Este trabalho foi financiado pela Fundação Lundbeck, a Fundação Carlsberg e Dagmar Marshall Foundation.

1. von Frey medidas de base antes da cirurgia Para von Frey procedimento de teste, consulte a seção 5. 2. Anestesia / preparação <ol><li> Anestesiar os animais (injeção intraperitoneal de uma mistura de ketamina 100mg/kg e 15 Xilazina mg / kg). </li><li> Colocar o animal em um lugar calmo até totalmente anestesiado (por exemplo, coberta com uma toalha de papel). </li><li> Verifique reflexos por beliscar a ponta da cauda e as patas com um par de pinças. Certifique-se que os animais não respondem antes de prosseguir. </li><li> Por via subcutânea injetar (área de ombro para trás) salina isotônica 0,5 ml com antibióticos, por exemplo, ampicilina (para evitar desidratação e evitar a infecção, embora este seja um pequeno procedimento cirúrgico). </li><li> Usando um barbeador elétrico, a barba do campo operatório de um pouco abaixo da área do joelho para a área do quadril (para destros pessoas o membro posterior esquerdo é recomendado). </li><li> Aplicar pomada oftálmica nos olhos com um chumaço de algodão hidrófilo. </li><li> Colocar o animal em seu lado direito e coloque o membro posterior esquerdo em uma pequena plataforma para mantê-la elevada. Segura a perna com fita adesiva. </li><li> Desinfectar o campo operatório com a alternância de scrubs de etanol e betadine de fora do sítio cirúrgico. </li></ol> 3. Cirurgia <ol><li> Localize o joelho com o polegar da mão esquerda e usar um bisturi para fazer uma app. Uma incisão cm no sentido longitudinal proximal ao joelho. </li><li> Abra a pele por dissecção romba com a ponta de uma tesoura esterilizada. </li><li> Separar a camada muscular por dissecção romba ao lado do vaso sangüíneo claramente visível, perto do osso da coxa (fêmur). Se feito corretamente, as camadas musculares facilmente separados sem qualquer sangramento, revelando o nervo ciático direito abaixo dos músculos. Se o sangramento ocorre por exemplo, danos a um vaso sanguíneo próximo ao joelho, use estéril algodão botões ou pedaços de olhar para absorver o sangue. Pressione até que o sangramento pare. </li><li> Posicione o mouse em um microscópio estéreo e separe cuidadosamente os músculos com um par de pinças estéreis (nr. 2) para visualizar o nervo ciático. Retratores também pode ser aplicada. </li><li> Identificar a área onde os ramos do nervo sural do nervo ciático. O nervo sural é o menor dos três ramos, ramificação à direita na perna esquerda. </li><li> Aplicar sutura (6-0) em torno dos outros dois ramos que ainda estão em execução em paralelo (os nervos tibial e fibular comum), sendo muito cuidadoso para não tocar no ramo sural. Este é um passo crítico como o nervo sural tem de ser deixada completamente intacto. </li><li> Faça um nó apertado cirúrgico. Se o primeiro nó está apertado, as contrações do membro será observado. </li><li> Agarre os nervos a ser cortado abaixo da sutura com um par de pinças (nr. 5) e cortar os nervos acima e abaixo de uma pinça com um pequeno par de tesouras. Pelo primeiro corte acima do par de pinças, puxando dos nervos é evitada. </li><li> Eliminar as extremidades da sutura com um par de tesouras micro e suavemente feche a camada muscular. Adicionar uma gota de lidocaína sobre a ferida e sutura com nós cirúrgicos. </li></ol> 4. Após a cirurgia <ol><li> Verifique se pomada ainda é suficiente. </li><li> Posicione o mouse em uma gaiola limpa sob uma toalha de papel em uma postura confortável. Se o quarto é frio, coloque uma almofada de calor sob uma parte da gaiola (somente sob parte da gaiola que o animal deve ser capaz de escapar a uma área mais fria se preferir). </li><li> Garantir água de fácil acesso e ração. </li></ol> 5. von Frey teste (linha de base, e desde o dia após a cirurgia) <ol><li> Coloque os ratos em vermelho cilindros de plástico colorido colocado sobre uma mesa de malha de arame de dois dias e um dia antes da cirurgia. Habituar por 15 min em cilindros antes do teste. A cor vermelha dos cilindros ajuda os ratos rapidamente relaxar, pois não podem ver um ao outro e estão em uma área mais escura. </li><li> Verificar se os ratos são calmas e aplicar filamentos von Frey para a parte lateral da pata: Começando com o filamento 0,02 g, primeiro aplique força para a pata esquerda cinco vezes durante um período total de 30 segundos (cerca de 2 segundos por estímulo) e avaliar a reação do camundongo após cada aplicação. Repita com o filamento mesmo ea pata esquerda de qualquer outros ratos, e depois começar tudo de novo com a pata direita do mouse antes de passar para a próxima filamento, por exemplo: <ul><li> Rato 1: pata esquerda 5 vezes com filamentos de 0,02 g </li><li> Mouse 2: pata esquerda 5 vezes com filamentos de 0,02 g etc </li><li> Rato 1: pata direita 5 vezes com filamentos de 0,02 g </li><li> Mouse 2: pata direita 5 vezes com filamentos de 0,02 g etc </li><li> Rato 1: pata esquerda 5 vezes com filamentos de 0,04 g </li><li> Mouse 2: pata esquerda 5 vezes com filamentos de 0,04 g etc </li></ul></li><li> Resposta em três dos cinco estímulos é considerada como uma reação positiva. Filamentos acima threshold pode ser aplicado para verificar o nível do limiar. Resposta = retirada pata súbita, repentina vacilar pata, lambendo súbita. </li></ol> 6. Resultados representativos <img src="/files/ftp_upload/3092/3092fig1.jpg" alt="Figura 1" /> Figura 1. Von Frey testes em camundongos C57BL / 6 ratos idade 80-10 semanas de idade foi realizada um dia antes da operação e repetidamente após a cirurgia. 4-8 animais foram incluídos em cada grupo. Von Frey testes do lado operado é representado por ipsilateral com o lado controle não operado é representado por contralateral. O dia após a cirurgia os animais desenvolvem hipersensibilidade significativo sobre a pata operada enquanto o não operado é apenas ligeiramente afetada em relação aos ratos sham operados. (* &lt;0,05, ** &lt;0,01, *** &lt;0,001, em relação ao contralateral ipsilateral).

