This work was supported by the Natural Science Foundation of China (31171355) and the Natural Science Foundation of Guangdong (S2011010003403, 2014A030313440).

Animal care, surgical procedure, and recording procedures were in accordance with the guidelines for the South China Normal University Animal Care and Use Committee.
1. Electrode Preparation (Figure 1A-C)
NOTE: Computer pin loci is simply a pronged contact as a part of signal interface in communication devices. It consists of a male connector that plugs into the female connector.
<ol>
	<li>Carefully separate the male and female pins from the computer pin loci (Figure 1A) with the help of a pincer. Connect the male and female pins together to form an electrode and apply cyanoacrylate&#160;to create a strong adhesive bond (Figure 1C).</li>
	<li>Put the electrodes into a beaker filled with distilled water for and place it to ultrasonic cleaner for&#160;10 min. Move them to a drying oven at 45 &#176;C for 30 min. Sterilize the electrodes using UV light for 30 min.</li>
</ol>
2. Surgical procedure (Figure 1D-F)
<ol>
	<li>Prepare the sterilized surgical instruments and stereotaxic apparatus. Anesthetize the neonatal rat pup using isoflurane anesthesia (2.5 %) with air. When the pup is deeply anesthetized, adjust the dose of isoflurane to 1.0%. Perform a tail or toe pinch prior to the surgery to ensure the proper depth of anesthesia.</li>
	<li>Fix the head of the pup in the stereotaxic apparatus by placing the ear bars into the ear canals and slightly tightening them. 
	NOTE: Do not excessively tighten the ear bars, as the neonatal skull is very soft.</li>
	<li>Maintain the sterile surgical field by spraying all equipment with 70 % ethanol. Make a 15-mm incision on the head using a scalpel. Using forceps, gently pull the scalp away from the midline at the four corners. Put some saline-soaked cotton below the skin to keep the incision wide open (Figure 1D).</li>
	<li>Find the bregma and lambda points on the skull and mark them with a pencil. Use a syringe needle (26 G) to make two burr holes into the prefrontal cortex (PFC) and hippocampus. 
	NOTE: The PFC is located at +1.8 mm posterior to bregma and -0.5 mm lateral to the midline, while the hippocampus is located at -2.0 mm anterior to bregma and &#177;0.5 mm lateral to the midline (Figure 1D and E). The depth of the electrode should not be more than 2 mm below the cortical surface to minimize brain damage.&#160;</li>
	<li>Use forceps to hold the electrodes and insert the reference and recording electrodes into the PFC and hippocampus, respectively. Apply erythromycin ointment around the electrode to avoid any possible infection. Fix the electrode using cyanoacrylate.</li>
	<li>Prepare dental acrylic cement so that it has a gluey and viscous consistency. Apply the dental cement to cover the electrodes and the rest of the skull. 
	NOTE: Thoroughly dry the skull before applying the dental cement.</li>
	<li>Apply 5% picric acid onto the electrodes to protect them. 
	NOTE: The entire procedure should be done in a biosafety hood to maintain sterile conditions.</li>
	<li>Remove the animal from the stereotaxic frame and inject 300 &#181;L of 10 % glucose subcutaneously. Place it on a heated blanket for recovery. Make sure that the animal is warm (37 &#176;C) and ambulatory (i.e., completely recovered). Administer buprenorphine intraperitoneally (0.05 mg/kg) for post-surgical pain. 
	NOTE: Do not leave an animal unattended until it has regained sufficient consciousness (i.e. normal behavior and movement).</li>
	<li>Return the pup to its home cage with their dam after it regains consciousness. Wait for two days until the animal is fully recovered.</li>
</ol>
3. EEG Recording
<ol>
	<li>After full recovery, connect the electrodes implanted on the skull of the pup to the amplifier in its own cage. Connect the amplifier to an analogue-to-digital converter and attach the converter to a computer; the connecting lines should be treated carefully so that they do not get tangled.</li>
	<li>Select at least 10,000 Hz sampling rate on the data acquisition unit for recording (the bandwidth of the transmitter is 1-100 Hz). Ensure that the data is sampled properly.</li>
	<li>After getting the baseline recording, inject the pup intraperitoneally with kainic acid (KA) (2 mg/kg) to induce epileptic seizures. 15 min after the KA injection observe and record the epileptic discharges.&#160;Seizure produce through KA are usually physical. 
	NOTE:&#160;The ictal-tonic duration is about 15.2 &#177;0.9 s, seizure duration is about 62&#177;5 s. Seizures can be prevented in the&#160;neonatal rat by giving IP injection of chloral hydrate (400 mg/kg).</li>
	<li>Save the digitized data and analyze it using signal-processing software packages, such as spike2. Reveal the power level of different frequency components in the neonatal EEG signal by performing a power spectrum analysis. Calculate the power in a 1-min timeframe by finding the root-mean-square amplitude from 1 to 100 Hz (EEG band) 9.</li>
</ol>

