This work was supported by Citizens United for Research in Epilepsy (grant number 35489); the National Institutes of Health (grant numbers R01NS100954, R01NS099188); and a Louisiana State University Health Sciences Center Malcolm Feist Postdoctoral Fellowship.

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The authors have nothing to disclose.

To obtain high quality EEG-ECG recordings that are free from artifacts, every precaution should be taken to prevent degradation or loosening of the implanted electrode and wires. As an EEG head implant becomes loose, the wire contacts with the brain will degrade leading to decreased signal amplitudes. Loose implants or poor wire contacts can also cause distortion of the electrical signals, introducing movement artifacts and background noise to the recordings. To prevent potential loosening of the head implant, apply a ge...

Electroencephalography (EEG) and electrocardiography (ECG) are powerful and widely used techniques for assessing in vivo brain and cardiac function, respectively. EEG is the recording of electrical brain activity by attaching electrodes to the scalp1. The signal recorded with non-invasive EEG represents voltage fluctuations arising from summated excitatory and inhibitory postsynaptic potentials generated mainly by cortical pyramidal neurons1,2. EEG is the most common neurodiagnostic test for evaluating and managing patients with epilepsy3,4. It is especially useful when epileptic seizures occur without obvious convulsive behavioral manifestations, such as absence seizures or non-convulsive status epilepticus5,6. Conversely, non-epilepsy related conditions that lead to convulsive episodes or loss of consciousness may be misdiagnosed as epileptic seizures without video-EEG monitoring7. In addition to its usefulness in the field of epilepsy, EEG is also widely used to detect abnormal brain activity associated with sleep disorders, encephalopathies, and memory disorders, as well as to supplement general anesthesia during surgeries2,8,9.
In contrast to EEG, ECG (or EKG as it is sometimes abbreviated) is the recording of the electrical activity of the heart10. ECGs are usually performed by attaching electrodes to the limb extremities and chest wall, which allows detection of the voltage changes generated by the myocardium during each cardiac cycle of contraction and relaxation10,11. The primary ECG waveform components of a normal cardiac cycle include the P wave, the QRS complex, and the T wave, which correspond to atrial depolarization, ventricular depolarization, and ventricular repolarization, respectively10,11. ECG monitoring is routinely used to identify cardiac arrhythmias and defects of the cardiac conduction system12. Among epilepsy patients, the importance of using ECG to identify potentially life-threatening arrhythmias is amplified since they are at significantly increased risk of sudden cardiac arrest, as well as sudden unexpected death in epilepsy13,14,15.
In addition to their clinical applications, EEG and ECG recordings have become an indispensable tool for identifying brain and heart dysfunction in mouse models of disease. Although traditionally these recordings have been performed separately, here we describe a technique to record video, EEG, and ECG simultaneously in mice. The simultaneous video-EEG-ECG method detailed here utilizes a tethered recording configuration in which the implanted electrode on the head of the mouse is hard-wired to the recording equipment. Historically, this tethered, or wired, &#160;configuration has been the standard and most extensively used method for EEG recordings in mice; however, wireless EEG telemetry systems have also been developed recently and are gaining in popularity16.
Compared to wireless EEG systems, the tethered arrangement possesses several technical advantages that may make it preferable depending on the desired application. These advantages include a greater number of channels for recording EEG or other biopotentials; lower electrode costs; electrode disposability; less susceptibility to signal loss; and greater frequency bandwidth (i.e., sampling rate) of recordings17. Done properly, the tethered recording method described here is capable of providing high quality, artifact-free EEG, and ECG data simultaneously, along with the corresponding video for behavioral monitoring. This EEG and ECG data can then be mined to identify neural, cardiac, or neurocardiac abnormalities such as seizures, changes in EEG power spectrum, cardiac conduction blocks (i.e., skipped heart beats), and changes in heart rate variability. To demonstrate the application of these EEG-ECG quantitative methods, we present an example experiment using a Kcna1 knockout (-/-) mouse. Kcna1-/- mice lack voltage-gated Kv1.1 &#945;-subunits and as a consequence exhibit spontaneous seizures, cardiac dysfunction, and premature death, making them an ideal model for simultaneous EEG-ECG evaluation of deleterious epilepsy-associated neurocardiac dysfunction.

