We wish to thank Pradeep Dumpala, DVM PhD, Sarah Blair, MA, and the husbandry staff at SUNY Upstate Medical University for their dedication and attention to caring for the rabbits. NIH-NINDS (1R61NS133273), Department of Pharmacology, SUNY Upstate Medical University

Continuous EEG/ECG Recordings in Rabbits Using Subdermal Electrode Placement

<ol>
	<li>Bosinski, C., Wagner, K., Zhou, X., Liu, L., Auerbach, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-system+monitoring+for+identification+of+seizures,+arrhythmias+and+apnea+in+conscious+restrained+rabbits.">Multi-system monitoring for identification of seizures, arrhythmias and apnea in conscious restrained rabbits.</a> J Vis Exp. (169), e62256 (2021).</li><li>Finlay, M. C., Lambiase, P. D., Ben-Simon, R., Taggart, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+mental+stress+on+dynamic+electrophysiological+properties+of+the+endocardium+and+epicardium+in+humans.">Effect of mental stress on dynamic electrophysiological properties of the endocardium and epicardium in humans.</a> Heart Rhythm. 13 (1), 175-182 (2016).</li><li>Shen, M. J., Zipes, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+the+autonomic+nervous+system+in+modulating+cardiac+arrhythmias.">Role of the autonomic nervous system in modulating cardiac arrhythmias.</a> Circulation Res. 114 (6), 1004-1021 (2014).</li><li>Xu, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Juvenile+myoclonic+epilepsy+and+sleep.">Juvenile myoclonic epilepsy and sleep.</a> Epilepsy Behav. 80, 326-330 (2018).</li><li>Bazil, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seizure+modulation+by+sleep+and+sleep+state.">Seizure modulation by sleep and sleep state.</a> Brain Res. 1703, 13-17 (2019).</li><li>Ryan, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+rate+and+autonomic+biomarkers+distinguish+convulsive+epileptic+vs.+Functional+or+dissociative+seizures.">Heart rate and autonomic biomarkers distinguish convulsive epileptic vs. Functional or dissociative seizures.</a> Seizure. 111, 178-186 (2023).</li><li>Brunner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+cardiac+arrhythmias+and+sudden+death+in+transgenic+rabbits+with+long+QT+syndrome.">Mechanisms of cardiac arrhythmias and sudden death in transgenic rabbits with long QT syndrome.</a> J Clin Invest. 118, 2246-2259 (2008).</li><li>Edwards, A. G., Louch, W. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Species-dependent+mechanisms+of+cardiac+arrhythmia:+A+cellular+focus.">Species-dependent mechanisms of cardiac arrhythmia: A cellular focus.</a> Clin Med Insights Cardiol. 11, 1179546816686061 (2017).</li><li>. Kaha Sciences Available from: <a target="_blank" href="https://www.adinstruments.com/kaha?creative=524197312959&amp;keyword=kaha%20telemetry&amp;matchtype=e&amp;network=g&amp;device=c&amp;gad_source=1&amp;gclid=CjwKCAjw8fu1BhBsEiwAwDrsjJLJeUjMCwMe-kCxFg2QdpP94gaAOd8qS6UBE6iU-IdP2XGxMvbT7hoCDZAQAvD_BwE">https://www.adinstruments.com/kaha?creative=524197312959&amp;keyword=kaha%20telemetry&amp;matchtype=e&amp;network=g&amp;device=c&amp;gad_source=1&amp;gclid=CjwKCAjw8fu1BhBsEiwAwDrsjJLJeUjMCwMe-kCxFg2QdpP94gaAOd8qS6UBE6iU-IdP2XGxMvbT7hoCDZAQAvD_BwE</a> (2024)</li><li>. Stellar telemetry Available from: <a target="_blank" href="https://www.tse-systems.com/products/stellar-implantable-telemetry/">https://www.tse-systems.com/products/stellar-implantable-telemetry/</a> (2024)</li><li>. Dsi implantable telemetry Available from: <a target="_blank" href="https://www.datasci.com/products/implantable-telemetry">https://www.datasci.com/products/implantable-telemetry</a> (2024)</li><li>. Stellar telemetry Available from: <a target="_blank" href="https://kruuse.com/products/consultation/examination/ekg/kruuse-televet-ii-telemetric-ecg-holter">https://kruuse.com/products/consultation/examination/ekg/kruuse-televet-ii-telemetric-ecg-holter</a> (2024)</li><li>Mishra, V., Gautier, N. M., Glasscock, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+Video-EEG-ECG+monitoring+to+identify+neurocardiac+dysfunction+in+mouse+models+of+epilepsy.">Simultaneous Video-EEG-ECG monitoring to identify neurocardiac dysfunction in mouse models of epilepsy.</a> J Vis Exp. (131), 57300 (2018).</li><li>. eeg/emg systems Available from: <a target="_blank" href="https://www.pinnaclet.com/eeg-emg-systems.html">https://www.pinnaclet.com/eeg-emg-systems.html</a> (2024)</li></ol>

