Name: brain death induction in mice using intra-arterial blood pressure monitoring and ventilation via tracheostomy
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Description: Watch this Scientific Journal Video about Brain Death Induction in Mice Using Intra-Arterial Blood Pressure Monitoring and Ventilation via Tracheostomy at JoVE.com

Animal experiments were performed in compliance with the Principles of Laboratory Animal Care formulated by the National Society for Medical Research and the Guide for the Care and Use of Laboratory Animals prepared by the National Academy of Science and published by the National Institutes of Health (NIH Publication No. 86-23, revised 1985). All experiments were approved by the Austrian Ministry of Education, Science and Culture (BMWF-66.011/0071-II/3b/2012).
1. Arterial catheterization
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V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Donor+brain+death+leads+to+differential+immune+activation+in+solid+organs+but+does+not+accelerate+ischaemia-reperfusion+injury.">Donor brain death leads to differential immune activation in solid organs but does not accelerate ischaemia-reperfusion injury.</a> Journal of Pathology. 239 (1), 84-96 (2016).</li><li>Atkinson, 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=Donor+brain+death+exacerbates+complement-dependent+ischemia/reperfusion+injury+in+transplanted+hearts.">Donor brain death exacerbates complement-dependent ischemia/reperfusion injury in transplanted hearts.</a> Circulation. 127 (12), 1290-1299 (2013).</li><li>Oberhuber, 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=Treatment+with+tetrahydrobiopterin+overcomes+brain+death-associated+injury+in+a+murine+model+of+pancreas+transplantation.">Treatment with tetrahydrobiopterin overcomes brain death-associated injury in a murine model of pancreas transplantation.</a> American Journal of Transplantation. 15 (11), 2865-2876 (2015).</li><li>Floerchinger, 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=Inflammatory+immune+responses+in+a+reproducible+mouse+brain+death+model.">Inflammatory immune responses in a reproducible mouse brain death model.</a> Transplant Immunology. 27 (1), 25-29 (2012).</li><li>Steen, P. 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BD, a risk factor for allograft quality in multi-organ donors, entails a plethora of pathophysiological changes, which can only be sufficiently assessed using in vivo models. Hemodynamic changes, cytokine storm, hormonal changes and their ultimate impact on organ graft quality and survival cannot be analyzed in vitro4. The majority of basic transplantation as well as immunological research is dependent on sophisticated diagnostic tools, which are widely available only in mice models. Mice models h...

Transplantation is currently the only curative treatment for end-stage organ failure. Until now, brain death (BD) patients have been the main source for organ donations, although living donation and donation after circulatory death are valuable alternatives1. BD is defined by an irreversible coma (with a known cause), the absence of brain stem reflexes and apnea2. Unfortunately, BD organs demonstrate inferior results in long-term graft survival independent of human leukocyte antigen (HLA)-mismatch and cold ischemic time3. Meanwhile, intensive research on this antigen-independent risk factor has been performed resulting in three main aspects of pathophysiological changes mediated as a consequence of BD: hemodynamic, hormonal, and inflammatory4.
To date, experimental BD models in rodents have been mostly performed using rats. In order to gain greater insight into the immunological consequences on solid organs following BD, we aimed to establish a murine model of BD, as currently only mouse models allow for comprehensive investigations into genetic or immunological factors. In this context, the mouse system provides a larger variety of analytical tools.
The principle of BD induction as described here is based on an increase in intracranial pressure induced by the inflation of a balloon catheter inserted under the skull. Increased intracranial pressure mimics the physiological mechanism of BD by blocking the perfusion of the cerebrum, cerebellum, and brain stem5,6. To guarantee sufficient perfusion of peripheral organs, blood pressure measurement is obligatory during the procedure. The catheter used for this purpose at the same time serves for saline administration in order to stabilize the blood pressure by fluid substitution. As BD is accompanied by cessation of spontaneous breathing, sufficient ventilation must be ensured. An electric blanket maintains physiological core body temperature.
In summary, this model will enable in-depth studies into the influence of BD-induced injury, on leukocyte migration7, compliment activation8, ischemic reperfusion injury9, and other factors.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Arterial catheter (BD Neoflon 26G)</td>
			<td>BD</td>
			<td>391349</td>
			<td></td>
		</tr>
		<tr>
			<td>Blood Pressure Transducers (APT300)</td>
			<td>Harvard Apparatus Inc.</td>
			<td>73-3862</td>
			<td></td>
		</tr>
		<tr>
			<td>Fogarty Arterial Embolectomy Catheter N&#176; 3</td>
			<td>Edwards Lifesciences Corporation</td>
			<td>120403F</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>FST</td>
			<td>11271-30</td>
			<td></td>
		</tr>
		<tr>
			<td>Homeothermic Blanket Systems with Flexible Probe</td>
			<td>Harvard Apparatus Inc.</td>
			<td>55-7020</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketansol</td>
			<td>Graeub</td>
			<td>6680110</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro scissor</td>
			<td>FST</td>
			<td>15018-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>FST</td>
			<td>12060-02</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolene 5-0</td>
			<td>Ethicon</td>
			<td>8698H</td>
			<td></td>
		</tr>
		<tr>
			<td>Pump 11 Elite Infusion Only Single</td>
			<td>Harvard Apparatus Inc.</td>
			<td>70-4500</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissor</td>
			<td>FST</td>
			<td>14075-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereotactic microscope</td>
			<td>Olympus</td>
			<td>SZX7</td>
			<td></td>
		</tr>
		<tr>
			<td>Transpore Tape</td>
			<td>3M</td>
			<td>1527-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Underpads</td>
			<td>Molinea.A</td>
			<td>274301</td>
			<td></td>
		</tr>
		<tr>
			<td>Ventilator for mice (MiniVent Model 845)</td>
			<td>Harvard Apparatus Inc.</td>
			<td>73-0043</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylasol</td>
			<td>Graeub</td>
			<td>7630109</td>
			<td></td>
		</tr>
	</tbody>
</table>