<ol>
	<li>Costigan, M., Scholz, J., Woolf, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuropathic+pain:+a+maladaptive+response+of+the+nervous+system+to+damage.">Neuropathic pain: a maladaptive response of the nervous system to damage.</a> Annu. Rev. Neurosci. 32, 1-32 (2009).</li><li>Decosterd, I., Woolf, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spared+nerve+injury:+an+animal+model+of+persistent+peripheral+neuropathic+pain.">Spared nerve injury: an animal model of persistent peripheral neuropathic pain.</a> Pain. 87, 149-158 (2000).</li><li>Bourquin, A. -. F., S&#252;veges, M., Pertin, M., Gilliar, N., Sardy, S., Davidson, A. C., Spahn, D. R., Decosterd, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+and+analysis+of+mechanical+allodynia-like+behavior+induced+by+spared+nerve+injury+(SNI)+in+the+mouse.">Assessment and analysis of mechanical allodynia-like behavior induced by spared nerve injury (SNI) in the mouse.</a> Pain. 122, 14.e1-14.e14 (2006).</li><li>Chaplan, S. R., Bach, F. W., Pogrel, J. W., Chung, J. M., Yaksh, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assessment+of+tactile+allodynia+in+the+rat+paw.">Quantitative assessment of tactile allodynia in the rat paw.</a> J. Neurosci. Methods. 53, 55-63 (1994).</li><li>Bennett, G. J., Xie, Y. -. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+peripheral+mononeuropathy+in+rat+that+produces+disorders+of+pain+sensation+like+those+seen+in+man.">A peripheral mononeuropathy in rat that produces disorders of pain sensation like those seen in man.</a> Pain. 33, 87-107 (1988).</li><li>Seltzer, Z., Dubner, R., Shir, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+behavioral+model+of+neuropathic+pain+disorders+produced+in+rats+by+partial+sciatic+nerve+injury.">A novel behavioral model of neuropathic pain disorders produced in rats by partial sciatic nerve injury.</a> Pain. 43, 205-218 (1990).</li><li>Hargreaves, K., Dubner, R., Brown, F., Flores, C., Joris, 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+new+and+sensitive+method+for+measuring+thermal+nociception+in+cutanous+hyperalgesia.">A new and sensitive method for measuring thermal nociception in cutanous hyperalgesia.</a> Pain. 32, 77-88 (1988).</li><li>Erichsen, H. K., Blackburn-Munro, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacological+characterization+of+the+spared+nerve+injury+model+of+neuropathic+pain.">Pharmacological characterization of the spared nerve injury model of neuropathic pain.</a> Pain. 98, 151-161 (2002).</li></ol>

