We thank Christine &#214;r&#252;n and Jan A. M. Sochurek for their help with experimental methods.

All procedures involving animal tissue follow the guidelines of the local Animal Care and Ethics Committee.
1. Preparation of organ culture and laser treatment
<ol>
	<li>Obtain freshly enucleated porcine eyes from the local abattoir. Keep them cool (4 &#176;C) in Dulbecco&#39;s modified Eagle medium (DMEM) with high glucose, supplemented with L-glutamine, sodium pyruvate, penicillin/streptomycin (1%), and porcine serum (10%), henceforth referred to in this article as full medium.</li>
	<li>Remove extracellular tissues with scissors and soak the eyes in 5% povidone-iodine ophthalmic solution for 5 min before placing them in sterilized phosphate-buffered saline (PBS) until use.</li>
	<li>Screen eyes for major anterior segment pathologies, such as corneal scarring, edema, and other opacities with a spectral-domain optical coherence tomography device (Table of Materials).</li>
	<li>Position the eyes in front of a slit-lamp unit equipped with a Nd:YAG laser (Table of Materials), which has a wavelength of 1,064 nm and a focal spot diameter of 10 &#181;m in air. 
	NOTE: For optimal positioning a 3D-printed holding apparatus is used, which was designed to hold the eye firm, without putting too much pressure on it (Figure 1).</li>
	<li>Use a magnification of 12x and deflect the illumination to visualize the individual corneal layers.</li>
	<li>Set the pulse energy (e.g., 1.6 mJ) and focus point (e.g., 0.16 mm) for selective ablation of endothelial cells.</li>
	<li>Place a clear cornea paracentesis close to the limbus and inject viscoelastic (Table of Materials) to stabilize the anterior chamber.</li>
	<li>Excise the laser-treated central cornea using an 8 mm trephine.</li>
	<li>Place the excised cornea in a well of a 12-well plate with the endothelial site facing upwards and incubate the specimen in 3 mL of full medium at 37 &#176;C for up to 3 days. 
	NOTE: Potential cytoprotective agents can be added to the medium during this step.</li>
</ol>
2. Preparation for histology
<ol>
	<li>Prepare Sorensen&#8217;s buffer with a pH of 7.4 containing 19.6 mL of 133 mM KH2PO4 and 80.4 mL of 133 mM Na2HPO4.</li>
	<li>Remove the medium from the cornea-containing well and fixate the tissue for 20 min at room temperature (RT) using methanol-free paraformaldehyde (4%) in Sorensen&#8217;s buffer.</li>
	<li>Place tissue in 20% sucrose in PBS until tissue sinks (1 h) and then in 30% sucrose in PBS overnight at RT. Take care to avoid contact with bubbles and the air surface interface. Embed tissue in optimal cutting temperature (OCT) compound and store at -80 &#176;C.</li>
	<li>Cut sections 10 &#956;m thick using a cryostat at -27 &#176;C. 
	NOTE: A camel hairbrush is useful to help guide the emerging section over the knife blade.</li>
	<li>Transfer the section to a microscope slide by touching the slide to the tissue within 1 min of cutting it to avoid freeze-drying of the tissue. Store the slides at -80 &#176;C.</li>
</ol>
3. Hematoxylin and eosin (H&#38;E) staining
<ol>
	<li>Air dry sections for several minutes to remove moisture.</li>
	<li>Stain with filtered 0.1% Mayers hematoxylin for 10 min in a 50 mL tube.</li>
	<li>In a Coplin jar, rinse in cool running ddH2O for 5 min and dip in 0.5% eosin 10x.</li>
	<li>Dip in ddH2O until the eosin stops streaking and then dip in 50% (10x) as well as 70% (10x) EtOH.</li>
	<li>Equilibrate in 95% EtOH (30 s) and 100% EtOH (60 s) before dipping in xylene several times.</li>
	<li>Finally mount and coverslip the specimen before taking images using a light microscope.</li>
</ol>

<ol>
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The authors have nothing to disclose.

