Name: arterial pouch microsurgical bifurcation aneurysm model in the rabbit
Uploaded: 2020-05-14T13:00:00
Description: Watch this Scientific Journal Video about Arterial Pouch Microsurgical Bifurcation Aneurysm Model in the Rabbit at JoVE.com

The authors thank Olgica Beslac and Kay Nettelbeck for their excellent support and technical assistance during the peri-operative phase and Alessandra Bergadano, DVM, PhD, for the dedicated supervision of the long-term animal health.

All veterinary care was performed in accordance with the institutional guidelines (all experiments were approved by the Local Committee for Animal Care of the Canton Bern, Switzerland (BE 108/16)) and conducted under supervision of a board-certified veterinarian anesthesiologist. The ARRIVE guidelines and the 3R principles were strictly followed17,18.
NOTE: House all animals at a room temperature of 22&#8210;24 Celsius (&#176;C)&#160;a...

Our study demonstrates the feasibility of creating a true bifurcation aneurysm model with different wall conditions in rabbits. Overall, 14 female New Zealand White rabbits with a mean weight of 3.7 &#177; 0.09 kg and mean age of 112 &#177; 3 days were included in the study. 85.72% of all aneurysms remained patent during a follow-up at 28 days. Two animals died prematurely (12.5% mortality).
Previous studies suggested a variety of extracranial aneurysm models to analyze the management of endov...

Subarachnoid hemorrhage resulting from intracranial aneurysm (IA) rupture&#160;can effectively be controlled by either endovascular or microsurgical occlusion techniques1,2,3,4. Different endovascular therapies, to overcome the main limitation of IA recurrence after coiling, gained importance over the past decades generating an increased need of testing endovascular devices. To test these novel treatment approaches, appropriate animal models that respect rheological properties, hemodynamics and aneurysm wall conditions are highly warranted5,6,7. In this context, clinical as well as preclinical studies have already revealed the important role of aneurysm wall conditions regarding aneurysm rupture and recurrence after occlusion, especially focusing on the loss of mural cells7,8,9.
So far, experimental aneurysms in rabbits have most often been created either by elastase incubated common carotid artery (CCA) stumps or venous pouches sutured into an artificial CCA bifurcation.10,11,12,13,14,15,16 Thus, a true arterial pouch bifurcation model has never been described.
The aim of this study was to design a safe, fast, and standardized technique for microsurgical creation of bifurcation aneurysms with different wall conditions in a rabbit model (Figure 1). This was achieved by suturing non-modified and modified arterial pouches into an artificial created bifurcation of both CCAs.