<table><tbody><tr><td>VistaVision stereozoom dissecting microscope</td><td>VWR</td><td></td><td></td></tr><tr><td>Dolan-Jenner MI-150 microscopy illuminator, with ring light</td><td>VWR</td><td>MI-150RL</td><td></td></tr><tr><td>CS Series scale</td><td>Ohaus</td><td>CS200</td><td>for weighing animal</td></tr><tr><td>T/Pump professional</td><td>Stryker</td><td></td><td>recirculating water heat pad system</td></tr><tr><td>Ideal Micro Drill</td><td>Roboz Surgical Instruments</td><td>RS-6300</td><td></td></tr><tr><td>Ideal Micro Drill Burr Set</td><td>Cell Point Scientific</td><td>60-1000</td><td>only need the 0.8-mm size</td></tr><tr><td>electric trimmer</td><td>Wahl</td><td>9962</td><td>mini clipper</td></tr><tr><td>tabletop vise</td><td>Eclipse Tools</td><td>PD-372</td><td>PD-372 Mini-tabletop suction vise</td></tr><tr><td>fine scissors</td><td>Fine Science Tools</td><td>14058-11</td><td>ToughCut, Straight, Sharp/Sharp, 11.5 cm</td></tr><tr><td>Crile-Wood needle holder</td><td>Fine Science Tools</td><td>12003-15</td><td>Straight, Serrated, 15 cm, with lock - For applying wound clips</td></tr><tr><td>Dumont #7 forceps</td><td>Fine Science Tools</td><td>11297-00</td><td>Standard Tips, Curved, Dumostar, 11.5 cm</td></tr><tr><td>Adson forceps</td><td>Fine Science Tools</td><td>11006-12</td><td>Serrated, Straight, 12 cm</td></tr><tr><td>Olsen-Hegar needle holder with suture cutter</td><td>Fine Science Tools</td><td>12002-12</td><td>Straight, Serrated, 12 cm, with lock</td></tr><tr><td>scalpel handle #3</td><td>Fine Science Tools</td><td>10003-12</td><td></td></tr><tr><td>surgical blades #15</td><td>Havel&#039;s</td><td>FHS15</td><td></td></tr><tr><td>6-0 surgical suture</td><td>Unify</td><td>S-N618R13</td><td>non-absorbable, monofilament, black</td></tr><tr><td>gauze sponges</td><td>Coviden</td><td>2346</td><td>12 ply, 7.6 cm x 7.6 cm</td></tr><tr><td>cotton-tipped swabs</td><td>Constix</td><td>SC-9</td><td>15.2-cm total length</td></tr><tr><td>super glue&amp;nbsp;</td><td>Loctite</td><td>LOC1364076</td><td>gel control</td></tr><tr><td>Michel wound clips, 7.5mm</td><td>Kent Scientific</td><td>INS700750</td><td></td></tr><tr><td>polycarboxylate dental cement kit</td><td>Prime-dent</td><td>010-036</td><td>Type 1 fine grain</td></tr><tr><td>tuberculin syringe</td><td>BD</td><td>309623</td><td></td></tr><tr><td>polyethylene tubing</td><td>Intramedic</td><td>427431</td><td>PE160, 1.143 mm (ID) x 1.575 mm (OD)</td></tr><tr><td>chlorhexidine&amp;nbsp;</td><td>Sigma-Aldrich</td><td>C9394</td><td></td></tr><tr><td>ethanol</td><td>Sigma-Aldrich</td><td>E7023-500ML</td><td></td></tr><tr><td>Puralube vet ointment</td><td>Dechra Veterinary Products</td><td></td><td>opthalamic eye ointment</td></tr><tr><td>mouse anesthetic cocktail</td><td></td><td></td><td>Ketamine (80 mg/kg), Xylazine (10 mg/kg), and Acepromazine (1 mg/kg)</td></tr><tr><td>carprofen</td><td></td><td></td><td>Rimadyl (trade name)</td></tr><tr><td>HydroGel</td><td>ClearH20</td><td>70-01-5022</td><td>hydrating gel; 56-g cups</td></tr><tr><td>Ponemah&amp;nbsp; software</td><td>Data Sciences International</td><td></td><td>data