This work was supported by grants from the American Heart Association Greater Southeast Affiliate (09GRNT2060421), the American Medical Association, and from the University of Florida Clinical and Translational Science Institute. Adam Mecca is a NIH/NINDS, NRSA predoctoral fellow (F30 NS-060335). Robert Regenhardt received predoctoral fellowship support from the University of Florida Multidisciplinary Training Program in Hypertension (T32 HL-083810).

This protocol was approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Florida and is in compliance with the "Guide for the Care and Use of Laboratory Animals" (eighth edition, National Academy of Sciences, 2011).
Materials
<ol>
 <li>Animals: Eight-week-old, male, Sprague Dawley rats (Charles River Farms, Wilmington, MA, USA) weighing 250-300 g at the time of surgery. </li>
 <li>Anesthesia
 <ol class="lalpha">
 <li>Inhalation anesthesia system (VetEquip In...

<ol>
	<li>Levasseur, J. E., Wei, E. P., Raper, A. J., Kontos, A. A., Patterson, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detailed+description+of+a+cranial+window+technique+for+acute+and+chronic+experiments.">Detailed description of a cranial window technique for acute and chronic experiments.</a> Stroke. 6, 308-317 (1975).</li><li>Baumbach, G. L., Dobrin, P. B., Hart, M. N., Heistad, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanics+of+cerebral+arterioles+in+hypertensive+rats.">Mechanics of cerebral arterioles in hypertensive rats.</a> Circ. Res. 62, 56-64 (1988).</li><li>Regrigny, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+melatonin+on+rat+pial+arteriolar+diameter+in+vivo.">Effects of melatonin on rat pial arteriolar diameter in vivo.</a> Br. J. Pharmacol. 127, 1666-1670 (1999).</li><li>Mecca, A. P., O'Connor, T. E., Katovich, M. J., Sumners, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candesartan+pretreatment+is+cerebroprotective+in+a+rat+model+of+endothelin-1-induced+middle+cerebral+artery+occlusion.">Candesartan pretreatment is cerebroprotective in a rat model of endothelin-1-induced middle cerebral artery occlusion.</a> Exp. Physiol. 94, 937-946 (2009).</li><li>Mecca, A. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebroprotection+by+angiotensin-(1-7)+in+endothelin-1-induced+ischaemic+stroke.">Cerebroprotection by angiotensin-(1-7) in endothelin-1-induced ischaemic stroke.</a> Exp. Physiol. 96, 1084-1096 (2011).</li></ol>

In summary, this cranial window preparation technique is very versatile as it can be altered to meet the needs of many experiments with minor modifications4, 5. For example, we have successfully monitored cerebral blood flow in specific MCA branches using laser doppler flowmetry to focus directly on a cerebral artery visualized through a cranial window (Mecca AP 2009 and 2011). In addition, a similar preparation with the dura incised can be used with topical administration of vasoactive compounds to create an ...