<ol><li>Pereda, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Electrical+synapses+and+their+functional+interactions+with+chemical+synapses%5BTitle%5D)+AND+%22Nat+Rev+Neurosci%22%5BJournal%5D)">Electrical synapses and their functional interactions with chemical synapses.</a> Nat Rev Neurosci. 15 (4), 250-263 (2014).</li>
<li>Chorev, E., Epsztein, J., Houweling, A. R., Lee, A. K., Brecht, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Electrophysiological+recordings+from+behaving+animals--going+beyond+spikes%5BTitle%5D)+AND+%22Curr+Opin+Neurobiol%22%5BJournal%5D)">Electrophysiological recordings from behaving animals--going beyond spikes.</a> Curr Opin Neurobiol. 19 (5), 513-519 (2009).</li>
<li>Freeborn, D. L., McDaniel, K. L., Moser, V. C., Herr, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Use+of+electroencephalography+%28EEG%29+to+assess+CNS+changes+produced+by+pesticides+with+different+modes+of+action%3A+effects+of+permethrin%2C+deltamethrin%2C+fipronil%2C+imidacloprid%2C+carbaryl%2C+and+triadimefon%5BTitle%5D)+AND+%22Toxicol+Appl+Pharmacol%22%5BJournal%5D)">Use of electroencephalography (EEG) to assess CNS changes produced by pesticides with different modes of action: effects of permethrin, deltamethrin, fipronil, imidacloprid, carbaryl, and triadimefon.</a> Toxicol Appl Pharmacol. 282 (2), 184-194 (2015).</li>
<li>Werhahn, K. J., Hartl, E., Hamann, K., Breimhorst, M., Noachtar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Latency+of+interictal+epileptiform+discharges+in+long-term+EEG+recordings+in+epilepsy+patients%5BTitle%5D)+AND+%22Seizure%22%5BJournal%5D)">Latency of interictal epileptiform discharges in long-term EEG recordings in epilepsy patients.</a> Seizure. 29, 20-25 (2015).</li>
<li>Staba, R. J., Stead, M., Worrell, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Electrophysiological+biomarkers+of+epilepsy%5BTitle%5D)+AND+%22Neurotherapeutics%22%5BJournal%5D)">Electrophysiological biomarkers of epilepsy.</a> Neurotherapeutics. 11 (2), 334-346 (2014).</li>
<li>Nimmrich, V., Draguhn, A., Axmacher, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Neuronal+Network+Oscillations+in+Neurodegenerative+Diseases%5BTitle%5D)+AND+%22Neuromolecular+Med%22%5BJournal%5D)">Neuronal Network Oscillations in Neurodegenerative Diseases.</a> Neuromolecular Med. 17 (3), 270-284 (2015).</li>
<li>Zayachkivsky, A., Lehmkuhle, M. J., Dudek, F. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Long-term+Continuous+EEG+Monitoring+in+Small+Rodent+Models+of+Human+Disease+Using+the+Epoch+Wireless+Transmitter+System%5BTitle%5D)+AND+%22J+Vis+Exp%22%5BJournal%5D)">Long-term Continuous EEG Monitoring in Small Rodent Models of Human Disease Using the Epoch Wireless Transmitter System.</a> J Vis Exp. (101), e52554(2015).</li>
<li>Zayachkivsky, A., Lehmkuhle, M. J., Fisher, J. H., Ekstrand, J. J., Dudek, F. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Recording+EEG+in+immature+rats+with+a+novel+miniature+telemetry+system%5BTitle%5D)+AND+%22J+Neurophysiol%22%5BJournal%5D)">Recording EEG in immature rats with a novel miniature telemetry system.</a> J Neurophysiol. 109 (3), 900-911 (2013).</li>
<li>Dzhala, V. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((NKCC1+transporter+facilitates+seizures+in+the+developing+brain%5BTitle%5D)+AND+%22Nat+Med%22%5BJournal%5D)">NKCC1 transporter facilitates seizures in the developing brain.</a> Nat Med. 11 (11), 1205-1213 (2005).</li>
<li>Tucker, A. M., Aquilina, K., Chakkarapani, E., Hobbs, C. E., Thoresen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Development+of+amplitude-integrated+electroencephalography+and+interburst+interval+in+the+rat%5BTitle%5D)+AND+%22Pediatr+Res%22%5BJournal%5D)">Development of amplitude-integrated electroencephalography and interburst interval in the rat.</a> Pediatr Res. 65 (1), 62-66 (2009).</li>
<li>Savard, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Involvement+of+neuronal+IL-1beta+in+acquired+brain+lesions+in+a+rat+model+of+neonatal+encephalopathy%5BTitle%5D)+AND+%22J+Neuroinflammation%22%5BJournal%5D)">Involvement of neuronal IL-1beta in acquired brain lesions in a rat model of neonatal encephalopathy.</a> J Neuroinflammation. 10, 110(2013).</li>
<li>Cuaycong, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+novel+approach+to+the+study+of+hypoxia-ischemia-induced+clinical+and+subclinical+seizures+in+the+neonatal+rat%5BTitle%5D)+AND+%22Dev+Neurosci%22%5BJournal%5D)">A novel approach to the study of hypoxia-ischemia-induced clinical and subclinical seizures in the neonatal rat.</a> Dev Neurosci. 33 (3-4), 241-250 (2011).</li>
</ol>

