This study was financially supported by the National Science Foundation of China (81471181 and 81870933) and the Opening Lab Program of Guangzhou Medical University (0506308) to Y Jiang, and by the National Science Foundation of China (81701471) and the Scientific Program of Guangzhou Municipal Health Commission (20191A011083) to Z Qiu, and by the National Science Foundation of China (81501009) to L Wu.

The protocol was reviewed and approved by the Institutional Animal Care and Use Committee of the Second Affiliated Hospital of Guangzhou Medical University. Rats were provided by the Animal Center of Southern Medical University. The experimental design is shown in Figure 1.
1. Animal and instruments
<ol>
	<li>Use 8-week-old male Sprague-Dawley rats weighing 250 &#177; 10 g.</li>
	<li>House the rats for at least 7 days before surgery under controlled environmenta...

<ol>
	<li>Charidimou, 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=Brain+hemorrhage+recurrence,+small+vessel+disease+type,+and+cerebral+microbleeds:+A+meta-analysis.">Brain hemorrhage recurrence, small vessel disease type, and cerebral microbleeds: A meta-analysis.</a> Neurology. 89 (8), 820-829 (2017).</li><li>Tao, 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=A+novel+brainstem+hemorrhage+model+by+autologous+blood+infusion+in+Rat:+White+Matter+Injury,+Magnetic+Resonance+Imaging,+and+Neurobehavioral+features.">A novel brainstem hemorrhage model by autologous blood infusion in Rat: White Matter Injury, Magnetic Resonance Imaging, and Neurobehavioral features.</a> Journal of Stroke and Cerebrovascular Diseases. 25 (5), 1102-1109 (2016).</li><li>Ichimura, 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=Surgical+treatment+for+primary+brainstem+hemorrhage+to+improve+postoperative+functional+outcomes.">Surgical treatment for primary brainstem hemorrhage to improve postoperative functional outcomes.</a> World Neurosurgery. 120, 1289-1294 (2018).</li><li>Behrouz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prognostic+factors+in+pontine+haemorrhage:+A+systematic+review.">Prognostic factors in pontine haemorrhage: A systematic review.</a> European Stroke Journal. 3 (2), 101-109 (2018).</li><li>Guo, X., 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=Brainstem+iron+overload+and+injury+in+a+rat+model+of+brainstem+hemorrhage.">Brainstem iron overload and injury in a rat model of brainstem hemorrhage.</a> Journal of Stroke and Cerebrovascular Diseases. 29 (8), 104956 (2020).</li><li>Chung, Y., Haines, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+brain+stem+surgery.">Experimental brain stem surgery.</a> Neurosurgery Clinics of North America. 4 (3), 405-414 (1993).</li><li>Lekic, T., Tang, J., Zhang, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rat+model+of+pontine+hemorrhage.">A rat model of pontine hemorrhage.</a> Acta Neurochirurgica Supplement. 105, 135-137 (2008).</li><li>Lekic, 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=Evaluation+of+the+hematoma+consequences,+neurobehavioral+profiles,+and+histopathology+in+a+rat+model+of+pontine+hemorrhage.">Evaluation of the hematoma consequences, neurobehavioral profiles, and histopathology in a rat model of pontine hemorrhage.</a> Journal of Neurosurgery. 118 (2), 465-477 (2013).</li><li>Shrestha, 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=Rat+brainstem+hemorrhage+model:+Key+points+to+success+in+modeling.">Rat brainstem hemorrhage model: Key points to success in modeling.</a> World Neurosurgery. 117, 106-116 (2018).</li><li>Luo, M., Tang, X., Zhu, J., Qiu, Z., Jiang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+of+acute+pontine+infarction+in+rats+by+electrical+stimulation.">Establishment of acute pontine infarction in rats by electrical stimulation.</a> Journal of Visualized Experiments. (162), (2020).</li><li>Wu, 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=Keep+warm+and+get+success:+The+role+of+postischemic+temperature+in+the+mouse+middle+cerebral+artery+occlusion+model.">Keep warm and get success: The role of postischemic temperature in the mouse middle cerebral artery occlusion model.</a> Brain Research Bulletin. 101, 12-17 (2014).</li></ol>

No conflicts of interest.

In the present study, we provided a protocol to generate a massive pontine hemorrhage rat model. This model can be used for the research on the pathophysiological mechanism and prognosis of massive pontine hemorrhage.
Throughout the experiment, 25 rats were used, of which only one died. The verification of MRI, gross anatomy, and the HE staining indicated that this method had a very low mortality rate and a high success rate. To establish massive pontine hemorrhage model, two problems must be ...

Intracerebral hemorrhage accounts for one-fifth of stroke patients. The prognosis of intracerebral hemorrhage depends on the speed, volume, and location of bleeding1,2. Compared to the forebrain hemorrhage, the brainstem hemorrhage has higher mortality and morbidity3. About 40% of brainstem hemorrhage occurs in the pons4. The etiology and pathophysiology of pontine hemorrhage are quite different and less studied than forebrain hemorrhage5.
There are two kinds of pontine hemorrhage animal models. One is spontaneous hemorrhage model induced by infusion of bacterial collagenase in the pons6,7,8. The biggest advantage of this model is that the bleeding is spontaneous. However, collagenase can only induce a small volume of pontine hemorrhage. Besides, collagenase might cause other injuries to the brain. The other model is induced by stereotactic injection of autologous blood into the pons9. The advantage of this model is that it is easy to master with a high success rate. Theoretically, researchers could inject any volume of blood into any location of pons. However, due to the back-leakage through the needle route, the injected volume is limited. Recently, the double-injection method has been promoted to reduce the back-leakage9. This method injects autologous blood twice with a 20-minute interval between the injections. The double-injection method is applied to induce mild (30 &#181;L) and moderate (60 &#181;L) pontine hemorrhage but not massive pontine hemorrhage. In the clinic, the majority of pontine hemorrhage patients with poor prognosis have massive hemorrhage (more than 10 mL).
In the previous study, we provided a protocol to establish a pontine ischemic stroke model in rat10. In this study, we modify the existing dual injection method, and provide a detailed protocol to induce massive pontine hemorrhage in a rat by dual injection of 100 &#181;L autologous blood at two different locations in the pons.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>100ml Saline solution</td>
			<td>Guangdong yixiang</td>
			<td>191222201 C1</td>
			<td>Preparing heparin diluent</td>
		</tr>
		<tr>
			<td>100&#956;l Microinjector</td>
			<td>Shanghai Gaoge</td>
			<td></td>
			<td>Injection of autologous blood</td>
		</tr>
		<tr>
			<td>1ml Syringe</td>
			<td>Jiangsu Zhiyu</td>
			<td>20191014</td>
			<td>Withdraw autologous blood from the tail vein</td>
		</tr>
		<tr>
			<td>75% Alcohol</td>
			<td>Shandong Lierkang</td>
			<td></td>
			<td>Disinfection of rat tail</td>
		</tr>
		<tr>
			<td>Adhesive tape</td>
			<td>Shanghai Jinzhong</td>
			<td></td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Animal anesthesia system</td>
			<td>RWD</td>
			<td>R510-31S-6</td>
			<td>Inducing and maintaining anesthesia</td>
		</tr>
		<tr>
			<td>Balance beam</td>
			<td>Jiangsu Saiangsi</td>
			<td></td>
			<td>For neurological deficit scores</td>
		</tr>
		<tr>
			<td>Blades</td>
			<td>Shanghai Feiying</td>
			<td>74-C</td>
			<td>For gross anatomy</td>
		</tr>
		<tr>
			<td>Bone cement</td>
			<td>Shanghai Xinshiji</td>
			<td>20180306</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Brain tank</td>
			<td>Shenzhen LEIYEA</td>
			<td></td>
			<td>For gross anatomy</td>
		</tr>
		<tr>
			<td>Butorphanol tartrate</td>
			<td>Jiangsu Hengrui</td>
			<td></td>
			<td>For pain management</td>
		</tr>
		<tr>
			<td>Electric cranial drill</td>
			<td>Nanjing&#160; Darwin biotechnology</td>
			<td>20180090018</td>
			<td>Making a burr hole on the skull</td>
		</tr>
		<tr>
			<td>EP tube</td>
			<td>Nantong Surui</td>
			<td></td>
			<td>Transfer autologous blood</td>
		</tr>
		<tr>
			<td>Erythromycin eye cream</td>
			<td>Yunnan pharmacy</td>
			<td></td>
			<td>Eyes protection</td>
		</tr>
		<tr>
			<td>HE dye liquor</td>
			<td>Solarbio</td>
			<td>G1120</td>
			<td>For HE staining</td>
		</tr>
		<tr>
			<td>Heating&#160;pad</td>
			<td>Dangerous Jungle</td>
			<td>JR01</td>
			<td>Keeping warm</td>
		</tr>
		<tr>
			<td>Heparin sodium injection</td>
			<td>Chengdu Haitong Pharmacal Company</td>
			<td>190701</td>
			<td>Preparing heparin diluent</td>
		</tr>
		<tr>
			<td>IndoPhors</td>
			<td>Guoyao of China</td>
			<td></td>
			<td>Sterilization</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>RWD</td>
			<td>20080701</td>
			<td>Inducing and maintaining anesthesia</td>
		</tr>
		<tr>
			<td>Light dark box</td>
			<td>Jiangsu Saiangsi</td>
			<td></td>
			<td>For neurological deficit scores</td>
		</tr>
		<tr>
			<td>Micro-injection pump</td>
			<td>Baoding Leifu</td>
			<td>TFD03-01-C</td>
			<td>Injection of autologous blood</td>
		</tr>
		<tr>
			<td>MRI system</td>
			<td>Philips</td>
			<td></td>
			<td>Confirmation of infarction in vivo</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>Shanghai Jinzhong</td>
			<td>J32020</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Penicilin</td>
			<td>Guoyao of China</td>
			<td></td>
			<td>Infection Prevention</td>
		</tr>
		<tr>
			<td>Q-tips</td>
			<td>Jiangxi Songhe</td>
			<td></td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Scalp heedle</td>
			<td>Jiangxi Hongda</td>
			<td>20200313</td>
			<td>Withdraw autologous blood from the tail vein</td>
		</tr>
		<tr>
			<td>Scalpel</td>
			<td>Shanghai Kaiyuan</td>
			<td>170902</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Shearing scissors</td>
			<td>Shanghai Jinzhong</td>
			<td>Y00040</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Stereotaxic apparatus</td>
			<td>RWD</td>
			<td>900-00001-00</td>
			<td>for surgical positioning</td>
		</tr>
		<tr>
			<td>Surgical towel</td>
			<td>Xinxiang Huakangweicai</td>
			<td>20070601</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Suture needle</td>
			<td>Shanghai Jinzhong</td>
			<td></td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Suture scissors</td>
			<td>Shanghai Jinzhong</td>
			<td>J25041</td>
			<td>Surgicl instruments</td>
		</tr>
		<tr>
			<td>Tissue holding forcepts</td>
			<td>Shanghai Jinzhong</td>
			<td>J31080</td>
			<td>Surgicl instruments</td>
		</tr>
	</tbody>
</table>

massive pontine hemorrhage by dual injection of autologous blood

We provide a protocol to establish a massive pontine hemorrhage model in a rat. Rats weighing about 250 grams were used in this study. One hundred microliters of autologous blood was taken from the tail vein and stereotaxically injected into the pons. The injection process was divided into 2 steps: First, 10 &#181;L of blood was injected into a specific location, anteroposterior position (AP) -9.0 mm; lateral (Lat) 0 mm; vertical (Vert) -9.2 mm, followed by a second injection of the residual blood located at AP -9.0 mm; Lat 0 mm; Vert -9.0 mm with a 20-minute interval. The balance beam test, limb placement test, and the modified Voestch neuroscore were used to evaluate neurological function. Magnetic Resonance Imaging (MRI) was used to assess the volume of hemorrhage in vivo. The symptoms of this model were in line with patients with massive pontine hemorrhage.

A total of 25 animals were used, 3 for control, 6 for 30 &#181;L, 6 for 60 &#181;L, and 10 for 100 &#181;L blood injections. One rat that received a 100 &#181;L injection of autologous blood (1/10) died within 24 hours after surgery.
Behavioral tests were conducted on Day 1, Day 3, Day 7 and Day 14 after surgery. The scores for the control group and blood-injection groups on different timepoints after surgery are presented in <s...

Watch this Scientific Journal Video about Massive Pontine Hemorrhage by Dual Injection of Autologous Blood at JoVE.com

Massive Pontine Hemorrhage by Dual Injection of Autologous Blood

We present a protocol to establish a massive pontine hemorrhage model in a rat via dual injection of autologous blood.

We provide a protocol to establish a massive pontine hemorrhage model in a rat. Rats weighing about 250 grams were used in this study. One hundred ...

We provide a protocol to establish massive pontine hemorrhage in a rat. This model is easy to establish, repeatable, and highly successful. Distilled injection of autologous rat method could be used to make hemorrhage in any of the brain regions.People who want to try these techniques should learn how to use a stereotaxic frame, and be familiar with pontine anatomy. Begin by placing a surgical drape over the mouse. Make an incision with a scalpel along the marked midline.Use a cotton swab to remove any potential blood. Then place a piece of forceps on each side of the scalp flap to expose the skull. Dip a cotton swab in 0.9%saline and gently remove the connective tissues from the skull bone.Use a marker pen to mark the central point of the bregma as the origin point. Perform a craniotomy using a micro drill, proceeding carefully. When finished remove the micro drill from the stereotaxic frame.Put a 100 microliter Hamilton syringe into the stereotaxic holder. Turn on the injection pump switch. Click the rapid inhalation button.Then aspirate heparin solution to 100 microliters and to drain it completely. Apply chlorhexidine and 75%alcohol surgical scrub to the whole tale from root to tip at least three times to disinfect the skin, soften the horniness and dilate the tail vein to increase the success rate of injection. Attach a scalp acupuncture to a one milliliter syringe, then insert the scalp acupuncture into a lateral tail vein three centimeters from the tail tip and to take 150 microliters of blood.Remove the scalp acupuncture from the one milliliter syringe and transfer the blood into a tube. Working quickly to prevent blood clotting. Change surgical gloves.Select the withdraw mode. Set the volume to 100 microliters and set the speed to 200 microliters per minute. Click the run button, and aspirate 100 microliters of blood into the Hamilton syringe.Switch to the infuse mode and set the speed to one microliter per minute. Advance the syringe until the tip reaches 9.2 millimeters below the surface of the brain and inject the first 10 microliters of blood. Click on the run button.Stop the injection and leave the syringe in position for 20 minutes to prevent blood from flowing into the subarachnoid space. Retract the syringe until the tip arrives at nine millimeters below the surface of the brain, then restart injection at the same speed of one microliter per minute until the residual blood has been injected completely. Leave the syringe in position for 10 minutes to avoid blood backflow.Remove the syringe from the brain slowly. Then use bone cement to cover the craniotomy hole. When the cement dries suture the wound with a four zero polyamide suture filament.After sewing three or four stitches tie 2 one-one standard surgical knots. Observe the rat every 15 minutes until it fully recovers from anesthesia, then return it to the original cage with a heating pad underneath. Provide the rat free access to food and water.A total of 25 animals were used for control 30 microliter, 60 microliter, and 100 microliter blood injections. Behavioral tests were conducted on days one, three, seven and 14 after surgery. Pontine hemorrhage caused neurological deficits like diminished corneal reflex and circling.Injection of 100 microliters of blood also induced the myotonia. MRI Scanning was performed 24 hours after surgery. In the blood injection groups, Hemorrhage was detected as a hypointense rim with an ISO to slightly hyperintense core in the Basiler part of the ponds.The volume of hemorrhage increased with the injection volume. The rats were sacrificed at 24 hours and 14 days after surgery. And two millimeter thick sections were made.Hemorrhage was detected surrounding the injection site and distributing in the base of the ponds. There was a slight edema around the hemorrhage in the 100 microliter blood injection group. Some of the rats were sacrificed three days after surgery and paraffin sections were made for HE staining.Results showed that in the blood injection groups inflammatory cells enriched in the para hemorrhage zone the hemoglobin remained contained with intact red blood cells. When attempting this protocol make sure to remember the injection position. This method can be used to induce a hemorrhage in any specific cerebral region.

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3.9K Görüntüleme.  The Second Affiliated Hospital of Guangzhou Medical University. Bir sıçanda büyük pontin kanaması oluşturmak için bir protokol sağlıyoruz. Bu modelin kurulumu kolaydır, tekrarlanabilir ve son derece başarılıdır. Otolog sıçan yönteminin damıtılmış enjeksiyonu, beyin bölgelerinden herhangi birinde kanama yapmak için kullanılabilir.Bu teknikleri denemek isteyen kişiler stereotaksik çerçeve kullanmayı öğrenmeli ve pontin anatomisine aşina olmalıdır. Farenin üzerine cerrahi bir örtü yerleştirerek başlayın. İşaret...