<table border="1">
<tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>Inhalation anesthesia system</td>
 <td> VetEquip Inc., Pleasanton, CA, USA</td>
 <td>901806</td>
 <td></td>
 </tr>
 <tr>
 <td>Isoflurane anesthetic</td>
 <td>Baxter Pharmaceutics, Deerfield, IL, USA</td>
 <td>1001936060</td>
 <td></td>
 </tr>
 <tr>
 <td>Small animal stereotaxic system </td>
 <td>David Kopf Instruments, Tujunga, CA, USA</td>
 <td>900</td>
 <td></td>
 </tr>
 <tr>
 <td>Non-rupture ear bars, rat</td>
 <td>David Kopf Instruments, Tujunga, CA, USA</td>
 <td>957</td>
 <td></td>
 </tr>
 <tr>
 <td>Rat gas anesthesia head holder </td>
 <td>David Kopf Instruments, Tujunga, CA, USA</td>
 <td>1929</td>
 <td></td>
 </tr>
 <tr>
 <td>BAT-12 microprobe thermometer</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>BAT-12</td>
 <td></td>
 </tr>
 <tr>
 <td>T/PUMP, Thermal blanket</td>
 <td>Gaymar Industries, Inc., Orchard Park, NY, USA</td>
 <td>T/PUMP, TP600</td>
 <td></td>
 </tr>
 <tr>
 <td>Metzenbaum Scissors</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>501254</td>
 <td></td>
 </tr>
 <tr>
 <td>Iris forceps</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>15915</td>
 <td></td>
 </tr>
 <tr>
 <td>Bulldog clamp retractors</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>14119-G</td>
 <td></td>
 </tr>
 <tr>
 <td>10 &mu;l syringe 26-gaugue</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>SGE010RNS</td>
 <td></td>
 </tr>
 <tr>
 <td>Bovie, high temperature cautery kit</td>
 <td>World Precision Instruments, Inc., Sarasota, FL, USA</td>
 <td>500392</td>
 <td></td>
 </tr>
 <tr>
 <td>Rat tooth forceps 0.12</td>
 <td>Stotz</td>
 <td>E1811</td>
 <td></td>
 </tr>
 <tr>
 <td>Micromotor drill</td>
 <td>Stoelting, Wood Dale, IL, USA</td>
 <td>51449</td>
 <td></td>
 </tr>
 <tr>
 <td>0.8 mm round drill bur</td>
 <td>Roboz Surgical Instrument Co., Inc., Gaithersburg, MD, USA</td>
 <td>RS-6280C-1</td>
 <td></td>
 </tr>
 <tr>
 <td>STORZ Bonn suturing forceps</td>
 <td>Bausch and Lomb, Inc., Rochester, NY, USA</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Nylon Suture, size 3.0</td>
 <td>Oasis, Mettawa, IL, USA</td>
 <td>MV-663</td>
 <td></td>
 </tr>
 <tr>
 <td>Cotton swabs</td>
 <td>Fisher Scientific, Pittsburg, PA, USA</td>
 <td>22-029-488</td>
 <td></td>
 </tr>
 <tr>
 <td>Puralube eye ointment</td>
 <td>Fisher Scientific, Pittsburg, PA, USA</td>
 <td>NC0138063</td>
 <td></td>
 </tr>
 <tr>
 <td>Electric hair clippers </td>
 <td>Oster, Providence, RI, USA</td>
 <td>78005-301</td>
 <td></td>
 </tr>
 <tr>
 <td>ET-1 diluted to 80 &mu;M concentration in PBS </td>
 <td>American Peptide, Sunnyvale, CA, USA</td>
 <td>88-1-10A</td>
 <td></td>
 </tr>
 <tr>
 <td>Chlorhexidine, 2% </td>
 <td>Agrilabs, St. Joseph, MO, USA</td>
 <td>1040, Rev. 6-06, NAC No.: 10580322</td>
 <td></td>
 </tr>
 <tr>
 <td>Surgical microscope </td>
 <td>Seiler Instrument and Manufacturing, St. Louis, MO, USA</td>
 <td>Evolution xR6</td>
 <td></td>
 </tr>
 <tr>
 <td>Sony Handycam</td>
 <td>Sony, Minato, Tokyo, Japan</td>
 <td>HDR-SR12</td>
 <td></td>
 </tr>
 <tr>
 <td>Fiber optic illuminator </td>
 <td>TechniQuip Corp., Livermore, CA, USA</td>
 <td>FO1&#x2013;150</td>
 <td></td>
 </tr>
 <tr>
 <td>VLC media Player</td>
 <td>(Paris, France)</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Image J software</td>
 <td>U.S. National Institutes of Health, Bethesda, MA, USA</td>
 <td></td>
 <td></td>
 </tr>
 </tbody>
</table>

utilizing a cranial window to visualize the middle cerebral artery during endothelin-1 induced middle cerebral artery occlusion

