VP is a participant in the Charit&#233; Clinical Scientist Program, funded by the Charit&#233; - Universit&#228;tsmedizin Berlin and the Berlin Institute of Health. TB is an SNSF PostDoc Mobility fellow. The authors receive grant support from EinsteinStiftung/A-2012-153 to PV.

ETHICS STATEMENT: Experiments involving animal subjects were performed in accordance with the guidelines and regulations set forth by Landesamt fuer Gesundheit und Soziales, Berlin, Germany (G0298/13) and the ARRIVE criteria, as applicable. For this study, 10- to 12-week-old male C57Bl/6J mice were used.
1. Lateral Chronic Cranial Window Preparation
<ol>
	<li>Perform anesthesia with a subcutaneous injection of ketamine (90 mg/kg) and xylazine (10 mg/kg). Test for adequate sedation with a pai...

<ol>
	<li>Mukherjee, D., Patil, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+and+the+global+burden+of+stroke.">Epidemiology and the global burden of stroke.</a> World Neurosurg. 76 (6), 85-90 (2011).</li><li>Ebinger, M., Pr&#252;ss, H., 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=Effect+of+the+use+of+ambulance-based+thrombolysis+on+time+to+thrombolysis+in+acute+ischemic+stroke:+a+randomized+clinical+trial.">Effect of the use of ambulance-based thrombolysis on time to thrombolysis in acute ischemic stroke: a randomized clinical trial.</a> JAMA. 311 (16), 1622-1631 (2014).</li><li>Ebinger, M., Lindenlaub, S., 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=Prehospital+thrombolysis:+a+manual+from+Berlin.">Prehospital thrombolysis: a manual from Berlin.</a> J vis Exp. (81), e50534 (2013).</li><li>Bogousslavsky, J., Van Melle, G., Regli, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Lausanne+Stroke+Registry:+analysis+of+1,000+consecutive+patients+with+first+stroke.">The Lausanne Stroke Registry: analysis of 1,000 consecutive patients with first stroke.</a> Stroke. 19 (9), 1083-1092 (1988).</li><li>Engel, O., Kolodziej, S., Dirnagl, U., Prinz, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+stroke+in+mice+-+middle+cerebral+artery+occlusion+with+the+filament+model.">Modeling stroke in mice - middle cerebral artery occlusion with the filament model.</a> J Vis Exp. (47), (2011).</li><li>Donnan, G. A., Fisher, M., Macleod, M., Davis, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stroke.">Stroke.</a> Lancet. 371 (9624), 1612-1623 (2008).</li><li>Meairs, S., Wahlgren, N., 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=Stroke+research+priorities+for+the+next+decade--A+representative+view+of+the+European+scientific+community.">Stroke research priorities for the next decade--A representative view of the European scientific community.</a> Cerebrovasc Dis. 22 (2-3), 75-82 (2006).</li><li>Rosamond, W., Flegal, K., 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=Heart+disease+and+stroke+statistics--2007+update:+a+report+from+the+American+Heart+Association+Statistics+Committee+and+Stroke+Statistics+Subcommittee.">Heart disease and stroke statistics--2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee.</a> Circulation. 115 (5), 69-171 (2007).</li><li>Moskowitz, M. A., Lo, E. H., Iadecola, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+science+of+stroke:+mechanisms+in+search+of+treatments.">The science of stroke: mechanisms in search of treatments.</a> Neuron. 67 (2), 181-198 (2010).</li><li>Dirnagl, U., Iadecola, C., Moskowitz, 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=Pathobiology+of+ischaemic+stroke:+an+integrated+view.">Pathobiology of ischaemic stroke: an integrated view.</a> Trends Neurosci. 22 (9), 391-397 (1999).</li><li>Dirnagl, U., Endres, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Found+in+Translation:+Preclinical+Stroke+Research+Predicts+Human+Pathophysiology,+Clinical+Phenotypes,+and+Therapeutic+Outcomes.">Found in Translation: Preclinical Stroke Research Predicts Human Pathophysiology, Clinical Phenotypes, and Therapeutic Outcomes.</a> Stroke. , (2014).</li><li>Prinz, V., Hetzer, A. -. M., 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=MRI+heralds+secondary+nigral+lesion+after+brain+ischemia+in+mice:+a+secondary+time+window+for+neuroprotection.">MRI heralds secondary nigral lesion after brain ischemia in mice: a secondary time window for neuroprotection.</a> J Cereb Blood Flow Metab. , (2015).</li><li>Shih, A. Y., Mateo, C., Drew, P. J., Tsai, P. S., Kleinfeld, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+polished+and+reinforced+thinned-skull+window+for+long-term+imaging+of+the+mouse+brain.">A polished and reinforced thinned-skull window for long-term imaging of the mouse brain.</a> J Vis Exp. (61), (2012).</li><li>Holtmaat, A., Bonhoeffer, T., 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=Long-term,+high-resolution+imaging+in+the+mouse+neocortex+through+a+chronic+cranial+window.">Long-term, high-resolution imaging in the mouse neocortex through a chronic cranial window.</a> Nat Protoc. 4 (8), 1128-1144 (2009).</li><li>Iadecola, C., Dirnagl, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microcircualtion--fantastic+voyage:+introduction.">The microcircualtion--fantastic voyage: introduction.</a> Stroke. 44 (6), 83 (2013).</li><li>Blinder, P., Tsai, P. S., Kaufhold, J. P., Knutsen, P. M., Suhl, H., Kleinfeld, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cortical+angiome:+an+interconnected+vascular+network+with+noncolumnar+patterns+of+blood+flow.">The cortical angiome: an interconnected vascular network with noncolumnar patterns of blood flow.</a> Nat Neurosc. 16 (7), 889-897 (2013).</li><li>Shih, A. Y., Driscoll, J. D., Drew, P. J., Nishimura, N., Schaffer, C. B., Kleinfeld, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+microscopy+as+a+tool+to+study+blood+flow+and+neurovascular+coupling+in+the+rodent+brain.">Two-photon microscopy as a tool to study blood flow and neurovascular coupling in the rodent brain.</a> J Cereb Blood Flow Metab. 32 (7), 1277-1309 (2012).</li><li>Cabrales, P., Carvalho, L. J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+microscopy+of+the+mouse+brain+microcirculation+using+a+closed+cranial+window.">Intravital microscopy of the mouse brain microcirculation using a closed cranial window.</a> J Vis Exp. (45), (2010).</li><li>Rosell, A., Agin, V., 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=Distal+occlusion+of+the+middle+cerebral+artery+in+mice:+are+we+ready+to+assess+long-term+functional+outcome.">Distal occlusion of the middle cerebral artery in mice: are we ready to assess long-term functional outcome.</a> Transl Stroke Res. 4 (3), 297-307 (2013).</li><li>Dorand, R. D., Barkauskas, D. S., Evans, T. A., Petrosiute, A., Huang, A. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+intravital+thinned+skull+and+cranial+window+approaches+to+study+CNS+immunobiology+in+the+mouse+cortex.">Comparison of intravital thinned skull and cranial window approaches to study CNS immunobiology in the mouse cortex.</a> Intravital. 3 (2), (2014).</li><li>Balkaya, M., 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=Assessing+post-stroke+behavior+in+mouse+models+of+focal+ischemia.">Assessing post-stroke behavior in mouse models of focal ischemia.</a> J Cereb Blood Flow Metab. 33 (3), 330-338 (2013).</li><li>Balkaya, M., Kr&#246;ber, J., Gertz, K., Peruzzaro, S., Endres, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+long-term+functional+outcome+in+a+murine+model+of+mild+brain+ischemia.">Characterization of long-term functional outcome in a murine model of mild brain ischemia.</a> J Neurosci Methods. 213 (2), 179-187 (2013).</li><li>Freret, T., Bouet, V., 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=Behavioral+deficits+after+distal+focal+cerebral+ischemia+in+mice:+Usefulness+of+adhesive+removal+test.">Behavioral deficits after distal focal cerebral ischemia in mice: Usefulness of adhesive removal test.</a> Beh Neurosci. 123 (1), 224-230 (2009).</li><li>Liu, S., Zhen, G., Meloni, B. P., Campbell, K., Winn, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RODENT+STROKE+MODEL+GUIDELINES+FOR+PRECLINICAL+STROKE+TRIALS+(1ST+EDITION).">RODENT STROKE MODEL GUIDELINES FOR PRECLINICAL STROKE TRIALS (1ST EDITION).</a> J Exp Stroke Trans Med. 2 (2), 2-27 (2009).</li><li>Florian, B., Vintilescu, R., 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=Long-term+hypothermia+reduces+infarct+volume+in+aged+rats+after+focal+ischemia.">Long-term hypothermia reduces infarct volume in aged rats after focal ischemia.</a> Neurosci Lett. 438 (2), 180-185 (2008).</li><li>Noor, R., Wang, C. X., Shuaib, A. <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+hyperthermia+on+infarct+volume+in+focal+embolic+model+of+cerebral+ischemia+in+rats.">Effects of hyperthermia on infarct volume in focal embolic model of cerebral ischemia in rats.</a> Neurosci Lett. 349 (2), 130-132 (2003).</li><li>Barber, P. A., Hoyte, L., Colbourne, F., Buchan, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature-regulated+model+of+focal+ischemia+in+the+mouse:+a+study+with+histopathological+and+behavioral+outcomes.">Temperature-regulated model of focal ischemia in the mouse: a study with histopathological and behavioral outcomes.</a> Stroke. 35 (7), 1720-1725 (2004).</li><li>Shin, H. K., Nishimura, M., 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=Mild+induced+hypertension+improves+blood+flow+and+oxygen+metabolism+in+transient+focal+cerebral+ischemia.">Mild induced hypertension improves blood flow and oxygen metabolism in transient focal cerebral ischemia.</a> Stroke. 39 (5), 1548-1555 (2008).</li><li>Kapinya, K. J., Prass, K., Dirnagl, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isoflurane+induced+prolonged+protection+against+cerebral+ischemia+in+mice:+a+redox+sensitive+mechanism.">Isoflurane induced prolonged protection against cerebral ischemia in mice: a redox sensitive mechanism.</a> Neuroreport. 13 (11), 1431-1435 (2002).</li><li>Gertz, K., Priller, J., 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=Physical+activity+improves+long-term+stroke+outcome+via+endothelial+nitric+oxide+synthase-dependent+augmentation+of+neovascularization+and+cerebral+blood+flow.">Physical activity improves long-term stroke outcome via endothelial nitric oxide synthase-dependent augmentation of neovascularization and cerebral blood flow.</a> Circ Res. 99 (10), 1132-1140 (2006).</li><li>Dirnagl, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bench+to+bedside:+the+quest+for+quality+in+experimental+stroke+research.">Bench to bedside: the quest for quality in experimental stroke research.</a> J Cereb Blood Flow Metab. 26 (12), 1465-1478 (2006).</li></ol>

Stroke is among the principal causes of long-term disability and death worldwide1. Beyond acute treatment, investigating new approaches and mechanisms to accelerate and enhance recovery after stroke remains a prime medical goal7. Experimental stroke researchers frequently employ rodent models of focal cerebral ischemia. In fact, models inducing transient or permanent MCAo mimic one of the most common types of focal cerebral ischemia in patients4. Besides proximal occlusion of the MCA, the...

Stroke is among the principal causes of long-term disability and death worldwide1, coming second after coronary heart disease. In addition, stroke is the primary cause of long-term disability, underscoring its tremendous socioeconomic impact6-8. Beyond acute treatment, investigating new approaches and mechanisms to accelerate and enhance recovery after stroke remains a prime medical goal7. 
In the last few decades, data from experimental stroke research has contributed substantially to understanding the complex pathophysiological cascades triggered by ischemia9,10. Excitotoxicity, apoptosis, peri-infarct depolarization, and inflammation have been identified as the most relevant mediators of cell death following focal cerebral ischemia. Moreover, using animal models of cerebral ischemia, important concepts, diagnostic modalities, and therapeutic approaches have been developed and validated (e.g., "penumbra" and thrombolysis)11.
The availability of experimental stroke models, combined with non-invasive imaging modalities (e.g., magnetic resonance imaging (MRI), computed tomography, or laser speckle contrast analysis), enables the researcher to investigate hyperacute and chronic pathophysiological changes induced by the ischemic insult in a longitudinal manner12. Along with studying the spatiotemporal profile of the evolving lesion, changes resembling neuronal plasticity can be investigated and correlated to functional outcomes and histological findings. Within the last few years, further methodological advances have been made using the combination of cerebral ischemia models and in vivo microscopy via cranial windows13. These new techniques allow investigators to analyze the neurovascular unit at the cellular and molecular level, with great analytic power in the acute, subacute, and chronic phases following focal cerebral ischemia14. Moreover, in vivo microscopy imaging of microcirculatory dynamics has revealed novel aspects of cerebral microvasculature function and angioarchitecture, with significant pathophysiological relevance15-17. 
In this protocol, we present how to perform a chronic CW preparation lateral to the sagittal sinus and how to surgically induce a distal stroke underneath the window. This mouse model can be applied to sequential imaging of acute, subacute, and chronic changes following focal cerebral ischemia via epi-illuminating, confocal laser scanning, and two-photon intravital microscopy.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Binocular surgical microscope</td>
			<td>Zeiss</td>
			<td>Stemi 2000 C</td>
			<td></td>
		</tr>
		<tr>
			<td>Light source for microscope</td>
			<td>Zeiss</td>
			<td>CL 6000 LED</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating pad with rectal probe</td>
			<td>FST</td>
			<td>21061-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereotactic frame</td>
			<td>Kopf</td>
			<td>Model 930</td>
			<td></td>
		</tr>
		<tr>
			<td>Anaethesia system for isoflurane</td>
			<td>Draeger</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Abott</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont forceps #5</td>
			<td>FST</td>
			<td>11251-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont forceps #7</td>
			<td>FST</td>
			<td>11271-30</td>
			<td></td>
		</tr>
		<tr>
			<td>Bipolar Forceps</td>
			<td>Erbe</td>
			<td>20195-501</td>
			<td></td>
		</tr>
		<tr>
			<td>Bipolar Forceps&#160;</td>
			<td colspan="2">Erbe&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; 20195-022</td>
			<td></td>
		</tr>
		<tr>
			<td>Microdrill</td>
			<td colspan="2">FST&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; 18000-17&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>FST</td>
			<td>12010-14</td>
			<td></td>
		</tr>
		<tr>
			<td>5-0 silk suture</td>
			<td>Feuerstein, Suprama</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>7-0 silk suture</td>
			<td>Feuerstein,Suprama</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>8-0 silk suture</td>
			<td>Feuerstein, Suprama</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Veterinary Recovery Chamber</td>
			<td>Peco Services</td>
			<td>V1200</td>
			<td></td>
		</tr>
	</tbody>
</table>

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

Focal cerebral ischemia (i.e., ischemic stroke) may cause major brain injury, leading to a severe loss of neuronal function and consequently to a host of motor and cognitive disabilities. Its high prevalence poses a serious health burden, as stroke is among the principal causes of long-term disability and death worldwide1. Recovery of neuronal function is, in most cases, only partial. So far, treatment options are very limited, in particular due to the narrow time window for thrombolysis2,3. Determining methods to accelerate recovery from stroke remains a prime medical goal; however, this has been hampered by insufficient mechanistic insights into the recovery process. Experimental stroke researchers frequently employ rodent models of focal cerebral ischemia. Beyond the acute phase, stroke research is increasingly focused on the sub-acute and chronic phase following cerebral ischemia. Most stroke researchers apply permanent or transient occlusion of the MCA in mice or rats. In patients, occlusions of the MCA are among the most frequent causes of ischemic stroke4. Besides proximal occlusion of the MCA using the filament model, surgical occlusion of the distal MCA is probably the most frequently used model in experimental stroke research5. Occlusion of a distal (to the branching of the lenticulo-striate arteries) MCA branch typically spares the striatum and primarily affects the neocortex. Vessel occlusion can be permanent or transient. High reproducibility of lesion volume and very low mortality rates with respect to the long-term outcome are the main advantages of this model. Here, we demonstrate how to perform a chronic cranial window (CW) preparation lateral to the sagittal sinus, and afterwards how to surgically induce a distal stroke underneath the window using a craniotomy approach. This approach can be applied for sequential imaging of acute and chronic changes following ischemia via epi-illuminating, confocal laser scanning, and two-photon intravital microscopy.

The timeline and representative results are shown in Figures 2 and 3. The cranial window preparation, with a small cranial window lateral to the superior sagittal sinus (Figure 2 B, C, D) results in a very low mortality and morbidity rate when performed by an experienced surgeon. All of the 10 animals survived, and all chronic CW could be used for high-quality imaging, even 28 days after surgery. There was no problem with wound infections...

Watch this Scientific Journal Video about Lateral Chronic Cranial Window Preparation Enables In Vivo Observation Following Distal Middle Cerebral Artery Occlusion in Mice at JoVE.com

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 mice.

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

Focal cerebral ischemia (i.e., ischemic stroke) may cause major brain injury, leading to a severe loss of neuronal function and consequently to a host of ...

The overall goal of this procedure is the preparation of a lateral cranial window combined with permanent middle cerebral artery occlusion. To facilitate longitudinal intravital microscopy in mice. This method can help to investigate and answer key questions in the field of cerebellar ischemia research.The main advantage of this technique is that it offers in vivo imaging of acute and chronic changes after stroke. Begin by administering anesthesia according to an approved animal protocol. Ensure that a surgical plane of anesthesia has been reached by administering a pain stimulus, such as a toe pinch, and noting the absence of a reaction.Next, use a rodent shaver to remove the fur from the neck to the eyes. Fix the head of the mouse in a Stereotaxic frame. Then cover the eyes with ophthalmic ointment to prevent dehydration.Clean the shaved area to remove all hairs, and sterilize the scalp with three applications of 74.1%ethanol and 10%tube Propranolol. Using a sterile scalpel, make a midline incision from the neck to the eyes. Then span the skin flap with four tenting sutures.Next, carefully scrape the periosteum on the left side of the skull. And remove it to the point where the temporal muscle begins. Now use a micro drill to thin the skull at the rim of the bone flap.To create a four-millimeter diameter frontoparietal craniotomy. Apply saline solution while drilling to avoid heat injury. Once drilled, elevate the bone flap with cannulas and remove it using micro forceps.Irrigate the area carefully and extensively with saline solution. Mix the dental glue until it has the proper consistency. Then apply it to the bone around the craniotomy.Place a six-millimeter diameter cover glass on the prepared glue. And fix it with the rest of the dental glue. Irrigation accelerates the curing process and ensures the seal is water-tight.Probe the dental glue with forceps to ensure that it is dried and hard. After the glue has cured, remove the tenting sutures and close the wound with skin sutures. Administer 0.5 milliliters of sterile saline subcutaneously for fluid balance.After surgery, monitor the animal in a heated recovery cage until recovered from anesthesia. Ensure that the animal is completely recovered before returning it to a cage with other animals. Always administer analgesia after surgery.Here, 10 milligrams per milliliter acetaminophen is added to the drinking water. Always provide mashed animal food in a petri dish placed on the floor to make eating simple and to avoid critical weight loss after surgery. Intravital microscopy can be performed on the first day after cranial window preparation.Apply isoflurane anesthesia according to an approved protocol. Fix the animal in a head-holder and ensure the nose cone is properly fitted. Open the skin suture and clean the window with cotton buds and sterile saline.After 24 hours, the cranial window should be filled with cerebrospinal fluid, which enables imaging. Perform the middle cerebral artery occlusion procedure five days after cranial window preparation, when the immune response to the procedure has receded. Here, an overview after craniotomy for MCAO induction is shown.The intraoperative photo shows the vessels after first and second bipolar contact. The distal MCA appears completely occluded. This picture provides a final overview using lower magnification.After inducing surgical anesthesia with isoflurane as before, shave the fur in the area between the eye and ear, apply ophthalmic ointment to both eyes, and disinfect the skin and surrounding fur with alcohol solution, as before. Place the mouse on a feedback-controlled heating pad to maintain body temperature. Place the animal in the lateral position and fix the nose in the anesthesia mask.Gently separate the skin of the incision made for the cranial window preparation and identify the temporal muscle underneath. Next, adjust the energy of the high frequency generator and use the bipolar mode. Use electrocoagulation forceps to carefully lift the temporal muscle from the skull, creating a muscle flap without totally removing the muscle.Then identify the middle cerebral artery below the transparent skull in the rostral part of the temporal area. Dorsal to the retro-orbital sinus. Thin the skull above the MCA branch with a micro drill, while continuously irrigating to avoid heat damage.Then lift the bone and remove it with micro forceps. Decrease the energy of the high frequency generator to three to five watt. Then, approach the artery from above and gently touch it with the bipolar forceps on both sides without lifting the vessel.Wait for thirty seconds, and then touch the artery gently with the tip of the bipolar forceps to ensure that the blood flow is permanently interrupted. After MCA occlusion, fix the temporal muscle with one or two stitches at the muscle insertion to cover the bone defect. Then, suture the wound and place the animal into the heated cage until recovered.This MRI was performed 24 hours after sham surgery, and does not show any lesioned cortical tissue. Whereas this MRI, performed 24 hours after ischemia, clearly depicts the ischemic lesion indicated by an asterisk, located underneath the chronic cranial window. This image shows intravital epifluorescense imaging and two-photon imaging of the cortical vasculature to monitor changes in microcirculation.Infarct volume assessed via MRI at 24 and 96 hours after ischemia, shows a mean lesion volume of 13.16 millimeters cubed at 24 hours, and 12.2 millimeters cubed at 96 hours. Once mastered, the cranial window preparation can be done in about 30 minutes. And the MCAO in about 15 minutes.Following this procedure, other methods, like MRI, or dual-photon microscopy can be performed to answer additional questions. These new techniques allow investigators to investigate a neurovascular unit at a molecular and cellular level. And most particularly, in the living brain.

lateral-chronic-cranial-window-preparation-enables-vivo-observation

Research

JoVE Journal

Neuroscience

11.5K 次观看.  Charité-Universitätsmedizin. The overall goal of this procedure is the preparation of a lateral cranial window combined with permanent middle cerebral artery occlusion. To facilitate longitudinal intravital microscopy in mice. This method can help to investigate and answer key questions in the field of cerebellar ischemia research.The main advantage of this technique is that it offers in vivo imaging of acute and chronic changes after stroke. Begin by administering anesthesia according to an approved animal protoc...

视频: 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...

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

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...

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...

quantification of neurovascular protection following repetitive hypoxic preconditioning and transient middle cerebral artery occlusion in mice

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

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...

modeling stroke in mice: permanent coagulation of the distal middle cerebral artery

Modeling Stroke in Mice: Permanent Coagulation of the Distal Middle Cerebral Artery

Various murine models of middle cerebral artery occlusion (MCAO) are widely used in experimental brain research. Here, we demonstrate the model of transcranial permanent distal MCAO which produces consistent cortical infarction of a size corresponding to damage imposed by the majority of human ischemic...

distal middle artery occlusion procedure to induce ischemic stroke in mice

Distal Middle Artery Occlusion Procedure to Induce Ischemic Stroke in Mice

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...

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

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...

induction of acute ischemic stroke in mice using the distal middle artery occlusion technique

Author Spotlight: Establishing a Reliable Distal MCA Occlusion Model in Mice for Stroke Research

Here, we present a protocol to establish a distal middle cerebral artery occlusion (dMCAO) model through transcranial electrocoagulation in C57BL/6J mice and evaluate the subsequent neurological behavior and histopathological...

Induction of Acute Ischemic Stroke in Mice Using the Distal Middle Artery Occlusion Technique

Occlusion of Distal Middle Artery to Develop an Ischemic Stroke Mouse Model

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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

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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

Transient Middle Cerebral Artery Occlusion Model of Stroke

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...

a modified transcranial middle cerebral artery occlusion model to study stroke outcomes in aged mice

Author Spotlight: Innovative Techniques and Future Directions in Stroke Research 

This protocol demonstrates a unique mouse stroke model with a medium-sized infarct and an excellent survival rate. This model allows preclinical stroke researchers to extend the ischemia duration, use aged mice, and assess long-term functional...

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

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...

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)...

performing permanent distal middle cerebral with common carotid artery occlusion in aged rats to study cortical ischemia with sustained disability

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

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...

intraluminal middle cerebral artery occlusion (mcao) model for ischemic stroke with laser doppler flowmetry guidance in mice

Intraluminal Middle Cerebral Artery Occlusion MCAO Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice

The intraluminal middle cerebral artery occlusion (MCAO) model is the most frequent used model among experimental ischemic stroke models. Here we will demonstrate the entire model in detail with the guide of Laser Doppler flowmetry, and its representative...

Intraluminal Middle Cerebral Artery Occlusion (MCAO) Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice

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

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable clinical state; in the development of animal models of focal ischemia, however, achieving reproducibility of experimentally induced infarct volume is essential. The rat is a widely used animal model for stroke due to its relatively low animal husbandry costs and to the similarity of its cranial circulation to that of humans2,3. In humans, the middle cerebral artery (MCA) is most commonly affected in stroke syndromes and multiple methods of MCA occlusion (MCAO) have been described to mimic this clinical syndrome in animal models. Because recanalization commonly occurs following an acute stroke in the human, reperfusion after a period of occlusion has been included in many of these models. In this video, we demonstrate the transient endovascular suture MCAO model in the spontaneously hypertensive rat (SHR). A filament with a silicon tip coating is placed intraluminally at the MCA origin for 60 minutes, followed by reperfusion. Note that the optimal occlusion period may vary in other rat strains, such as Wistar or Sprague-Dawley. Several behavioral indicators of stroke in the rat are shown. Focal ischemia is confirmed using T2-weighted magnetic resonance images and by staining brain sections with 2,3,5-triphenyltetrazolium chloride (TTC) 24 hours after MCAO.

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 shown.

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide1. In human stroke, there exists a highly variable ...

Stroke is the third most common cause of mortality and the leading cause of acquired adult disability in developed countries. To date, therapeutic options are limited to a small proportion of stroke patients within the first hours after stroke. Novel therapeutic strategies are being extensively investigated, especially to prolong the therapeutic time window. These current investigations include the study of important pathophysiological pathways after stroke, such as post-stroke inflammation, angiogenesis, neuronal plasticity, and regeneration. Over the last decade, there has been increasing concern about the poor reproducibility of experimental results and scientific findings among independent research groups. To overcome the so-called &#8220;replication crisis&#8221;, detailed standardized models for all procedures are urgently needed. As an effort within the &#8220;ImmunoStroke&#8221; research consortium (https://immunostroke.de/), a standardized mouse model of transient middle cerebral artery occlusion (MCAo) is proposed. This model allows the complete restoration of the blood flow upon removal of the filament, simulating the therapeutic or spontaneous clot lysis that occurs in a large proportion of human strokes. The surgical procedure of this &#8220;filament&#8221; stroke model and tools for its functional analysis are demonstrated in the accompanying video.

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 therapy.

Stroke is the third most common cause of mortality and the leading cause of acquired adult disability in developed countries. To date, therapeutic options ...

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their activity in vivo in behaving mice. This paper describes a method for the implantation of a chronic cranial window to allow for the longitudinal imaging of brain cells in awake, head-restrained mice. In combination with genetic strategies and viral injections, it is possible to label specific cells and regions of interest with structural or physiological markers. This protocol demonstrates how to combine viral injections to label neurons in the vicinity of GCaMP6-expressing astrocytes in the cortex for simultaneous imaging of both cells through a cranial window. Multiphoton imaging of the same cells can be performed for days, weeks, or months in awake, behaving animals. This approach provides researchers with a method for viewing cellular dynamics in real time and can be applied to answer a number of questions in neuroscience.

Implantation of a Cranial Window for Repeated In Vivo Imaging in Awake Mice

Presented here is a protocol for the implantation of a chronic cranial window for the longitudinal imaging of brain cells in awake, head-restrained mice.

To fully understand the cellular physiology of neurons and glia in behaving animals, it is necessary to visualize their morphology and record their ...

There is no effective treatment available for most patients suffering with ischemic stroke, making development of novel therapeutics imperative. The brain's ability to self-heal after ischemic stroke is limited by inadequate blood supply in the impacted area. Encephalomyosynangiosis (EMS) is a neurosurgical procedure that achieves angiogenesis in patients with moyamoya disease. It involves craniotomy with placement of a vascular temporalis muscle graft on the ischemic brain surface. EMS has never been studied in the setting of acute ischemic stroke in mice. The hypothesis driving this study is that EMS enhances cerebral angiogenesis at the cortical surface surrounding the muscle graft. The protocol shown here describes the procedure and provides initial data supporting the feasibility and efficacy of the EMS approach. In this protocol, after 60 min of transient middle cerebral artery occlusion (MCAo), mice were randomized to either MCAo or MCAo + EMS treatment. The EMS was performed 3-4 h after occlusion. The mice were sacrificed 7 or 21 days after MCAo or MCAo + EMS treatment. Temporalis graft viability was measured using nicotinamide adenine dinucleotide reduced-tetrazolium reductase assay. A mouse angiogenesis array quantified angiogenic and neuromodulating protein expression. Immunohistochemistry was used to visualize graft bonding with brain cortex and change in vessel density. The preliminary data here suggest that grafted muscle remained viable 21 days after EMS. Immunostaining showed successful graft implantation and increase in vessel density near the muscle graft, indicating increased angiogenesis. Data show that EMS increases fibroblast growth factor (FGF) and decreases osteopontin levels after stroke. Additionally, EMS after stroke did not increase mortality suggesting that protocol is safe and reliable. This novel procedure is effective and well-tolerated and has the potential to provide information of novel interventions for enhanced angiogenesis after acute ischemic stroke.

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 mice.

There is no effective treatment available for most patients suffering with ischemic stroke, making development of novel therapeutics imperative. The ...

Establishing a Transcranial Middle Cerebral Artery Occlusion Mice Model

In experimental stroke research, middle cerebral artery occlusion (MCAO) with an intraluminal filament is widely used to model ischemic stroke in mice. The filament MCAO model typically exhibits a massive cerebral infarction in C57Bl/6 mice that sometimes includes brain tissue in the territory supplied by the posterior cerebral artery, which is largely due to a high incidence of posterior communicating artery atresia. This phenomenon is considered a major contributor to the high mortality rate observed in C57Bl/6 mice during long-term stroke recovery after filament MCAO. Thus, many chronic stroke studies exploit distal MCAO models. However, these models usually produce infarction only in the cortex area, and consequently, the assessment of post-stroke neurologic deficits could be a challenge. This study has established a modified transcranial MCAO model in which the MCA at the trunk is partially occluded either permanently or transiently via a small cranial window. Since the occlusion location is relatively proximal to the origin of the MCA, this model generates brain damage in both the cortex and striatum. Extensive characterization of this model has demonstrated an excellent long-term survival rate, even in aged mice, as well as readily detectable neurologic deficits. Therefore, the MCAO mouse model described here represents a valuable tool for experimental stroke research.

This protocol demonstrates a unique mouse stroke model with a medium-sized infarct and an excellent survival rate. This model allows preclinical stroke researchers to extend the ischemia duration, use aged mice, and assess long-term functional outcomes.

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

Stroke stands as a major cause of death or chronic disability globally. Nevertheless, existing optimal treatments are limited to reperfusion therapies during the acute phase of ischemic stroke. To gain insights into stroke physiopathology and develop innovative therapeutic approaches, in vivo rodent models of stroke play a fundamental role. The availability of genetically modified animals has particularly propelled the use of mice as experimental stroke models.
In stroke patients, occlusion of the middle cerebral artery (MCA) is a common occurrence. Consequently, the most prevalent experimental model involves intraluminal occlusion of the MCA, a minimally invasive technique that doesn't require craniectomy. This procedure involves inserting a monofilament through the external carotid artery (ECA) and advancing it through the internal carotid artery (ICA) until it reaches the branching point of the MCA. After a 45 min arterial occlusion, the monofilament is removed to allow reperfusion. Throughout the process, cerebral blood flow is monitored to confirm the reduction during occlusion and subsequent recovery upon reperfusion. Neurological and tissue outcomes are evaluated using behavioral tests and magnetic resonance imaging (MRI) studies.

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 tests.

Stroke stands as a major cause of death or chronic disability globally. Nevertheless, existing optimal treatments are limited to reperfusion therapies ...

Ischemic stroke remains the predominant cause of mortality and functional impairment among the adult populations globally. Only a minority of ischemic stroke patients are eligible to receive intravascular thrombolysis or mechanical thrombectomy therapy within the optimal time window. Among those stroke survivors, around two-thirds suffer neurological dysfunctions over an extended period. Establishing a stable and repeatable experimental ischemic stroke model is extremely significant for further investigating the pathophysiological mechanisms and developing effective therapeutic strategies for ischemic stroke. The middle cerebral artery (MCA) represents the predominant location of ischemic stroke in humans, with the MCA occlusion serving as the frequently employed model of focal cerebral ischemia. In this protocol, we describe the methodology of establishing the distal MCA occlusion (dMCAO) model through transcranial electrocoagulation in C57BL/6 mice. Since the occlusion site is located at the cortical branch of MCA, this model generates a moderate infarcted lesion restricted to the cortex. Neurological behavioral and histopathological characterization have demonstrated visible motor dysfunction, neuron degeneration, and pronounced activation of microglia and astrocytes in this model. Thus, this dMCAO mouse model provides a valuable tool for investigating the ischemiastroke and worth of popularization.

Here, we present a protocol to establish a distal middle cerebral artery occlusion (dMCAO) model through transcranial electrocoagulation in C57BL/6J mice and evaluate the subsequent neurological behavior and histopathological features.

Ischemic stroke remains the predominant cause of mortality and functional impairment among the adult populations globally. Only a minority of ischemic ...

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

To begin, lay an eight to 10 weeks anesthetized C57 black six male mouse on the surgical bench. Using blunt forceps, pull out the tongue and hold it with fingers. Insert a laryngoscope into the mouth and visualize the vocal cord.Stabilize the mouse chin on the laryngoscope and hold the 20 gauge intravenous, or IV catheter with a guide wire inserted in it. Then slightly insert the guide wire into the vocal cord and slowly push the 20 gauge IV catheter into the trachea until its wing part is even with the nose tip. Once the mouse is connected to the ventilator, keep it in a lateral position with the right temporal area facing up.Maintain the rectal temperature at 37 degrees Celsius using a heating pad and a heat lamp. After locating the zygomatic arch and incising the temporal muscle, use two forceps to dissect the underlying zygomatic arch and expose the joint between the maxilla and zygomatic bones. Then using scissors, cut a three millimeter portion of the zygomatic arch and remove it.Finally, separate the masseter muscle from the skull base. Position four small retractors in different directions and expose the cranial skull base with one retractor pulling the trigeminal nerve branches laterally. Apply a saline drop to the skull above the middle cerebral artery, or MCA trunk and proximal to the rhinal cortex branch.Use an electrical grinder to thin the skull until a small fracture is visible. And with the tip of the forceps, remove the thin skull. Place a single-strand loop of black braided silk on top of the MCA.Then insert an 8-O microsurgical needle to lift the MCA trunk and tie the suture under the needle, leaving the needle's two ends on top of the silk thread loop knot. For transient middle cerebral artery occlusion, or MCAO, slightly tighten the silk thread knot under the needle to block arterial blood flow, representing MCAO onset. Use the forceps to hold the suture and slowly remove the needle at the end of the ischemia.The laser speckle contrast imaging confirmed the reduced blood supply in the right MCA. For transient MCAO after suture removal, the cerebral blood flow reperfusion was evident, and further improved after 24 hours. TTC staining of the brain after 24 hours of stroke demonstrated the generation of infarcted tissue in both the cortical and lateral striatum areas in young and aged mice.The infarct size was moderate compared to filament MCAO.

Surgical Procedure for Transient Middle Cerebral Artery Occlusion

To begin, position the anesthetized mouse on the operating table. Maintain body temperature using a rectal probe connected to a heating pad. Make an incision on the skin of the head in the direction of the sagittal suture, starting from the ears to the area between the eyes.Retract the skin and remove the periosteum on the right side of the skull. Then find the coordinates, 2.5 millimeters lateral from bregma. Apply cyanoacrylate to the doppler holder and attach it for laser-doppler flowmetry.After the glue has dried, connect the doppler probe. Then, check for the correct signal readout for assessing the cerebral blood flow. To perform artery occlusion, turn the mouse over to the supine position and fix it to the surgical table with medical tape.Then make a midline incision on the neck. Pull the skin laterally, followed by pulling away the salivary glands using retractors. This exposes the carotid territory.Identify the vascular anatomy of the common carotid artery, or CCA, the ICA, and the ECA, as well as the different arteries derived from them. For easier handling, detach CCA, followed by ECA from the connective tissue. Then cauterize the superior thyroid artery and detach ICA from the connective tissue.Check again to make sure the main arteries are fully detached from the connective tissue. Next, wrap 6-0 silk sutures around the ECA at the maxillary lingual bifurcation. Then suture around the CCA.Place a vascular clip interrupting blood circulation from the ICA. Make a small incision in the ECA close to the area where the tight knot is located. Insert the monofilament until the thick coating has completely entered the arterial lumen.Tighten the second knot to hold the monofilament inside the artery and to prevent the pressure exerted by the blood from pushing it out. Cut the ECA below the first knot and rotate the stump to orient it in the direction of the ICA. Advance the monofilament via the ICA until the point where the MCA branches out.The occlusion is reflected in an abrupt blood flow drop in the LDF readout. After 40 minutes, anesthetize the mouse again and place it back on the surgical table. Remove the stitches from the neck.After 45 minutes of occlusion, loosen the knot holding the monofilament in place. Pull slowly and gently on the filament and check that tissue recanalization occurs. Then pull out the filament and tighten the knot to prevent blood loss, clean the blood and untie the CCA knot.Ensure that there is no arterial wall damage. Remove the retractors and reposition the muscles, glands, and skin. Suture the skin using a 6-0 suture and apply disinfectant.Disconnect the Doppler probe and detach the holder. Finally, suture and disinfect the skin of the head. The outcome of the transient middle cerebral artery occlusion procedure was evaluated using in-vivo MRI neuroimaging.Lesion evolution assessed at different time points after reperfusion showed that progression of the lesion volume takes approximately two days to complete. Behavioral tests, such as grip strength test, showed a loss of strength in mice after 24 hours of transient middle cerebral artery occlusion. Also, upon stimulation in the corner test, the mice showed a preference to turn to the right side, which was ipsilateral to the lesion, indicating a successful middle cerebral artery occlusion on the right side.

To begin, wipe the heating surgery board with 75%ethanol and set the temperature to 37 degrees Celsius. Place the anesthetized mouse in a right lateral position on the board with the head positioned away. To protect the cornea from drying, apply eye ointment.After shaving the fur from the left orbit to the left ear canal, use a depilatory cream to remove the remaining fur. Disinfect the surgical area three times with povidone iodine and 75%ethanol. Perform a toe-pinch assessment.After making a vertical incision between the left orbit and the left ear canal, retract the soft skin tissue to expose the temporal muscle. Using straight micro forceps, separate the apical and dorsal segments of the temporal muscle from the skull. Identify the Y-shaped bifurcation of the middle cerebral artery, or MCA, beneath the temporal bone.Then using an electric cranial drill, thin out the skull to make a bone window until the dura mater becomes visible. Remove the dura mater above the MCA with curved micro forceps. Using electric coagulation forceps, coagulate the artery at the site's proximal and distal to the bifurcation.Monitor the blood flow of the left MCA cortical branch in a laser speckle blood-flow meter. Then suture the muscle and the skin separately with polyglycolic acid sutures, and apply diclofenac sodium gel and mupirocin ointment to the skin incision. Place the mouse in a recovery chamber.