The results of this pilot study indicate that a Nd:YAG laser can be used to selectively ablate corneal endothelial cells when appropriate parameters for energy dose and focus point position are chosen.
As the endothelial function is important for corneal transparency and safeguarding the cornea from stromal edema, models of endothelial dysfunction play an important role in the development of anti-edematous drugs or surgical procedures. There are several established in vitro models for mimickin...

Transparency of the cornea is essential for the transmission of light to the retina and its photoreceptors1. In this regard, a relative state of dehydration is critical to keep the collagen fibers within the corneal stroma correctly aligned. This homeostasis is maintained by corneal endothelial cells (CEC) located on the Descemet&#8217;s membrane (DM)2. The endothelium is the innermost corneal layer. It has an important barrier and pump function, which is crucial for corneal transparency3. In contrast to the epithelium, the endothelium is not able to self-renew4. Therefore, any cell damage caused by disease or trauma stimulates the remaining endothelial cells to enlarge and migrate, to cover resulting defects and to maintain corneal functionality5. However, if the CEC density falls below a critical threshold, decompensation of the endothelium leads to an edema, resulting in blurred vision and discomfort or even severe pain4. Despite the availability of drugs to relieve symptoms, currently the only definitive treatment in these cases is corneal transplantation, which can be performed in the form of a full-thickness graft or a lamellar endothelial transplantation. The latter procedure is available as Descemet&#39;s membrane endothelial keratoplasty (DMEK) as well as Descemet&#39;s stripping automated endothelial keratoplasty (DSAEK)6. However, the protection of remaining CEC and enhancing their survival could be an alternative target, which needs an adequate disease model to test potential therapeutic drugs.
Current CEC loss disease models focus on the destruction of the endothelium through the injection of toxic agents (e.g., benzalkonium chloride) into the anterior chamber or by mechanical abrasion of the cells using an invasive descemetorhexis technique7,8. While these models are well established, disadvantages such as general inflammatory response and imprecise collateral damage exist. Therefore, these models are more likely to represent final stages of the disease, when the above-mentioned surgical options are inevitable.
With advances in cellular treatment strategies such as stem cells and gene therapy, the application of these cellular therapies could be useful in early stages of CEC loss9. Subsequently, we need a model that represents these earlier stages of the disease more adequately. In this regard, cell culture models have improved over the last decade but are still limited in their validity, as cells in vitro cannot come close to replicating the complex interactions that occur between the different cell types within the cornea10. Therefore, ex vivo and in vivo disease models are still in high demand and improving the existing ones is of utmost interest.
Noninvasive, intraocular surgery by photodisruption using a neodymium:YAG (Nd:YAG) laser has become a routine procedure for ophthalmologists worldwide since its introduction in the late 1970s11. Photodisruption relies on nonlinear light absorption leading to the formation of plasma, generation of acoustic shock waves, and creation of cavitation bubbles, whenever the application site is located in a liquid environment12. In general, these processes contribute to the intended effect of precise tissue cutting. However, they can also be the source of unnecessary collateral damage limiting the local confinement of laser surgery13.
The prediction of resulting mechanical effects has significantly improved through characterization of the shock wave propagation and cavitation course. It is our goal to target CEC with as little damage to surrounding tissue as possible to provide a noninvasive, laser-assisted experimental disease model for the early stages of CEC loss. For this purpose, it is necessary to determine the optimal pulse energies and positions of the focal spots of the laser.

<table border="0" cellpadding="0" cellspacing="0" style="width:933px;" width="932">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:313px;">BARRON VACUUM TREPHINE</td>
			<td style="width:213px;">Katena</td>
			<td style="width:344px;">K20-2058</td>
			<td style="width:63px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Cryostat</td>
			<td>Leica</td>
			<td>CM 3050S</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Dulbecco&#8217;s Modified Eagle&#8217;s Medium - high glucose</td>
			<td>PAA</td>
			<td>E-15009</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Eye holder</td>
			<td>Self</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Inverted Microscope</td>
			<td>Leica</td>
			<td>DMI 6000 B</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">KH2PO4</td>
			<td>Merck</td>
			<td>529568</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Na2HPO4</td>
			<td>Merck</td>
			<td>1065860500</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Nd:YAG laser</td>
			<td>Zeiss Meditec</td>
			<td>visuLAS YAG II plus</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">OCT Tissue Tek</td>
			<td>Sakura Finetechnical</td>
			<td>4583</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Penicillin-Streptomycin</td>
			<td>Sigma-Aldrich</td>
			<td>P4333</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Phosphate Buffered Saline (PBS)</td>
			<td>Gibco</td>
			<td>10010056</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Porcine serum</td>
			<td>Sigma-Aldrich</td>
			<td>12736C</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Spectral-domain optical coherence tomograph</td>
			<td>Heidelberg Engineering</td>
			<td>Spectralis</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Tissue culture plate 12-well</td>
			<td>Sarstedt</td>
			<td>833921</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Two-Photon Microscope</td>
			<td>JenLab</td>
			<td>DermaInspect</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Viscoelastic</td>
			<td>OmniVision</td>
			<td>Methocel</td>
			<td></td>
		</tr>
	</tbody>
</table>

development of a noninvasive, laser-assisted experimental model of corneal endothelial cell loss

Nd:YAG lasers have been used to perform noninvasive intraocular surgery, such as capsulotomy for several decades now. The incisive effect relies on the optical breakdown at the laser focus. Acoustic shock waves and cavitation bubbles are generated, causing tissue rupture. Bubble sizes and pressure amplitudes vary with pulse energy and position of the focal point. In this study, enucleated porcine eyes were positioned in front of a commercially available Nd:YAG laser. Variable pulse energies as well as different positions of the focal spots posterior to the cornea were tested. Resulting lesions were evaluated by two-photon microscopy and histology to determine the best parameters for an exclusive detachment of corneal endothelial cells (CEC) with minimum collateral damage. The advantages of this method are the precise ablation of CEC, reduced collateral damage, and above all, the non-contact treatment.

Using the procedure presented here, we treated eyes with a Nd:YAG laser, evaluating different pulse energies (1.0&#8722;4.6 mJ) and positions of focal points (distance from the posterior surface of the cornea: 0.0&#8722;0.2 mm) to find the optimal parameters. Multiple replicates (n = 3) were evaluated for each constellation of the laser parameters (12 x 21).
In addition to the above-mentioned protocol, specimen was analyzed with a two-photon microscope before fixation and H&#38;E staining. The...

Watch this Scientific Journal Video about Development of a Noninvasive, Laser-Assisted Experimental Model of Corneal Endothelial Cell Loss at JoVE.com

Development of a Noninvasive, Laser-Assisted Experimental Model of Corneal Endothelial Cell Loss

Here, we present a protocol to detach corneal endothelial cells (CEC) from Descemet&#8217;s membrane (DM) using a neodymium:YAG (Nd:YAG) laser as an ex vivo disease model for bullous keratopathy (BK).

Nd:YAG lasers have been used to perform noninvasive intraocular surgery, such as capsulotomy for several decades now. The incisive effect relies on the ...

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5.3K Views.  University of Lübeck. Here, we present a protocol to detach corneal endothelial cells (CEC) from Descemet’s membrane (DM) using a neodymium:YAG (Nd:YAG) laser as an ex vivo disease model for bullous keratopathy (BK).

Video: Development of a Noninvasive, Laser-Assisted Experimental Model of Corneal Endothelial Cell Loss

Orthotopic Aortic Transplantation: A Rat Model to Study the Development of Chronic Vasculopathy

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant vasculopathy (TVP).
The commonly used animal model for cardiovascular chronic rejection studies is the heterotopic heart transplant model performed in laboratory rodents. This model is used widely in experiments since Ono and Lindsey (3) published their technique. To analyze the findings in the blood vessels, the heart has to be sectioned and all vessels have to be measured.
Another method to investigate chronic rejection in cardiovascular questionings is the aortic transplant model (1, 2). In the orthotopic aortic transplant model, the aorta can easily be histologically evaluated (2). The PVG-to-ACI model is especially useful for CAV studies, since acute vascular rejection is not a major confounding factor and Cyclosporin A (CsA) treatment does not prevent the development of CAV, similar to what we find in the clinical setting (4). A7-day period of CsA is required in this model to prevent acute rejection and to achieve long-term survival with the development of TVP.
This model can also be used to investigate acute cellular rejection and media necrosis in xenogeneic models (5).

This video demonstrates the orthotopic aortic transplant model as a simple model to study the development of transplant vasculopathy (TVP) in rats.

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant ...

Corneal Donor Tissue Preparation for Endothelial Keratoplasty

Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes1,2. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection3-6.
Initially, cornea donor posterior lamellar dissection for DSEK was performed manually1 resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing.
Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in terms of the quality of the tissue7 or patient outcomes8,9 using eye bank precut tissue versus surgeon-prepared tissue for DSAEK surgery. For most corneal surgeons, the availability of precut DSAEK corneal tissue saves time and money10, and reduces the stress of performing the donor corneal dissection in the operating room. In part because of the ability of the eye banks to provide high quality posterior lamellar corneal in a timely manner, DSAEK has become the standard of care for surgical management of corneal endothelial disease.
The procedure that we are describing is the preparation of the posterior lamellar cornea at the eye bank for transplantation in DSAEK surgery (Figure 1).

Endothelial corneal transplantation is a surgical technique for treatment of posterior corneal diseases. Mechanical microkeratome dissection to prepare tissue results in thinner, more symmetric grafts with less endothelial cell loss and improved outcomes. Dissections can be performed at the eye bank prior to corneal transplantation surgery.

Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes1,2. Since its inception, traditional full ...

An Alkali-burn Injury Model of Corneal Neovascularization in the Mouse

Under normal conditions, the cornea is avascular, and this transparency is essential for maintaining good visual acuity. Neovascularization (NV) of the cornea, which can be caused by trauma, keratoplasty or infectious disease, breaks down the so called &lsquo;angiogenic privilege' of the cornea and forms the basis of multiple visual pathologies that may even lead to blindness. Although there are several treatment options available, the fundamental medical need presented by corneal neovascular pathologies remains unmet. In order to develop safe, effective, and targeted therapies, a reliable model of corneal NV and pharmacological intervention is required. Here, we describe an alkali-burn injury corneal neovascularization model in the mouse. This protocol provides a method for the application of a controlled alkali-burn injury to the cornea, administration of a pharmacological compound of interest, and visualization of the result. This method could prove instrumental for studying the mechanisms and opportunities for intervention in corneal NV and other neovascular disorders.

Neovascularization (NV) of the cornea can complicate multiple visual pathologies. Utilizing a controlled, alkali-burn injury model, a quantifiable level of corneal NV can be produced for mechanistic study of corneal NV and evaluation of potential therapies for neovascular disorders.

Under normal conditions, the cornea is avascular, and this transparency is essential for maintaining good visual acuity. Neovascularization (NV) of the ...

Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation

Corneal transplantation is the most common form of organ transplantation in the United States with between 45,000 and 55,000 procedures performed each year. While several animal models exist for this procedure and mice are the species that is most commonly used. The reasons for using mice are the relative cost of using this species, the existence of many genetically defined strains that allow for the study of immune responses, and the existence of an extensive array of reagents that can be used to further define responses in this species. This model has been used to define factors in the cornea that are responsible for the relative immune privilege status of this tissue that enables corneal allografts to survive acute rejection in the absence of immunosuppressive therapy. It has also been used to define those factors that are most important in rejection of such allografts. Consequently, much of what we know concerning mechanisms of both corneal allograft acceptance and rejection are due to studies using a murine model of corneal transplantation. In addition to describing a model for acute corneal allograft rejection, we also present for the first time a model of late-term corneal allograft rejection.

Mice have been used as a model for studying many forms of transplantation, including corneal transplantation. We describe in this report a murine model for both acute and late-term corneal transplantation.

Corneal transplantation is the most common form of organ transplantation in the United States with between 45,000 and 55,000 procedures performed each ...

Corneal Donor Tissue Preparation for Descemet's Membrane Endothelial Keratoplasty

Descemet&#8217;s Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, along with its basement membrane (Descemet&#39;s membrane) is introduced onto the recipient&#39;s posterior stroma3. Unlike Descemet&#8217;s Stripping Automated Endothelial Keratoplasty (DSAEK), where additional donor stroma is introduced, no unnatural stroma-to-stroma interface is created. As a result, the natural anatomy of the cornea is preserved as much as possible allowing for improved recovery time and visual acuity4. Endothelial Keratoplasty (EK) is the procedure of choice for treatment of endothelial dysfunction. The advantages of EK include rapid recovery of vision, preservation of ocular integrity and minimal refractive change due to use of a small, peripheral incision1. DSAEK utilizes donor tissue prepared with partial thickness stroma and endothelium. The rapid success and utilization of this procedure can be attributed to availability of eye-bank prepared precut tissue. The benefits of eye-bank preparation of donor tissue include elimination of need for specialized equipment in the operating room and availability of back up donor tissue in case of tissue perforation during preparation. In addition, high volume preparation of donor tissue by eye-bank technicians may provide improved quality of donor tissue. DSAEK may have limited best corrected visual acuity due to creation of a stromal interface between the donor and recipient cornea. Elimination of this interface with transplantation of only donor Descemet&#39;s membrane and endothelium in DMEK may improve visual outcomes and reduce complications after EK5. Similar to DSAEK, long term success and acceptance of DMEK is dependent on ease of availability of precut, eye-bank prepared donor tissue. Here we present a stepwise approach to donor tissue preparation which may reduce some barriers eye-banks face in providing DMEK grafts.

Corneal Donor Tissue Preparation for Descemet&#039;s Membrane Endothelial Keratoplasty

Endothelial keratoplasty is a surgical technique continuously evolving as advancements result in transplantation of thinner grafts with each succession1. Here we present a technique for controlled manual tissue dissection to allow safe and repeatable separation of endothelium and Descemet&#39;s membranes from donor corneoscleral buttons for transplantation2.

Descemet&#8217;s Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, ...

Evaluation of a Novel Laser-assisted Coronary Anastomotic Connector - the Trinity Clip - in a Porcine Off-pump Bypass Model

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated.

This paper describes a novel nonocclusive coronary anastomotic connector in a porcine off-pump coronary artery bypass (OPCAB) model. This easy-to-use coronary connector has intrinsic potential to facilitate minimally invasive OPCAB surgery.

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the ...

Neural Stem Cell Transplantation in Experimental Contusive Model of Spinal Cord Injury

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can be used both to investigate the biological responses to injury and to test potential therapies. Contusion or compression injury delivered to the surgically exposed spinal cord are the most widely used models of the pathology. In this report the experimental contusion is performed by using the Infinite Horizon (IH) Impactor device, which allows the creation of a reproducible injury animal model through definition of specific injury parameters. Stem cell transplantation is commonly considered a potentially useful strategy for curing this debilitating condition. Numerous studies have evaluated the effects of transplanting a variety of stem cells. Here we demonstrate an adapted method for spinal cord injury followed by tail vein injection of cells in CD1 mice. In short, we provide procedures for: i) cell labeling with a vital tracer, ii) pre-operative care of mice, iii) execution of a contusive spinal cord injury, and iv) intravenous administration of post mortem neural precursors. This contusion model can be utilized to evaluate the efficacy and safety of stem cell transplantation in a regenerative medicine approach.

Spinal cord injury is a traumatic condition that causes severe morbidity and high mortality. In this work we describe in detail a contusion model of spinal cord injury in mice followed by a transplantation of neural stem cells.

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can ...

Facial Nerve Axotomy in Mice: A Model to Study Motoneuron Response to Injury

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and either cut or crush it to induce peripheral nerve injury. Advantages of this surgery are its simplicity, high reproducibility, and the lack of effect on vital functions or mobility from the subsequent facial paralysis, thus resulting in a relatively mild surgical outcome compared to other nerve injury models. A major advantage of using a cranial nerve injury model is that the motoneurons reside in a relatively homogenous population in the facial motor nucleus in the pons, simplifying the study of the motoneuron cell bodies. Because of the symmetrical nature of facial nerve innervation and the lack of crosstalk between the facial motor nuclei, the operation can be performed unilaterally with the unaxotomized side serving as a paired internal control. A variety of analyses can be performed postoperatively to assess the physiologic response, details of which are beyond the scope of this article. For example, recovery of muscle function can serve as a behavioral marker for reinnervation, or the motoneurons can be quantified to measure cell survival. Additionally, the motoneurons can be accurately captured using laser microdissection for molecular analysis. Because the facial nerve axotomy is minimally invasive and well tolerated, it can be utilized on a wide variety of genetically modified mice. Also, this surgery model can be used to analyze the effectiveness of peripheral nerve injury treatments. Facial nerve injury provides a means for investigating not only motoneurons, but also the responses of the central and peripheral glial microenvironment, immune system, and target musculature. The facial nerve injury model is a widely accepted peripheral nerve injury model that serves as a powerful tool for studying nerve injury and regeneration.

We present a surgical protocol detailing how to perform a cut or crush axotomy on the facial nerve in the mouse. The facial nerve axotomy can be employed to study the physiological response to nerve injury and test therapeutic techniques.

The goal of this surgical protocol is to expose the facial nerve, which innervates the facial musculature, at its exit from the stylomastoid foramen and ...

A Neonatal Mouse Spinal Cord Compression Injury Model

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal cord. A major current area of research is focused on the mechanisms of adaptive plasticity that underlie spontaneous or induced functional recovery following SCI. Spontaneous functional recovery is reported to be greater early in life, raising interesting questions about how adaptive plasticity changes as the spinal cord develops. To facilitate investigation of this dynamic, we have developed a SCI model in the neonatal mouse. The model has relevance for pediatric SCI, which is too little studied. Because neural plasticity in the adult involves some of the same mechanisms as neural plasticity in early life1, this model may potentially have some relevance also for adult SCI. Here we describe the entire procedure for generating a reproducible spinal cord compression (SCC) injury in the neonatal mouse as early as postnatal (P) day 1. SCC is achieved by performing a laminectomy at a given spinal level (here described at thoracic levels 9-11) and then using a modified Yasargil aneurysm mini-clip to rapidly compress and decompress the spinal cord. As previously described, the injured neonatal mice can be tested for behavioral deficits or sacrificed for ex vivo physiological analysis of synaptic connectivity using electrophysiological and high-throughput optical recording techniques1. Earlier and ongoing studies using behavioral and physiological assessment have demonstrated a dramatic, acute impairment of hindlimb motility followed by a complete functional recovery within 2 weeks, and the first evidence of changes in functional circuitry at the level of identified descending synaptic connections1.

This article describes a method for generating a reproducible spinal cord compression injury (SCI) in the neonatal mouse. The model provides an advantageous platform for studying mechanisms of adaptive plasticity that underlie spontaneous functional recovery.

Spinal cord injury (SCI) typically causes devastating neurological deficits, particularly through damage to fibers descending from the brain to the spinal ...

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging

Cerebral malaria is a sign of severe malarial disease and is often a harbinger of death. While aggressive management can be life-saving, the detection of cerebral malaria can be difficult. We present an experimental mouse model of cerebral malaria that shares multiple features of the human disease, including edema and microvascular pathology. Using magnetic resonance imaging (MRI), we can detect and track the blood-brain barrier disruption, edema development, and subsequent brain swelling. We describe multiple MRI techniques that can visualize these pertinent pathological changes. Thus, we show that MRI represents a valuable tool to visualize and track pathological changes, such as edema, brain swelling, and microvascular pathology, in vivo.

In Vivo Tracking of Edema Development and Microvascular Pathology in a Model of Experimental Cerebral Malaria Using Magnetic Resonance Imaging

We describe a mouse model of experimental cerebral malaria and show how inflammatory and microvascular pathology can be tracked in vivo using magnetic resonance imaging.

Cerebral malaria is a sign of severe malarial disease and is often a harbinger of death. While aggressive management can be life-saving, the detection of ...