Creation of a cranial window is a method that allows direct visualization of structures on the cortical surface of the brain1-3. This technique can be performed in many locations overlying the rat cerebrum, but is most easily carried out by creating a craniectomy over the readily accessible frontal or parietal bones. Most frequently, we have used this technique in combination with the endothelin-1 middle cerebral artery occlusion model of ischemic stroke to quantify the changes in middle cerebral artery vessel diameter that occur with injection of endothelin-1 into the brain parenchyma adjacent to the proximal MCA4, 5. In order to visualize the proximal portion of the MCA during endothelin -1 induced MCAO, we use a technique to create a cranial window through the temporal bone on the lateral aspect of the rat skull (Figure 1). Cerebral arteries can be visualized either with the dura intact or with the dura incised and retracted. Most commonly, we leave the dura intact during visualization since endothelin-1 induced MCAO involves delivery of the vasoconstricting peptide into the brain parenchyma. This bypasses the need to incise the dura directly over the visualized vessels for drug delivery. This protocol will describe how to create a cranial window to visualize cerebral arteries in a step-wise fashion, as well as how to avoid many of the potential pitfalls pertaining to this method.

Still images taken from the captured video show that the change in cerebral artery diameter after ET-1 injection can be readily appreciated using this cranial window technique (Figure 2). Within minutes of ET-1 injection, the vessel will begin to constrict. Eventually the vessels will be difficult to visualize and the brain tissue will become pale. After about 20 min the effects of ET-1 will diminish and the vessels will begin to dilate, gradually returning to baseline diameter after about 45 min. In add...

Watch this Scientific Journal Video about Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion at JoVE.com

Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion

This article describes a method for visualizing rat cerebral arteries through a cranial window using temporal craniectomy in order to view proximal portions of the middle cerebral artery (Figure 1). This versatile method can be combined with various techniques of drug delivery to measure cerebral artery reactivity in vivo.

Creation of a cranial window is a method that allows direct visualization of structures on the cortical surface of the brain1-3. This technique can be ...

utilizing-cranial-window-to-visualize-middle-cerebral-artery-during

Research

JoVE Journal

Medicine

14.8K vues.  University of Florida. Cet article décrit une méthode pour visualiser les artères cérébrales de rats à travers une fenêtre crânienne à l'aide craniectomie temporelle afin de voir les parties proximales de l'artère cérébrale moyenne ( Figure 1). Cette méthode polyvalent peut être combiné avec différentes techniques de délivrance de médicaments à mesurer la réactivité artère cérébrale In vivo.

Vidéo: Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion

This article describes a method for visualizing rat cerebral arteries through a cranial window using temporal craniectomy in order to view proximal portions of the middle cerebral artery (Figure 1). This versatile method can be combined with various techniques of drug delivery to measure cerebral artery reactivity in...

endothelin-1 induced middle cerebral artery occlusion model for ischemic stroke with laser doppler flowmetry guidance in rat

Endothelin-1 Induced Middle Cerebral Artery Occlusion Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Rat

Several animal models of cerebral ischemia have been developed to simulate the human condition of stroke. This protocol describes the endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAO) model for ischemic stroke in rats.  In addition, important considerations, advantages, and shortcomings of this model are...

mouse model of middle cerebral artery occlusion

Mouse Model of Middle Cerebral Artery Occlusion

We demonstrate in the video a method for producing a middle cerebral artery occlusion in adult mice using an intraluminal monofilament. We also show how to evaluate the extent of cerebral infarction by 2,3,5-triphenyltetrazolium chloride (TTC)...

a modified model preparation for middle cerebral artery occlusion reperfusion

Author Spotlight: A Novel Approach to Cerebral Ischemia Modeling &amp;#8211; Enhancing Reperfusion and Simplifying Procedure

This protocol describes the process of preparing for middle cerebral artery occlusion reperfusion via the common carotid...

A Modified Model Preparation for Middle Cerebral Artery Occlusion Reperfusion

transient middle cerebral artery occlusion model of stroke

Author Spotlight: Assessing Ischemic Stroke Damage Through Middle Cerebral Artery Occlusion Model 

This protocol describes the model of transient focal cerebral ischemia in mice through intraluminal occlusion of the middle cerebral artery. Additionally, examples of outcome assessment are shown using magnetic resonance imaging and behavioral...