acquisition and analysis software; version 5.2 or greater with Electrocardiogram Module</td></tr><tr><td>7700 Digital Signal conditioner</td><td>Data Sciences International</td><td></td><td></td></tr><tr><td>12 Channel Isolated Bio-potential Pod</td><td>Data Sciences International</td><td></td><td></td></tr><tr><td>fish tank</td><td>Topfin</td><td></td><td>for use as recording chamber; 20.8 gallon aquarium; 40.8 cm (L) X 21.3 cm (W) X 25.5 cm (H)</td></tr><tr><td>Digital Communication Module (DCOM)</td><td>Data Sciences International</td><td>13-7715-70</td><td></td></tr><tr><td>12 Channel Isolated Bio-potential Pod</td><td>Data Sciences International</td><td>12-7770-BIO12</td><td></td></tr><tr><td>serial link cable</td><td>Data Sciences International</td><td>J03557-20</td><td>connects DCOM to bio-potential pod</td></tr><tr><td>Acquisition Interface (ACQ-7700USB)</td><td>Data Sciences International</td><td>PNM-P3P-7002</td><td></td></tr><tr><td>network video camera</td><td>Axis Communications</td><td></td><td>P1343, day/night capability</td></tr><tr><td>8-Port Gigabit Smart Switch</td><td>Cisco</td><td>SG200-08</td><td>8-port gigabit ethernet swith with 4 power over ethernet supported ports (Cisco Small Business 200 Series)</td></tr><tr><td>10-pin male nanoconnector with guide post hole</td><td>Omnetics</td><td>NPS-10-WD-30.0-C-G</td><td>electrode for implantation on the mouse head</td></tr><tr><td>10-socket female nanoconnector with guide post</td><td>Omnetics</td><td>NSS-10-WD-2.0-C-G</td><td>connector for electrode implant</td></tr><tr><td>1.5-mm female touchproof connector cables</td><td>PlasticsOne</td><td>441</td><td>1 signal, gold-plated; for connecting the wiring from the head-mount implant to the bio-potential pod</td></tr><tr><td>soldering iron</td><td>Weller</td><td>WESD51 BUNDLE</td><td>digital soldering station</td></tr><tr><td>solder</td><td>Bernzomatic</td><td>327797</td><td>lead free, silver bearing, acid flux core solder</td></tr><tr><td>heat shrink tubing</td><td>URBEST</td><td></td><td>collection of tubing with 1.5- to 10-mm internal diameters</td></tr><tr><td>heat gun</td><td>Dewalt</td><td>D26960</td><td></td></tr><tr><td>mounting tape (double-sided)</td><td>3M Scotch</td><td>MMM114</td><td>114/DC Heavy Duty Mounting Tape, 2.54 cm x 1.27 m&amp;nbsp;</td></tr><tr><td>desktop computer</td><td>Dell</td><td></td><td>recommended minimum requirements: 3rd Gen Intel Core i7-3770 processor with HD4000 graphics; 4 GB RAM, 1 GB AMD Radeon HD 7570 video card; 1 TB hard drive; Windows 7 OS&amp;nbsp;</td></tr><tr><td>permanent marker</td><td>Sharpie</td><td>37001</td><td>black color, ultra fine point</td></tr><tr><td>toothpicks</td><td></td><td></td><td>for mixing and applying the polycarboxylate dental cement</td></tr><tr><td>LabChart Pro software</td><td>ADInstruments</td><td></td><td>power spectrum software; version 8.1.3 or greater</td></tr><tr><td>Kubios HRV software</td><td>Univ. of Eastern Finland</td><td></td><td>HRV analysis software; version 2.2</td></tr><tr><td>Notepad</td><td>Microsoft</td><td></td><td>simple text editor software</td></tr></tbody></table>