<table>
	<tbody>
		<tr>
			<td>3-0 resorbable suture</td>
			<td>Ethicon Inc., USA</td>
			<td>VCP428G</td>
			<td></td>
		</tr>
		<tr>
			<td>4-0 non-absorbable suture</td>
			<td>B. Braun, Germany</td>
			<td>G0762563</td>
			<td></td>
		</tr>
		<tr>
			<td>6-0 non-absorbable suture</td>
			<td>B. Braun, Germany</td>
			<td>C0766070</td>
			<td></td>
		</tr>
		<tr>
			<td>9-0 non-absorbable suture</td>
			<td>B. Braun, Germany</td>
			<td>G1111140</td>
			<td></td>
		</tr>
		<tr>
			<td>Adrenaline</td>
			<td>Amino AG</td>
			<td>1445419</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Amiodarone</td>
			<td>Helvepharm AG</td>
			<td>5078567</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Anesthesia machine</td>
			<td>Dr&#228;ger</td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Aspirin</td>
			<td>Sanofi-Aventis (Suisse) SA</td>
			<td>622693</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Atropine</td>
			<td>Labatec Pharma SA</td>
			<td>6577083</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Bandpass filter blue</td>
			<td>Thorlabs</td>
			<td>FD1B</td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Bandpass filter green</td>
			<td>Thorlabs</td>
			<td>FGV9</td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Bipolar forceps</td>
			<td></td>
			<td></td>
			<td>any other</td>
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		<tr>
			<td>Bicycle spotlight</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Biemer vessel clip (2 x)</td>
			<td>B. Braun Medical AG, Aesculap, Switzerland</td>
			<td>FD560R</td>
			<td>temporary</td>
		</tr>
		<tr>
			<td>Bispectral index (neonatal)</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Blood pressure cuff (neonatal)</td>
			<td></td>
			<td></td>
			<td>any other</td>
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		<tr>
			<td>Clamoxyl</td>
			<td>GlaxoSmithKline AG</td>
			<td>758808</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Dexmedetomidine</td>
			<td>Ever Pharma</td>
			<td>136740-1</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Electrocardiogram electrodes</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Elastase</td>
			<td>Sigma Aldrich</td>
			<td>45125</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Ephedrine</td>
			<td>Amino AG</td>
			<td>1435734</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Esmolol</td>
			<td>OrPha Swiss GmbH</td>
			<td>3284044</td>
			<td>any generic</td>
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			<td>Fentanyl (intravenous use)</td>
			<td>Janssen-Cilag AG</td>
			<td>98683</td>
			<td>any generic</td>
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			<td>Fentanyl (transdermal)</td>
			<td>Mepha Pharma AG</td>
			<td>4008286</td>
			<td>any generic</td>
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			<td>Fluoresceine</td>
			<td>Curatis AG</td>
			<td>5030376</td>
			<td>any generic</td>
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			<td>Fragmin</td>
			<td>Pfizer PFE Switzerland GmbH</td>
			<td>1906725</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Glyco</td>
			<td></td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Heating pad</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Isotonic sodium chloride solution (0.9%)</td>
			<td>Fresenius KABI</td>
			<td>336769</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>Pfizer</td>
			<td>342261</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Laboratory shaker</td>
			<td>Stuart</td>
			<td>SRT6</td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Lidocaine</td>
			<td>Streuli Pharma AG</td>
			<td>747466</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Longuettes</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Metacam</td>
			<td>Boehringer Ingelheim</td>
			<td>P7626406</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Methadone</td>
			<td>Streuli Pharma AG</td>
			<td>1084546</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Microtubes</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Micro needle holder</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Midazolam</td>
			<td>Accord Healthcare AG</td>
			<td>7752484</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>O2-Face mask</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Operation microscope</td>
			<td>Wild Heerbrugg</td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Papaverine</td>
			<td>Bichsel</td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Prilocaine-lidocaine creme</td>
			<td>Emla</td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Propofol</td>
			<td>B. Braun Medical AG, Switzerland</td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Pulse oxymeter</td>
			<td></td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Rectal temperature probe (neonatal)</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Ropivacaine</td>
			<td>Aspen Pharma Schweiz GmbH</td>
			<td>1882249</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Scalpell</td>
			<td>Swann-Morton</td>
			<td>210</td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Small animal shaver</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Smartphone</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Soft tissue forceps</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Soft tissue spreader</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Stainless steel sponge bowls</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Sterile micro swabs</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Stethoscope</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Straight and curved micro-forceps</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Straight and curved micro-scissors</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Straight and curved forceps</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Surgery drape</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Surgical scissors</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Syringes 1 ml, 2ml and 5 ml</td>
			<td></td>
			<td></td>
			<td>any other</td>
		</tr>
		<tr>
			<td>Tris-Buffer</td>
			<td>Sigma Aldrich</td>
			<td>93302</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Vascular clip applicator</td>
			<td>B. Braun, Germany</td>
			<td>FT495T</td>
			<td></td>
		</tr>
		<tr>
			<td>Vein and arterial catheter 22 G</td>
			<td></td>
			<td></td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Vitarubin</td>
			<td>Streuli Pharma AG</td>
			<td>6847559</td>
			<td>any generic</td>
		</tr>
		<tr>
			<td>Yasargil titan standard clip (2 x)</td>
			<td>B. Braun Medical AG, Aesculap, Switzerland</td>
			<td>FT242T</td>
			<td>temporary</td>
		</tr>
	</tbody>
</table>