The authors have nothing to disclose. A portion of the information contained within this manuscript is also present in the first author's Master's thesis (Laura Williams) with suitable permission.

We present a detailed protocol for the generation of a custom wire harness, the in-house fabrication of an implant, and the procedure for the sterile implantation of the EEG/ECG electrodes, wires, and port. This setup facilitates the collection of continuous, high quality EEG/ECG recordings in an efficient, safe, and financially feasible way. This protocol generates a system in which both EEG and ECG data can be collected in rabbits without the need for restrainers or&#160;constant supervision. Continuous long-term EEG a...

We previously developed a protocol to collect acute (&#60; 5 h) video/EEG/ECG recordings from rabbits. It involves the use of nine subdermal EEG and ECG pin electrodes, placement of the rabbit in a restrainer, and the investigator closely monitoring the rabbit for the entire duration of the recording1. While this system provides high-quality video/EEG/ECG recordings, it has several limitations. Arrhythmias, epileptic seizures, and other EEG/ECG abnormalities may be triggered by various physiological and environmental substrates, so these events may be missed when conducting intermittent recordings. Thus, this recording platform does not facilitate comprehensive and accurate assessments of neuro-cardiac electrical function throughout the day, during various physiological states, or in the rabbits&#39; normal housing environment.
Continuous video/EEG/ECG monitoring is important for evaluating cardiac and neuronal electrical function during various physiological states. It facilitates accurate assessment&#160;of the prevalence and incidence of epileptiform activity and arrhythmias, as well as the concordance and progression of multi-system changes surrounding episodic events. For example, circadian fluctuations in autonomic function, as well as stress and activity-mediated autonomic changes, greatly influence heart rate and ECG metrics and can provide a trigger for arrhythmias2,3. In certain types of epilepsy (e.g., juvenile myoclonic epilepsy), seizures are more likely to occur during sleep or within 1-2 h of waking up4. The dynamic changes in electrical activity in the brain during sleep can influence the susceptibility, origin, and spread of seizures5.
Stress, activity, and motor seizures can cause muscle artifacts and dislodgement of the electrodes, which influences the quality and stability of the recordings. In particular, during pro-convulsant studies, rabbits experience myoclonic, clonic, tonic, and clonic-tonic seizures. The tonic phase involves the involuntary extension of the neck, which can dislodge the pin electrodes and thus interrupt the signal during a critical phase of the experiment. As such, the temporary system involving pin electrodes has critical limitations that must be addressed. Moreover, as the rabbits are in a restrainer, documenting the full extent of the motor manifestations is difficult.