A Model of Transient Cerebral Ischemia by Occlusion of Middle Cerebral Artery

https://cloudfront.jove.com/CDNSource/teasers/65857_b.jpg

Transient Middle Cerebral Artery Occlusion Model of Stroke

lateral chronic cranial window preparation enables in vivo observation following distal middle cerebral artery occlusion in mice

Lateral Chronic Cranial Window Preparation Enables In Vivo Observation Following Distal Middle Cerebral Artery Occlusion in Mice

Surgical occlusion of a distal middle cerebral artery branch (MCAo) is a frequently used model in experimental stroke research. This manuscript describes the basic technique of permanent MCAo, combined with the insertion of a lateral cranial window, which offers the opportunity for longitudinal intravital microscopy in...

Lateral Chronic Cranial Window Preparation Enables In Vivo Observation Following Distal Middle Cerebral Artery Occlusion in Mice

preparing middle cerebral artery occlusion reperfusion via the common carotid artery

Preparing Middle Cerebral Artery Occlusion Reperfusion via the Common Carotid Artery

surgical procedure for transient middle cerebral artery occlusion

Surgical Procedure for Transient Middle Cerebral Artery Occlusion  

middle cerebral artery occlusion allowing reperfusion via common carotid artery repair in mice

Middle Cerebral Artery Occlusion Allowing Reperfusion via Common Carotid Artery Repair in Mice

Intraluminal filament occlusion of the middle cerebral artery is the most frequently used in vivo model of experimental stroke in rodents. An alternative surgical approach to allow common carotid artery repair is performed here, which allows the reperfusion of the common carotid artery and a full reperfusion to the middle cerebral artery...

modeling stroke in mice: transient middle cerebral artery occlusion via the external carotid artery

Modeling Stroke in Mice: Transient Middle Cerebral Artery Occlusion via the External Carotid Artery

Different models of middle cerebral artery occlusion (MCAo) are used in experimental stroke research. Here, an experimental stroke model of transient MCAo via the external carotid artery (ECA) is described, which aims to mimic human stroke, in which the cerebrovascular thrombus is removed due to spontaneous clot lysis or...

a model for encephalomyosynangiosis treatment after middle cerebral artery occlusion-induced stroke in mice

A Model for Encephalomyosynangiosis Treatment after Middle Cerebral Artery Occlusion-Induced Stroke in Mice

The protocol aims to provide methods for encephalomyosynangiosis-grafting of a vascular temporalis muscle flap on the pial surface of ischemic brain tissue-for the treatment of non-moyamoya acute ischemic stroke. The approach's efficacy in increasing angiogenesis is evaluated using a transient middle cerebral artery occlusion model in...

modeling stroke in mice - middle cerebral artery occlusion with the filament model

Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model

Filamentous occlusion of  the Middle cerebral artery is a common model for studying ischemic stroke in...

handcrafted silicone coated filament for mice middle cerebral artery occlusion models

This protocol describes a straightforward method for creating coated filaments for the middle cerebral artery occlusion (MCAO) model in mice using silicone, nylon sutures, and syringe needles. This method allows for the production of filaments with a consistent diameter and various silicone wrapping lengths tailored to experimental...

Handcrafted Silicone Coated Filament for Mice Middle Cerebral Artery Occlusion Models

surgical approach for middle cerebral artery occlusion and reperfusion induced stroke in mice

Surgical Approach for Middle Cerebral Artery Occlusion and Reperfusion Induced Stroke in Mice

In order to understand the pathophysiology of stroke, it is important to use reliable models. This paper will describe one of the most frequently used stroke models in mice, termed the middle cerebral artery occlusion (MCAo) model (also termed the intraluminal filament or suture model) with...

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

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

optimization of the longa middle cerebral artery occlusion method for complete reperfusion

This protocol presents a step-by-step guide for researchers to perform the middle cerebral artery occlusion procedure on mice using the modified Longa external carotid artery method. Modifications presented in this article aim to increase the accuracy of middle cerebral artery occlusion and ensure complete...