brain death induction in mice using intra-arterial blood pressure monitoring and ventilation via tracheostomy

While both living donation and donation after circulatory death provide alternative opportunities for organ transplantation, donation after donor brain death (BD) still represents the major source for solid transplants. Unfortunately, the irreversible loss of brain function is known to induce multiple pathophysiological changes, including hemodynamic as well as hormonal modifications, finally leading to a systemic inflammatory response. Models that allow a systematic investigation of these effects in vivo are scarce. We present a murine model of BD induction, which could aid investigations into the devastating effects of BD on allograft quality. After implementing intra-arterial blood pressure measurement via the common carotid artery and reliable ventilation via a tracheostomy, BD is induced by steadily increasing intracranial pressure using a balloon catheter. Four hours after BD induction, organs may be harvested for analysis or for further transplantation procedures. Our strategy enables the comprehensive analysis of donor BD in a murine model, therefore allowing an in-depth understanding of BD-related effects in solid organ transplantation and potentially paving the way to optimized organ preconditioning.

The murine BD model was successfully performed more than 100 times with a success rate of over 90%. Additionally, post interventional organ transplantation of heart and kidney has been safely performed7.
BD induces a variety of pathophysiological changes that may be further investigated using this model. As shown in Figure 1, the blood pressure shows an initial hypertensive p...

Watch this Scientific Journal Video about Brain Death Induction in Mice Using Intra-Arterial Blood Pressure Monitoring and Ventilation via Tracheostomy at JoVE.com

Brain Death Induction in Mice Using Intra-Arterial Blood Pressure Monitoring and Ventilation via Tracheostomy

We present a murine model of brain death induction in order to evaluate the influence of its pathophysiological effects on organs as well as on consecutive grafts in the context of solid organ transplantation.

While both living donation and donation after circulatory death provide alternative opportunities for organ transplantation, donation after donor brain ...