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Etapas críticas Danos ao nervo sural devem ser evitados a fim de estudar alterações patológicas na lesão do nervo sural seguintes intacto para os nervos tibial e fibular comum. Danos colaterais do nervo sural pode levar à paralisia e pode assim ser visualizado como arrastar do membro operado traseiras. Apenas o lado lateral da pata é inervado pelo nervo sural poupado e, portanto, apenas esta área desenvolve neuropatia. Testes de outras áreas, inervados pelos nervos seccionados, pode viés fortemente a avaliação do limiar de mecânica alterada. Possíveis modificações Outros tipos de ligaduras podem ser complementares em termos de estudar as condições de dor patológica após a lesão do nervo periférico, como a lesão constrição crônica [5] ou ligadura parcial do nervo [6]. Cada experimental procedimento resulta em alterações fenotípicas distintas que devem ser considerados antes da pós-operatório de testes. Além disso, outros testes sensoriais, tais como hiperalgesia térmica pode ser aplicada [7], embora este fenótipo é menos robusto SNI seguinte. Aplicações futuras Esta técnica pode ser usada para testes de drogas alteram o desenvolvimento ou manutenção de alodinia mecânica [8]. Análise do nervo ciático, os gânglios da raiz dorsal (DRG) e / ou o cabo de coluna lombar permitir a investigação dos mecanismos moleculares responsáveis ​​pelo fenótipo induzido. Experimentação animal foi realizada de acordo com boas práticas de laboratório em plena conformidade com os regulamentos dinamarquês e europeu. Todos os experimentos foram aprovados pelo dinamarquês Experimentos em animais Inspecção do Ministério da Justiça (número de permissão 2006/561-1206).

<table border="1"><tbody><tr><td> Anestesia: Ketamina e Xilazina </td><td> Bisturi </td></tr><tr><td> Pomada oftálmica </td><td> Par de pinças nr. 2 </td></tr><tr><td> Barbeador elétrico </td><td> Par de pinças nr. 5 </td></tr><tr><td> Luvas </td><td> Tesoura para dissecção romba </td></tr><tr><td> 70% (v / v) de etanol </td><td> Micro tesoura </td></tr><tr><td> Algodão brotos / olhar </td><td> 6,0 sutura não absorvível Prolene </td></tr><tr><td> Microscópio estéreo </td><td> 2 x agulha titulares </td></tr><tr><td> Fita adesiva </td><td> Calor pad </td></tr><tr><td colspan="2"> filamentos de von Frey (0,02-2,0 g para ratos) (Stoelting) </td></tr></tbody></table>