Therefore, it is important to develop a procedure to implant electrodes for long-term continuous and stable multi-system recordings when the animal is in its normal unrestrained environment. This will facilitate detailed assessments during a wide range of physiological states and in response to environmental triggers. It will also be valuable for capturing rare episodic events. As the setup does not require the investigator to be present during the recording, it increases the efficiency and throughput of the research platform. It also minimizes the frequency of people disturbing the rabbits. Finally, as this procedure allows for the animals to stay in their natural housing environment throughout the recording, it improves the quality of life for the rabbits and improves overall animal welfare.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3:1 heat shrink wrap with adhesive</td>
			<td>N/A</td>
			<td>Wirefly</td>
			<td>Adhesive lined polyolefin tubing designed to shrink 1/3 diameter when heated. Isolate electrodes when connecting wires and plugs, connecting pieces of the wire harness together</td>
		</tr>
		<tr>
			<td>Absorbent Pads</td>
			<td>-</td>
			<td>any</td>
			<td>Absorbent pads for Fluid collection</td>
		</tr>
		<tr>
			<td>BD E-Z Scrub 116 Surgical Scrub Brush/Sponge</td>
			<td>371163</td>
			<td>BD E-Z Scrub</td>
			<td>3% PCMX Surgical Scrub Brush/Sponge To scrub prior to operating for aseptic technique</td>
		</tr>
		<tr>
			<td>Biopsy Punches</td>
			<td>1315</td>
			<td>ARGENT, McKesson</td>
			<td>6 mm circular cutting blade for circular incision for port</td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>-</td>
			<td>-</td>
			<td>0.3 mg/mL Buprenorphine For post-operative pain control</td>
		</tr>
		<tr>
			<td>Butt connectors</td>
			<td>X003C7S38P</td>
			<td>SVAAR</td>
			<td>Tinned copper butt splice 26-22 AWG non-insulated butt connectors Connecting carbon fiber wires from the electrodes to the plug</td>
		</tr>
		<tr>
			<td>Cautery Pen</td>
			<td>https://jorvet.com/product/cautery-kit-accessories/</td>
			<td>Jorgensen Laboratories, Inc.</td>
			<td>Hand-held Bovie Cautery Pen For controlling bleeding</td>
		</tr>
		<tr>
			<td>Coaxial cable through-wall bushing</td>
			<td>COAX BUSH WH</td>
			<td>Commercial Electric</td>
			<td>Plastic bushing with 6.9mm inner diameter opening and 1cm+ post Wire port</td>
		</tr>
		<tr>
			<td>Cohesiant Wrap</td>
			<td>https://healthypets.com/vetone-cohesiant-wrap-blue-2x5yd/</td>
			<td>AmerisourceBergen</td>
			<td>4in x 5yd self-adherent wrap For post-operative wound protection</td>
		</tr>
		<tr>
			<td>Disposable Scalpel with Handle</td>
			<td>https://www.securos.com/</td>
			<td>Securos Surgical AmerisourceBergen</td>
			<td>Sterile disposable scalpels For making incisions</td>
		</tr>
		<tr>
			<td>Electrical Slip Ring</td>
			<td></td>
			<td>Taidacent</td>
			<td>High Speed Ball Conductive Slip Ring 12 way 2A Collector ring rotary joint rotary connector, Electrical slip ring to allow free movement of animal without binding up the wire harness</td>
		</tr>
		<tr>
			<td>Eye lube pro</td>
			<td>https://domespharma.us/eye-lube-pro-detailer-final-v6/</td>
			<td>Sentrx</td>
			<td>Lubricating Gel Prevents eye drying/damage during anesthesia</td>
		</tr>
		<tr>
			<td>GLUture</td>
			<td>503763</td>
			<td>World Precision Instrument</td>
			<td>Topical Tissue Adhesive For closure of incision sites&#160;</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>ANADA # 200-129</td>
			<td>Isospire</td>
			<td>Isoflurane For anesthesia</td>
		</tr>
		<tr>
			<td>Isopropyl alcohol</td>
			<td>500205</td>
			<td>VETone</td>
			<td>70% isopropyl alcohol Topical antiseptic</td>
		</tr>
		<tr>
			<td>Jet Liquid</td>
			<td>1403</td>
			<td>Lang Dental Mfg. Co., Inc.</td>
			<td>Fast curing acrylic resin liquid Dental acrylic resin liquid for sealing the bushing and the wires for the wire exit port.&#160; Also used to seal the port to the skin.</td>
		</tr>
		<tr>
			<td>Jet Tooth Shade Powder</td>
			<td>1420</td>
			<td>Lang Dental Mfg. Co., Inc.</td>
			<td>Fast curing provisional crown and bridge acrylic resin powder. Dental acrylic powder for sealing the bushing and the wires for the wire exit port.&#160; Also used to seal the port to the skin.</td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>-</td>
			<td>-</td>
			<td>100 mg/mL Ketamine For sedation</td>
		</tr>
		<tr>
			<td>Metal shower sheathing</td>
			<td>HOS-960M</td>
			<td>Waterpik</td>
			<td>Ultra-Flexible Replacement Metal Shower Hose, Extra Long for Handheld Shower Heads, 96-inch, Chrome Metal sheathing for wire harness</td>
		</tr>
		<tr>
			<td>MR Conditional/CT Electrodes Array and Extension Set</td>
			<td>MRQW32415</td>
			<td>RhythmLink</td>
			<td>Quick connect system with male-female plugs and 8 leads. Plugs used for port-wire harness connection.&#160; Wires and DIN connectors used for the wire harness</td>
		</tr>
		<tr>
			<td>Polypropylene Blue Monofilament Sutures</td>
			<td>P8665</td>
			<td>SECUROPRO</td>
			<td>3-0, FS-2, 18&#8221; reverse cutting suture. Close any surgical incisions</td>
		</tr>
		<tr>
			<td>Retractor cable</td>
			<td>&#8206;0487-013</td>
			<td>West Coast Manufacturing Company</td>
			<td>Industrial Retractable Reel with 48&#34; Stainless Steel Cable, Steel Bracket Back, Chrome Front, 8 oz. Retraction, Plastic Hose Clamp. Pulls excess wire harness up and away from animal</td>
		</tr>
		<tr>
			<td>Rubber gasket</td>
			<td>E-3603 NSF-51</td>
			<td>Saint Gobain</td>
			<td>Clear rubber tubing cut to 1.5 cm width. Gasket for protection/maintaining a seal.&#160;</td>
		</tr>
		<tr>
			<td>Small Webb Electrodes</td>
			<td>SWEBB1215</td>
			<td>RhythmLink</td>
			<td>6mm, flat disc [WEBB*] electrode, silver-chloride, wire, Subdermal electrodes</td>
		</tr>
		<tr>
			<td>Sterile Latex Surgical Gloves</td>
			<td>10122</td>
			<td>AmerisourceBergen</td>
			<td>Sterile Latex Gloves, Powder-Free, Donned for sterile surgical technique</td>
		</tr>
		<tr>
			<td>Sterile marker</td>
			<td>DYNJSM01</td>
			<td>Medline</td>
			<td>Sterile Marker, Mark incision/electrode sites&#160;</td>
		</tr>
		<tr>
			<td>Sterile surgical drapes with adhesive</td>
			<td>-</td>
			<td>any</td>
			<td>Sterile surgical drapes with adhesive strip on one side, Create a fixed sterile field&#160;</td>
		</tr>
		<tr>
			<td>Veterinary anesthesia masks</td>
			<td>-</td>
			<td>any</td>
			<td>Plastic cones with rubber gaskets to seal over rabbit&#8217;s face. Various sizes. Delivery of inhaled anesthesia</td>
		</tr>
		<tr>
			<td>Veterinary Betadine Surgical Scrub</td>
			<td>NDC 67618-154-16</td>
			<td>Betadine</td>
			<td>Povidone-iodine, 7.5%, Antiseptic Sudsing Skin Cleanser</td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>-</td>
			<td>-</td>
			<td>100 mg/mL Xylazine, For sedation</td>
		</tr>
	</tbody>
</table>

surgical implant procedure and wiring configuration for continuous long-term eeg/ecg monitoring in rabbits

A multi-system approach that includes the continuous collection of electroencephalogram (EEG) and electrocardiogram (ECG) recordings facilitates a comprehensive assessment of electrical activity in the brain and heart, particularly leading up to and surrounding episodic events. Building on our previous protocol that facilitates the collection of intermittent EEG/ECG recordings from conscious restrained rabbits, we developed a protocol for the collection of continuous EEG/ECG recordings from unrestrained rabbits. This new method enables high-quality 24/7 recordings in the housing cage, which captures the normal range of physiological states and enables the rabbits to move, eat, drink, and sleep freely. It enables comprehensive assessments of the prevalence, incidence, and susceptibility to EEG/ECG abnormalities, seizures, arrhythmias, and sudden death. This procedure involves the surgical placement of subdermal electrodes and the design and manufacturing of a robust wiring system that is impervious to damage by the rabbits. The surgical procedure includes two incisions and the sub-dermal tunneling of nine electrodes and wires that exit through a custom-made port. The external connector attaches to a wire harness that includes an electrical swivel, which allows for&#160;free range of rabbit motion throughout its cage. Additionally, the wires are enclosed in a metal sheath suspended by a retractor cable from the ceiling of the rabbit&#39;s cage. The wires are then connected to an amplifier/digitizer for the acquisition of high-quality continuous EEG/ECG recordings.

Using this surgical technique, there were not any cases of mortality during or after the surgery. There is a risk of infection and incomplete wound healing, particularly if the rabbit scratches or bites at the incision site. Pre-/post-operative antibiotics, covering the incision with a dry sterile piece of gauze, and fitting the rabbit with a vest help protect the surgical site and allow for better healing. All recordings are conducted in the rabbit&#39;s standard housing cage, which is w...

Surgical Implant Procedure and Wiring Configuration for Continuous Long-Term EEG/ECG Monitoring in Rabbits

The study outlines a protocol for the design, manufacturing, and placement of a novel continuous EEG/ECG recording system in rabbits. This hard-wired system allows for continuous EEG/ECG recordings from nine distinct electrodes on the head and chest, which facilitates comprehensive assessments of electrical activity in the brain and heart.

A multi-system approach that includes the continuous collection of electroencephalogram (EEG) and electrocardiogram (ECG) recordings facilitates a ...

surgical-implant-procedure-wiring-configuration-for-continuous-long

Research

JoVE Journal

Medicine

343 Views.  SUNY Upstate Medical University. The study outlines a protocol for the design, manufacturing, and placement of a novel continuous EEG/ECG recording system in rabbits. This hard-wired system allows for continuous EEG/ECG recordings from nine distinct electrodes on the head and chest, which facilitates comprehensive assessments of electrical activity in the brain and heart.

Video: Surgical Implant Procedure and Wiring Configuration for Continuous Long-Term EEG/ECG Monitoring in Rabbits

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise.
Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G&#160;catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling.
After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage.
The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals required for a study.

Here we present a protocol to assess cardiopulmonary function in awake swine, at rest and during graded treadmill exercise. Chronic instrumentation allows for repeated hemodynamic measurements uninfluenced by cardiodepressive anesthetic agents.

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early ...

A Step by Step Protocol for Subretinal Surgery in Rabbits

Age related macular degeneration (AMD), retinitis pigmentosa, and other RPE related diseases are the most common causes for irreversible loss of vision in adults in industrially developed countries. RPE transplantation appears to be a promising therapy, as it may replace dysfunctional RPE, restore its function, and thereby vision.
Here we describe a method for transplanting a cultured RPE monolayer on a scaffold into the subretinal space (SRS) of rabbits. After vitrectomy xenotransplants were delivered into the SRS using a custom made shooter consisting of a 20-gauge metallic nozzle with a polytetrafluoroethylene (PTFE) coated plunger. The current technique evolved in over 150 rabbit surgeries over 6 years. Post-operative follow-up can be obtained using non-invasive and repetitive in vivo imaging such as spectral domain optical coherence tomography (SD-OCT) followed by perfusion-fixed histology.
The method has well-defined steps for easy learning and high success rate. Rabbits are considered a large eye animal model useful in preclinical studies for clinical translation. In this context rabbits are a cost-efficient and perhaps convenient alternative to other large eye animal models.

Retinal pigment epithelium (RPE) replacement strategies and gene-based therapy are considered for several retinal degenerative conditions. For clinical translation, large eye animal models are required to study surgical techniques applicable in patients. Here we present a rabbit model for subretinal surgery geared towards RPE transplantation, which is versatile and cost-efficient.

Age related macular degeneration (AMD), retinitis pigmentosa, and other RPE related diseases are the most common causes for irreversible loss of vision in ...

Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. Indeed, research focusing on the discovery of new potential therapeutic targets using genetically altered mice requires a reliable, long-term assessment of the systemic arterial pressure variation. Currently, the gold standard for obtaining long-term measurements of blood pressure in ambulatory mice uses implantable radio-transmitters, which require&#160;artery cannulation. This technique eliminates the need for tethering, restraining, or anesthetizing the animals which introduce stress and artifacts during data sampling. However, arterial blood pressure monitoring in mice via catheterization can be rather challenging due to the small size of the arteries. Here we present a step-by-step guide to illustrate the crucial key passages for a successful subcutaneous implantation of radio-transmitters and carotid artery cannulation in mice. We also include examples of long-term blood pressure activity taken from freely moving mice after a period of post-surgery recovery. Following this procedure will allow reliable direct blood pressure recordings from multiple animals simultaneously.

The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. ...

Preclinical Model of Hind Limb Ischemia in Diabetic Rabbits

Peripheral vascular disease is a widespread clinical problem that affects millions of patients worldwide. A major consequence of peripheral vascular disease is the development of ischemia. In severe cases, patients can develop critical limb ischemia in which they experience constant pain and an increased risk of limb amputation. Current therapies for peripheral ischemia include bypass surgery or percutaneous interventions such as angioplasty with stenting or atherectomy to restore blood flow. However, these treatments often fail to the continued progression of vascular disease or restenosis or are contraindicated due to the overall poor health of the patient. A promising potential approach to treat peripheral ischemia involves the induction of therapeutic neovascularization to allow the patient to develop collateral vasculature. This newly formed network alleviates peripheral ischemia by restoring perfusion to the affected area. The most frequently employed preclinical model for peripheral ischemia utilizes the creation of hind limb ischemia in healthy rabbits through femoral artery ligation. In the past, however, there has been a strong disconnect between the success of preclinical studies and the failure of clinical trials regarding treatments for peripheral ischemia. Healthy animals typically have robust vascular regeneration in response to surgically induced ischemia, in contrast to the reduced vascularity and regeneration in patients with chronic peripheral ischemia. Here, we describe an optimized animal model for peripheral ischemia in rabbits that includes hyperlipidemia and diabetes. This model has reduced collateral formation and blood pressure recovery in comparison to a model with a higher cholesterol diet. Thus, the model may provide better correlation with human patients with compromised angiogenesis from the common co-morbidities that accompany peripheral vascular disease.

We describe a surgical procedure used to induce peripheral ischemia in rabbits with hyperlipidemia and diabetes. This surgery acts as a preclinical model for conditions experienced in peripheral artery disease in patients. Angiography is also described as a means to measure the extent of introduced ischemia and recovery of perfusion.

Peripheral vascular disease is a widespread clinical problem that affects millions of patients worldwide. A major consequence of peripheral vascular ...

Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits

Patients with ion channelopathies are at a high risk of developing seizures and fatal cardiac arrhythmias. There is a higher prevalence of heart disease and arrhythmias in people with epilepsy (i.e., epileptic heart.) Additionally, cardiac and autonomic disturbances have been reported surrounding seizures. 1:1,000 epilepsy patients/year die of sudden unexpected death in epilepsy (SUDEP). The mechanisms for SUDEP remain incompletely understood. Electroencephalograms (EEG) and electrocardiograms (ECG) are two techniques routinely used in the clinical setting to detect and study the substrates/triggers for seizures and arrhythmias. While many studies and descriptions of this methodology are in rodents, their cardiac electrical activity differs significantly from humans. This article provides a description of a non-invasive method for recording simultaneous video-EEG-ECG-oximetry-capnography in conscious rabbits. As cardiac electrical function is similar in rabbits and humans, rabbits provide an excellent model of translational diagnostic and therapeutic studies. In addition to outlining the methodology for data acquisition, we discuss the analytical approaches for examining neuro-cardiac electrical function and pathology in rabbits. This includes arrhythmia detection, spectral analysis of EEG and a seizure scale developed for restrained rabbits.

Using simultaneous video-EEG-ECG-oximetry-capnography, we developed a methodology to evaluate the susceptibility of rabbit models to develop provoked arrhythmias and seizures. This novel recording system establishes a platform to test the efficacy and safety of therapeutics and can capture the complex cascade of multi-system events that culminate in sudden death.

Patients with ion channelopathies are at a high risk of developing seizures and fatal cardiac arrhythmias. There is a higher prevalence of heart disease ...

Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ineffective in many patients. To improve patient care, novel and innovative therapeutic concepts causally targeting arrhythmia mechanisms are needed. To study the complex pathophysiology of arrhythmias, suitable animal models are necessary, and mice have been proven to be ideal model species to evaluate the genetic impact on arrhythmias, to investigate fundamental molecular and cellular mechanisms, and to identify potential therapeutic targets.
Implantable telemetry devices are among the most powerful tools available to study electrophysiology in mice, allowing continuous ECG recording over a period of several months in freely moving, awake mice. However, due to the huge number of data points (&gt;1 million QRS complexes per day), analysis of telemetry data remains challenging. This article describes a step-by-step approach to analyze ECGs and to detect arrhythmias in long-term telemetry recordings using the software, Ponemah, with its analysis modules, ECG Pro and Data Insights, developed by Data Sciences International (DSI). To analyze basic ECG parameters, such as heart rate, P wave duration, PR interval, QRS interval, or QT duration, an automated attribute analysis was performed using Ponemah to identify P, Q, and T waves within individually adjusted windows around detected R waves. 
Results were then manually reviewed, allowing adjustment of individual annotations. The output from the attribute-based analysis and the pattern recognition analysis was then used by the Data Insights module to detect arrhythmias. This module allows an automatic screening for individually defined arrhythmias within the recording, followed by a manual review of suspected arrhythmia episodes. The article briefly discusses challenges in recording and detecting ECG signals, suggests strategies to improve data quality, and provides representative recordings of arrhythmias detected in mice using the approach described above.

Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules.

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ...

Technique for Obtaining Mesenchymal Stem Cell from Adipose Tissue and Stromal Vascular Fraction Characterization in Long-Term Cryopreservation

Human mesenchymal stem cells derived from adipose tissue have become increasingly attractive as they show appropriate features and are an accessible source for regenerative clinical applications. Different protocols have been used to obtain adipose-derived stem cells. This article describes different steps of an improved time-saving protocol to obtain a more significant amount of ADSC, showing how to cryopreserve and thaw ADSC to obtain viable cells for culture expansion. One hundred milliliters of lipoaspirate were collected, using a 26 cm three-hole and 3 mm caliber syringe liposuction, from the abdominal area of nine patients who subsequently underwent elective abdominoplasty. The stem cells isolation was carried out with a series of washes with Dulbecco&#39;s Phosphate Buffered Saline (DPBS) solution supplemented with calcium and the use of collagenase. Stromal Vascular Fraction (SVF) cells were cryopreserved, and their viability was checked by immunophenotyping. The SVF cellular yield was 15.7 x 105 cells/mL, ranging between 6.1-26.2 cells/mL. Adherent SVF cells reached confluence after an average of 7.5 (&#177;4.5) days, with an average cellular yield of 12.3 (&#177; 5.7) x 105 cells/mL. The viability of thawed SVF after 8 months, 1 year, and 2 years ranged between 23.06%-72.34% with an average of 47.7% (&#177;24.64) with the lowest viability correlating with cases of two-year freezing. The use of DPBS solution supplemented with calcium and bag resting times for fat precipitation with a shorter time of collagenase digestion resulted in an increased stem cell final cellular yield. The detailed procedure for obtaining high yields of viable stem cells was more efficient regarding time and cellular yield than the techniques from previous studies. Even after a long period of cryopreservation, viable ADSC cells were found in the SVF.

The present protocol describes an improved methodology for ADSC isolation resulting in a tremendous cellular yield with time gain compared to the literature. This study also provides a straightforward method for obtaining a relatively large number of viable cells after long-term cryopreservation.

Human mesenchymal stem cells derived from adipose tissue have become increasingly attractive as they show appropriate features and are an accessible ...

Dynamic Navigation for Dental Implant Placement

In modern implantology, the application of surgical navigation systems is becoming increasingly important. In addition to static surgical navigation methods, a guide-independent dynamic navigation implant placement procedure is becoming more widespread. The procedure is based on computer-guided dental implant placement utilizing optical control. This work aims to demonstrate the technical steps of a new dynamic computer-aided implant surgery (DCAIS)&#160;system (design, calibration, surgery) and check the accuracy of the results. Based on cone-beam computed tomography (CBCT) scans, the exact positions of implants are determined with dedicated software. The first step of the operation is the calibration of the navigation system, which can be performed in two ways: 1) based on CBCT images taken with a marker or 2) based on CBCT images without markers. Implants are inserted with the aid of real-time navigation according to the preoperative plans. The accuracy of the interventions can be evaluated based on postoperative CBCT images. The preoperative images containing the planned positions of the implants and postoperative CBCT images were compared based on the angulation (degree), platform, and apical deviation (mm) of the implants. To evaluate the data, we calculated the standard deviation (SD), mean, and standard error of the mean (SEM) of deviations within planned and performed implant positions. Differences between the two calibration methods were compared based on this data. Based on the interventions performed so far, the use of DCAIS allows for high-precision implant placement. A calibration system that does not require labeled CBCT recording allows for surgical intervention with similar accuracy as a system that uses labeling. The accuracy of the intervention can be improved by training.

Dynamic computer-aided implant surgery (DCAIS) is a controlled implant surgical placement method performed without a surgical template using optical control. The real-time intraoperative control of movement and position of the surgical device simplifies the procedure and gives more freedom to the surgeon, providing similar precision as static navigation methods.

In modern implantology, the application of surgical navigation systems is becoming increasingly important. In addition to static surgical navigation ...

A Surgical Model of Heart Failure with Preserved Ejection Fraction in Tibetan Minipigs

More than half of heart failure (HF) cases are classified as heart failure with preserved ejection fraction (HFpEF) worldwide. Large animal models are limited for investigating the fundamental mechanisms of HFpEF and identifying potential therapeutic targets. This work provides a detailed description of the surgical procedure of descending aortic constriction (DAC) in Tibetan minipigs to establish a large animal model of HFpEF. This model used a precisely controlled constriction of the descending aorta to induce chronic pressure overload in the left ventricle. Echocardiography was used to evaluate the morphological and functional changes in the heart. After 12 weeks of DAC stress, the ventricular septum was hypertrophic, but the thickness of the posterior wall was significantly reduced, accompanied by dilation of the left ventricle. However, the LV ejection fraction of the model hearts was maintained at &gt;50% during the 12-week period. Furthermore, the DAC model displayed cardiac damage, including fibrosis, inflammation, and cardiomyocyte hypertrophy. Heart failure marker levels were significantly elevated in the DAC group. This DAC-induced HFpEF in minipigs is a powerful tool for investigating molecular mechanisms of this disease and for preclinical testing.

The present protocol describes a step-by-step procedure to establish a minipig model of heart failure with preserved ejection fraction using descending aortic constriction. The methods for evaluating cardiac morphology, histology, and function of this disease model are also presented.

More than half of heart failure (HF) cases are classified as heart failure with preserved ejection fraction (HFpEF) worldwide. Large animal models are ...