Optimization of the Longa Middle Cerebral Artery Occlusion Method for Complete Reperfusion

a middle cerebral artery occlusion technique for inducing post-stroke depression in rats

A Middle Cerebral Artery Occlusion Technique for Inducing Post-stroke Depression in Rats

Here we present a protocol to induce post-stroke depression in rats by occluding the middle cerebral artery via the internal carotid artery. We use the Porsolt forced swim test and the sucrose preference test to confirm and evaluate induced depressive...

focal cerebral ischemia model by endovascular suture occlusion of the middle cerebral artery in the rat

Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat

Surgical induction of ischemic brain damage in the rat is a widely used model for stroke research. Here we demonstrate the induction of focal cerebral ischemia by occlusion of the middle cerebral artery. Visualization of the resulting infarct by histological staining and magnetic resonance imaging is also...

optimized system for cerebral perfusion monitoring in the rat stroke model of intraluminal middle cerebral artery occlusion

Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion

Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in...

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are very limited. To meet the need for novel therapeutic approaches, experimental stroke research frequently employs rodent models of focal cerebral ischaemia. Most researchers use permanent or transient occlusion of the middle cerebral artery (MCA) in mice or rats.
Proximal occlusion of the middle cerebral artery (MCA) via the intraluminal suture technique (so called filament or suture model) is probably the most frequently used model in experimental stroke research. The intraluminal MCAO model offers the advantage of inducing reproducible transient or permanent ischaemia of the MCA territory in a relatively non-invasive manner. Intraluminal approaches interrupt the blood flow of the entire territory of this artery. Filament occlusion thus arrests flow proximal to the lenticulo-striate arteries, which supply the basal ganglia. Filament occlusion of the MCA results in reproducible lesions in the cortex and striatum and can be either permanent or transient. In contrast, models inducing distal (to the branching of the lenticulo-striate arteries) MCA occlusion typically spare the striatum and primarily involve the neocortex. In addition these models do require craniectomy. In the model demonstrated in this article, a silicon coated filament is introduced into the common carotid artery and advanced along the internal carotid artery into the Circle of Willis, where it blocks the origin of the middle cerebral artery. In patients, occlusions of the middle cerebral artery are among the most common causes of ischaemic stroke. Since varying ischemic intervals can be chosen freely in this model depending on the time point of reperfusion, ischaemic lesions with varying degrees of severity can be produced. Reperfusion by removal of the occluding filament at least partially models the restoration of blood flow after spontaneous or therapeutic (tPA) lysis of a thromboembolic clot in humans.
In this video we will present the basic technique as well as the major pitfalls and confounders which may limit the predictive value of this model.

Filamentous occlusion of the Middle cerebral artery is a common model for studying ischemic stroke in mice.

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are ...

Stroke is the most common fatal neurological disease in the United States 1. The majority of strokes (88%) result from blockage of blood vessels in the brain (ischemic stroke) 2. Since most ischemic strokes (~80%) occur in the territory of middle cerebral artery (MCA) 3, many animal stroke models that have been developed have focused on this artery. The intraluminal monofilament model of middle cerebral artery occlusion (MCAO) involves the insertion of a surgical filament into the external carotid artery and threading it forward into the internal carotid artery (ICA) until the tip occludes the origin of the MCA, resulting in a cessation of blood flow and subsequent brain infarction in the MCA territory 4. The technique can be used to model permanent or transient occlusion 5. If the suture is removed after a certain interval (30 min, 1 h, or 2 h), reperfusion is achieved (transient MCAO); if the filament is left in place (24 h) the procedure is suitable as a model of permanent MCAO. This technique does not require craniectomy, a neurosurgical procedure to remove a portion of skull, which may affect intracranial pressure and temperature 6. It has become the most frequently used method to mimic permanent and transient focal cerebral ischemia in rats and mice 7,8. To evaluate the extent of cerebral infarction, we stain brain slices with 2,3,5-triphenyltetrazolium chloride (TTC) to identify ischemic brain tissue 9. In this video, we demonstrate the MCAO method and the determination of infarct size by TTC staining.

We demonstrate in the video a method for producing a middle cerebral artery occlusion in adult mice using an intraluminal monofilament. We also show how to evaluate the extent of cerebral infarction by 2,3,5-triphenyltetrazolium chloride (TTC) staining.