arterial pouch microsurgical bifurcation aneurysm model in the rabbit

Endovascular treatment for intracranial aneurysms gained importance over the past decades, consequently there is an increased need of testing endovascular devices. Animal models respecting rheological, hemodynamic and aneurysm wall conditions are highly warranted. Therefore, the aim of the present study was to design a novel standardized and reproducible surgical technique to create autologous arterial pouch bifurcation aneurysms with non-modified and modified wall conditions in rabbits.
Bifurcation aneurysms were created by end-to-side anastomosis of the right on the left common carotid artery, both serving as parent arteries for the arterial pouch, which was microsurgically sewn on. Grafts were taken from the proximal right common carotid artery, either for the control (n = 7, immediate autologous re-implantation) or modified (n = 7, incubated with 100 international units elastase for 20 minutes before autologous re-implantation) group. Pouch and parent artery patency were controlled by fluorescence angiography immediately after creation. At follow-up (28 days), all rabbits underwent contrast enhanced magnetic resonance angiography and fluorescence angiography followed by aneurysm harvesting, macroscopic and histological evaluation.
A total of 16 female New Zealand White rabbits were operated upon. Two animals died prematurely. At follow-up, 85.72% of all aneurysms remained patent. Both groups revealed an increase in aneurysm size over time; this was more pronounced in the control group (6.48 &#177; 1.81 mm3 at time of creation vs. 19.85 &#177; 6.40 mm3 at follow-up, p = 0.037) than in the modified group (8.03 &#177; 1.08 mm3 at time of creation vs. 20.29 &#177; 6.16 mm3 at follow-up, p = 0.054).
Our findings demonstrate the adequacy of this new rabbit model which allows for the creation of bifurcation aneurysms with different wall conditions in a microsurgical approach. Given the excellent long-term patency and the property of aneurysm growth over time, this model may serve as an important tool for preclinical evaluation of novel endovascular therapies.

Following a pilot series of seven animals, totally 16 animals were included in the experimental protocol. Two animals died prematurely and were therefore excluded from the final analysis (12.5% mortality). Calculated on 14 animals, immediate aneurysm patency rate during fluorescence angiography was 71.43% in both, the control and modified group. Four aneurysms had to be reopened with consecutive thrombus evacuation and after a repeated fluorescence angiography there was a documented patency in all cases (100%). Aneurysm ...

Watch this Scientific Journal Video about Arterial Pouch Microsurgical Bifurcation Aneurysm Model in the Rabbit at JoVE.com

Arterial Pouch Microsurgical Bifurcation Aneurysm Model in the Rabbit

Developing and testing endovascular devices for intracranial aneurysm treatment is still of great importance. Most aneurysm models used today miss either the important characteristics of an arterial degenerated wall or the hemodynamics of a true bifurcation. Therefore, we aimed to design a novel arterial pouch bifurcation model in rabbits.

Endovascular treatment for intracranial aneurysms gained importance over the past decades, consequently there is an increased need of testing endovascular ...

As the development and testing of endovascular devices in intracranial aneurysm treatment is still greatly needed. We have designed a novel arterial pouch bifurcation model in rabbits. This model uses a single, highly standardized and easily reproducible microsurgical technique to create a autologous material pouch bifurcation aneurysms with modified and non-modified wall conditions in rabbits.After confirming a lack of response to pedal reflex in an anesthetized adult rabbit, make a median skin incision from the manubrium sterni to the level of the larynx, and use a scalpel, surgical scissors, and forceps to sharply dissect the skin and soft tissue. Using micro forceps and surgical scissors, enter the anterior upper ridge of the sternocleidomastoid muscle immediately on the left side by blunt dissection. And macroscopically perform a blunt preparation to carefully distally separate the left common carotid artery from the vagal nerve to avoid laryngeal paresis.Administer 40 milligrams per milliliter of papaverine locally into the artery and position the papaverine soaked artery below the autologous muscle tissue to protect the vessel from dehydration under the light of the surgical microscope. Switch sides and perform the same dissection on the right side of the animal as just demonstrated. When the right common carotid artery has been isolated inject 500 international units per kilogram of heparin systemically via a venous ear catheter.After tightening the six zero ligature, use a temporary vessel clip to clamp the right common carotid artery as far distally as possible to avoid endothelial damage, to create a long vessel segment for irrigation to prevent thrombogenesis. To harvest the pouch, cut the distal vessel to the four zero nonabsorbable ligature. Then cut the vessel distal to the 6-0 non-absorbable ligature.Meticulously clean the arterial pouch of all soft tissue and use a vessel clip to measure the length, width, and depth of the pouch. If a pouch degradation is needed, pre-incubate the cleaned pouch with 100 units of porcine elastase dissolved in five milliliters of Tris buffer at room temperature for 20 minutes. For further preparation of the common carotid artery, place two micro swabs directly beneath the common carotid artery to allow the vessel to be moved superficially and place an additional micro swab with a blue padding under the left artery at the distal third for better visualization of the artery.Change sides to access the left side of the animal and use micro scissors and forceps to make a two millimeter fish mouth incision on the proximal side of the right common carotid artery. Use the second temporary vessel clip to clamp the left distal common carotid artery and clamp the proximal left common carotid artery with two additional temporary vessel clips. When all of the clamps have been placed, liberate the distal third of the left common carotid artery completely from the soft tissue and perform an arteriotomy.Now flush the recipient vessel with heparinized saline and liberate the complex from a adventitia, then suture the right common carotid artery to the left common carotid artery. Transfer the arterial pouch from the heparinized saline solution into the surgical field where the bifurcation is planned. While keeping all of the aspects of the vessel complex hydrated with a continuous saline irrigation, suture the pouch to the vessel, and then remove all of the temporary vascular clamps in stepwise manner.When all of the clamps have been removed, administer one milliliter of fluorescein intravenously to perform fluorescence angiography of the vessel complex. Then close the operative situs according to standard protocols. In this experimental analysis, animals with aneurysms induced by either the vital or elastase pouch methods demonstrated an increase in aneurysm size over time.The average duration of the surgical procedure for the control group was 164 plus or minus 10 minutes compared to 201 plus or minus 13 minutes for the modified group. An average of 24 plus or minus one interrupted sutures was needed to create aneurysms in the controlled group, while 25 plus or minus two stitches were required in the elastase group. Measurements can then be performed by using three dimensional reconstructions of the MR imaging and detailed histological analysis.A careful separation of the common carotid artery from the vagal nerve is essential for avoiding postoperative complications. To avoid thrombogenesis, keep the vessel and arterial pouch complex hydrated. Given the excellent patiency achieved with aneurysm growth over time, this model may serve as an important tool for the preclinical evaluation of novel endovascular devices.