The authors declare no conflict of interest.

Here, we report surgical and recording procedures to acquire EEG in freely moving neonatal rat pups by wired method (Figure 3). It has been suggested that the P7-P12 rat pup is at the developmental age that corresponds to a full-term human neonate 10,11. It is technically difficult to obtain high-quality EEG recording data when working with rat pups in this age group. In addition, it requires specialized handling and great care 8.
Previous studies examining in vivo EEG recordings in neonatal rats have been conducted using wired recording solutions in P12 or older animals 12, but these approaches are very costly. By relying on simple electrodes, we have been able to make an electrode (Figure 1) that reduces the cost of the experiment to as little as $1 while still giving high-density EEG recordings. Surgical implantation in this method can take as little as 10 min, depending on the complexity of the surgery.
The critical steps in this protocol is the implantation of electrodes. It should be done carefully. To maintain constant contact of the electrode with the skull, the following steps are important to consider. Firstly, remove the tissue debris on the skull with the help of sterilized cotton swab because it may set apart the electrode from the skull. Secondly, use cyanoacrylate&#160;properly to attach the electrode with the skull. Thirdly, keep the adequate viscosity of dental cement. It is better to apply dental cement in two layers; first layer should be a little dense to cover the skull while the second layer should be a little runny to cover the corners of first layer. Tap the dental cement gently with a pipette tip to settle it down to make the strong adhesive bond. If it is too watery it may build an insulating layer under the electrode, and if it is too dense, the dental cement will easily fall off from the skull due to its own weight. It is also important to maintain the pup&#39;s body temperature at 37 &#176;C throughout the surgery for survival.
The application of this procedure is limited to recording EEG in neonatal rat pups between the ages of P8 and P15 because the growing pups may remove the dental cement and electrode from their skull. In terms of further applications, this method can also be used to record the electrical activity of adult rats and mice after minor modification. Moreover, this method lends itself well to use in various behavioral experiments, such as the elevated plus maze.

