The authors are thankful to the Vice Chancellor for Research of the Ardabil University of Medical Sciences (Ardabil, Iran) for the financial support (grant No: 9607).

All procedures were performed in accordance with the guidelines of Ardabil University of Medical Sciences Research Council for conducting animal studies (Ethical ID number: IR.ARUMS.REC.1394.08). In this visualized study, we used adult male Sprague-Dawley rats (300-350g) obtained from Pasture Institute (Tehran, Iran).
1. Anesthesia and Flowmetry
<ol>
	<li>Induce anesthesia using 4% isoflurane and maintain it with isoflurane (1-1.5%) in a mixture of nitrous oxide (70% v/v) and oxygen (30% v/v) for the duration of the surgery.</li>
	<li>Place an anaesthetized animal in the prone posture on a feed-back controlled heating blanket and maintain the body temperature at 37&#177;0.5 &#176;C by means of a rectal probe connected to this heating unit.</li>
	<li>Apply a small amount of ophthalmic ointment on both eyes to prevent dryness.</li>
	<li>Shave the surgical region on the left side of the skull with electric clippers. Use betadine solution with a gauze pad to disinfect the skin. Rinse this region with a sterile pad containing 70% ethanol and repeat both steps for three cycles17.</li>
	<li>For analgesia, inject 0.2 mL of 0.5% bupivacaine subcutaneously into the surgery region17.</li>
	<li>Make a 1 cm long skin incision on the skull (extending from the lateral canthus of the left eye to the base of left ear) and dissect the left temporalis muscle to expose the skull. Then, create a small burr hole 5 mm lateral to and 1 mm posterior to the bregma18 to ease placement of the tip of the Doppler flowmeter pencil probe.</li>
	<li>Turn the rat from the prone to supine position, and then put the laser pencil probe into the previously drilled skull blind-hole to monitor the regional cerebral blood flow (rCBF).</li>
	<li>Record each animal&#39;s baseline rCBF and consider this as 100%. Notably, middle cerebral artery occlusion (MCAO) is started whenever a decrease in rCBF of more than 80% is detected19,20.</li>
</ol>
2. Induction of the Focal Cerebra Ischemia
<ol>
	<li>Shave the neck region and disinfect the skin with betadine solution and 70% ethanol. Inject 0.2 mL of 0.5% bupivacaine subcutaneously in surgery site for analgesia17.</li>
	<li>Make a 2 cm long surgical incision in the ventral surface of the neck to access the left common carotid artery (LCCA). Isolate the LCCA from the neighboring fascia and the vagus nerve to access bifurcation of the external carotid artery (ECA) and the internal carotid artery (ICA).</li>
	<li>Ligate permanently either the LCCA or ECA employing a 5-0 silk suture and dissect ICA free to the level of pterygopalatine artery.</li>
	<li>Loosely place a tie of 5-0 silk suture around LCCA, and then temporarily ICA clamp with a vascular micro-clip.</li>
	<li>Make a small incision on the LCCA prior to the previously placed loose tie, and then insert a 4-0 silicon-coated nylon suture into the luminal space of ICA and tighten the suture around the LCCA to secure the nylon suture and prevent blood leaking.</li>
	<li>Remove the vascular micro-clip from the ICA. Then, advance a silicon coated intraluminal filament until observing a marked decline in rCBF that indicates occlusion of the MCA origin. At the end of ischemic period (90 min), start reperfusion by withdrawing the intraluminal suture21.</li>
</ol>
3. Jugular Vein Cannulation and Evans Blue (EB) Injection
<ol>
	<li>Make a 1 cm longitudinal incision in the neck to the left side of the midline and then bluntly dissect away superficial fascia to access the external branch of the left jugular vein (LGV). Then, permanently ligate the cranial end of the LGV with 5-0 silk suture. Loosely place two ties around the vein, and then temporarily clamp the cardiac end of the LGV with a vascular micro-clamp.</li>
	<li>Make a small incision on the LGV between two sutures, and then insert heparinized serum filled catheter into the luminal space of the LGV and advance it approximately 10 mm. Afterward, tighten the ligatures around the vein to secure the catheter and prevent bleeding. Inject small amounts of serum to avoid collapsing the vein.</li>
	<li>At the beginning of the reperfusion period, slowly inject EB dye (1 mL/kg of 2% EB solution in saline) over a 5 min period. Subsequently, wash the cannula by injection of 0.5 mL normal saline and withdraw the injection cannula from the vein12,22.</li>
	<li>Finally, suture the neck and head incisions and inject 0.05 mg/kg buprenorphine intraperitoneally (IP) and repeat the injection every 6-8 h during reperfusion period for post-operative analgesia17.</li>
	<li>Inject 5 mL of pre-warmed saline(IP) to provide hydration in the recovery cage17.</li>
	<li>Place the animal in a special recovery cage equipped with temperature and air conditioning control and monitor the recovery of the animal from anesthesia.</li>
</ol>
4. Assessment of the Blood Brain Barrier Permeability
<ol>
	<li>After 24 h of reperfusion, deeply anesthetize the animal with sodium thiopental. Then, open the thoracic cavity by making a small hole beneath the sternum.</li>
	<li>Make a small opening in the right atrium and inject 250 mL of pre-warmed 0.9% saline (37 &#730;C) at a pressure of 110 mmHg through the left ventricle for 15 min to wash EB away from the circulation until the normal saline exits from the atrium becomes colorless23.</li>
	<li>Immediately remove the brain from the skull and place it in the brain matrix. Dissect the olfactory bulb and cerebellum, and then using a clean razor blade, separate the right hemisphere of the brain from the left (Lesioned) along the midline.</li>
	<li>Weigh each hemisphere and homogenize them separately in 2.5 mL of phosphate buffered saline, and mix this with 2.5 mL of trichloroacetic acid (60%) for 2 min using a vortex machine.</li>
	<li>Centrifuge brain samples for 30 min at 1,322 x g and allow the samples to cool down in a 4 &#176;C refrigerator for 10 min.</li>
	<li>Use the supernatants to estimate the EB absorbance by a spectrophotometer at 610 nm23.</li>
	<li>Calculate EB concentrations against a standard curve and express results as &#181;g/g of the brain tissue.</li>
</ol>
5. Production of the EB Standard Curve
<ol>
	<li>Prepare 10 sample solutions of EB with concentrations of 1-10 &#181;g of EB in 5 mL of phosphate buffered saline.</li>
	<li>Measure the absorbance values of each sample at 610 nm using a spectrophotometer.</li>
	<li>Make a scatter chart using a spreadsheet and present EB concentrations on the X axis and the absorbance values on the Y axis (Figure 1).</li>
	<li>Define a linear trend-line for the curve with its equation. Then, use it to obtain the EB concentration of samples.</li>
	<li>Report the final results of EB extravasation as &#181;g/g of the brain tissue weight.</li>
</ol>
6. Sham Operation
<ol>
	<li>Perform the same surgical process with rats in sham-operated group (including making an incision in the neck region and EB injection) but exclude the MCAO.</li>
</ol>

<ol>
	<li>Jin, G., 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=Protecting+against+cerebrovascular+injury:+contributions+of+12/15-lipoxygenase+to+edema+formation+after+transient+focal+ischemia.">Protecting against cerebrovascular injury: contributions of 12/15-lipoxygenase to edema formation after transient focal ischemia.</a> Stroke. 39 (9), 2538-2543 (2008).</li><li>Lo, E. H., Dalkara, T., 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=Mechanisms,+challenges+and+opportunities+in+stroke.">Mechanisms, challenges and opportunities in stroke.</a> Nat Rev Neurosci. 4 (5), 399-415 (2003).</li><li>Tam, S. J., Watts, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Connecting+vascular+and+nervous+system+development:+angiogenesis+and+the+blood-brain+barrier.">Connecting vascular and nervous system development: angiogenesis and the blood-brain barrier.</a> Annu Rev Neurosci. 33, 379-408 (2010).</li><li>Zhang, C., 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=The+potential+use+of+H102+peptide-loaded+dual-functional+nanoparticles+in+the+treatment+of+Alzheimer's+disease.">The potential use of H102 peptide-loaded dual-functional nanoparticles in the treatment of Alzheimer's disease.</a> J Control Release. , (2014).</li><li>Obermeier, B., Daneman, R., Ransohoff, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development,+maintenance+and+disruption+of+the+blood-brain+barrier.">Development, maintenance and disruption of the blood-brain barrier.</a> Nat Med. 19 (12), 1584-1596 (2013).</li><li>Fang, W., 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=Attenuated+Blood-Brain+Barrier+Dysfunction+by+XQ-1H+Following+Ischemic+Stroke+in+Hyperlipidemic+Rats.">Attenuated Blood-Brain Barrier Dysfunction by XQ-1H Following Ischemic Stroke in Hyperlipidemic Rats.</a> Mol Neurobiol. 52 (1), 162-175 (2015).</li><li>Huang, 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=CXCR4+antagonist+AMD3100+protects+blood-brain+barrier+integrity+and+reduces+inflammatory+response+after+focal+ischemia+in+mice.">CXCR4 antagonist AMD3100 protects blood-brain barrier integrity and reduces inflammatory response after focal ischemia in mice.</a> Stroke. 44 (1), 190-197 (2013).</li><li>Omidi, Y., Barar, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impacts+of+blood-brain+barrier+in+drug+delivery+and+targeting+of+brain+tumors.">Impacts of blood-brain barrier in drug delivery and targeting of brain tumors.</a> Bioimpacts. 2 (1), 5-22 (2012).</li><li>Cho, 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=Three-dimensional+blood-brain+barrier+model+for+in+vitro+studies+of+neurovascular+pathology.">Three-dimensional blood-brain barrier model for in vitro studies of neurovascular pathology.</a> Sci Rep. 5, (2015).</li><li>Barar, J., Rafi, M. A., Pourseif, M. M., Omidi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+transport+machineries+and+targeted+therapy+of+brain+diseases.">Blood-brain barrier transport machineries and targeted therapy of brain diseases.</a> Bioimpacts. 6 (4), 225-248 (2016).</li><li>Kaya, 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=Magnesium+sulfate+attenuates+increased+blood-brain+barrier+permeability+during+insulin-induced+hypoglycemia+in+rats.">Magnesium sulfate attenuates increased blood-brain barrier permeability during insulin-induced hypoglycemia in rats.</a> Can J Physiol Pharmacol. 79 (9), 793-798 (2001).</li><li>Pasban, E., Panahpour, H., Vahdati, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+oxygen+therapy+does+not+protect+the+brain+from+vasogenic+edema+following+acute+ischemic+stroke+in+adult+male+rats.">Early oxygen therapy does not protect the brain from vasogenic edema following acute ischemic stroke in adult male rats.</a> Sci Rep. 7 (1), 3221 (2017).</li><li>Haghnejad Azar, A., Oryan, S., Bohlooli, S., Panahpour, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-Tocopherol+Reduces+Brain+Edema+and+Protects+Blood-Brain+Barrier+Integrity+following+Focal+Cerebral+Ischemia+in+Rats.">Alpha-Tocopherol Reduces Brain Edema and Protects Blood-Brain Barrier Integrity following Focal Cerebral Ischemia in Rats.</a> Med Princ Pract. 26 (1), 17-22 (2017).</li><li>Belayev, L., Busto, R., Zhao, W., Ginsberg, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+evaluation+of+blood-brain+barrier+permeability+following+middle+cerebral+artery+occlusion+in+rats.">Quantitative evaluation of blood-brain barrier permeability following middle cerebral artery occlusion in rats.</a> Brain Res. 739 (1-2), 88-96 (1996).</li><li>Bodsch, W., Hossmann, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=125I-antibody+autoradiography+and+peptide+fragments+of+albumin+in+cerebral+edema.">125I-antibody autoradiography and peptide fragments of albumin in cerebral edema.</a> J Neurochem. 41 (1), 239-243 (1983).</li><li>Jiang, Q., 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=Quantitative+evaluation+of+BBB+permeability+after+embolic+stroke+in+rat+using+MRI.">Quantitative evaluation of BBB permeability after embolic stroke in rat using MRI.</a> J Cereb Blood FlowMetab. 25 (5), 583-592 (2005).</li><li>Ulu&#231;, K., Miranpuri, A., Kujoth, G. C., Akt&#252;re, E., Ba&#351;kaya, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=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.</a> J Vis Exp. (48), (2011).</li><li>Hungerhuber, E., Zausinger, S., Westermaier, T., Plesnila, N., Schmid-Elsaesser, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+bilateral+laser+Doppler+fluxmetry+and+electrophysiological+recording+during+middle+cerebral+artery+occlusion+in+rats.">Simultaneous bilateral laser Doppler fluxmetry and electrophysiological recording during middle cerebral artery occlusion in rats.</a> J Neurosci Methods. 154 (1-2), 109-115 (2006).</li><li>Panahpour, H., Nouri, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-Ischemic+Treatment+with+candesartan+protect+from+cerebral+ischemic/reperfusioninjury+in+normotensive+rats.">Post-Ischemic Treatment with candesartan protect from cerebral ischemic/reperfusioninjury in normotensive rats.</a> Int J Pharm Pharm Sci. 4 (4), 286-289 (2012).</li><li>Panahpour, H., Dehghani, G. A., Bohlooli, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enalapril+attenuates+ischaemic+brain+oedema+and+protects+the+blood-brain+barrier+in+rats+via+an+anti-oxidant+action.">Enalapril attenuates ischaemic brain oedema and protects the blood-brain barrier in rats via an anti-oxidant action.</a> Clin Exp Pharmacol Physiol. 41 (3), 220-226 (2014).</li><li>Panahpour, H., Nekooeian, A. A., Dehghani, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blockade+of+Central+Angiotensin+II+AT1+Receptor+Protects+the+Brain+from+Ischemia/Reperfusion+Injury+in+Normotensive+Rats.">Blockade of Central Angiotensin II AT1 Receptor Protects the Brain from Ischemia/Reperfusion Injury in Normotensive Rats.</a> Iran J Med Sci. 39 (6), 536-542 (2014).</li><li>Panahpour, H., Nekooeian, A. A., Dehghani, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candesartan+attenuates+ischemic+brain+edema+and+protects+the+blood-brain+barrier+integrity+from+ischemia/reperfusion+injury+in+rats.">Candesartan attenuates ischemic brain edema and protects the blood-brain barrier integrity from ischemia/reperfusion injury in rats.</a> Iran Biomed J. 18 (4), 232-238 (2014).</li><li>Kaya, 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=The+effects+of+magnesium+sulfate+on+blood-brain+barrier+disruption+caused+by+intracarotid+injection+of+hyperosmolar+mannitol+in+rats.">The effects of magnesium sulfate on blood-brain barrier disruption caused by intracarotid injection of hyperosmolar mannitol in rats.</a> Life sci. 76 (2), 201-212 (2004).</li><li>Sch&#246;ller, 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=Characterization+of+microvascular+basal+lamina+damage+and+blood-brain+barrier+dysfunction+following+subarachnoid+hemorrhage+in+rats.">Characterization of microvascular basal lamina damage and blood-brain barrier dysfunction following subarachnoid hemorrhage in rats.</a> Brain Res. 1142, 237-246 (2007).</li><li>Bodsch, W., Hossmann, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=125I-Antibody+Autoradiography+and+Peptide+Fragments+of+Albumin+in+Cerebral+Edema.">125I-Antibody Autoradiography and Peptide Fragments of Albumin in Cerebral Edema.</a> J Neurochem. 41 (1), 239-243 (1983).</li><li>Sandoval, K. E., Witt, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+tight+junction+permeability+and+ischemic+stroke.">Blood-brain barrier tight junction permeability and ischemic stroke.</a> Neurobiol Dis. 32 (2), 200-219 (2008).</li><li>Zhu, 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=Baicalin+reduces+the+permeability+of+the+blood-brain+barrier+during+hypoxia+in+vitro+by+increasing+the+expression+of+tight+junction+proteins+in+brain+microvascular+endothelial+cells.">Baicalin reduces the permeability of the blood-brain barrier during hypoxia in vitro by increasing the expression of tight junction proteins in brain microvascular endothelial cells.</a> J Ethnopharmacol. 141 (2), 714-720 (2012).</li><li>Kucuk, 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=Effects+of+losartan+on+the+blood-brain+barrier+permeability+in+long-term+nitric+oxide+blockade-induced+hypertensive+rats.">Effects of losartan on the blood-brain barrier permeability in long-term nitric oxide blockade-induced hypertensive rats.</a> Life Sci. 71 (8), 937-946 (2002).</li><li>Uyama, 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=Quantitative+evaluation+of+vascular+permeability+in+the+gerbil+brain+after+transient+ischemia+using+Evans+blue+fluorescence.">Quantitative evaluation of vascular permeability in the gerbil brain after transient ischemia using Evans blue fluorescence.</a> J Cereb Blood Flow Metab. 8 (2), 282-284 (1988).</li><li>Kleinig, T. J., Vink, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suppression+of+inflammation+in+ischemic+and+hemorrhagic+stroke:+therapeutic+options.">Suppression of inflammation in ischemic and hemorrhagic stroke: therapeutic options.</a> Curr Opin Neurol. 22 (3), 294-301 (2009).</li><li>Del Zoppo, G. J., Mabuchi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+microvessel+responses+to+focal+ischemia.">Cerebral microvessel responses to focal ischemia.</a> J Cereb Blood Flow Metab. 23 (8), 879-894 (2003).</li><li>Fluri, F., Schuhmann, M. K., Kleinschnitz, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+ischemic+stroke+and+their+application+in+clinical+research.">Animal models of ischemic stroke and their application in clinical research.</a> Drug Des Devel Ther. 9, 3445-3454 (2015).</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>Shin, H. 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=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>Bottiger, B. W., 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=Global+cerebral+ischemia+due+to+cardiocirculatory+arrest+in+mice+causes+neuronal+degeneration+and+early+induction+of+transcription+factor+genes+in+the+hippocampus.">Global cerebral ischemia due to cardiocirculatory arrest in mice causes neuronal degeneration and early induction of transcription factor genes in the hippocampus.</a> Brain Res Mol Brain Res. 65 (2), 135-142 (1999).</li></ol>

The authors have nothing to disclose.

Thus far, various methods such as autoradiography and detection of the radioactive tracers24,25, immunofluorescence microscopy26,27, and EB extravasation technique20,23 have been used to evaluate the blood-brain barrier damage. EB dye is strongly able to bind to the serum albumin and is used as a tracer for detecting vascular leakage and quantifyi...

Vasogenic brain edema due to blood-brain barrier (BBB) disruption remains an important complication of the ischemic stroke and a major determinant of the survival rate in the stroke patients1,2. The blood-brain barrier (BBB), which is formed by brain capillary endothelial cells (BCECs) and composed of distinct neurovascular components (e.g., tight junctions among BCECs, pericytes, astroglial, and neuronal cells3), provides a specialized and dynamic interface between the central nervous system (CNS) and peripheral blood-circulation4,5. Insults such as ischemia-reperfusion injuries could disrupt the functional integrity of the BBB and lead to subsequent penetration of circulating leukocytes into the brain parenchyma that ultimately trigger cerebral inflammation and primary brain injuries6,7. Animal models are needed for the exact detection of the dysfunction of BBB following occurrence of a stroke. Such models are of great importance for studying underlying pathophysiological mechanisms and introducing new neuroprotective strategies. In vitro cell culture-based models of the BBB have been highly developed and used for molecular study of the BBB physiopathology8,9,10. Nevertheless, in vivo animal models, which produce ischemic damage of the BBB similar to human clinical conditions, are also very worthwhile in this regard. Quantitative detection of the extravasation of Evans blue (EB) is a well-accepted and sensitive technique that has been used for assessment of the BBB integrity and function in neurodegenerative diseases, including ischemic stroke11,12,13,14. This method is cost-effective, feasible, reproducible, and completely applicable in any experimental laboratory. Its implementation does not require advanced equipment, such as radioactive tracers15 or magnetic resonance imaging (MRI)16, that are prerequisites for other methods. In this article, we comprehensively demonstrate basic technical processes of BBB assessment using EB extravasation in rat models of ischemic stroke.

<table border="0" cellpadding="0" cellspacing="0" width="829">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:208px;">Isoflurane</td>
			<td style="width:203px;">Piramal</td>
			<td style="width:225px;">AWN 34041100</td>
			<td style="width:193px;">20 - 25 &#176;C</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">2,3,5-Triphenyltetrazolium chloride (TTC)</td>
			<td>Molekula</td>
			<td>31216368</td>
			<td>4 years</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Sprague&#8211;Dawley rats&#160;</td>
			<td>Pasture Institute (Tehran, Iran)</td>
			<td></td>
			<td>300-350g</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Evans Blue&#160;</td>
			<td>Sigma-Aldrich&#160;</td>
			<td>314-13-6</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Trichloroacetic acid&#160;</td>
			<td>Sigma-Aldrich&#160;</td>
			<td>76-03-9</td>
			<td>2 years</td>
		</tr>
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			<td height="22" style="height:22px;">Anesthesia Machine for Small Animals |</td>
			<td>&#160;Kent Scientific</td>
			<td>SS-01</td>
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			<td height="22" style="height:22px;">Power Lab system</td>
			<td>AD Instruments</td>
			<td>ML880</td>
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			<td height="22" style="height:22px;">Laser Doppler flowmeter</td>
			<td>AD Instruments</td>
			<td>ML191</td>
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		<tr height="22">
			<td height="22" style="height:22px;">Heating feed back system</td>
			<td>Harvard Appratus</td>
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			<td height="22" style="height:22px;">Vascular micro clamp</td>
			<td>FineScience Tools</td>
			<td>18055-03</td>
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			<td height="22" style="height:22px;">Silk 5-0 suture thread</td>
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			<td>682G</td>
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		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Ethilon 4-0 suture thread&#160;</td>
			<td>Ethicon</td>
			<td>EH6740G</td>
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an in vivo assessment of blood-brain barrier disruption in a rat model of ischemic stroke

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier (BBB). Rats with induced ischemic stroke were established and used as in vivo models to investigate the functional integrity of the BBB. Spectrophotometric detection of Evans blue (EB) in the brain samples with ischemic injury could provide reliable justification for the research and development of novel therapeutic modalities. This method generates reproducible results, and is applicable in any laboratory without a need for special equipment. Here, we present a visualized and technical guideline on the detection of the extravasation of EB following induction of ischemic stroke in rats.

There was no significant difference in EB levels in the right hemisphere versus the left hemisphere of the sham-operated rats (1.06 &#177; 0.1 &#181;g/g and 1.1 &#177; 0.09 &#181;g/g, respectively). As shown in Figures 2A-2B, induction of transient ischemia (90 min ischemia/ 24 h reperfusion) caused a significant difference in EB levels (10.41 &#177; 0.84 &#181;g/g, p &#60;0.001) in the left hemisphere of ischemic rats, as compared to the respective hemisphere in...

Watch this Scientific Journal Video about An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke at JoVE.com

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

The overall goal of this procedure is to provide a highly reproducible technique for in vivo assessment of the blood-brain barrier disruption in rat models of ischemic stroke.

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier ...

an-vivo-assessment-blood-brain-barrier-disruption-rat-model-ischemic

Research

JoVE Journal

Neuroscience

11.3K Views.  Ardabil University of Medical Sciences. The overall goal of this procedure is to provide a highly reproducible technique for in vivo assessment of the blood-brain barrier disruption in rat models of ischemic stroke.

Video: An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model

Epithelial and endothelial cells (EC) are building paracellular barriers which protect the tissue from the external and internal environment. The blood-brain barrier (BBB) consisting of EC, astrocyte end-feet, pericytes and the basal membrane is responsible for the protection and homeostasis of the brain parenchyma. In vitro BBB models are common tools to study the structure and function of the BBB at the cellular level. A considerable number of different in vitro BBB models have been established for research in different laboratories to date. Usually, the cells are obtained from bovine, porcine, rat or mouse brain tissue (discussed in detail in the review by Wilhelm et al. 1). Human tissue samples are available only in a restricted number of laboratories or companies 2,3. While primary cell preparations are time consuming and the EC cultures can differ from batch to batch, the establishment of immortalized EC lines is the focus of scientific interest.
Here, we present a method for establishing an immortalized brain microvascular EC line from neonatal mouse brain. We describe the procedure step-by-step listing the reagents and solutions used. The method established by our lab allows the isolation of a homogenous immortalized endothelial cell line within four to five weeks. The brain microvascular endothelial cell lines termed cEND 4 (from cerebral cortex) and cerebEND 5 (from cerebellar cortex), were isolated according to this procedure in the F&ouml;rster laboratory and have been effectively used for explanation of different physiological and pathological processes at the BBB. Using cEND and cerebEND we have demonstrated that these cells respond to glucocorticoid- 4,6-9 and estrogen-treatment 10 as well as to pro-infammatory mediators, such as TNFalpha 5,8. Moreover, we have studied the pathology of multiple sclerosis 11 and hypoxia 12,13 on the EC-level. The cEND and cerebEND lines can be considered as a good tool for studying the structure and function of the BBB, cellular responses of ECs to different stimuli or interaction of the EC with lymphocytes or cancer cells.

Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model

This method describes how to isolate and immortalize microvascular endothelial cells from mouse brain. We describe a step-by-step protocol starting from the homogenization of brain tissue, digestion steps, seeding and immortalization of the cells. Usually, it takes about five weeks to obtain a homogenous, immortalized microvascular endothelial cell line.

Epithelial and endothelial cells (EC) are building paracellular barriers which protect the tissue from the external and internal environment. The ...

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Assessment of Blood-brain Barrier Permeability by Intravenous Infusion of FITC-labeled Albumin in a Mouse Model of Neurodegenerative Disease

Disruption of blood-brain barrier (BBB) integrity is a common feature for different neurological and neurodegenerative diseases. Although the interplay between perturbed BBB homeostasis and the pathogenesis of brain disorders needs further investigation, the development and validation of a reliable procedure to accurately detect BBB alterations may be crucial and represent a useful tool for potentially predicting disease progression and developing targeted therapeutic strategies.
Here, we present an easy and efficient procedure for evaluating BBB leakage in a neurodegenerative condition like that occurring in a preclinical mouse model of Huntington disease, in which defects in the permeability of BBB are clearly detectable precociously in the disease. Specifically, the high molecular weight fluorescein isothiocyanate labelled (FITC)-albumin, which is able to cross the BBB only when the latter is impaired, is acutely infused into a mouse jugular vein and its distribution in the vascular or parenchymal districts is then determined by fluorescence microscopy.
Accumulation of green fluorescent-albumin in the brain parenchyma functions as an index of aberrant BBB permeability and, when quantitated by using Image J processing software, is reported as Green Fluorescence Intensity.

In this study, we present an easy and efficient procedure for evaluating the disruption of the blood-brain barrier under neurodegenerative conditions. To achieve our objective, we infused high molecular weight fluorescein isothiocyanate labelled (FITC)-albumin into mouse jugular vein and evaluated its leakage into the brain parenchyma by fluorescence microscopy.

Disruption of blood-brain barrier (BBB) integrity is a common feature for different neurological and neurodegenerative diseases. Although the interplay ...

Optimized Management of Endovascular Treatment for Acute Ischemic Stroke

This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from hospital admission to reperfusion. Rapid restoration of cerebral blood flow is essential for the outcomes of patients with acute ischemic stroke. Endovascular treatment (EVT) has become the standard of care to accomplish this in patients with acute stroke due to large vessel occlusion (LVO). To achieve reperfusion of ischemic brain regions as fast as possible, all in-hospital time delays have to be carefully avoided. Therefore, management of patients with acute ischemic stroke was optimized with an interdisciplinary standard operating procedure (SOP). Stroke neurologists, diagnostic as well as interventional neuroradiologists, and anesthesiologists streamlined all necessary processes from patient admission and diagnosis to EVT of eligible patients. Target times for every step were established. Actually achieved times were prospectively recorded along with clinical data and imaging scores for all endovascularly treated stroke patients. These data were regularly analyzed and discussed in interdisciplinary team meetings. Potential issues were evaluated and all staff involved was trained to adhere to the SOP. This streamlined patient management approach and enhanced interdisciplinary collaboration reduced time from patient admission to reperfusion significantly and was accompanied by a beneficial effect on clinical outcomes.

The outcome of patients with acute ischemic stroke depends on swift restoration of cerebral blood flow. This protocol aims at optimizing the management of such patients by minimizing peri-procedural timings and rendering the time from hospital admission to reperfusion as short as possible.

This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from ...

An In Vivo Blood-brain Barrier Permeability Assay in Mice Using Fluorescently Labeled Tracers

Blood-brain barrier (BBB) is a specialized barrier that protects the brain microenvironment from toxins and pathogens in the circulation and maintains brain homeostasis. The principal sites of the barrier are endothelial cells of the brain capillaries whose barrier function results from tight intercellular junctions and efflux transporters expressed on the plasma membrane. This function is regulated by pericytes and astrocytes that together form the neurovascular unit (NVU). Several neurological diseases such as stroke, Alzheimer&#39;s disease (AD), brain tumors are associated with an impaired BBB function. Assessment of the BBB permeability is therefore crucial in evaluating the severity of the neurological disease and the success of the treatment strategies employed.
We present here a simple yet robust permeability assay that have been successfully applied to several mouse models both, genetic and experimental. The method is highly quantitative and objective in comparison to the tracer fluorescence analysis by microscopy that is commonly applied. In this method, mice are injected intraperitoneally with a mix of aqueous inert fluorescent tracers followed by anesthetizing the mice. Cardiac perfusion of the animals is performed prior to harvesting brain, kidneys or other organs. Organs are homogenized and centrifuged followed by fluorescence measurement from the supernatant. Blood drawn from the cardiac puncture just before perfusion serves for normalization purpose to the vascular compartment. The tissue fluorescence is normalized to the wet weight and serum fluorescence to obtain a quantitative tracer permeability index. For additional confirmation, the contralateral hemi-brain preserved for immunohistochemistry can be utilized for tracer fluorescence visualization purposes.

An In Vivo Blood-brain Barrier Permeability Assay in Mice Using Fluorescently Labeled Tracers

Here we present a mouse brain vascular permeability assay using intraperitoneal injection of fluorescent tracers followed by perfusion that is applicable to animal models of blood-brain barrier dysfunction. One hemi-brain is used for assessing permeability quantitatively and the other for tracer visualization/immunostaining. The procedure takes 5 - 6 h for 10 mice.

Blood-brain barrier (BBB) is a specialized barrier that protects the brain microenvironment from toxins and pathogens in the circulation and maintains ...

The Power of Interstimulus Interval for the Assessment of Temporal Processing in Rodents

Temporal processing deficits have been implicated as a potential elemental dimension of higher-level cognitive processes, commonly observed in neurocognitive disorders. Despite the popularization of prepulse inhibition (PPI) in recent years, many current protocols promote using a percent of control measure, thereby precluding the assessment of temporal processing. The present study used cross-modal PPI and gap prepulse inhibition (gap-PPI) to demonstrate the benefits of employing a range of interstimulus intervals (ISIs) to delineate effects of sensory modality, psychostimulant exposure, and age. Assessment of sensory modality, psychostimulant exposure, and age reveals the utility of an approach varying the interstimulus interval (ISI) to establish the shape of the ISI function, including increases (sharper curve inflections) or decreases (flattening of the response amplitude curve) in startle amplitude. Additionally, shifts in peak response inhibition, suggestive of a differential sensitivity to the manipulation of ISI, are often revealed. Thus, the systematic manipulation of ISI affords a critical opportunity to evaluate temporal processing, which may reveal the underlying neural mechanisms involved in neurocognitive disorders.

Temporal processing, a preattentive process, may underlie deficits in higher-level cognitive processes, including attention, commonly observed in neurocognitive disorders. Using prepulse inhibition as an exemplar paradigm, we present a protocol for manipulating interstimulus interval (ISI) to establish the shape of the ISI function to provide an assessment of temporal processing.

Temporal processing deficits have been implicated as a potential elemental dimension of higher-level cognitive processes, commonly observed in ...

A Preclinical Model to Assess Brain Recovery After Acute Stroke in Rats

The purpose of this study was to establish and validate an animal brain ischemia model in the recovery and sequela stages. A middle cerebral artery occlusion/reperfusion (MCAO/R) model in male Sprague-Dawley rats was chosen. By changing the rat&#39;s weight (260&#8722;330 g), the thread bolt type (2636/2838/3040/3043) and the brain infarct time (2-3 h), a higher Longa&#39;s score, a larger infarct volume and a greater model success ratio were screened using the Longa&#39;s score and TTC staining. The optimum model condition (300 g, 3040 thread bolt, 3 h brain infarct time) was acquired and used in a 1-90 day observation period after reperfusion via assessment of sensorimotor functions and infarct volume. At these conditions, the bilateral asymmetry test had a significant difference from 1 to 90 days, and the grid-walking test had a significant difference from 1 to 60 days; both differences could be a suitable sensorimotor functional test. Thus, the most appropriate condition of a novel rat model in the recovery and sequela stages of brain ischemia was found: 300 g rats that underwent MCAO with a 3040 thread bolt for a 3 h brain infarct and then reperfused. The appropriate sensorimotor functional tests were a bilateral asymmetry test and a grid-walking test.

The&#160;purpose of this study is to establish and validate an animal model for research in the recovery and sequela stages of brain ischemia by testing brain infarction and sensorimotor function after middle cerebral artery occlusion/reperfusion (MCAO/R) after 1-90 days in rats.

The purpose of this study was to establish and validate an animal brain ischemia model in the recovery and sequela stages. A middle cerebral artery ...

A Benchtop Approach to the Location Specific Blood Brain Barrier Opening using Focused Ultrasound in a Rat Model

Stereotaxic surgery is the gold standard for localized drug and gene delivery to the rodent brain. This technique has many advantages over systemic delivery including precise localization to a target brain region and reduction of off target side effects. However, stereotaxic surgery is highly invasive which limits its translational efficacy, requires long recovery times, and provides challenges when targeting multiple brain regions. Focused ultrasound (FUS) can be used in combination with circulating microbubbles to transiently open the blood brain barrier (BBB) in millimeter sized regions. This allows intracranial localization of systemically delivered agents that cannot normally cross the BBB. This technique provides a noninvasive alternative to stereotaxic surgery. However, to date this technique has yet to be widely adopted in neuroscience laboratories due to the limited access to equipment and standardized methods. The overall goal of this protocol is to provide a benchtop approach to FUS BBB opening (BBBO) that is affordable and reproducible and can therefore be easily adopted by any laboratory.

Focused ultrasound with microbubble agents can open the blood brain barrier focally and transiently. This technique has been used to deliver a wide range of agents across the blood brain barrier. This article provides a detailed protocol for the localized delivery to the rodent brain with or without MRI guidance.

Stereotaxic surgery is the gold standard for localized drug and gene delivery to the rodent brain. This technique has many advantages over systemic ...

Measuring Post-Stroke Cerebral Edema, Infarct Zone and Blood-Brain Barrier Breakdown in a Single Set of Rodent Brain Samples

One of the most common causes of morbidity and mortality worldwide is ischemic stroke. Historically, an animal model used to stimulate ischemic stroke involves middle cerebral artery occlusion (MCAO). Infarct zone, brain edema and blood-brain barrier (BBB) breakdown are measured as parameters that reflect the extent of brain injury after MCAO. A significant limitation to this method is that these measurements are normally obtained in different rat brain samples, leading to ethical and financial burdens due to the large number of rats that need to be euthanized for an appropriate sample size. Here we present a method to accurately assess brain injury following MCAO by measuring infarct zone, brain edema and BBB permeability in the same set of rat brains. This novel technique provides a more efficient way to evaluate the pathophysiology of stroke.

This protocol describes a novel technique of measuring the three most important parameters of ischemic brain injury on the same set of rodent brain samples. Using only one brain sample is highly advantageous in terms of ethical and economic costs.

One of the most common causes of morbidity and mortality worldwide is ischemic stroke. Historically, an animal model used to stimulate ischemic stroke ...

A Rat Model of EcoHIV Brain Infection

It has been well studied that the EcoHIV infected mouse model is of significant utility in investigating HIV associated neurological complications. Establishment of the EcoHIV infected rat model for studies of drug abuse and neurocognitive disorders, would be beneficial in the study of neuroHIV and HIV-1 associated neurocognitive disorders (HAND). In the present study, we demonstrate the successful creation of a rat model of active HIV infection using chimeric HIV (EcoHIV). First, the lentiviral construct of EcoHIV was packaged in cultured 293 FT cells for 48 hours. Then, the conditional medium was concentrated and titered. Next, we performed bilateral stereotaxic injections of the EcoHIV-EGFP into F344/N rat brain tissue. One week after infection, EGFP fluorescence signals were detected in the infected brain tissue, indicating that EcoHIV successfully induces an active HIV infection in rats. In addition, immunostaining for the microglial cell marker, Iba1, was performed. The results indicated that microglia were the predominant cell type harboring EcoHIV. Furthermore, EcoHIV rats exhibited alterations in temporal processing, a potential underlying neurobehavioral mechanism of HAND as well as synaptic dysfunction eight weeks after infection. Collectively, the present study extends the EcoHIV model of HIV-1 infection to the rat offering a valuable biological system to study HIV-1 viral reservoirs in the brain as well as HAND and associated comorbidities such as drug abuse.

Here, we present a protocol to establish a new rat model of active HIV infection using chimeric HIV (EcoHIV), which is critical for enhancing our understanding of HIV-1 viral reservoirs in the brain and offering a system to study HIV-associated neurocognitive disorders and associated comorbidities (i.e., drug abuse).

It has been well studied that the EcoHIV infected mouse model is of significant utility in investigating HIV associated neurological complications. ...