Although donation after donor brain death is the main source for solid-organ transplantation, the irreversible loss of brain function induces pathophysiological changes that lead to a systemic inflammatory response. This murine model of brain-death induction allows the use of a large variety of analytical tools and knockout models to study the pathways of brain-death regulation. For arterial catheterization after confirming a lack of response to pedal reflex and removing the upper abdominal hair, disinfect the exposed skin with 70%ethanol and use dissecting scissors to make a midline incision in the skin.Using forceps, blunt dissect the submandibular glands and neck muscle tissue and separate the tissues to expose the common carotid artery. Place three 8-0 silk ligatures beneath the right common carotid artery and place a clamp on the proximal ligature. Bring tension in the artery so that the flow is suspended and close the most distal ligature.Insert a 26-gauge arterial catheter through a small preformed skin hole on the cranial aspect of the incision. Squeeze the catheter with the forceps if the lumen is too large to reduce the backflow and secure the catheter with all three sutures, then use a single 5-0 monofilament nonabsorbable to fix the catheter to the skin near the preformed skin hole. To perform a tracheostomy, use forceps to blunt dissect the pretracheal musculature and place two 8-0 silk ligatures beneath the trachea.Insert the ventilation tube between two tracheal cartilages to avoid unilateral ventilation and secure the tube with both prepared ligatures, then close the skin with a 6-0 monofilament nonabsorbable running suture and ventilate the mouse with a frequency of 150 per minute and a tidal volume of 200 microliters. To induce brain death in the experimental animal, arrange the mouse to the prone position and, holding the skin with forceps, use surgical scissors to remove the skin from the skull. Drill a one-millimeter caliper borehole perimedially above the left parietal cortex and use blunt forceps to penetrate the final tissue bridge of the skull.After removing any sharp edges, insert a balloon catheter prefilled with saline with all of the air evacuated. When the catheter is entirely within the cranial cavity, use a syringe pump to begin inflating the catheter at approximately 0.1 millimeters per minute over a period of 10 to 15 minutes. When brain death occurs, stop the inflation of the balloon catheter and place a heating blanket over the mouse to avoid hypothermia.After brain death has been confirmed, monitor and document the blood pressure regularly, infusing 100 microliters of saline every 30 minutes to stabilize the blood pressure of the animal. After four hours of brain death, exclude any animals without beating hearts and harvest the mouse organs and tissues of interest according to standard protocols. After brain-death induction, the blood pressure exhibits an initial hypertensive peak followed by a prolonged hypotensive phase.Another well-established observation is that brain-death induction leads to activation of the immune system. Indeed, after four hours of brain death in this model, an organ-specific upregulation of immune markers is observed at the mRNA level. After a predefined period of brain death, the organs may be harvested for their direct analysis or for subsequent organ transplantation.This model will enable in-depth studies into the influence of brain-death induced injury and has already revealed new insights into complement activation and leukocyte migration.

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Research

JoVE Journal

Neuroscience

Monitoring Changes in the Intracellular Calcium Concentration and Synaptic Efficacy in the Mollusc Aplysia

It has been suggested that changes in intracellular calcium mediate the induction of a number of important forms of synaptic plasticity (e.g., homosynaptic facilitation) 1. These hypotheses can be tested by simultaneously monitoring changes in intracellular calcium and alterations in synaptic efficacy. We demonstrate how this can be accomplished by combining calcium imaging with intracellular recording techniques. Our experiments are conducted in a buccal ganglion of the mollusc Aplysia californica. This preparation has a number of experimentally advantageous features: Ganglia can be easily removed from Aplysia and experiments use adult neurons that make normal synaptic connections and have a normal ion channel distribution. Due to the low metabolic rate of the animal and the relatively low temperatures (14-16 &deg;C) that are natural for Aplysia, preparations are stable for long periods of time. 
To detect changes in intracellular free calcium we will use the cell impermeant version of Calcium Orange 2 which is easily 'loaded' into a neuron via iontophoresis. When this long wavelength fluorescent dye binds to calcium, fluorescence intensity increases. Calcium Orange has fast kinetic properties 3 and, unlike ratiometric dyes (e.g., Fura 2), requires no filter wheel for imaging. It is fairly photo stable and less phototoxic than other dyes (e.g., fluo-3) 2,4. Like all non-ratiometric dyes, Calcium Orange indicates relative changes in calcium concentration. But, because it is not possible to account for changes in dye concentration due to loading and diffusion, it can not be calibrated to provide absolute calcium concentrations. 
An upright, fixed stage, compound microscope was used to image neurons with a CCD camera capable of recording around 30 frames per second. In Aplysia this temporal resolution is more than adequate to detect even a single spike induced alteration in the intracellular calcium concentration. Sharp electrodes are simultaneously used to induce and record synaptic transmission in identified pre- and postsynaptic neurons. At the conclusion of each trial, a custom script combines electrophysiology and imaging data. To ensure proper synchronization we use a light pulse from a LED mounted in the camera port of the microscope. Manipulation of presynaptic calcium levels (e.g. via intracellular EGTA injection) allows us to test specific hypotheses, concerning the role of intracellular calcium in mediating various forms of plasticity.

Monitoring Changes in the Intracellular Calcium Concentration and Synaptic Efficacy in the Mollusc Aplysia

We demonstrate how changes in the intracellular free calcium concentration and synaptic efficacy can be simultaneously monitored in a ganglion preparation of Aplysia. We image intracellular calcium using a fluorescent dye, Calcium Orange, and induce and monitor synaptic transmission with sharp (intracellular) electrodes.

It has been suggested that changes in intracellular calcium mediate the induction of a number of important forms of synaptic plasticity (e.g., ...

