JMS received funding from NIH/NINDS R01 NS110793 and K12 (Neurosurgeon Research Career Development Program). BAM received funding from NIH/NINDS K08 NS112580-01A1, University of Kentucky Neuroscience Research Priority Area Award, and a Hydrocephalus Association Innovator Award.

NOTE: All animal protocols were approved by the institutions&#39; Animal Care and Use Committee. See the Table of Materials for details about all materials, reagents, equipment, and software used in this protocol.
1. Preparation of hemoglobin and CSF solutions
<ol>
	<li>Prepare a sterile&#160;artificial CSF (aCSF) solution by adding 500 &#181;L of the aCSF solution to a 1.5 mL microtube and store on ice.</li>
	<li>Prepare a sterile 150 mg/mL hemoglobin solut...

<ol>
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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=Longitudinal+CSF+Iron+Pathway+Proteins+in+Posthemorrhagic+Hydrocephalus:+Associations+with+Ventricle+Size+and+Neurodevelopmental+Outcomes.">Longitudinal CSF Iron Pathway Proteins in Posthemorrhagic Hydrocephalus: Associations with Ventricle Size and Neurodevelopmental Outcomes.</a> Annals of Neurology. 90 (2), (2021).</li><li>Strahle, J. 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=Role+of+Hemoglobin+and+Iron+in+hydrocephalus+after+neonatal+intraventricular+hemorrhage.">Role of Hemoglobin and Iron in hydrocephalus after neonatal intraventricular hemorrhage.</a> Neurosurgery. 75 (6), (2014).</li><li>Garton, T. P., He, Y., Garton, H. J. L., Keep, R. F., Xi, G., Strahle, 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=Hemoglobin-induced+neuronal+degeneration+in+the+hippocampus+after+neonatal+intraventricular+hemorrhage.">Hemoglobin-induced neuronal degeneration in the hippocampus after neonatal intraventricular hemorrhage.</a> Brain Research. 1635, (2016).</li><li>Goulding, D. S., Caleb Vogel, ., Gensel, R., Morganti, J. C., Stromberg, J. M., Miller, A. J., A, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+brain+inflammation,+white+matter+oxidative+stress,+and+myelin+deficiency+in+a+model+of+neonatal+intraventricular+hemorrhage.">Acute brain inflammation, white matter oxidative stress, and myelin deficiency in a model of neonatal intraventricular hemorrhage.</a> Journal of Neurosurgery: Pediatrics. 26 (6), (2020).</li><li>Strahle, J., Garton, H. J. L., Maher, C. O., Muraszko, K. M., Keep, R. F., Xi, G. <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+Hydrocephalus+After+Neonatal+and+Adult+Intraventricular+Hemorrhage.">Mechanisms of Hydrocephalus After Neonatal and Adult Intraventricular Hemorrhage.</a> Translational Stroke Research. 3, (2012).</li><li>Jinnai, 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=A+Model+of+Germinal+Matrix+Hemorrhage+in+Preterm+Rat+Pups.">A Model of Germinal Matrix Hemorrhage in Preterm Rat Pups.</a> Frontiers in Cellular Neuroscience. 14, (2020).</li><li>Georgiadis, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+acute+brain+injuries+and+neurobehavioral+profiles+in+a+rabbit+model+of+germinal+matrix+hemorrhage.">Characterization of acute brain injuries and neurobehavioral profiles in a rabbit model of germinal matrix hemorrhage.</a> Stroke. 39 (12), (2008).</li><li>Cherian, S. S., Love, S., Silver, I. A., Porter, H. J., Whitelaw, A. G. L., Thoresen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Posthemorrhagic+ventricular+dilation+in+the+neonate:+Development+and+characterization+of+a+rat+model.">Posthemorrhagic ventricular dilation in the neonate: Development and characterization of a rat model.