Name: Middle Cerebral Artery Occlusion (MCAO) to Induce Stroke in a Murine Model
Uploaded: 2023-05-05T14:50:00
Description: Watch this Scientific Journal Video about Middle Cerebral Artery Occlusion MCAO to Induce Stroke in a Murine Model at JoVE.com

middle cerebral artery occlusion (mcao) to induce stroke in a murine model

Etablering af en transkraniel mellemhjernearterie okklusionsmusmodel

Nearly 800,000 people suffer a stroke in the US every year, and most of these strokes are ischemic in nature1. Timely restoration of the cerebral blood flow with tissue plasminogen activator (tPA) and/or thrombectomy is currently the most effective treatment for stroke patients; however, the full recovery of neurologic functions in the long term is rare2,3. Thus, searching for novel stroke therapy that targets functional improvement is an intense area of research that requires clinically relevant animal models of stroke. 
The most common ischemic stroke model in rodents uses intraluminal middle cerebral artery occlusion (MCAO) to induce stroke. In this model, initially developed by Zea Longa in 1989, a nylon filament is introduced into the internal carotid artery (ICA) to block the blood flow to the middle cerebral artery (MCA)4. However, this model has limitations. First, when the filament is inserted into the ICA, the blood flow to the posterior cerebral artery (PCA) could be partially blocked as well, especially in mice. Critically, the posterior communicating artery (PcomA), a small artery that connects anterior and posterior cerebral circulation, is frequently underdeveloped in some mouse strains, such as C57Bl/6, the strain predominantly used in experimental stroke research. This patency of the PcomA is believed to contribute to the variability in lesion size in mice after stroke5. Indeed, when blood flow to the PCA drops precipitously during MCAO, and the PcomA is unable to provide sufficient collateral blood flow, the stroke infarct can expand into the territory of the PCA. Moreover, in this model, a long duration of ischemia leads to a higher chance of mortality in mice. Consequently, a short MCAO duration of 30-60 min is typically used in mice. However, most stroke patients experience a few hours of ischemia before reperfusion treatment. Thus, a mouse stroke model with an extended duration of ischemia is of high clinical relevance. 
The overall goal of this procedure is to model ischemic stroke in mice that have a medium-sized infarct and an excellent survival rate. This transcranial MCAO model addresses critical attributes of clinical stroke, as prolonged ischemia can be performed, and aged mice tolerate this model well, allowing for the long-term assessment of functional recovery.

Forfatter Spotlight: Innovative teknikker og fremtidige retninger inden for slagtilfælde 

En modificeret transkraniel midterste cerebral arterieokklusionsmodel til undersøgelse af slagtilfælderesultater hos ældre mus

Stroke affects nearly 800, 000 people annually in the US.Around 87%of this, ischemic, presenting as a severe medical condition. However, there are limited treatment options available especially during the chronic stroke phase. Our research aims to develop a recovery enhancing therapy to reduce disability and improve the quality of life for stroke patients.They widely use the filament, the middle cerebral artery occlusion model, as a drawback where the inserted filament can block a blood flow to the posterior cerebral artery. The C57BL/6 in mice often have an undisturbed posterior communicating artery leading to a high mortality in the later chronic stroke recovery phase. Our modified transcranial middle cerebral artery occlusion model partially across the MCA at the trunk generating brain damage in the cortex and the striatum via a small cranial window.This model achieves a high long-term survival rate, detectable neurological deficits, and works well even in aged mice. Our transcranial MCAO model can incorporate the critical attributes of clinical stroke, such as delayed reperfusion, neurological deficits, and aging factor. This model can be used to evaluate the therapeutical potential of new stroke treatments on long-term function recovery.

Watch this Scientific Journal Video about Middle Cerebral Artery Occlusion MCAO to Induce Stroke in a Murine Model at JoVE.com

Middle Cerebral Artery Occlusion (MCAO) to Induce Stroke in a Murine Model  

Midterste cerebral arterieokklusion (MCAO) for at fremkalde slagtilfælde i en murinmodel

Til at begynde med skal du lægge en otte til 10 ugers bedøvet C57 sort seks hanmus på den kirurgiske bænk. Brug stump tang til at trække tungen ud og holde den med fingrene. Indsæt et laryngoskop i munden og visualiser stemmebåndet.Stabiliser musehagen på laryngoskopet og hold 20 gauge intravenøst eller IV-kateter med en styretråd indsat i den. Indsæt derefter styretråden let i stemmebåndet og skub langsomt 20 gauge IV-kateteret ind i luftrøret, indtil dets vingedel er jævn med næsespidsen. Når musen er tilsluttet ventilatoren, skal du holde den i en lateral position med det højre temporale område opad.Oprethold rektaltemperaturen ved 37 grader Celsius ved hjælp af en varmepude og en varmelampe. Efter at have lokaliseret den zygomatiske bue og skåret den tidlige muskel, skal du bruge to tang til at dissekere den underliggende zygomatiske bue og udsætte leddet mellem maxilla og zygomatiske knogler. Brug derefter en saks til at skære en tre millimeter del af den zygomatiske bue og fjern den.Til sidst adskilles tyggemusklerne fra kraniebasen. Placer fire små retraktorer i forskellige retninger, og udsæt kraniekraniebasen med en retraktor, der trækker trigeminusnervegrenene sideværts. Påfør en saltvandsdråbe på kraniet over den midterste hjernearterie eller MCA-bagagerum og proksimal til rhinal cortex-grenen.Brug en elektrisk kværn til at tynde kraniet, indtil en lille brud er synlig. Og fjern den tynde kraniet med spidsen af tangen. Placer en enkeltstrenget løkke af sort flettet silke oven på MCA.Indsæt derefter en 8-O mikrokirurgisk nål til at løfte MCA-stammen og binde suturen under nålen, hvilket efterlader nålens to ender oven på silketrådsbåndknuden. For forbigående midterste cerebral arterieokklusion eller MCAO skal du stramme silketrådknuden lidt under nålen for at blokere arteriel blodgennemstrømning, der repræsenterer MCAO-debut. Brug tangen til at holde suturen og fjern langsomt nålen i slutningen af iskæmien.Laserpletkontrastbilleddannelsen bekræftede den reducerede blodforsyning i den rigtige MCA. For forbigående MCAO efter suturfjernelse var cerebral blodgennemstrømningsreperfusion tydelig og yderligere forbedret efter 24 timer. TTC-farvning af hjernen efter 24 timers slagtilfælde viste dannelsen af infarktvæv i både kortikale og laterale striatumområder hos unge og ældre mus.Infarktstørrelsen var moderat sammenlignet med filament MCAO.

Research

JoVE Journal

Neuroscience

Middle Cerebral Artery Occlusion (MCAO) to Induce Stroke in a Murine Model

A Modified Transcranial Middle Cerebral Artery Occlusion Model to Study Stroke Outcomes in Aged Mice

In experimental stroke research, middle cerebral artery occlusion (MCAO) with an intraluminal filament is widely used to model ischemic stroke in mice. ...