Stroke is the most common fatal neurological disease in the United States 1. The majority of strokes (88%) result from blockage of blood vessels in the ...

The Application Of Permanent Middle Cerebral Artery Ligation in the Mouse

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to develop suitable animal models to study the events that unfold during ischemic insult. These techniques include transient or permanent, focal or global ischemia models using many different animal models, with the most common being rodents.
The permanent MCA ligation method which is also referred as pMCAo in the literature is used extensively as a focal ischemia model in rodents 1-6. This method was originally described for rats by Tamura et al. in 1981 7. In this protocol a craniotomy was used to access the MCA and the proximal regions were occluded by electrocoagulation. The infarcts involve mostly cortical and sometimes striatal regions depending on the location of the occlusion. This technique is now well established and used in many laboratories 8-13. Early use of this technique led to the definition and description of &#x201C;infarct core&#x201D; and &#x201C;penumbra&#x201D; 14-16, and it is often used to evaluate potential neuroprotective compounds 10, 12, 13, 17. Although the initial studies were performed in rats, permanent MCA ligation has been used successfully in mice with slight modifications 18-20 .
This model yields reproducible infarcts and increased post-survival rates. Approximately 80% of the ischemic strokes in humans happen in the MCA area 21 and thus this is a very relevant model for stroke studies. Currently, there is a paucity of effective treatments available to stroke patients, and thus there is a need for good models to test potential pharmacological compounds and evaluate physiological outcomes. This method can also be used for studying intracellular hypoxia response mechanisms in vivo. 
Here, we present the MCA ligation surgery in a C57/BL6 mouse. We describe the pre-surgical preparation, MCA ligation surgery and 2,3,5 Triphenyltetrazolium chloride (TTC) staining for quantification of infarct volumes.

Middle cerebral artery (MCA) ligation is a technique to study focal cerebral ischemia in animal models. In this method, the middle cerebral artery is exposed by craniotomy and ligated by cauterization. This method gives highly reproducible infarct volumes and increased post-operative survival rates compared to other methods available.

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to ...

Stroke is the number one cause of disability and third leading cause of death in the world, costing an estimated $70 billion in the United States in 20091, 2. Several models of cerebral ischemia have been developed to mimic the human condition of stroke. It has been suggested that up to 80% of all strokes result from ischemic damage in the middle cerebral artery (MCA) area3. In the early 1990s, endothelin-1 (ET-1) 4 was used to induce ischemia by applying it directly adjacent to the surface of the MCA after craniotomy. Later, this model was modified 5 by using a stereotaxic injection of ET-1 adjacent to the MCA to produce focal cerebral ischemia. The main advantages of this model include the ability to perform the procedure quickly, the ability to control artery constriction by altering the dose of ET-1 delivered, no need to manipulate the extracranial vessels supplying blood to the brain as well as gradual reperfusion rates that more closely mimics the reperfusion in humans5-7. On the other hand, the ET-1 model has disadvantages that include the need for a craniotomy, as well as higher variability in stroke volume8. This variability can be reduced with the use of laser Doppler flowmetry (LDF) to verify cerebral ischemia during ET-1 infusion. Factors that affect stroke variability include precision of infusion and the batch of the ET-1 used6. Another important consideration is that although reperfusion is a common occurrence in human stroke, the duration of occlusion for ET-1 induced MCAO may not closely mimic that of human stroke where many patients have partial reperfusion over a period of hours to days following occlusion9, 10. This protocol will describe in detail the ET-1 induced MCAO model for ischemic stroke in rats. It will also draw attention to special considerations and potential drawbacks throughout the procedure.

Several animal models of cerebral ischemia have been developed to simulate the human condition of stroke. This protocol describes the endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAO) model for ischemic stroke in rats. In addition, important considerations, advantages, and shortcomings of this model are discussed.

Stroke is the number one cause of disability and third leading cause of death in the world, costing an estimated $70 billion in the United States in ...