</a> Journal of Neuropathology and Experimental Neurology. 62 (3), (2003).</li><li>Balasubramaniam, J., Xue, M., Buist, R. J., Ivanco, T. L., Natuik, S., del Bigio, ., 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=Persistent+motor+deficit+following+infusion+of+autologous+blood+into+the+periventricular+region+of+neonatal+rats.">Persistent motor deficit following infusion of autologous blood into the periventricular region of neonatal rats.</a> Experimental Neurology. (1), (2006).</li><li>Volpe, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brain+injury+in+premature+infants:+a+complex+amalgam+of+destructive+and+developmental+disturbances.">Brain injury in premature infants: a complex amalgam of destructive and developmental disturbances.</a> The Lancet Neurology. 8 (1), (2009).</li><li>Dobbing, J., Sands, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+aspects+of+the+brain+growth+spurt.">Comparative aspects of the brain growth spurt.</a> Early Human Development. 3 (1), (1979).</li><li>Craig, 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=Quantitative+analysis+of+perinatal+rodent+oligodendrocyte+lineage+progression+and+its+correlation+with+human.">Quantitative analysis of perinatal rodent oligodendrocyte lineage progression and its correlation with human.</a> Experimental Neurology. 181 (2), (2003).</li><li>Lodygensky, G. A., Vasung, L., Sv Sizonenko, ., H&#252;ppi, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroimaging+of+cortical+development+and+brain+connectivity+in+human+newborns+and+animal+models.">Neuroimaging of cortical development and brain connectivity in human newborns and animal models.</a> Journal of Anatomy. 217 (4), (2010).</li><li>Dean, J. 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=Strain-specific+differences+in+perinatal+rodent+oligodendrocyte+lineage+progression+and+its+correlation+with+human.">Strain-specific differences in perinatal rodent oligodendrocyte lineage progression and its correlation with human.</a> Developmental Neuroscience. 33 (34), (2011).</li><li>Engelhardt, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+blood-brain+barrier.">Development of the blood-brain barrier.</a> Cell and Tissue Research. 314 (1), (2003).</li><li>Daneman, R., Zhou, L., Kebede, A. A., Barres, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pericytes+are+required+for+blood&#285;&#8364;&amp;#34;brain+barrier+integrity+during+embryogenesis.">Pericytes are required for blood&#285;&#8364;&amp;#34;brain barrier integrity during embryogenesis.</a> Nature. 468 (7323), (2010).</li><li>Alles, Y. C. J., Greggio, S., Alles, R. M., Azevedo, P. N., Xavier, L. L., DaCosta, J. C. <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+preclinical+rodent+model+of+collagenase-induced+germinal+matrix/intraventricular+hemorrhage.">A novel preclinical rodent model of collagenase-induced germinal matrix/intraventricular hemorrhage.</a> Brain Research. 1356, (2010).</li><li>Christian, E. 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=Trends+in+hospitalization+of+preterm+infants+with+intraventricular+hemorrhage+and+hydrocephalus+in+the+United+States.">Trends in hospitalization of preterm infants with intraventricular hemorrhage and hydrocephalus in the United States.</a> Journal of Neurosurgery: Pediatrics. 17 (3), 2000-2010 (2016).</li></ol>

The authors declare that they have no conflicts of interest.

This IVH model utilizing hemoglobin injection allows for the study of the pathology of IVH specifically mediated by hemoglobin. For complementary studies, hemoglobin can also be easily delivered in vitro and does not confound biochemical assays for proteins made by microglia/macrophages that are present in whole blood.
The leading theories of IVH-PHH include the mechanical obstruction of CSF circulation, the disruption of cilia lining the ependymal walls, inflammation, fibrosis, and i...

Neonatal IVH originates from the germinal matrix, a site of rapid cell division that is adjacent to the lateral ventricles of the developing brain. This highly vascular structure is vulnerable to hemodynamic instability related to premature birth. Blood is released into the lateral ventricles in germinal matrix hemorrhage (GMH)-IVH when fragile blood vessels within the germinal matrix rupture. In the case of grade IV IVH, periventricular hemorrhagic infarction may also contribute to the release of blood products within the brain.1 The combination of GMH-IVH may cause PHH, particularly after high-grade hemorrhage (grades III and IV)1. PHH can be treated with the placement of a ventriculoperitoneal shunt, but shunt placement does not reverse the brain injury that may occur from IVH. Although modern neonatal intensive care has lowered rates of IVH2, 3, there are no specific treatments for the brain injury or hydrocephalus caused by IVH once it has occurred. A significant limitation in developing preventative treatments for IVH-induced brain injury and PHH is the incomplete understanding of IVH pathophysiology.
Recently, early CSF levels of key blood breakdown product hemoglobin have been shown to be associated with the later development of PHH in neonates with high-grade IVH4. Furthermore, CSF levels of iron-handling pathway proteins&#8212;hemoglobin, ferritin, and bilirubin&#8212;are associated with ventricle size in neonatal IVH. This was also shown in a multicenter cohort of infants with preterm PHH, where higher ventricular CSF levels of ferritin were associated with larger ventricle size5.
In this study, we developed a clinically relevant model of IVH-induced brain injury and hydrocephalus utilizing hemoglobin injection into the brain ventricles, which allows for quantification of brain injury and PHH and the testing of new therapeutic strategies (Figure 1)6, 7. This IVH model utilizes neonatal rat pups, which are placed under general anesthesia for the duration of the procedure. A midline incision is made on the scalp, and coordinates derived from skull landmarks&#8212;the bregma or lambda&#8212;are used to target the lateral ventricles for injection. Slow injection using an infusion pump delivers hemoglobin into the ventricle. This protocol is easy to use, versatile, and can model different components of IVH that result in PHH.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >0.3 mL insulin syringe</td>
			<td >BD Microfine + Insulin Syringe</td>
			<td >230-4533</td>
			<td >0.3-0.5 mL synringes will work</td>
		</tr>
		<tr >
			<td >1.5 mL microtube</td>
			<td >USA Scientific</td>
			<td >1615-5500</td>
			<td>Lot No. K194642H -3 511</td>
		</tr>
		<tr >
			<td >4.7T MRI</td>
			<td >Agilent/Varian</td>
			<td >4.7T/33 cm</td>
			<td>Agilent/Varian DirectDrive 4.7-T (200-MHz) MRI system</td>
		</tr>
		<tr >
			<td >6-0 monofilament suture</td>
			<td >ETHICON</td>
			<td >667G</td>
			<td></td>
		</tr>
		<tr >
			<td >9.4T MRI</td>
			<td >Bruker</td>
			<td >BioSpec 94/20</td>
			<td>Used in this protocol without the cryoprobe</td>
		</tr>
		<tr >
			<td >Analytical balance</td>
			<td >CCURIS Instruments</td>
			<td >W3200-320</td>
			<td></td>
		</tr>
		<tr >
			<td >Artificial CSF (aCSF)</td>
			<td >Tocris Bioscience</td>
			<td >3525</td>
			<td>Batch No: 72A</td>
		</tr>
		<tr >
			<td >Betadine</td>
			<td >Purdue Products L.P.</td>
			<td >301005-00</td>
			<td >NDC 67618-150-09</td>
		</tr>
		<tr >
			<td >Carprofen (injectable)</td>
			<td >Zoetis Inc.&#160;</td>
			<td>PI 4019448</td>
			<td>Rimadyl</td>
		</tr>
		<tr >
			<td >Ethanol</td>
			<td >Decon Laboratories</td>
			<td >2701</td>
			<td></td>
		</tr>
		<tr >
			<td >Heating pad</td>
			<td >Sunbeam</td>
			<td >E12107-819</td>
			<td>UL 612A, Z-1228-001</td>
		</tr>
		<tr >
			<td >Hemoglobin</td>
			<td >MP Biomedicals</td>
			<td >100714</td>
			<td>LOT NO. SR02321</td>
		</tr>
		<tr >
			<td >Isoflurane</td>
			<td >Piramal Critical Care</td>
			<td >NDC 66794-017-25</td>
			<td></td>
		</tr>
		<tr >
			<td >Isoflurane vaporizer</td>
			<td >VETEQUIP</td>
			<td >911103</td>
			<td></td>
		</tr>
		<tr >
			<td >Light for stereotactic insturment</td>
			<td >Dolan-Jenner industries</td>
			<td >Fiber-Lite MI-150</td>
			<td></td>
		</tr>
		<tr >
			<td >Microinjection syringe pump</td>
			<td >World Precision Instruments</td>
			<td >MICRO21</td>
			<td>Serial 184034 T08K</td>
		</tr>
		<tr >
			<td >MRI software</td>
			<td >Bruker BioSpin</td>
			<td >Paravision 360 3.2</td>
			<td></td>
		</tr>
		<tr >
			<td >Oxygen</td>
			<td >Airgas Healthcare</td>
			<td >UN1072</td>
			<td>LOT NUMBER S1432080XA02</td>
		</tr>
		<tr >
			<td >Sprague Dawley rats</td>
			<td >Charles River Laboratories</td>
			<td >Strain code: 001</td>
			<td></td>
		</tr>
		<tr >
			<td >Stereotactic instrument</td>
			<td >KOPF Instuments</td>
			<td >Model 900LS Lazy Susan</td>
			<td></td>
		</tr>
		<tr >
			<td >Sterile cotton tipped applicator</td>
			<td >Fischerbrand</td>
			<td >23-400-118</td>
			<td></td>
		</tr>
		<tr >
			<td >Surgical blade</td>
			<td >covetrus</td>
			<td >#10</td>
			<td></td>
		</tr>
		<tr >
			<td >Topical triple antibiotic</td>
			<td >Triple Antibiotic Ointment</td>
			<td >NDC 51672-2120-1</td>
			<td></td>
		</tr>
		<tr >
			<td >Ventricle volume quantification software</td>
			<td >ITK-SNAP</td>
			<td >ITK-SNAP 4.0.0 beta</td>
			<td></td>
		</tr>
	</tbody>
</table>

modeling neonatal intraventricular hemorrhage through intraventricular injection of hemoglobin

Neonatal intraventricular hemorrhage (IVH) is a common consequence of premature birth and leads to brain injury, posthemorrhagic hydrocephalus (PHH), and lifelong neurological deficits. While PHH can be treated by temporary and permanent cerebrospinal fluid (CSF) diversion procedures (ventricular reservoir and ventriculoperitoneal shunt, respectively), there are no pharmacological strategies to prevent or treat IVH-induced brain injury and hydrocephalus. Animal models are needed to better understand the pathophysiology of IVH and test pharmacological treatments. While there are existing models of neonatal IVH, those that reliably result in hydrocephalus are often limited by the necessity for large-volume injections, which may complicate modeling of the pathology or introduce variability in the clinical phenotype observed.
Recent clinical studies have implicated hemoglobin and ferritin in causing ventricular enlargement after IVH. Here, we develop a straightforward animal model that mimics the clinical phenotype of PHH utilizing small-volume intraventricular injections of the blood breakdown product hemoglobin. In addition to reliably inducing ventricular enlargement and hydrocephalus, this model results in white matter injury, inflammation, and immune cell infiltration in periventricular and white matter regions. This paper describes this clinically relevant, simple method for modeling IVH-PHH in neonatal rats using intraventricular injection and presents methods for quantifying ventricle size post injection.

The success of injection was confirmed by radiologic&#160;and immunohistochemical means. Animals that underwent hemoglobin injection developed moderate acute ventriculomegaly when assessed via MRI (Figure 2A), with significantly larger lateral ventricles at 24 h and 72 h post hemoglobin injection compared to aCSF-injected animals (Figure 2B,C). While there was no significant difference in lateral ventricle volume between hemoglobin-injected and ...

Watch this Scientific Journal Video about Modeling Neonatal Intraventricular Hemorrhage Through Intraventricular Injection of Hemoglobin at JoVE.com

Modeling Neonatal Intraventricular Hemorrhage Through Intraventricular Injection of Hemoglobin

We present a model of neonatal intraventricular hemorrhage using rat pups that mimics the pathology seen in humans.

Neonatal intraventricular hemorrhage (IVH) is a common consequence of premature birth and leads to brain injury, posthemorrhagic hydrocephalus (PHH), and ...

This protocol is significant because we develop a clinically relevant model of IVH induced brain injury and hydrocephalus, utilizing hemoglobin injection into the ventricles, which allows for subsequent quantification of ventricle volumes in the application, to testing new therapeutic strategies. The main advantage of this technique is that it allows for the study of the pathology of IVH that is specifically mediated by hemoglobin and iron pathway blood breakdown products. This technique is also easy to use and versatile.The implications of this technique extend towards developing therapies for post-hemorrhagic hydrocephalus, as it allows for further understanding of IVH pathophysiology and the valuation of clinically relevant treatment strategies for the prevention of neurological sequela following IVH. Demonstrating the procedure will be Sruthi Ramagiri, an Associate Post-doc from the Australia Laboratory. To begin place the anesthetized rat prone in the stereotactic apparatus with its nose positioned in the anesthesia adapter.Then secure the head by tightening the non-rupture ear bars on the external auditory meatus. To clean the head, first touch a sterile cotton tipped applicator soaked in Betadine at the center of the head and move outwards to spread the Betadine in circles. Then repeat the process with an applicator soaked in 70%ethanol.Next, using a scalpel, make a 0.3 centimeter incision vertically down the center of the head to expose the bregma of the skull. Then dry the area using a cotton tipped applicator. To set up the stereotactic injector, draw the previously prepared hemoglobin solution into a 0.3 or 0.5 milliliter syringe, and place the syringe in the stereotactic injector system.Next, turn on the stereotactic injector interface, and click on the configuration button to enter the injection volume, and rate settings. Click on volume, and set the volume at 20, 000 nanoliters. Then click on infusion rate, and set the rate at 8, 000 nanoliters per minute.Click on the reset position button to exit the configuration. Flush the needle tip by clicking the infuse button until a small bead of hemoglobin appears at the needle tip, then use a cotton tipped applicator to gently remove the bead. To begin the animal injection, set the bregma as zero on the stereotactic injecting system by adjusting the mediolateral, and anteroposterior positions of the syringe.Then lower the syringe needle to touch the skull at the bregma gently. After identifying the coordinates of choice, raise the syringe needle one centimeter above the skull to clear the scalp. Set the mediolateral and anteroposterior coordinates.Then lower the syringe for the needle to gently touch the skull and set the dorsoventral coordinate over 30 seconds. Once the coordinates have been set, begin injection by clicking the run button on the stereotactic injector interface. After the injection is finished, leave the needle in place for two minutes to minimize the backflow of the solution.Next, slowly withdraw the syringe along the dorsoventral coordinate over two minutes, until the needle tip is two centimeters above the scalp. Then rotate the stereotactic injector arm away from the operative field and close the scalp with a 6-O monofilament suture. For MRI, perform T2 weighted imaging by selecting a T2 weighted fast spin echo sequence.After setting the MRI parameters as described in the text, click the continue button to start the sequence. For image processing and brain volume analysis, open the native T2 weighted data in the segmentation software. To manually delineate the lateral ventricles, click on the paintbrush mode and select the square brush style, then adjust the brush size to one.Next, click layout inspector, select axial view and click zoom to fit. Then place the cursor on the image and trace and fill the lateral ventricle space. Finally, click on segmentation in the toolbar, followed by volume and statistics to view the segmented volumes.Animals that underwent hemoglobin injection developed moderate ventriculomegaly when assessed via MRI. With significantly larger lateral ventricles at 24 hours, and 72 hours post hemoglobin injection, compared to ACSF injected animals. Although the difference in lateral ventricular volume between the two groups of rats was not significant after 38 days, MRI scans demonstrated that 44%of the rats receiving hemoglobin still had unresolved ventriculomegaly.Moreover, in comparison to ACSF, injection of hemoglobin resulted in a significant decrease in the white matter volume after 38 days. Hemoglobin also promoted an inflammatory response in vivo as evident from the significantly higher level of the pro-inflammatory cytokine tumor necrosis factor alpha after injecting hemoglobin, but not saline or whole blood. Furthermore, immunohistochemical staining of the glial fibrillar acidic protein revealed a significantly higher activation of astrocytes after hemoglobin injection, than after ACSF injection.The most important thing to remember when attempting this procedure is to set the correct injection coordinates to ensure hemoglobin delivery into the lateral ventricles. Following this procedure, CSF tracers can be delivered into the CSF space to evaluate changes in CSF circulation, and efflux patterns following IVH. This additional method addresses how CSF flow is altered in IVH PHH.

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2.7K visualizações.  University of Kentucky. Esse protocolo é significativo porque desenvolvemos um modelo clinicamente relevante de lesão cerebral induzida por IVH e hidrocefalia, utilizando injeção de hemoglobina nos ventrículos, o que permite a posterior quantificação dos volumes ventrículos na aplicação, para testar novas estratégias terapêuticas. A principal vantagem desta técnica é que ela permite o estudo da patologia da IVH que é especificamente mediada por hemoglobina e produtos de degradação do sangue da via d...