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 ...

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in adult mammalian animals remains elusive. In this study, we describe an experimental procedure for measuring calcium dynamics through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy. This method enables recordings and quantifications of neural activity in bilateral mouse brain regions one at a time in the same experiment for a prolonged period in vivo. Key aspects of this method, which can be completed within an hour, include minimally invasive surgery procedures for creating dual optical windows, and the use of 2P imaging. Although we only demonstrate the technique in the S1 area, the method can be applied to other regions of the living brain facilitating the elucidation of structural and functional complexities of brain neural networks.

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

We describe an experimental procedure for measuring neuronal activity through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy in vivo.

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in ...

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 ...

Monitoring Neuronal Survival via Longitudinal Fluorescence Microscopy

Standard cytotoxicity assays, which require the collection of lysates or fixed cells at multiple time points, have limited sensitivity and capacity to assess factors that influence neuronal fate. These assays require the observation of separate populations of cells at discrete time points. As a result, individual cells cannot be followed prospectively over time, severely limiting the ability to discriminate whether subcellular events, such as puncta formation or protein mislocalization, are pathogenic drivers of disease, homeostatic responses, or merely coincidental phenomena. Single-cell longitudinal microscopy overcomes these limitations, allowing the researcher to determine differences in survival between populations and draw causal relationships with enhanced sensitivity. This video guide will outline a representative workflow for experiments measuring single-cell survival of rat primary cortical neurons expressing a fluorescent protein marker. The viewer will learn how to achieve high-efficiency transfections, collect and process images enabling the prospective tracking of individual cells, and compare the relative survival of neuronal populations using Cox proportional hazards analysis.

Here, we present a protocol to monitor survival on a single-cell basis and identify variables that significantly predict cell death.

Standard cytotoxicity assays, which require the collection of lysates or fixed cells at multiple time points, have limited sensitivity and capacity to ...

Assessment of Long-term Depression Induction in Adult Cerebellar Slices

Synaptic plasticity provides a mechanism for learning and memory. For cerebellar motor learning, long-term depression (LTD) of synaptic transmissions from parallel fibers (PF) to Purkinje cells (PC) is considered the basis for motor learning, and deficiencies of both LTD and motor learning are observed in various gene-manipulated animals. Common motor learning sets, such as adaptation of the optokinetic reflex (OKR), the vestibular-ocular reflex (VOR), and rotarod test were used for evaluation of motor learning ability. However, results obtained from the GluA2-carboxy terminus modified knock-in mice demonstrated normal adaptation of the VOR and the OKR, despite lacking PF-LTD. In that report, induction of LTD was only attempted using one type of stimulation protocol at room temperature. Thus, conditions to induce cerebellar LTD were explored in the same knock-in mutants using various protocols at near physiological temperature. Finally, we found stimulation protocols, by which LTD could be induced in these gene-manipulated mice. In this study, a set of protocols are proposed to evaluate LTD-induction, which will more accurately allow examination of the causal relationship between LTD and motor learning. In conclusion, experimental conditions are crucial when evaluating LTD in gene-manipulated mice.

In some gene-manipulated animals, using a single protocol may fail to induce LTD in cerebellar Purkinje cells, and there may be a discrepancy between LTD and motor learning. Multiple protocols are necessary to assess LTD-induction in gene-manipulated animals. Standard protocols are shown.

Synaptic plasticity provides a mechanism for learning and memory. For cerebellar motor learning, long-term depression (LTD) of synaptic transmissions from ...

Induction of Leptomeningeal Cells Modification Via Intracisternal Injection

The protocol outlined here describes how to safely and manually inject solutions through the cisterna magna while eliminating the risk of damage to the underlying parenchyma. Previously published protocols recommend using straight needles that should be lowered to a maximum of 1-2 mm from the dural surface. The sudden drop in resistance once the dural membrane has been punctured makes it difficult to maintain the needle in a steady position. Our method, instead, employs a needle bent at the tip that can be stabilized against the occipital bone of the skull, thus preventing the syringe from penetrating into the tissue after perforation of the dural membrane. The procedure is straightforward, reproducible, and does not cause long-lasting discomfort in the operated animals. We describe the intracisternal injection strategy in the context of genetic fate mapping of vascular leptomeningeal cells. The same technique can, furthermore, be utilized to address a wide range of research questions, such as probing the role of leptomeninges in neurodevelopment and the spreading of bacterial meningitis, through genetic ablation of genes putatively implicated in these phenomena. Additionally, the procedure can be combined with an automatized infusion system for a constant delivery and used for tracking cerebrospinal fluid movement via injection of fluorescently labelled molecules.

We describe an intracisternal injection that employs a needle bent at the tip that can be stabilized to the skull, thus eliminating the risk of damage to the underlying parenchyma. The approach can be used for genetic fate mapping and manipulations of leptomeningeal cells and for tracking cerebrospinal fluid movement.

The protocol outlined here describes how to safely and manually inject solutions through the cisterna magna while eliminating the risk of damage to the ...

Intra-Arterial Delivery of Neural Stem Cells to the Rat and Mouse Brain: Application to Cerebral Ischemia

Neural stem cell (NSC) therapy is an emerging innovative treatment for stroke, traumatic brain injury and neurodegenerative disorders. As compared to intracranial delivery, intra-arterial administration of NSCs is less invasive and produces a more diffuse distribution of NSCs within the brain parenchyma. Further, intra-arterial delivery allows the first-pass effect in the brain circulation, lessening the potential for trapping of cells in peripheral organs, such as liver and spleen, a complication associated with peripheral injections. Here, we detail the methodology, in both mice and rats, for delivery of NSCs through the common carotid artery (mouse) or external carotid artery (rat) to the ipsilateral hemisphere after an ischemic stroke. Using GFP-labeled NSCs, we illustrate the widespread distribution achieved throughout the rodent ipsilateral hemisphere at 1 d, 1 week and 4 weeks after postischemic delivery, with a higher density in or near the ischemic injury site. In addition to long-term survival, we show evidence of differentiation of GFP-labeled cells at 4 weeks. The intra-arterial delivery approach described here for NSCs can also be used for administration of therapeutic compounds, and thus has broad applicability to varied CNS injury and disease models across multiple species.

A method for delivering neural stem cells, adaptable for injecting solutions or suspensions, through the common carotid artery (mouse) or external carotid artery (rat) after ischemic stroke is reported. Injected cells are distributed broadly throughout the brain parenchyma and can be detected up to 30 d after delivery.

Neural stem cell (NSC) therapy is an emerging innovative treatment for stroke, traumatic brain injury and neurodegenerative disorders. As compared to ...

Induction of Complete Transection-Type Spinal Cord Injury in Mice

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, such as cell transplantation methods, are being researched to overcome the debilitating disabilities arising from SCI. Most pre-clinical animal trials are conducted in rodent models of SCI. While rat models of SCI have been widely used, mouse models have received less attention, even though mouse models can have significant advantages over rat models. The small size of mice equates to lower animal maintenance costs than for rats, and the availability of numerous transgenic mouse models is advantageous for many types of studies. Inducing repeatable and precise injury in the animals is the primary challenge for SCI research, which in small rodents requires high-precision surgery. The transection-type injury model has been a commonly used injury model over the last decade for transplantation-based therapeutic research, however a standardized method for inducing a complete transection-type injury in mice does not exist. We have developed a surgical protocol for inducing a complete transection type injury in C57BL/6 mice at thoracic vertebral level 10 (T10). The procedure uses a small tip drill instead of rongeurs to precisely remove the lamina, after which a thin blade with rounded cutting edge is used to induce the spinal cord transection. This method leads to reproducible transection-type injury in small rodents with minimal collateral muscle and bone damage and therefore minimizes confounding factors, specifically where behavioral functional outcomes are analyzed.

This protocol describes how to create a precise laminectomy for induction of stable transection-type spinal cord injury in the mouse model, with minimal collateral damage for spinal cord injury research.

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, ...

Induction of Diffuse Axonal Brain Injury in Rats Based on Rotational Acceleration

Traumatic brain injury (TBI) is a major cause of death and disability. Diffuse axonal injury (DAI) is the predominant mechanism of injury in a large percentage of TBI patients requiring hospitalization. DAI involves widespread axonal damage from shaking, rotation or blast injury, leading to rapid axonal stretch injury and secondary axonal changes that are associated with a long-lasting impact on functional recovery. Historically, experimental models of DAI without focal injury have been difficult to design. Here we validate a simple, reproducible and reliable rodent model of DAI that causes widespread white matter damage without skull fractures or contusions.

This protocol validates a reliable, easy-to-perform and reproducible rodent model of brain diffuse axonal injury (DAI) that induces widespread white matter damage without skull fractures or contusions.

Traumatic brain injury (TBI) is a major cause of death and disability. Diffuse axonal injury (DAI) is the predominant mechanism of injury in a large ...