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal models of acute ischemic stroke allows to confirm successful arterial occlusion and exclude subarachnoid hemorrhage. Cerebral perfusion monitoring can also be used to study intracranial collateral circulation, which is emerging as a powerful determinant of stroke outcome and a possible therapeutic target. Despite a recognized role of Laser Doppler perfusion monitoring as part of the current guidelines for experimental cerebral ischemia, a number of technical difficulties exist that limit its widespread use. One of the major issues is obtaining a secure and prolonged attachment of a deep-penetration Laser Doppler probe to the animal skull. In this video, we show our optimized system for cerebral perfusion monitoring during transient middle cerebral artery occlusion by intraluminal filament in the rat. We developed in-house a simple method to obtain a custom made holder for twin-fibre (deep-penetration) Laser Doppler probes, which allow multi-site monitoring if needed. A continuous and prolonged monitoring of cerebral perfusion could easily be obtained over the intact skull.

Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal ...

Embolic Middle Cerebral Artery Occlusion (MCAO) for Ischemic Stroke with Homologous Blood Clots in Rats

Clinically, thrombolytic therapy with use of recombinant tissue plasminogen activator (tPA) remains the most effective treatment for acute ischemic stroke. However, the use of tPA is limited by its narrow therapeutic window and by increased risk of hemorrhagic transformation. There is an urgent need to develop suitable stroke models to study new thrombolytic agents and strategies for treatment of ischemic stroke. At present, two major types of ischemic stroke models have been developed in rats and mice: intraluminal suture MCAO and embolic MCAO. Although MCAO models via the intraluminal suture technique have been widely used in mechanism-driven stroke research, these suture models do not mimic the clinical situation and are not suitable for thrombolytic studies. Among these models, the embolic MCAO model closely mimics human ischemic stroke and is suitable for preclinical investigation of thrombolytic therapy. This embolic model was first developed in rats by Overgaard et al.1 in 1992 and further characterized by Zhang et al. in 19972. Although embolic MCAO has gained increasing attention, there are technical problems faced by many laboratories. To meet increasing needs for thrombolytic research, we present a highly reproducible model of embolic MCAO in the rat, which can develop a predictable infarct volume within the MCA territory. In brief, a modified PE-50 tube is gently advanced from the external carotid artery (ECA) into the lumen of the internal carotid artery (ICA) until the tip of the catheter reaches the origin of the MCA. Through the catheter, a single homologous blood clot is placed at the origin of the MCA. To identify the success of MCA occlusion, regional cerebral blood flow was monitored, neurological deficits and infarct volumes were measured. The techniques presented in this paper should help investigators to overcome technical problems for establishing this model for stroke research.

Embolic Middle Cerebral Artery Occlusion MCAO for Ischemic Stroke with Homologous Blood Clots in Rats

In this paper, we demonstrate a standard method for producing an embolic middle cerebral artery occlusion with homologous blood clots (fibrin-rich) in adult rat. This model closely mimics human ischemic stroke and is suitable for preclinical study of thrombolytic therapy for ischemic stroke.

Clinically, thrombolytic therapy with use of recombinant tissue plasminogen activator (tPA) remains the most effective treatment for acute ischemic ...

Quantification of Neurovascular Protection Following Repetitive Hypoxic Preconditioning and Transient Middle Cerebral Artery Occlusion in Mice

Experimental animal models of stroke are invaluable tools for understanding stroke pathology and developing more effective treatment strategies. A 2 week protocol for repetitive hypoxic preconditioning (RHP) induces long-term protection against central nervous system (CNS) injury in a mouse model of focal ischemic stroke. RHP consists of 9 stochastic exposures to hypoxia that vary in both duration (2 or 4 hr) and intensity (8% and 11% O2). RHP reduces infarct volumes, blood-brain barrier (BBB) disruption, and the post-stroke inflammatory response for weeks following the last exposure to hypoxia, suggesting a long-term induction of an endogenous CNS-protective phenotype. The methodology for the dual quantification of infarct volume and BBB disruption is effective in assessing neurovascular protection in mice with RHP or other putative neuroprotectants. Adult male Swiss Webster mice were preconditioned by RHP or duration-equivalent exposures to 21% O2 (i.e. room air). A 60 min transient middle cerebral artery occlusion (tMCAo) was induced 2 weeks following the last hypoxic exposure. Both the occlusion and reperfusion were confirmed by transcranial laser Doppler flowmetry. Twenty-two hr after reperfusion, Evans Blue (EB) was intravenously administered through a tail vein injection. 2 hr later, animals were sacrificed by isoflurane overdose and brain sections were stained with 2,3,5- triphenyltetrazolium chloride (TTC). Infarcts volumes were then quantified. Next, EB was extracted from the tissue over 48 hr to determine BBB disruption after tMCAo. In summary, RHP is a simple protocol that can be replicated, with minimal cost, to induce long-term endogenous neurovascular protection from stroke injury in mice, with the translational potential for other CNS-based and systemic pro-inflammatory disease states.