the spared nerve injury (sni) model of induced mechanical allodynia in mice

Dor neuropática periférica é uma condição de dor crônica grave que pode resultar de trauma de nervos sensoriais no sistema nervoso periférico. A lesão do nervo poupado modelo (SNI) induz sintomas da dor neuropática, tais como dor ou seja alodinia mecânica devido a estímulos táteis que normalmente não provocar uma resposta dolorosa [1]. O modelo do rato SNI envolve ligadura de dois dos três ramos do nervo ciático (nervo tibial eo nervo fibular comum), enquanto o nervo sural é deixada intacta [2]. Os resultados da lesão em hipersensibilidade marcada na região lateral da pata, que é inervado pelo nervo sural poupado. O lado não-operado do mouse pode ser usado como um controle. As vantagens do modelo de SNI são a robustez da resposta e que não requerem habilidades de microcirurgia especialista. O limite para a resposta à dor mecânica é determinada por meio de testes com filamentos de von Frey de aumentar a força de flexão, que são repetidamente pressionado contra a região lateral da pata [3], [4]. Uma reação positiva dor é definida como a retirada de pata súbita, vacilar e / ou pata lambendo induzida pelo filamento. Uma resposta positiva em três dos cinco estímulos repetitivos é definido como o limiar de dor. Como demonstrado no protocolo de vídeo, camundongos C57BL / 6 alodinia experiência profunda, logo no dia seguinte à cirurgia e manter isso por várias semanas.

Watch this Scientific Journal Video about The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice at JoVE.com

The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice

Poupado do Nervo modelo animal de lesão é descrita aqui como um modelo do rato da dor neuropática periférica seguintes denervação parcial do nervo ciático por a lesão do tibial e nervo peroneal comum ramos, deixando o nervo sural restante intacto. Modificação comportamental resultante da alodinia mecânica é quantificada por filamentos de von Frey.

Poupado da lesão do nervo Model (SNI) de alodinia mecânica induzida em camundongos

Peripheral neuropathic pain is a severe chronic pain condition which may result from trauma to sensory nerves in the peripheral nervous system. The spared ...

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Research

JoVE Journal

Medicine

The Spared Nerve Injury (SNI) Model of Induced Mechanical Allodynia in Mice

63.0K visualizações.  Aarhus University. Poupado do Nervo modelo animal de lesão é descrita aqui como um modelo do rato da dor neuropática periférica seguintes denervação parcial do nervo ciático por a lesão do tibial e nervo peroneal comum ramos, deixando o nervo sural restante intacto. Modificação comportamental resultante da alodinia mecânica é quantificada por filamentos de von Frey.

Vídeo: The Spared Nerve Injury SNI Model of Induced Mechanical Allodynia in Mice

Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often unreported mortality rates that may confound analyses. Bilateral renal pedicle clamping is commonly used to induce IR-AKI, but differences between effective clamp pressures and/or renal responses to ischemia between kidneys often lead to more variable results. In addition, shorter clamp times are known to induce more variable tubular injury, and while mice undergoing bilateral injury with longer clamp times develop more consistent tubular injury, they often die within the first 3 days after injury due to severe renal insufficiency. To improve post-injury survival and obtain more consistent and predictable results, we have developed two models of unilateral ischemia-reperfusion injury followed by contralateral nephrectomy. Both surgeries are performed using a dorsal approach, reducing surgical stress resulting from ventral laparotomy, commonly used for mouse IR-AKI surgeries. For induction of moderate injury BALB/c mice undergo unilateral clamping of the renal pedicle for 26 min and also undergo simultaneous contralateral nephrectomy. Using this approach, 50-60% of mice develop moderate AKI 24 hr after injury but 90-100% of mice survive. To induce more severe AKI, BALB/c mice undergo renal pedicle clamping for 30 min followed by contralateral nephrectomy 8 days after injury. This allows functional assessment of renal recovery after injury with 90-100% survival. Early post-injury tubular damage as well as post injury fibrosis are highly consistent using this model.

We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.

Isquemia-reperfusão modelo de lesão renal aguda e Pós Lesão fibrose em camundongos

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

Medicina

Tibial Nerve Transection - A Standardized Model for Denervation-induced Skeletal Muscle Atrophy in Mice

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of denervation-induced skeletal muscle atrophy in rodents. Although originally developed and used extensively in the rat due to its larger size, the tibial nerve in mice is big enough that it can be easily manipulated with either crush or transection, leaving the peroneal and sural nerve branches of the sciatic nerve intact and thereby preserving their target muscles. Thus, this model offers the advantages of inducing less morbidity and impediment of ambulation than the sciatic nerve transection model and also allows investigators to study the physiologic, cellular and molecular biologic mechanisms regulating the process of muscle atrophy in genetically engineered mice. The tibial nerve supplies the gastrocnemius, soleus and plantaris muscles, so its transection permits the study of denervated skeletal muscle composed of fast twitch type II fibers and/or slow twitch type I fibers. Here we demonstrate the tibial nerve transection model in the C57Black6 mouse. We assess the atrophy of the gastrocnemius muscle, as a representative muscle, at 1, 2, and 4 weeks post-denervation by measuring muscle weights and fiber type specific cross-sectional area on paraffin-embedded histologic sections immunostained for fast twitch myosin.

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of skeletal muscle atrophy. The model surgical protocol is described and demonstrated in C57Black6 mice. &#160;

Secção do nervo tibial - um modelo padronizado para denervação induzida por atrofia muscular em ratos

The tibial nerve transection model is a well-tolerated, validated, and reproducible model of denervation-induced skeletal muscle atrophy in rodents. ...

The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice

Neuropathic pain arises as a consequence of a lesion or a disease affecting the somatosensory system. This syndrome results from maladaptive changes in injured sensory neurons and along the entire nociceptive pathway within the central nervous system. It is usually chronic and challenging to treat. In order to study neuropathic pain and its treatments, different models have been developed in rodents. These models derive from known etiologies, thus reproducing peripheral nerve injuries, central injuries, and metabolic-, infectious- or chemotherapy-related neuropathies. Murine models of peripheral nerve injury often target the sciatic nerve which is easy to access and allows nociceptive tests on the hind paw. These models rely on a compression and/or a section. Here, the detailed surgery procedure for the &#34;cuff model&#34; of neuropathic pain in mice is described. In this model, a cuff of PE-20 polyethylene tubing of standardized length (2 mm) is unilaterally implanted around the main branch of the sciatic nerve. It induces a long-lasting mechanical allodynia, i.e., a nociceptive response to a normally non-nociceptive stimulus that can be evaluated by using von Frey filaments. Besides the detailed surgery and testing procedures, the interest of this model for the study of neuropathic pain mechanism, for the study of neuropathic pain sensory and anxiodepressive aspects, and for the study of neuropathic pain treatments are also discussed.

Neuropathic pain is a consequence of a lesion or disease affecting the somatosensory system. The &#8220;cuff model&#8221; of neuropathic pain in mice consists of the implantation of a polyethylene cuff around the main branch of the sciatic nerve. Mechanical allodynia is tested using von Frey filaments.

O ciático Nervo cuffing Modelo de Dor Neuropática em Ratos

Neuropathic pain arises as a consequence of a lesion or a disease affecting the somatosensory system. This syndrome results from maladaptive changes in ...

Facial Nerve Axotomy in Mice: A Model to Study Motoneuron Response to Injury

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and either cut or crush it to induce peripheral nerve injury. Advantages of this surgery are its simplicity, high reproducibility, and the lack of effect on vital functions or mobility from the subsequent facial paralysis, thus resulting in a relatively mild surgical outcome compared to other nerve injury models. A major advantage of using a cranial nerve injury model is that the motoneurons reside in a relatively homogenous population in the facial motor nucleus in the pons, simplifying the study of the motoneuron cell bodies. Because of the symmetrical nature of facial nerve innervation and the lack of crosstalk between the facial motor nuclei, the operation can be performed unilaterally with the unaxotomized side serving as a paired internal control. A variety of analyses can be performed postoperatively to assess the physiologic response, details of which are beyond the scope of this article. For example, recovery of muscle function can serve as a behavioral marker for reinnervation, or the motoneurons can be quantified to measure cell survival. Additionally, the motoneurons can be accurately captured using laser microdissection for molecular analysis. Because the facial nerve axotomy is minimally invasive and well tolerated, it can be utilized on a wide variety of genetically modified mice. Also, this surgery model can be used to analyze the effectiveness of peripheral nerve injury treatments. Facial nerve injury provides a means for investigating not only motoneurons, but also the responses of the central and peripheral glial microenvironment, immune system, and target musculature. The facial nerve injury model is a widely accepted peripheral nerve injury model that serves as a powerful tool for studying nerve injury and regeneration.

We present a surgical protocol detailing how to perform a cut or crush axotomy on the facial nerve in the mouse. The facial nerve axotomy can be employed to study the physiological response to nerve injury and test therapeutic techniques.

Axotomia do nervo facial em ratos: um modelo para estudo de resposta motoneuron para Injury

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and ...

Photothrombosis-induced Focal Ischemia as a Model of Spinal Cord Injury in Mice

Spinal cord injury (SCI) is a devastating clinical condition causing permanent changes in sensorimotor and autonomic functions of the spinal cord (SC) below the site of injury. The secondary ischemia that develops following the initial mechanical insult is a serious complication of the SCI and severely impairs the function and viability of surviving neuronal and non-neuronal cells in the SC. In addition, ischemia is also responsible for the growth of lesion during chronic phase of injury and interferes with the cellular repair and healing processes. Thus there is a need to develop a spinal cord ischemia model for studying the mechanisms of ischemia-induced pathology. Focal ischemia induced by photothrombosis (PT) is a minimally invasive and very well established procedure used to investigate the pathology of ischemia-induced cell death in the brain. Here, we describe the use of PT to induce an ischemic lesion in the spinal cord of mice. Following retro-orbital sinus injection of Rose Bengal, the posterior spinal vein and other capillaries on the dorsal surface of SC were irradiated with a green light resulting in the formation of a thrombus and thus ischemia in the affected region. Results from histology and immunochemistry studies show that PT-induced ischemia caused spinal cord infarction, loss of neurons and reactive gliosis. Using this technique a highly reproducible and relatively easy model of SCI in mice can be achieved that would serve the purpose of scientific investigations into the mechanisms of ischemia induced cell death as well as the efficacy of neuroprotective drugs. This model will also allow exploration of the pathological changes that occur following SCI in live mice like axonal degeneration and regeneration, neuronal and astrocytic Ca2+ signaling using two-photon microscopy.

Photothrombosis is a minimally invasive and highly reproducible procedure to induce focal ischemia in the spinal cord and serves as a model of spinal cord injury in mice.

Fototrombose induzida por isquemia focal como um Modelo de Lesão Medular em Ratos

Spinal cord injury (SCI) is a devastating clinical condition causing permanent changes in sensorimotor and autonomic functions of the spinal cord (SC) ...

A Repetitive Concussive Head Injury Model in Mice

Despite the concussion/ mild traumatic brain injury (mTBI) being the most frequent occurrence of traumatic brain injury, there is still a lack of knowledge on the injury and its effects. To develop a better understanding of concussions, animals are often used because they provide a controlled, rigorous, and efficient model. Studies have adapted traditional animal models to perform mTBI to stimulate mild injury severity by changing the injury parameters. These models have been used because they can produce morphologically similar brain injuries to the clinical condition and provide a spectrum of injury severities. However, they are limited in their ability to present the identical features of injuries in patients. Using a traditional impact system, a repetitive concussive injury (rCHI) model can induce mild to moderate human-like concussion. The injury degree can be determined by measuring the period of loss of consciousness (LOC) with a sign of a transient termination of breathing. The rCHI model is beneficial to use for its accuracy and simplicity in determining mTBI effects and potential treatments.

Concussion presents the most common type of traumatic brain injury. Therefore, a repetitive concussive animal model, which replicates the important features of an injury in patients, may provide a means to study concussion in a rigorous, controlled, and efficient manner.

A principal modelo lesões repetitivas Concussive em Ratos

Despite the concussion/ mild traumatic brain injury (mTBI) being the most frequent occurrence of traumatic brain injury, there is still a lack of ...

Induction of Accelerated Atherosclerosis in Mice: The "Wire-Injury" Model

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. Moreover, by rupture of the defective vascular wall, atherosclerosis induces occlusive thrombus formation, which represents the main cause of myocardial infarction or stroke and the most frequent cause of death. Despite the advances in the cardiovascular field, many questions remain unanswered, and additional basic research is essential to improve our understanding of the molecular mechanisms during atherosclerosis and its effects. Due to limited clinical studies, there is a need for representative animal models recreating atherosclerotic conditions such as neointima formation after stent implantation, balloon angioplasty, or endarterectomy. Since the mouse presents many advantages and is the most frequently used model for studying molecular processes, the current study proposes an invasive procedure of endothelial denudation, also known as the wire-injury model, which is representative of the human condition of neointima formation in arteries after revascularization procedures.

Induction of Accelerated Atherosclerosis in Mice: The &quot;Wire-Injury&quot; Model

This study describes an invasive procedure for the induction of accelerated atherosclerosis in mice. In comparison to other methods using electric- or cryo-induced injury, mechanical-induced injury mimics the human condition of restenosis after revascularization therapies and is ideal for the study of the molecular mechanisms involved.

Indução de Aterosclerose Acelerada em Camundongos: O Modelo de "Lesão por Fio"

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. ...

A Tissue Displacement-based Contusive Spinal Cord Injury Model in Mice

Producing a consistent and reproducible contusive spinal cord injury (SCI) is critical to minimizing behavioral and histological variabilities between experimental animals. Several contusive SCI models have been developed to produce injuries using different mechanisms. The severity of the SCI is based on the height that a given weight is dropped, the injury force, or the spinal cord displacement. In the current study, we introduce a novel mouse contusive SCI device, the Louisville Injury System Apparatus (LISA) impactor, which can create a displacement-based SCI with high injury velocity and accuracy. This system utilizes laser distance sensors combined with advanced software to produce graded and highly-reproducible injuries. We performed a contusive SCI at the 10th thoracic vertebral (T10) level in mice to demonstrate the step-by-step procedure. The model can also be applied to the cervical and lumbar spinal levels.

We introduce a tissue displacement-based contusive spinal cord injury model that can produce a consistent contusive spinal cord injury in adult mice.

Um Modelo de Lesão Medular Contusiva Baseado em Cilindrada de Tecidos em Ratos

Producing a consistent and reproducible contusive spinal cord injury (SCI) is critical to minimizing behavioral and histological variabilities between ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

Medição de contratilidade isométrica da artéria mesentérica Mouse usando fio miografia

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

A Reversible Silicon Oil-Induced Ocular Hypertension Model in Mice

Elevated intraocular pressure (IOP) is a well-documented risk factor for glaucoma. Here we describe a novel, effective method for consistently inducing stable IOP elevation in mice that mimics the post-operative complication of using silicone oil (SO) as a tamponade agent in human vitreoretinal surgery. In this protocol, SO is injected into the anterior chamber of the mouse eye to block the pupil and prevent inflow of aqueous humor. The posterior chamber accumulates aqueous humor and this in turn increases the IOP of the posterior segment. A single SO injection produces reliable, sufficient, and stable IOP elevation, which induces significant glaucomatous neurodegeneration. This model is a true replicate of secondary glaucoma in the eye clinic. To further mimic the clinical setting, SO can be removed from the anterior chamber to reopen the drainage pathway and allow inflow of aqueous humor, which is drained through the trabecular meshwork (TM) at the angle of the anterior chamber. Because IOP quickly returns to normal, the model can be used to test the effect of lowering IOP on glaucomatous retinal ganglion cells. This method is straightforward, does not require special equipment or repeat procedures, closely simulates clinical situations, and may be applicable to diverse animal species. However, minor modifications may be required.

Here, we present a protocol to induce ocular hypertension and glaucomatous neurodegeneration in mouse eyes by intracameral injection of silicone oil and the procedure for silicone oil removal from the anterior chamber to return elevated intraocular pressure to normal.

Um modelo reversível da hipertensão ocular óleo-induzida do silicone nos ratos

Elevated intraocular pressure (IOP) is a well-documented risk factor for glaucoma. Here we describe a novel, effective method for consistently inducing ...