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Neuroscience

Detection of Neuritic Plaques in Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks of Alzheimer's disease. The central component of neuritic plaques is a small filamentous protein called amyloid &beta; protein (A&beta;)1, which is derived from sequential proteolytic cleavage of the beta-amyloid precursor protein (APP) by &beta;-secretase and &gamma;-secretase. The amyloid hypothesis entails that A&gamma;-containing plaques as the underlying toxic mechanism in AD pathology2. The postmortem analysis of the presence of neuritic plaque confirms the diagnosis of AD. To further our understanding of A&gamma; neurobiology in AD pathogenesis, various mouse strains expressing AD-related mutations in the human APP genes were generated. Depending on the severity of the disease, these mice will develop neuritic plaques at different ages. These mice serve as invaluable tools for studying the pathogenesis and drug development that could affect the APP processing pathway and neuritic plaque formation. In this protocol, we employ an immunohistochemical method for specific detection of neuritic plaques in AD model mice. We will specifically discuss the preparation from extracting the half brain, paraformaldehyde fixation, cryosectioning, and two methods to detect neurotic plaques in AD transgenic mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thiofalvin S staining method.

Detection of Neuritic Plaques in Alzheimer&#039;s Disease Mouse Model

One of the pathological characteristics of AD is the formation of Amyloid &#x03B2; protein positive neuritic plaques. In this protocol we describe two methods to detect neuritic plaques in transgenic AD model mice: immunohistochemical detection using the ABC and DAB method and fluorescent detection using thioflavin S staining method.

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia. Neuritic plaque formation is one of the pathological hallmarks ...

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs) 2. Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis.
The development of larval ChOs during embryogenesis has been studied extensively 10,11,13,15,16. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells 1,9,14. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite 8,12. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system.
Multiple ChOs have been described in the adult fly 7. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy 3,5,17,4.
In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs 18 and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary.
Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.

Visualization of Proprioceptors in Drosophila Larvae and Pupae

A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

The Corneal Micropocket Assay: A Model of Angiogenesis in the Mouse Eye

The mouse corneal micropocket assay is a robust and quantitative in vivo assay for evaluating angiogenesis. By using standardized slow-release pellets containing specific growth factors that trigger blood vessel growth throughout the naturally avascular cornea, angiogenesis can be measured and quantified. In this assay the angiogenic response is generated over the course of several days, depending on the type and dose of growth factor used. The induction of neovascularization is commonly triggered by either basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF). By combining these growth factors with sucralfate and hydron (poly-HEMA (poly(2-hydroxyethyl methacrylate))) and casting the mixture into pellets, they can be surgically implanted in the mouse eye. These uniform pellets slowly-release the growth factors over five or six days (bFGF or VEGF respectively) enabling sufficient angiogenic response required for vessel area quantification using a slit lamp. This assay can be used for different applications, including the evaluation of angiogenic modulator drugs or treatments as well as comparison between different genetic backgrounds affecting angiogenesis. A skilled investigator after practicing this assay can implant a pellet in less than 5 min per eye.