This protocol describes repetitive hypoxic preconditioning, or brief exposures to systemic hypoxia that reduce infarct volumes and blood-brain barrier disruption following transient middle cerebral artery occlusion in mice. It also details dual quantification of infarct volume and blood-brain barrier disruption after stroke to assess the efficacy of neurovascular protection.

Experimental animal models of stroke are invaluable tools for understanding stroke pathology and developing more effective treatment strategies. A 2 week ...

Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, obesity and diabetes. Accordingly, when evaluating therapies for stroke in animals, it is important to select a model with excellent face validity. Ischemic stroke accounts for 80% of all strokes, and the majority of these occur in the territory of the middle cerebral artery (MCA), often inducing infarcts that affect the sensorimotor cortex, causing persistent plegia or paresis on the contralateral side of the body. We demonstrate in this video a method for producing ischemic stroke in elderly rats, which causes sustained sensorimotor disability and substantial cortical infarcts. Specifically, we induce permanent distal middle cerebral artery occlusion (MCAO) in elderly female rats by using diathermy forceps to occlude a short segment of this artery. The carotid artery on the ipsilateral side to the lesion was then permanently occluded and the contralateral carotid artery was transiently occluded for 60 min. We measure the infarct size using structural T2-weighted magnetic resonance imaging (MRI) at 24 hr and 8 weeks after stroke. In this study, the mean infarct volume was 4.5% &#177; 2.0% (standard deviation) of the ipsilateral hemisphere at 24 hr (corrected for brain swelling using Gerriet&#8217;s equation, n = 5). This model is feasible and clinically relevant as it permits the induction of sustained sensorimotor deficits, which is important for the elucidation of pathophysiological mechanisms and novel treatments.

Here we present a protocol to produce permanent distal middle cerebral artery occlusion in elderly female rats with simultaneous occlusion of the carotid arteries to generate large cortical infarcts and sustained deficits. We show confirmation of the lesion size using structural MRI at 24 hr and 8 weeks after stroke.

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, ...

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ischemic in origin and occur in the territory of the middle cerebral artery (MCA). Currently the only Food and Drug Administration (FDA) approved drug for the treatment of this devastating disease is tissue plasminogen activator (tPA). However, tPA has a small therapeutic window for administration (3 - 6 hr), and is only effective in 4% of the patients who actually receive it. Current research focuses on understanding the pathophysiology of stroke in order to find potential therapeutic targets. Thus, reliable models are crucial, and the MCA occlusion (MCAo) model (also termed the intraluminal filament or suture model) is deemed to be the most clinically relevant surgical model of ischemic stroke, and is fairly non-invasive and easily reproducible. Typically the MCAo model is used with rodents, especially with mice due to all the genetic variations available for this species. Here we describe (and present in the video) how to successfully perform the MCAo model (with reperfusion) in mice to generate reliable and reproducible data.

In order to understand the pathophysiology of stroke, it is important to use reliable models. This paper will describe one of the most frequently used stroke models in mice, termed the middle cerebral artery occlusion (MCAo) model (also termed the intraluminal filament or suture model) with reperfusion.

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ...

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Neonatal stroke is a significant cause of early brain injury requiring a translational model with consistent focal injury patterns and high reproducibility in order to enable study. This study describes the detailed surgical procedure for creating a non-hemorrhagic, unilateral focal ischemia-reperfusion injury in full-term-equivalent rodents.

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature ...