single impact creates enough pathology that cognitive impairment is measurable at least 1 month after injury. A step-by-step protocol to induce a CHI in mice using a stereotaxically guided electromagnetic impactor is defined in the paper. The benefits of the mild midline CHI model include the reproducibility of the injury-induced changes with low mortality. The model has been temporally characterized up to 1 year after the injury for neuroimaging, neurochemical, neuropathological, and behavioral changes. The model is complementary to open skull models of controlled cortical impact using the same impactor device. Thus, labs can model both mild diffuse TBI and focal moderate-to-severe TBI with the same impactor.

The protocol describes mild traumatic brain injury in a mouse model. In particular, a step-by-step protocol to induce a mild midline closed head injury and the characterization of the animal model is fully explained.

Modelo de Lesão Cerebral Traumática Leve em Camundongos com Controle Eletromagnético

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and ...

Assessing Changes in Synaptic Plasticity Using an Awake Closed-Head Injury Model of Mild Traumatic Brain Injury

Mild traumatic brain injuries (mTBIs) are a prevalent health issue in North America. There is increasing pressure to utilize ecologically valid models of closed-head mTBI in the preclinical setting to increase translatability to the clinical population. The awake closed-headed injury (ACHI) model uses a modified controlled cortical impactor to deliver closed-headed injury, inducing clinically relevant behavioral deficits without the need for a craniotomy or the use of an anesthetic.
This technique does not normally induce fatalities, skull fractures, or brain bleeds, and is more consistent with being a mild injury. Indeed, the mild nature of the ACHI procedure makes it ideal for studies investigating repetitive mTBI (r-mTBI). Growing evidence indicates that r-mTBI can result in a cumulative injury that produces behavioral symptoms, neuropathological changes, and neurodegeneration. r-mTBI is common in youths playing sports, and these injuries occur during a period of robust synaptic reorganization and myelination, making the younger population particularly vulnerable to the long-term influences of r-mTBI.
Further, r-mTBI occurs in cases of intimate partner violence, a condition for which there are few objective screening measures. In these experiments, synaptic function was assessed in the hippocampus in juvenile rats that had experienced r-mTBI using the ACHI model. Following the injuries, a tissue slicer was utilized to make hippocampal slices to evaluate bidirectional synaptic plasticity in the hippocampus at either 1 or 7 days following the r-mTBI. Overall, the ACHI model provides researchers with an ecologically valid model to study changes in synaptic plasticity following mTBI and r-mTBI.

Here, it is demonstrated how an awake closed-head injury model can be used for examining the effects of repeated mild traumatic brain injury (r-mTBI) on synaptic plasticity in the hippocampus. The model replicates important features of r-mTBI in patients and is used in conjunction with in vitro electrophysiology.

Avaliação das Alterações na Plasticidade Sináptica Utilizando um Modelo de Traumatismo Cranioencefálico Leve

Mild traumatic brain injuries (mTBIs) are a prevalent health issue in North America. There is increasing pressure to utilize ecologically valid models of ...

Maintenance of a Lateral Fluid Percussion Injury Device

Traumatic brain injury (TBI) accounts for roughly 2.5 million emergency room visits and hospitalizations annually and is a leading cause of death and disability in children and young adults. TBI is caused by a sudden force applied to the head and, to better understand human TBI and its underlying mechanisms, experimental injury models are necessary. Lateral fluid percussion injury (LFPI) is a commonly used injury model due to similarities in the pathological changes found in human TBI compared to LFPI, including hemorrhages, vascular disruption, neurological deficits, and neuron loss. LFPI employs a pendulum and a fluid-filled cylinder, the latter having a moveable piston at one end, and a Luer lock connection to stiff, fluid-filled tubing at the other end. Preparation of the animal involves performing a craniectomy and attaching a Luer hub over the site. The next day, the tubing from the injury device is connected to the Luer hub on the animal's skull and the pendulum is raised to a specified height and released. The impact of the pendulum with the piston generates a pressure pulse which is transmitted to the intact dura mater of the animal via the tubing and produces the experimental TBI. Proper care and maintenance are essential for the LFPI device to function reliably, as the character and severity of the injury can vary greatly depending on the condition of the device. Here, we demonstrate how to properly clean, fill, and assemble the LFPI device, and ensure that it is adequately maintained for optimal results.

Proper care and maintenance are essential for a lateral fluid percussion injury (LFPI) device to function reliably. Here, we demonstrate how to properly clean, fill, and assemble an LFPI device, and ensure that it is adequately maintained for optimal results.

Manutenção de um dispositivo de lesão por percussão de fluido lateral

Traumatic brain injury (TBI) accounts for roughly 2.5 million emergency room visits and hospitalizations annually and is a leading cause of death and ...

Validando a resposta a lesões e avaliações comportamentais em um modelo de rato mTBI

Rat Model of Closed-Head Mild Traumatic Injury and its Validation

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful insights, developing a stable and reproducible animal model is essential. In this study, we report a detailed description of a closed-head mTBI model and a representative validation method using Sprague-Dawley rats to verify the modeling effect. The model involves dropping a 550 g mass weight from a height of 100 cm directly onto the head of a rat on a destructible surface, followed by a 180-degree turn. To assess the injury, rats underwent a series of neurobehavioral assessments 10 min post-injury, including time of loss of consciousness, first seeking-behavior time, escape ability, and beam balance ability test. During the acute and subacute stages following the injury, behavioral tests were conducted to assess motor coordination ability (Beam task), anxiety (Open Field test), and learning and memory abilities (Morris Water Maze test). The closed-head mTBI model produced a consistent injury response with minimal mortality and replicated real-life situations. The validation method effectively verified the model development and ensured the stability and consistency of the model.

Autor em destaque: Avançando na pesquisa de lesões cerebrais traumáticas - um modelo de cabeça fechada para replicação precisa e avaliação rápida 

Here, we present a closed-head mild traumatic brain injury (mTBI) rat model and its validation exhibiting remarkable similarity to human mTBI concerning behavioral manifestations during the acute and subacute stages.

Modelo de Lesão Traumática Leve de Cabeça Fechada em Rato e sua Validação

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful ...