The work was supported by the Lundbeck Foundation and the Lundbeck Grant of Excellence (no. R59-A5404). Funders had no role in any part of the manuscript.

This procedure is done in accordance with the European Union&#39;s Directive 2010/63/EU regarding the protection of animals used for scientific purposes and approved by the Danish Animal Experiments Inspectorate (license no. 2016-15-0201-00940). Surgery is performed using aseptic technique to the widest extent possible, including sterile instruments, gloves, catheters, and sutures. The study used male and female Sprague-Dawley rats weighing 230-350 g, group housed in 12-h light/dark cycle, with constant temperature of 22...

<ol>
	<li>van Gijn, J., Kerr, R. S., Rinkel, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subarachnoid+haemorrhage.">Subarachnoid haemorrhage.</a> Lancet. 369 (9558), 306-318 (2007).</li><li>de Rooij, N. K., Linn, F. H. H., vander Plas, J. A., Algra, A., Rinkel, G. J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incidence+of+subarachnoid+haemorrhage:+a+systematic+review+with+emphasis+on+region,+age,+gender+and+time+trends.">Incidence of subarachnoid haemorrhage: a systematic review with emphasis on region, age, gender and time trends.</a> Journal of Neurology, Neurosurgery, and Psychiatry. 78 (12), 1365-1372 (2007).</li><li>Feigin, V. L., Lawes, C. M., Bennett, D. A., Barker-Collo, S. L., Parag, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Worldwide+stroke+incidence+and+early+case+fatality+reported+in+56+population-based+studies:+a+systematic+review.">Worldwide stroke incidence and early case fatality reported in 56 population-based studies: a systematic review.</a> The Lancet, Neurology. 8 (4), 355-369 (2009).</li><li>Maher, M., Schweizer, T. A., Macdonald, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+spontaneous+subarachnoid+hemorrhage:+guidelines+and+gaps.">Treatment of spontaneous subarachnoid hemorrhage: guidelines and gaps.</a> Stroke. 51 (4), 1326-1332 (2020).</li><li>Pickard, J. D., 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+oral+nimodipine+on+cerebral+infarction+and+outcome+after+subarachnoid+haemorrhage:+British+aneurysm+nimodipine+trial.">Effect of oral nimodipine on cerebral infarction and outcome after subarachnoid haemorrhage: British aneurysm nimodipine trial.</a> British Medical Journal (Clinical Research ed.). 298 (6674), 636-642 (1989).</li><li>Daou, B. J., Koduri, S., Thompson, B. G., Chaudhary, N., Pandey, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+and+experimental+aspects+of+aneurysmal+subarachnoid+hemorrhage.">Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage.</a> CNS Neuroscience and Therapeutics. 25 (10), 1096-1112 (2019).</li><li>Fujii, 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=Early+brain+injury,+an+evolving+frontier+in+subarachnoid+hemorrhage+research.">Early brain injury, an evolving frontier in subarachnoid hemorrhage research.</a> Translational Stroke Research. 4 (4), 432-446 (2013).</li><li>Roos, Y. B., 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=Complications+and+outcome+in+patients+with+aneurysmal+subarachnoid+haemorrhage:+A+prospective+hospital+based+cohort+study+in+the+Netherlands.">Complications and outcome in patients with aneurysmal subarachnoid haemorrhage: A prospective hospital based cohort study in the Netherlands.</a> Journal of Neurology, Neurosurgery, and Psychiatry. 68 (3), 337-341 (2000).</li><li>Vergouwen, M. D. I., 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=Definition+of+delayed+cerebral+ischemia+after+aneurysmal+subarachnoid+hemorrhage+as+an+outcome+event+in+clinical+trials+and+observational+studies:+proposal+of+a+multidisciplinary+research+group.">Definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as an outcome event in clinical trials and observational studies: proposal of a multidisciplinary research group.</a> Stroke. 41 (10), 2391-2395 (2010).</li><li>Brown, R. J., Kumar, A., Dhar, R., Sampson, T. R., Diringer, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+delayed+infarcts+and+angiographic+vasospasm+after+aneurysmal+subarachnoid+hemorrhage.">The relationship between delayed infarcts and angiographic vasospasm after aneurysmal subarachnoid hemorrhage.</a> Neurosurgery. 72 (5), 702-707 (2013).</li><li>Dhar, 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=Relationship+between+angiographic+vasospasm+and+regional+hypoperfusion+in+aneurysmal+subarachnoid+hemorrhage.">Relationship between angiographic vasospasm and regional hypoperfusion in aneurysmal subarachnoid hemorrhage.</a> Stroke. 43 (7), 1788-1794 (2012).</li><li>Macdonald, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+neurological+deterioration+after+subarachnoid+haemorrhage.">Delayed neurological deterioration after subarachnoid haemorrhage.</a> Nature Reviews. Neurology. 10 (1), 44-58 (2014).</li><li>Marbacher, 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=Systematic+review+of+in+vivo+animal+models+of+subarachnoid+hemorrhage:+species,+standard+parameters,+and+outcomes.">Systematic review of in vivo animal models of subarachnoid hemorrhage: species, standard parameters, and outcomes.</a> Translational Stroke Research. 10 (3), 250-258 (2019).</li><li>Prunell, G. F., Mathiesen, T., Svendgaard, N. -. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+experimental+model+in+rats+for+study+of+the+pathophysiology+of+subarachnoid+hemorrhage.">A new experimental model in rats for study of the pathophysiology of subarachnoid hemorrhage.</a> Neuroreport. 13 (18), 2553-2556 (2002).</li><li>Prunell, G. F., Mathiesen, T., Diemer, N. H., Svendgaard, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+subarachnoid+hemorrhage:+subarachnoid+blood+volume,+mortality+rate,+neuronal+death,+cerebral+blood+flow,+and+perfusion+pressure+in+three+different+rat+models.">Experimental subarachnoid hemorrhage: subarachnoid blood volume, mortality rate, neuronal death, cerebral blood flow, and perfusion pressure in three different rat models.</a> Neurosurgery. 52 (1), 165-176 (2003).</li><li>Prunell, G. F., 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=Experimental+Subarachnoid+Hemorrhage:+Cerebral+blood+flow+and+brain+metabolism+during+the+acute+phase+in+three+different+models+in+the+rat.">Experimental Subarachnoid Hemorrhage: Cerebral blood flow and brain metabolism during the acute phase in three different models in the rat.</a> Neurosurgery. 54 (2), 426-437 (2004).</li><li>Velthuis, B. 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=Subarachnoid+hemorrhage:+Aneurysm+detection+and+preoperative+evaluation+with+CT+angiography.">Subarachnoid hemorrhage: Aneurysm detection and preoperative evaluation with CT angiography.</a> Radiology. 208 (2), 423-430 (1998).</li><li>Leclerc, J. L., 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=A+comparison+of+pathophysiology+in+humans+and+rodent+models+of+subarachnoid+hemorrhage.">A comparison of pathophysiology in humans and rodent models of subarachnoid hemorrhage.</a> Frontiers in Molecular Neuroscience. 11, 71 (2018).</li><li>Prunell, G. F., Svendgaard, N. A., Alkass, K., Mathiesen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflammation+in+the+brain+after+experimental+subarachnoid+hemorrhage.">Inflammation in the brain after experimental subarachnoid hemorrhage.</a> Neurosurgery. 56 (5), 1082-1091 (2005).</li><li>Prunell, G. F., Svendgaard, N. A., Alkass, K., Mathiesen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+cell+death+related+to+acute+cerebral+blood+flow+changes+following+subarachnoid+hemorrhage+in+the+rat+brain.">Delayed cell death related to acute cerebral blood flow changes following subarachnoid hemorrhage in the rat brain.</a> Journal of Neurosurgery. 102 (6), 1046-1054 (2005).</li><li>Spray, S., Haanes, K. A., Edvinsson, L., Johansson, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subacute+phase+of+subarachnoid+haemorrhage+in+female+rats:+increased+intracranial+pressure,+vascular+changes+and+impaired+sensorimotor+function.">Subacute phase of subarachnoid haemorrhage in female rats: increased intracranial pressure, vascular changes and impaired sensorimotor function.</a> Microvascular Research. 135, 104127 (2020).</li><li>Ansar, S., Vikman, P., Nielsen, M., Edvinsson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebrovascular+ETB,+5-HT1B,+and+AT1+receptor+upregulation+correlates+with+reduction+in+regional+CBF+after+subarachnoid+hemorrhage.">Cerebrovascular ETB, 5-HT1B, and AT1 receptor upregulation correlates with reduction in regional CBF after subarachnoid hemorrhage.</a> American Journal of Physiology - Heart and Circulatory Physiology. 293 (6), 3750-3758 (2007).</li><li>Hansen-Schwartz, 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=Subarachnoid+hemorrhage+enhances+endothelin+receptor+expression+and+function+in+rat+cerebral+arteries.">Subarachnoid hemorrhage enhances endothelin receptor expression and function in rat cerebral arteries.</a> Neurosurgery. 52 (5), 1188-1194 (2003).</li><li>Hayman, E. G., Wessell, A., Gerzanich, V., Sheth, K. N., Simard, 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=Mechanisms+of+global+cerebral+edema+formation+in+aneurysmal+subarachnoid+hemorrhage.">Mechanisms of global cerebral edema formation in aneurysmal subarachnoid hemorrhage.</a> Neurocritical Care. 26 (2), 301-310 (2017).</li><li>Miyata, 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=Vasa+vasorum+formation+is+associated+with+rupture+of+intracranial+aneurysms.">Vasa vasorum formation is associated with rupture of intracranial aneurysms.</a> Journal of Neurosurgery. , 1-11 (2019).</li><li>Tada, Y., 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=Roles+of+hypertension+in+the+rupture+of+intracranial+aneurysms.">Roles of hypertension in the rupture of intracranial aneurysms.</a> Stroke. 45 (2), 579-586 (2014).</li><li>Nuki, Y., 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=Elastase-induced+intracranial+aneurysms+in+hypertensive+mice.">Elastase-induced intracranial aneurysms in hypertensive mice.</a> Hypertension. 54 (6), 1337-1344 (1979).</li><li>Marbacher, S., Wanderer, S., Strange, F., Gr&#252;ter, B. E., Fandino, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Saccular+aneurysm+models+featuring+growth+and+rupture:+A+systematic+review.">Saccular aneurysm models featuring growth and rupture: A systematic review.</a> Brain Sciences. 10 (2), 101 (2020).</li><li>Altay, 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=Isoflurane+on+brain+inflammation.">Isoflurane on brain inflammation.</a> Neurobiology of Disease. 62, 365-371 (2014).</li><li>Hockel, K., Trabold, R., Sch&#246;ller, K., T&#246;r&#246;k, E., Plesnila, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+anesthesia+on+pathophysiology+and+mortality+following+subarachnoid+hemorrhage+in+rats.">Impact of anesthesia on pathophysiology and mortality following subarachnoid hemorrhage in rats.</a> Experimental and Translational Stroke Medicine. 4 (1), 5 (2012).</li><li>Kamp, M. A., 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=A+Systematic+and+meta-analysis+of+mortality+in+experimental+mouse+models+analyzing+delayed+cerebral+ischemia+after+subarachnoid+hemorrhage.">A Systematic and meta-analysis of mortality in experimental mouse models analyzing delayed cerebral ischemia after subarachnoid hemorrhage.</a> Translational Stroke Research. 8 (3), 206-219 (2017).</li><li>Povlsen, G. K., Johansson, S. E., Larsen, C. C., Samraj, A. K., Edvinsson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+events+triggering+delayed+vasoconstrictor+receptor+upregulation+and+cerebral+ischemia+after+subarachnoid+hemorrhage.">Early events triggering delayed vasoconstrictor receptor upregulation and cerebral ischemia after subarachnoid hemorrhage.</a> BMC Neuroscience. 14, 34 (2013).</li></ol>

The pre-chiasmatic single injection model of SAH mimics several important elements of human SAH, including the spike in ICP, reduction of CBF, transient global ischemia, upregulation of neuroinflammatory markers, and CVS14,15,16,18,19,20. The ICP-probe was also used as a port for intrathecal administration (<strong class="xfi...

Non-traumatic subarachnoid hemorrhage (SAH) is a form of stroke, representing around 5% of all cases. The most common cause of non-traumatic SAH is the sudden rupture of an aneurysm (aSAH), which accounts for 85% of SAHs. Other causes include the rupture of an arterio-venous malformation, coagulopathies, and rupture of veins in perimesencephalic hemorrhage1. The incidence rate is 9 per 100,000 person-years with mortality around one in three and another third requiring the support of daily living following SAH2,3.
Following initial stabilization and diagnosis confirmation, treatment depends on the severity of the hemorrhage. The most severely afflicted patients will have an extra-ventricular drain inserted into the ventricles to reduce the intracerebral pressure (ICP) and be admitted to the neurointensive care unit, where they are monitored closely. Patients will undergo an angiography to identify the (probable) aneurysm and afterward have the aneurysm coiled or clipped to prevent rebleeding4. Despite numerous trials of pharmacological therapies, only nimodipine, a calcium-channel antagonist, has shown to improve outcomes5. Multiple clinical trials are currently underway. Please see the review by Daou and colleagues for an extensive list6.
The rupture of an aneurysm has been described as the sudden onset of the worst headache ever experienced or a thunderclap headache. The rupture results in a steep rise in the ICP followed by a reduction in the cerebral blood flow (CBF). This reduction results in global ischemia of the brain, which can result in a loss of consciousness. This more mechanistic pathway, along with the initiated breakdown of the extravasated elements of blood, gives rise to cytokine release and activation of the innate immune system resulting in sterile neuroinflammation. Furthermore, breakdown of the blood-brain barrier, resulting in cerebral edema and disturbance in the ion homeostasis, is often observed. All these changes and more, coined early brain injury (EBI), occur within the first couple of days and results in neuronal loss and apoptosis7.
Approximately 1/3 of patients afflicted with aSAH will develop delayed cerebral ischemia (DCI) between day 4-148. DCI is defined as either the debut of a focal, neurological impairment or a drop of minimum two points on the Glasgow coma scale lasting for a minimum of 1 h, when other causes, including seizures and re-bleeding is excluded. DCI is associated with an increased risk of death and decreased functional outcome following aSAH9. Cerebral vasospasm (CVS), the narrowing of the cerebral arteries, has been known to be associated with DCI for decades and was formerly thought to be the sole reason for DCI. It has since been shown that CVS can occur without the development of DCI and more factors, including microvascular thrombosis and constriction, cortical spreading depression, and an inflammatory response of EBI have since been identified10,11,12.
Due to the large influence of EBI and DCI on the course of the disease and the outcome of the patients afflicted, animal models need to mimic these to the largest degree possible, while still being reproducible. Researchers have employed a wide range of different models in a variety of animals from mice to non-human primates to try and simulate aSAH. Sprague-Dawley and Wistar wildtype rats are currently the most commonly used laboratory animals, and the most common models are the endovascular perforation model, the cisterna-magna double injection model, and lastly the pre-chiasmatic single injection model, which will be described in this article13.
The pre-chiasmatic, single injection model was originally developed by Prunell and colleagues to counter some of the shortcomings of the other experimental models14. The surgery, when mastered, is highly reproducible and minimizes variation between animals. The model mimics SAH in humans on multiple points, including the sudden rise in ICP following the injection of blood, resulting in transient global ischemia due to a fall in the CBF15,16. It affects the anterior circulation, which is where most aSAH in humans occur17. The mortality ranges from 10%-33% depending on the study and amount of blood injected14,18. Delayed cell death and neuroinflammation can be detected on day 2 and 7 thereby providing variables to study the consequences of EBI and DCI19,20.
The study presents an updated description of the pre-chiasmatic single injection model in the rat along with a description of how to utilize the ICP-probe as a port for intrathecal administration of pharmaceutics.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>16 G peripheral vein catheter</td>
			<td>BD Venflon</td>
			<td>393229</td>
			<td>Needle shortened, distal 1 cm curved. Wings removed</td>
		</tr>
		<tr>
			<td>Anesthesia bell/ chamber</td>
			<td>Unknown</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Blood gas analyzer</td>
			<td>Radiometer</td>
			<td>ABL80</td>
			<td></td>
		</tr>
		<tr>
			<td>Blood pressure (BP) monitor</td>
			<td>Adinstruments</td>
			<td>ML117</td>
			<td>Connects to Powerlab</td>
		</tr>
		<tr>
			<td>Curved forceps, 12 cm x 3</td>
			<td>F.S.T</td>
			<td>11001-12</td>
			<td>For anesthesia</td>
		</tr>
		<tr>
			<td>Cylindrical pillow, 28 cm x 4 cm</td>
			<td>Homemade</td>
			<td></td>
			<td>Made from surgical towels</td>
		</tr>
		<tr>
			<td>Data acquisition hardware</td>
			<td>Adinstruments</td>
			<td>ML870 Powerlab</td>
			<td></td>
		</tr>
		<tr>
			<td>Data acquistion software</td>
			<td>Adinstruments</td>
			<td>LabChart 6.0</td>
			<td></td>
		</tr>
		<tr>
			<td>Drill</td>
			<td>KMD</td>
			<td>1189</td>
			<td></td>
		</tr>
		<tr>
			<td>Drill controller</td>
			<td>Silfradent</td>
			<td>300 IN</td>
			<td></td>
		</tr>
		<tr>
			<td>Flexible light</td>
			<td>Schott</td>
			<td>KL200</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating pad</td>
			<td>Minco</td>
			<td>1135</td>
			<td></td>
		</tr>
		<tr>
			<td>Hypodermic needle, 20 G</td>
			<td>KD Medical</td>
			<td>301300</td>
			<td>Connects to stereotaxic frame</td>
		</tr>
		<tr>
			<td>ICP monitor</td>
			<td>Adinstruments</td>
			<td>ML117</td>
			<td>Connects to Powerlab</td>
		</tr>
		<tr>
			<td>Isoflurane vaporizer</td>
			<td>Ohmeda</td>
			<td>TEC3</td>
			<td></td>
		</tr>
		<tr>
			<td>Laptop</td>
			<td>Lenovo</td>
			<td>T410</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser doppler monitor</td>
			<td>Adinstruments</td>
			<td>ML191</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser doppler probe</td>
			<td>Oxford Optronics</td>
			<td>MSF100XP</td>
			<td>Connects to laser doppler monitor</td>
		</tr>
		<tr>
			<td>Needle holder, 13 cm</td>
			<td>F.S.T</td>
			<td>12001-13</td>
			<td>For anesthesia</td>
		</tr>
		<tr>
			<td>Precision syringe, 0.025 mL</td>
			<td>Hamilton</td>
			<td>547407</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereotaxic frame</td>
			<td>Kopf Instruments</td>
			<td>M900</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical microscope</td>
			<td>Carl Zeiss</td>
			<td>F170</td>
			<td></td>
		</tr>
		<tr>
			<td>Suture needle</td>
			<td>Allgaier</td>
			<td>1245</td>
			<td>For anesthesia</td>
		</tr>
		<tr>
			<td>Temperaure controller</td>
			<td>CWE,INC.</td>
			<td>TC-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Transducer x 2</td>
			<td>Adinstruments</td>
			<td>MLT0699</td>
			<td>Connects to BP and ICP monitor</td>
		</tr>
		<tr>
			<td>Ventilator</td>
			<td>Ugo Basile</td>
			<td>7025</td>
			<td></td>
		</tr>
		<tr>
			<td>Veterinary clipper</td>
			<td>Aesculap</td>
			<td>GT421</td>
			<td></td>
		</tr>
		<tr>
			<td>3-pronged Blair retractor, 13.5 cm</td>
			<td>Agnthos</td>
			<td>17022--13</td>
			<td></td>
		</tr>
		<tr>
			<td>Blunt Alm retractor</td>
			<td>F.S.T</td>
			<td>17008-07</td>
			<td></td>
		</tr>
		<tr>
			<td>Curved forceps, 12 cm x 2</td>
			<td>F.S.T</td>
			<td>11001-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle holder, 13 cm</td>
			<td>F.S.T</td>
			<td>12001-13</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Dumont forceps, 11 cm</td>
			<td>F.S.T</td>
			<td>11252-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Halsted-Mosquito hemostat x 2</td>
			<td>F.S.T</td>
			<td>13008-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Iris scissor, 9 cm</td>
			<td>F.S.T</td>
			<td>14090-09</td>
			<td></td>
		</tr>
		<tr>
			<td>Straight Vannas scissor, 10.5 cm</td>
			<td>F.S.T</td>
			<td>15018-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Absorpable swabs</td>
			<td>Kettenbach</td>
			<td>31603</td>
			<td></td>
		</tr>
		<tr>
			<td>Black silk thread, 4-0, 5 x 15 cm</td>
			<td>V&#246;mel</td>
			<td>14757</td>
			<td></td>
		</tr>
		<tr>
			<td>Bone wax</td>
			<td>Aesculap</td>
			<td>1029754</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbomer eye gel 2 mg/g</td>
			<td>Paranova</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton swab</td>
			<td>Heinz Herenz</td>
			<td>WA-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton tipped applicator x 4</td>
			<td>Selefa</td>
			<td>120788</td>
			<td></td>
		</tr>
		<tr>
			<td>Hypodermic needle, 23 G x2</td>
			<td>KD Medical</td>
			<td>900284</td>
			<td>Connects to stopcock. Remove distal end</td>
		</tr>
		<tr>
			<td>Hypodermic needle, 23 G x3</td>
			<td>KD Medical</td>
			<td>900284</td>
			<td>Remove distal end. 2 connects to stopcock, 1 to syringe</td>
		</tr>
		<tr>
			<td>ICP probe:</td>
			<td>Homemade</td>
			<td></td>
			<td>Made of the following:</td>
		</tr>
		<tr>
			<td>Polythene tubing, 20 mm</td>
			<td>Smiths medical</td>
			<td>800/100/200</td>
			<td>Inner diameter (ID): 0.58 mm, Outer diameter (OD): 0.96 mm.</td>
		</tr>
		<tr>
			<td>Silicone tubing, 10 mm</td>
			<td>Fisher</td>
			<td>15202710</td>
			<td>ID: 0.76 mm, OD: 2.4 mm.</td>
		</tr>
		<tr>
			<td>Silicone tubing, 2 mm</td>
			<td>Fisher</td>
			<td>11716513</td>
			<td>ID: 1.0 mm, OD: 3.0 mm.</td>
		</tr>
		<tr>
			<td>Micro hematocrit tubes</td>
			<td>Brand</td>
			<td>7493 11</td>
			<td></td>
		</tr>
		<tr>
			<td>OP-towel, 45 cm x75 cm</td>
			<td>M&#246;lnlycke</td>
			<td>800430</td>
			<td></td>
		</tr>
		<tr>
			<td>PinPort adapter, 22 G</td>
			<td>Instech</td>
			<td>PNP3F22</td>
			<td></td>
		</tr>
		<tr>
			<td>PinPort injector</td>
			<td>Instech</td>
			<td>PNP3M</td>
			<td></td>
		</tr>
		<tr>
			<td>Polythene tubing, 2 x 20 cm</td>
			<td>Smiths medical</td>
			<td>800/100/200</td>
			<td>Connects to syringe. ID: 0.58 mm, OD: 0.96 mm.</td>
		</tr>
		<tr>
			<td>Rubberband</td>
			<td>Unknown</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel, 10 blade</td>
			<td>Kiato</td>
			<td>23110</td>
			<td></td>
		</tr>
		<tr>
			<td>Spinalneedle, 25 G x 3.5&#39;&#39;</td>
			<td>Braun</td>
			<td>5405905-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Stopcock system, Discofix x 2</td>
			<td>Braun</td>
			<td>16494C</td>
			<td>Connects to transducer</td>
		</tr>
		<tr>
			<td>Suture, 4-0, monofil, non-resorbable x 3</td>
			<td>Ethicon</td>
			<td>EH7145H</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe, 1 mL</td>
			<td>BD Plastipak</td>
			<td>1710023</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe, luer-lock, 10 mL x 4</td>
			<td>BD Plastipak</td>
			<td>305959</td>
			<td>Connects to transducer</td>
		</tr>
		<tr>
			<td>Tissue adhesive glue</td>
			<td>3M</td>
			<td>1469SB</td>
			<td></td>
		</tr>
		<tr>
			<td>0.5% Chlorhexidine spirit</td>
			<td>Faaborg Pharma</td>
			<td>210918</td>
			<td></td>
		</tr>
		<tr>
			<td>Carprofen 50 mg/mL</td>
			<td>ScanVet</td>
			<td>43715</td>
			<td>Diluted 1:10</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Baxter</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isotonic saline</td>
			<td>Amgros</td>
			<td>16404</td>
			<td></td>
		</tr>
		<tr>
			<td>Lidocaine-Adrenaline 10 mg/5 &#181;g/mL</td>
			<td>Amgros</td>
			<td>16318</td>
			<td></td>
		</tr>
	</tbody>
</table>

pre-chiasmatic, single injection of autologous blood to induce experimental subarachnoid hemorrhage in a rat model

Despite advances in treatment over the last decades, subarachnoid hemorrhage (SAH) continues to carry a high burden of morbidity and mortality, largely afflicting a fairly young population. Several animal models of SAH have been developed to investigate the pathophysiological mechanisms behind SAH and to test pharmacological interventions. The pre-chiasmatic, single injection model in the rat presented in this article is an experimental model of SAH with a predetermined blood volume. Briefly, the animal is anesthetized, intubated, and kept under mechanical ventilation. Temperature is regulated with a heating pad. A catheter is placed in the tail artery, enabling continuous blood pressure measurement as well as blood sampling. The atlantooccipital membrane is incised and a catheter for pressure recording is placed in the cisterna magna to enable intracerebral pressure measurement. This catheter can also be used for intrathecal therapeutic interventions. The rat is placed in a stereotaxic frame, a burr hole is drilled anteriorly to the bregma, and a catheter is inserted through the burr hole and placed just anterior to the optic chiasm. Autologous blood (0.3 mL) is withdrawn from the tail catheter and manually injected. This results in a rise of intracerebral pressure and a decrease of cerebral blood flow. The animal is kept sedated for 30 min and given subcutaneous saline and analgesics. The animal is extubated and returned to its cage. The pre-chiasmatic model has a high reproducibility rate and limited variation between animals due to the pre-determined blood volume. It mimics SAH in humans making it a relevant model for SAH research.

Women have an increased risk of aSAH compared to men. Despite this, male rodents are primarily used in experiments due to possible bias from heterogeneity of estrus cycle in females. The representative results presented here are from a recent publication comparing female and male rats, confirming that the model produces similar results in female animals compared to male21. The study included 34 female Sprague-Dawley rats (18 SAHs and 16 shams). Shams did not have the spinal needle descended to the...

Watch this Scientific Journal Video about Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model at JoVE.com

Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model

Subarachnoid hemorrhage continues to carry a high burden of mortality and morbidity in man. To facilitate further research into the condition and its pathophysiology, a pre-chiasmatic, single injection model is presented.

Despite advances in treatment over the last decades, subarachnoid hemorrhage (SAH) continues to carry a high burden of morbidity and mortality, largely ...

This model of subarachnoid hemorrhage helps us better understand the pathophysiological mechanisms and the consequences. This will hopefully result in generating therapies, reducing the burden of disease in afflicted patients. The main advantage of this technique is its highly reproducible, as a fixed amount of blood is injected.Furthermore, it resembles a human subarachnoid hemorrhage in key parameters. To make the ICP probe, burn one end of a 20 millimeter piece of polythene tubing, making a circular plate and keeping the lumen open. Then slip a one millimeter silicone tubing ring over the polythene tubing before connecting a 10 millimeter piece of silicone tubing to the end of the polythene tubing.Next, anesthetize, intubate, and catheterize a Sprague Dawley rat before placing it in a stereotaxic frame. Following administration of local anesthesia, make an eight millimeter skin incision caudally from the needle puncture in the midline. Under a dissecting microscope, dissect all the muscles bluntly in layers to identify the atlantooccipital membrane.Then use the arm retractor to restrain the neck musculature, placing the retractor caudally if needed. After checking that the sterile ICP probe is connected to the ICP transducer, flush the ICP probe with saline, making sure that there are no air bubbles in the probe. Using a 23 gauge needle, incise the atlantooccipital membrane, making a hole to gently coax the ICP probe through the membrane.Pull the probe lightly and ensure that it shows a pulsating curve ranging between zero to five millimeters of mercury. If not, remove the probe, recheck the connection to the transducer, and confirm the flow through the lumen. In the area where the atlantooccipital membrane wraps around the probe, apply two drops of tissue glue.Then move the one millimeter silicone tubing forward toward the membrane, before applying additional glue to minimize the risk of ICP probe displacement. Once the ICP probe is glued, remove the retractor. Then, using a non-resorbable monofilament 4-0 suture, place one horizontal mattress suture at the caudal end of the incision and one simple interrupted suture at the cephalic end.To place the laser-doppler probe, make a 15 millimeter incision caudally in the midline, starting just anterior to the eyes. After removing the connective tissue and the muscles with forceps, use the end of a sterile cotton swab as a rougine to identify the bregma and the coronal sutures. After placing the armed retractor, place a 25 gauge spinal needle in the stereotaxic frame exactly on the bregma and note the position.Next, remove the needle from the bregma. Move the frame anteriorly by 6.5 millimeters. Then replace the needle in the midline to mark the side of drilling.Drill until the dura mater is identified below the bone. Using straight forceps, gently remove the bone fragments. Then fill the cavity with bone wax.Next, three to four millimeters lateral to the right of the bregma and just anterior to the coronal suture for the laser-doppler, drill another hole. Taking care not to penetrate the dura mater. Look for the vessels where the laser-doppler can measure the blood flow.Place the laser doppler and check the values. A minimum value of 100 flux units is required. If the values remain acceptable after removing the microscope, add one drop of glue to fix the probe.Recheck to confirm whether the value is above 80 flux units. To induce subarachnoid hemorrhage, insert the needle gently through the skull in the midline between the hemispheres until resistance is felt due to the base of the skull. Retract the needle by one millimeter to ensure correct placement just anteriorly to the optic chiasm.To ensure the most homogenous result when injecting the blood, turn the needle clockwise by 90 degrees such that the needle tip points to the right. Then remove the stiletto. After a 15 minute equilibration, adjust the level of anesthesia to obtain a mean arterial blood pressure in the range 80 to 100 millimeters of mercury.Then perform a blood gas analysis to confirm that the pH, partial pressure of carbon dioxide and partial pressure of oxygen are within physiological parameters. Next, using a one milliliter syringe with a blunt 23 gauge needle, withdraw 500 microliters of blood from the tail catheter. To avoid injection of air, fill the dead space of the spinal needle chamber with blood.After adjusting the volume of the blood in the syringe to 300 microliters, connect the syringe to the spinal needle. Then, grasping firmly around the syringe, inject the blood manually to surpass mean arterial pressure. Observe a steep rise in the intracerebral pressure and a concurrent steep fall in the cerebral blood flow.30 minutes after the induction of subarachnoid hemorrhage, remove the needle and the laser-doppler probe. And fill the cavities with bone wax. Using non-resorbable monofilament 4-0 suture, close the incision with two horizontal mattress sutures.To use the ICP probe for injections into the cisterna magna, remove the silicone tubing and insert a pin port adapter to the polythene tubing. To perform an intrathecal administration while the animal is awake, place a pin port injector on a precision syringe. Then administer the treatment through the pin port adapter.If intrathecal administrations do not have to be performed, cut the simple interrupted suture. Then, using scissors, shorten the ICP probe as much as possible and glue the end to prevent cerebrospinal fluid leakage. Close the incision with a non-absorbable monofilament 4-0 suture.In the evaluation of gross sensory motor function using the rotating pole test, rats with experimentally induced subarachnoid hemorrhage performed significantly worse 24 and 48 hours after the surgery compared to sham animals. Sensitivity to endothelin-1, an agonist for the endothelin-1 receptor family significantly increased two days after subarachnoid hemorrhage in the basilar and the middle cerebral arteries of the experimental rats compared to those of the sham controls. Both arteries of the experimental rats also exhibited a similar increase in sensitivity to 5-carboxamidotryptamine, an agonist for the 5-hydroxytryptamine receptor family.Following the procedure, neurobehavioral tests as well as tissue analysis including immunohistochemistry, PCR, western blotting analyzer can be performed to analyze consequences and mechanisms.

pre-chiasmatic-single-injection-autologous-blood-to-induce

Research

JoVE Journal

Neuroscience

2.1K visualizações.  Rigshospitalet. Esse modelo de hemorragia subaracnóidea nos ajuda a entender melhor os mecanismos fisiopatológicos e suas consequências. Espera-se que isso resulte na geração de terapias, reduzindo a carga da doença em pacientes aflitos. A principal vantagem desta técnica é a sua alta reprodutível, pois uma quantidade fixa de sangue é injetada.Além disso, assemelha-se a uma hemorragia subaracnóidea humana em parâmetros-chave. Para fazer a sonda ICP, queime uma extremidade de um pedaço de...