The protocol describes the corneal micropocket assay as developed in mice.

The mouse corneal micropocket assay is a robust and quantitative in vivo assay for evaluating angiogenesis. By using standardized slow-release pellets ...

In Vitro Modeling of Cancerous Neural Invasion: The Dorsal Root Ganglion Model

One way that solid tumors disseminate is through neural invasion. This route is well-known in cancers of the head and neck, prostate, and pancreas. These neurotropic cancer cells have a unique ability to migrate unidirectionally along nerves towards the central nervous system (CNS). The dorsal root ganglia (DRG)/cancer cell model is a three dimensional (3D) in vitro model frequently used for studying the interaction between neural stroma and cancer cells. In this model, mouse or human cancer cell lines are grown in ECM adjacent to preparations of freshly dissociated cultured DRG. In this article, the DRG isolation protocol from mice, and implantation in petri dishes for co-culturing with pancreatic cancer cells are demonstrated. Five days after implantation, the cancer cells made contact with the DRG neurites. Later, these cells formed bridgeheads to facilitate more extensive polarized, neurotropic migration of cancer cells.

In Vitro Modeling of Cancerous Neural Invasion: The Dorsal Root Ganglion Model

This video article shows the use of the dorsal root ganglia (DRG)/cancer cell model in pancreatic ductal adenocarcinoma.

One way that solid tumors disseminate is through neural invasion. This route is well-known in cancers of the head and neck, prostate, and pancreas. These ...

The Use of Trace Eyeblink Classical Conditioning to Assess Hippocampal Dysfunction in a Rat Model of Fetal Alcohol Spectrum Disorders

Neonatal rats were administered a relatively high concentration of ethyl alcohol (11.9% v/v) during postnatal days 4-9, a time when the fetal brain undergoes rapid organizational change and is similar to accelerated brain changes that occur during the third trimester in humans. This model of fetal alcohol spectrum disorders (FASDs) produces severe brain damage, mimicking the amount and pattern of binge-drinking that occurs in some pregnant alcoholic mothers. We describe the use of trace eyeblink classical conditioning (ECC), a higher-order variant of associative learning, to assess long-term hippocampal dysfunction that is typically seen in alcohol-exposed adult offspring. At 90 days of age, rodents were surgically prepared with recording and stimulating electrodes, which measured electromyographic (EMG) blink activity from the left eyelid muscle and delivered mild shock posterior to the left eye, respectively. After a 5 day recovery period, they underwent 6 sessions of trace ECC to determine associative learning differences between alcohol-exposed and control rats. Trace ECC is one of many possible ECC procedures that can be easily modified using the same equipment and software, so that different neural systems can be assessed. ECC procedures in general, can be used as diagnostic tools for detecting neural pathology in different brain systems and different conditions that insult the brain.

Trace eyeblink classical conditioning (ECC) was used to assess hippocampal-dependent associative learning in adult rats that were administered a high concentration (11.9% v/v) of alcohol during early neonatal brain development. In general, ECC procedures are sound diagnostic tools for detecting brain dysfunction across many psychological and biomedical settings.

Neonatal rats were administered a relatively high concentration of ethyl alcohol (11.9% v/v) during postnatal days 4-9, a time when the fetal brain ...

A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor determining patient outcome and is therefore frequently taken as a study endpoint. However, in small animal studies on SAH, quantification of cerebral vasospasm is a major challenge. Here, an ex vivo method is presented that allows quantification of volumes of entire vessel segments, which can be used as an objective measure to quantify cerebral vasospasm. In a first step, endovascular casting of the cerebral vasculature is performed using a radiopaque casting agent. Then, cross-sectional imaging data are acquired by micro computed tomography. The final step involves 3-dimensional reconstruction of the virtual vascular tree, followed by an algorithm to calculate center lines and volumes of the selected vessel segments. The method resulted in a highly accurate virtual reconstruction of the cerebrovascular tree shown by a diameter-based comparison of anatomical samples with their virtual reconstructions. Compared with vessel diameters alone, the vessel volumes highlight the differences between vasospastic and non-vasospastic vessels shown in a series of SAH and sham-operated mice.

The goal of this article is to present a method that allows a 3-dimensional reconstruction of the cerebrovascular tree in mice after micro computed tomography and determination of volumes of entire vessel segments that can be used to quantify cerebral vasospasm in murine models of subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor ...

Fluorescence Angiography for Evaluation of Aneurysm Perfusion and Parent Artery Patency in Rat and Rabbit Aneurysm Models

Brain aneurysm treatment focuses on achieving complete occlusion, as well as preserving blood flow in the parent artery. Fluorescein sodium and indocyanine green are used to enable the observation of blood flow and vessel perfusion status, respectively. The aim of this study is to apply FVA to verify real-time blood flow, vessel perfusion status and occlusion of aneurysms after induction of sidewall aneurysms in rabbits and rats, as well as to validate the procedure in these species.
Twenty sidewall aneurysms were created in 10 rabbits by suturing a decellularized arterial vessel pouch on the carotid artery of a donor rabbit. In addition, 48 microsurgical sidewall aneurysms were created in 48 rats. During follow-up at one month after creation, the parent artery/aneurysm complex was dissected and FVA was performed using an intravenous fluorescein (10%, 1 mL) injection via an ear vein catheterization in rabbits and a femoral vein catherization in rats. Aneurysms were then harvested, and patency was evaluated macroscopically.
Macroscopically, 14 out of 16 aneurysms in rabbits indicated no residual parent artery perfusion with totally occluded luminae, however 11 (79%) were detected by FVA. Four aneurysms were excluded due to technical problems. In rats, residual aneurysm perfusion was macroscopically observed in 25 out of 48 cases. Of the 23 without macroscopic evidence of perfusion, FVA confirmed the incidence of 22 aneurysms (96%). There were no adverse events associated with FVA. Fluorescein is easily applicable and no special equipment is needed. It is a safe and extremely effective method for evaluating parent artery integrity and aneurysm patency/residual perfusion in an experimental setting with rabbits and rats. FVA using fluorescein as a contrast agent appears to be effective in controlling patency of aneurysms and the underlying vessel and can even be adapted to bypass surgery.

We present a protocol to efficiently evaluate aneurysm perfusion and vessel patency of sidewall aneurysm in rats and rabbits, using fluorescein-based fluorescence video angiography (FVA). With a positive predictive value of 92.6%, it is a simple but very effective and economical method with no special equipment required.

Brain aneurysm treatment focuses on achieving complete occlusion, as well as preserving blood flow in the parent artery. Fluorescein sodium and ...

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.

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 ...

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 ...

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage

Among strokes, subarachnoid hemorrhage (SAH) consecutive to the rupture of a cerebral arterial aneurysm represents 5-9% but is responsible for about 30% of the total stroke-related mortality with an important morbidity in terms of neurological outcome. A delayed cerebral vasospasm (CVS) may occur most often in association with a delayed cerebral ischemia. Different animal models of SAH are now being used including endovascular perforation and direct injection of blood into the cisterna magna or even the prechiasmatic cistern, each exhibiting distinct advantages and disadvantages. In this article, a standardized mouse model of SAH by double direct injection of determined volumes of autologous whole blood into the cisterna magna is presented. Briefly, mice were weighed and then anesthetized by isoflurane inhalation. Then, the animal was placed in a reclining position on a heated blanket maintaining a rectal temperature of 37 &#176;C and positioned in a stereotactic frame with a cervical bend of about 30&#176;. Once in place, the tip of an elongated glass micropipette filled with the homologous arterial blood taken from carotid artery of another mouse of the same age and gender (C57Bl/6J) was positioned at a right angle in contact with the atlanto-occipital membrane by means of a micromanipulator. Then 60 &#181;L of blood was injected in the cisterna magna followed by a 30&#176; downward tilt of the animal for 2 minutes. The second infusion of 30 &#181;L of blood into the cisterna magna was performed 24 h after the first one. The individual follow-up of each animal is carried out daily (careful evaluation of weight and well-being). This procedure allows a predictable and highly reproducible distribution of blood, likely accompanied by intracranial pressure elevation that can be mimicked by an equivalent injection of an artificial cerebral spinal fluid (CSF), and represents an acute to mild-model of SAH inducing low mortality.

We described in this protocol a standardized subarachnoid hemorrhage (SAH) mouse model by a double injection of autologous whole-blood into the cisterna magna. The high degree of standardization of the double-injection procedure represents a middle-to-acute model of SAH with relative safety regarding mortality.

Among strokes, subarachnoid hemorrhage (SAH) consecutive to the rupture of a cerebral arterial aneurysm represents 5-9% but is responsible for about 30% ...