simultaneous video-eeg-ecg monitoring to identify neurocardiac dysfunction in mouse models of epilepsy

In epilepsy, seizures can evoke cardiac rhythm disturbances such as heart rate changes, conduction blocks, asystoles, and arrhythmias, which can potentially increase risk of sudden unexpected death in epilepsy (SUDEP). Electroencephalography (EEG) and electrocardiography (ECG) are widely used clinical diagnostic tools to monitor for abnormal brain and cardiac rhythms in patients. Here, a technique to simultaneously record video, EEG, and ECG in mice to measure behavior, brain, and cardiac activities, respectively, is described. The technique described herein utilizes a tethered (i.e., wired) recording configuration in which the implanted electrode on the head of the mouse is hard-wired to the recording equipment. Compared to wireless telemetry recording systems, the tethered arrangement possesses several technical advantages such as a greater possible number of channels for recording EEG or other biopotentials; lower electrode costs; and greater frequency bandwidth (i.e., sampling rate) of recordings. The basics of this technique can also be easily modified to accommodate recording other biosignals, such as electromyography (EMG) or plethysmography for assessment of muscle and respiratory activity, respectively. In addition to describing how to perform the EEG-ECG recordings, we also detail methods to quantify the resulting data for seizures, EEG spectral power, cardiac function, and heart rate variability, which we demonstrate in an example experiment using a mouse with epilepsy due to Kcna1 gene deletion. Video-EEG-ECG monitoring in mouse models of epilepsy or other neurological disease provides a powerful tool to identify dysfunction at the level of the brain, heart, or brain-heart interactions.

To demonstrate how to analyze the data from EEG-ECG recordings to identify neurocardiac abnormalities, results are shown for a 24-h EEG-ECG recording of a Kcna1-/- mouse (2 months old). These mutant animals, which are engineered to lack voltage-gated Kv1.1 α-subunits encoded by the Kcna1 gene, are a frequently used genetic model of epilepsy since they exhibit reliable and frequent generalized tonic-clonic seizure activity beginning at ab...

Watch this Scientific Journal Video about Simultaneous Video-EEG-ECG Monitoring to Identify Neurocardiac Dysfunction in Mouse Models of Epilepsy at JoVE.com

Simultaneous Video-EEG-ECG Monitoring to Identify Neurocardiac Dysfunction in Mouse Models of Epilepsy

Here, we present a protocol to record brain and heart bio signals in mice using simultaneous video, electroencephalography (EEG), and electrocardiography (ECG). We also describe methods to analyze the resulting EEG-ECG recordings for seizures, EEG spectral power, cardiac function, and heart rate variability.

In epilepsy, seizures can evoke cardiac rhythm disturbances such as heart rate changes, conduction blocks, asystoles, and arrhythmias, which can ...

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Research

JoVE Journal

Genetics

25.3K Views.  Louisiana State University Health Sciences Center. Hier presenteren we een protocol om te slaan van de hersenen en hart bio signalen in muizen met behulp van gelijktijdige video, elektro-encefalografie (EEG) en elektrocardiogram (ECG). Ook beschrijven we methoden voor het analyseren van de resulterende opnamen van het EEG-ECG voor vangsten, EEG spectrale vermogen, hartfunctie en hartfrequentie-variabiliteit.

Video: Simultaneous Video-EEG-ECG Monitoring to Identify Neurocardiac Dysfunction in Mouse Models of Epilepsy

Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury

The lateral fluid percussion injury (FPI) model is well established and has been used to study TBI and post-traumatic epilepsy (PTE). However, considerable variability has been reported for the specific parameters used in different studies that have employed this model, making it difficult to harmonize and interpret the results between laboratories. For example, variability has been reported regarding the size and location of the craniectomy, how the Luer lock hub is placed relative to the craniectomy, the atmospheric pressure applied to the dura and the duration of the pressure pulse. Each of these parameters can impact injury severity, which directly correlates with the incidence of PTE. This has been manifested as a wide range of mortality rates, righting reflex times and incidence of convulsive seizures reported. Here we provide a detailed protocol for the method we have used to help facilitate harmonization between studies. We used FPI in combination with a wireless EEG telemetry system to continuously monitor for electrographic changes and detect seizure activity.&#160; FPI is induced by creating a 5 mm craniectomy over the left hemisphere, between the Bregma and Lambda and adjacent to the lateral ridge. A Luer lock hub is secured onto the skull over the craniectomy. This hub is connected to the FPI device, and a 20-millisecond pressure pulse is delivered directly to the intact dura through pressure tubing connected to the hub via a twist lock connector. Following recovery, rats are re-anesthetized to remove the hub. Five 0.5 mm, stainless steel EEG electrode screws are placed in contact with the dura through the skull and serve as four recording electrodes and one reference electrode. The electrode wires are collected into a pedestal connector which is secured into place with bone cement. Continuous video/EEG recordings are collected for up to 4 weeks post TBI.

Here we present a protocol to induce severe TBI with the lateral fluid percussion injury (FPI) model in adult, male Wistar rats. We also demonstrate the use of a wireless telemetry system to collect continuous video-EEG recordings and monitor for epileptiform discharges consistent with post-traumatic epileptogenesis.&#160;

The lateral fluid percussion injury (FPI) model is well established and has been used to study TBI and post-traumatic epilepsy (PTE). However, ...

Behavior

Inducing Post-Traumatic Epilepsy in a Mouse Model of Repetitive Diffuse Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of acquired epilepsy. TBI can result in a focal or diffuse brain injury. Focal injury is a result of direct mechanical forces, sometimes penetrating through the cranium, creating a direct lesion in the brain tissue. These are visible during brain imaging as areas with contusion, laceration, and hemorrhage. Focal lesions induce neuronal death and glial scar formation and are present in 20%&minus;25% of all people who incur a TBI. However, in the majority of TBI cases, injury is caused by acceleration-deceleration forces and subsequent tissue shearing, resulting in nonfocal, diffuse damage. A subpopulation of TBI patients continues to develop post-traumatic epilepsy (PTE) after a latency period of months or years. Currently, it is impossible to predict which patients will develop PTE, and seizures in PTE patients are challenging to control, necessitating further research. Until recently, the field was limited to only two animal/rodent models with validated spontaneous post-traumatic seizures, both presenting with large focal lesions with massive tissue loss in the cortex and sometimes subcortical structures. In contrast to these approaches, it was determined that diffuse TBI induced using a modified weight drop model is sufficient to initiate development of spontaneous convulsive and non-convulsive seizures, even in the absence of focal lesions or tissue loss. Similar to human patients with acquired post-traumatic epilepsy, this model presents with a latency period after injury before seizure onset. In this protocol, the community will be provided with a new model of post-traumatic epilepsy, detailing how to induce diffuse non-lesional TBI followed by continuous long-term video-electroencephalographic animal monitoring over the course of several months. This protocol will detail animal handling, the weight drop procedure, the electrode placement for two acquisition systems, and the frequent challenges encountered during each of the steps of surgery, postoperative monitoring, and data acquisition.

This systematic protocol describes a new animal model of post-traumatic epilepsy after repetitive mild traumatic brain injury. The first part details steps for traumatic brain injury induction using a modified weight drop model. The second part provides instructions on the surgical approach for single- and multi-channel electroencephalographic data acquisition systems.

Traumatic brain injury (TBI) is a leading cause of acquired epilepsy. TBI can result in a focal or diffuse brain injury. Focal injury is a result of ...

Simultaneous Monitoring of Wireless Electrophysiology and Memory Behavioral Test as a Tool to Study Hippocampal Neurogenesis

Brainwaves amplitude obtained from electroencephalography (EEG) has been well-recognized as a basis for cognitive capacity, memory, and learning on animals and humans. Adult neurogenesis mechanism is also linked to memory and learning improvement. Traditionally, researchers used to assess learning and memory parameters in rodent models by behavioral tasks. Therefore, the simultaneous monitoring of behavioral changes and EEG is particularly interesting in correlating data between brain activity and task-related behaviors. However, most of the equipment required to perform both studies are either complex, expensive, or uses a wired setup network that hinders the natural animals&#8217; movement. In this study, EEG was recorded with a wireless electrophysiology device along with the execution of a novel object recognition task (NORT). The animal&#8217;s behavior was monitored simultaneously by a video tracking system. Both recordings were analyzed offline by their timestamps which were synched to link EEG signals with the animal&#8217;s actions. Subjects consist of adult Wistar rats after medium-term environmental enrichment treatment. Six skull screw electrodes were fixed in pairs on both hemispheres over frontal, central, and parietal regions and were referenced to an electrode located posterior of the nasal bone. NORT protocol consists of exposing the animal to two identical objects for 10 min. After 2 h and 24 h, one of the objects was replaced with a novel one. Exploration time for each object was monitored by a behavioral tracking software (BTS) and EEG data recording. The analysis of the EEG synced with behavioral data consists of estimations of alpha and beta relative band power and comparisons between novel object recognition versus familiar object exploration, between three experimental stages. In this manuscript, we have discussed electrodes manufacturing process, epidural electrodes implantation surgery, environmental enrichment protocol, NORT protocol, BTS setup, EEG &#8211; BTS coupling for simultaneous monitoring in real-time, and EEG data analysis based on automatic events detection.

The protocol presented here provides information on the simultaneous electroencephalography (EEG) and behavioral assessment in real-time. We have discussed all steps involved in this protocol as an attractive solution for researchers in many fields of neuroscience, particularly in learning and memory areas.

Brainwaves amplitude obtained from electroencephalography (EEG) has been well-recognized as a basis for cognitive capacity, memory, and learning on ...

Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System

Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test interventions at various stages of the disease process. These animal models are particularly difficult to implement in immature rodents, a classic model organism for laboratory study of these disorders. Recording continuous EEG in young animal models of seizures and other neurological disorders presents a technical challenge due to the small physical size of young rodents and their dependence on the dam prior to weaning. Therefore, there is not only a clear need for improving pre-clinical research that will better identify those therapies suitable for translation to the clinic but also a need for new devices capable of recording continuous EEG in immature rodents. Here, we describe the technology behind and demonstrate the use of a novel miniature telemetry system, specifically engineered for use in immature rats or mice, which is also effective for use in adult animals.

Here we demonstrate the use of a wireless enabling technology for electroencephalogram (EEG) in neonatal rodent models of human disease. With telemetry, there are no encumbering connections, thus allowing natural behaviors.

Many progressive neurologic diseases in humans, such as epilepsy, require pre-clinical animal models that slowly develop the disease in order to test ...

Neuroscience

The Pilocarpine Model of Temporal Lobe Epilepsy and EEG Monitoring Using Radiotelemetry System in Mice

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status epilepticus (SE) is frequently selected to recapitulate spontaneous recurrent seizures (SRS). Here we present a protocol of SE induction by intraperitoneal (i.p.) injection of pilocarpine and monitoring of chronic recurring seizures in live animals using a wireless telemetry video and electroencephalogram (EEG) system. We demonstrated notable behavioral changes that need attention after pilocarpine injection and their correlation with hippocampal neuronal loss at 7 days and 6 weeks post-pilocarpine. We also describe the experimental procedures of electrode implantation for video and EEG recording, and analysis of the frequency and duration of chronic recurrent seizures. Finally, we discuss the possible reasons why the expected results are not achieved in each case. This provides a basic overview of modeling chronic epilepsy in mice and guidelines for troubleshooting. We believe this protocol can serve as a baseline for suitable models of chronic epilepsy and epileptogenesis.

This manuscript describes a method of inducing status epilepticus by systemic pilocarpine injection and of monitoring spontaneous recurrent seizures in live animals using a wireless telemetry video and electroencephalogram system. This protocol can be utilized for studying the pathophysiologic mechanisms of chronic epilepsy, epileptogenesis, and acute seizures.

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status ...

Medicine

Continuous Video Electroencephalogram during Hypoxia-Ischemia in Neonatal Mice

Hypoxia ischemia is the most common cause of neonatal seizures. Animal models are crucial for understanding the mechanisms and physiology underlying neonatal seizures and hypoxia ischemia. This manuscript describes a method for continuous video electroencephalogram (EEG) monitoring in neonatal mice to detect seizures and analyze EEG background during hypoxia ischemia. Use of video and EEG in conjunction allows description of seizure semiology and confirmation of seizures. This method also allows analysis of power spectrograms and EEG background pattern trends over the experimental time period. In this hypoxia ischemia model, the method allows EEG recording prior to injury to obtain a normative baseline and during injury and recovery. Total monitoring time is limited by the inability to separate pups from the mother for longer than four hours. Although, we have used a model of hypoxic-ischemic seizures in this manuscript, this method for neonatal video EEG monitoring could be applied to diverse disease and seizure models in rodents.

This manuscript describes a method for continuous video EEG recordings using multiple depth electrodes in neonatal mice undergoing hypoxia-ischemia.

Hypoxia ischemia is the most common cause of neonatal seizures. Animal models are crucial for understanding the mechanisms and physiology underlying ...

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 ...

Continuous EEG/ECG Recordings in Rabbits Using Subdermal Electrode Placement

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.

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 ...

Intermittent Photic Stimulation in Rabbit Model: A Technique to Induce Epileptic Seizures and Simultaneously Record Multisystem Parameters

Source: Bosinski, C., et al. <a href="https://www.jove.com/v/62256">Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits.</a> J. Vis. Exp. (2021).
In this video, we show a procedure for simultaneous recording of video-EEG-ECG-capnography-oximetry data generated by inducing seizures in a rabbit model.

Source: Bosinski, C., et al. Multi-system Monitoring for Identification of Seizures, Arrhythmias and Apnea in Conscious Restrained Rabbits. J. Vis. Exp. ...

JoVE Encyclopedia of Experiments

Biology

Large Animal Models

Leporine

 Simultaneous Electroencephalography and Magnetoencephalography to Identify Seizure-Prone Brain Regions 

Source:&#160;<a style='text-decoration:none;' href='https://app.jove.com/v/54883/interictal-high-frequency-oscillations-detected-with-simultaneous'><span style='-webkit-text-decoration-skip:none;font-family:Arial,sans-serif;font-size:12pt;font-style:normal;font-variant:normal;font-weight:400;text-decoration-skip-ink:none;vertical-align:baseline;white-space:pre-wrap;'>Papadelis, C.,&#160;et al.,<span style='-webkit-text-decoration-skip:none;font-family:Arial,sans-serif;font-size:12pt;font-style:normal;font-variant:normal;font-weight:400;text-decoration-skip-ink:none;vertical-align:baseline;white-space:pre-wrap;'> Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy.&#160;J. Vis. Exp.<span style='-webkit-text-decoration-skip:none;font-family:Arial,sans-serif;font-size:12pt;font-style:normal;font-variant:normal;font-weight:400;text-decoration-skip-ink:none;vertical-align:baseline;white-space:pre-wrap;'> (2016).</a> &#160;This video demonstrates the method of using electroencephalography (EEG) and magnetoencephalography (MEG) recordings to identify interictal epileptiform discharges (IEDs) and high-frequency oscillations (HFOs) to locate seizure-prone regions in the brain.

Simultaneous Video-EEG-ECG Monitoring to Identify Neurocardiac Dysfunction in Mouse Models of Epilepsy

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