It is well established that continuous communication between neurons is required to obtain normal brain function. The interneuronal communication primarily takes place at synapses, where information from one neuron is conveyed to a second neuron. This synaptic transmission is mediated by two types of dedicated structural arrangements: electrical or chemical synapses 1. Electrophysiology is the field that captures the electrical potential produced during interneuronal communication that control overall body functions and behavior 2. EEG is the most commonly used method among many electrophysiological techniques.
EEG is a technique used to detect changes in electrical signals produced by internal or external stimuli. Moreover, it is an essential test for clinical diagnosis and outcome prediction of various neurological conditions such as epilepsy, Parkinson&#39;s and Alzheimer&#39;s disease, as well as effects of pharmacological and toxicological agents 3. Generally, an epileptic patient shows hyperexcitability and impaired functional connectivity within the brain; these are summarized as interictal epileptiform discharges (IEDs) and can be recorded by EEG in the form of sharp, transient spikes; sharp waves; spike-wave complexes; or polyspikes 4. The main feature of the epileptic brain is the spontaneous occurrence of epileptic seizures, which can be recorded either from the scalp or from the brain parenchyma in order to locate the brain area responsible for the seizures 5. Furthermore, EEG also has very important implications in neurodegenerative disorders like Alzheimer&#39;s disease (AD). Research suggests that altered EEG recordings and impaired oscillatory networks in AD patients are common. However, our knowledge about the pathophysiology of network oscillations in neurodegenerative diseases is surprisingly incomplete and needs to be further explored 6.
In this protocol, we have designed a simple electrode with which one can record EEG to understand the electrical communication in both the normal and the pathological brain. The surgical implantation in this method is cheaper than other available procedures 7. Moreover, this method can be used to record high-quality and stable EEG signals for longer timeframes (i.e., 2-4 h every day for 1 week). In addition, we used lighter electrodes (weighing approximately 26 mg) that enable the animals to behave more naturally 8. This method is widely applicable to the study of EEG in neonatal rat pups that requires the amplifier and digitizer, commonly used in electrophysiology lab and does not require any additional devices.

<table><tbody><tr><td>Computer pin</td><td></td><td></td><td></td></tr><tr><td>Pincer</td><td>DELI Group Co., Ltd.</td><td></td><td></td></tr><tr><td>502 super glue</td><td>DELI Group Co., Ltd.</td><td>7144</td><td></td></tr><tr><td>Drying oven</td><td>Boxun</td><td>GZX-9140MBE</td><td></td></tr><tr><td>Isofluorane</td><td>RWD Life Science</td><td>902-0000-522</td><td></td></tr><tr><td>Stereotaxic apparatus</td><td>RWD Life Science</td><td>900-0068-507</td><td></td></tr><tr><td>Anesthesia apparatus</td><td>RWD Life Science</td><td>902-0000-510</td><td></td></tr><tr><td>Homeothermic Heating Device</td><td>Harvard Apparatus</td><td>K 024509</td><td></td></tr><tr><td>Amplifier Model 3000&amp;nbsp;</td><td>A-M Systems</td><td>61558</td><td></td></tr><tr><td>Micro1401 Analog Digital converter</td><td>Cambridge Electronic Design Ltd.</td><td>4383</td><td>Data acquisition unit</td></tr><tr><td>Spike2</td><td>Cambridge Electronic Design Ltd.</td><td></td><td></td></tr></tbody></table>

recording eeg in freely moving neonatal rats using a novel method

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such as epilepsy and neurodegenerative disorders. However, it is technically difficult to obtain EEG recordings in neonates as it requires specialized handling and great care. Here, we present a novel method to record EEG in neonatal rat pups (P8-P15). We designed a simple and reliable electrode using computer pin loci; it can be easily implanted into the skull of a rat pup to record high-quality EEG signals in the normal and epileptic brain. Pups were given an intraperitoneal (i.p.) injection of the neurotoxin kainic acid (KA) to induce epileptic seizures. The surgical implantation performed in this procedure is less expensive than other EEG procedures for neonates. This method allows one to record high-quality and stable EEG signals for more than 1 week. Furthermore, this procedure can also be applied to adult rats and mice to study epilepsy or other neurological disorders.

If the above surgical procedures are conducted properly, one channel rat neonatal pup EEG recording will be successfully performed. 10 min after the KA injection, a regular pattern of behavioral signs emerged in the form of irregular movements and scratching, tremors, and loss of balance. Figure 2 shows the representative raw EEG traces and interictal, ictal-tonic, and ictal-clonic expanded traces. Recurrent interictal and ictal EEG discharge patterns started 15-60 min (30 &#177;5.2 min; mean &#177;SEM) after KA injection (Figure 2A and 2B). Figure 2D and 2E represents the tonic-clonic seizures that are the most common type. The ictal-tonic duration lasted 15.2 &#177;0.9 s (Figure 2D). The representative results showed that tonic discharges were followed by clonic bursts (Figure 2B, 2D, and 2E).
<img alt="Figure 1" src="/files/ftp_upload/55489/55489fig1.jpg" /> 
Figure 1: Illustration of Surgical Implantation Protocol. (A) Tiny computer pins. (B) Female pin (left) and male pin (right). The scale bar is used to measure the length of the female pin. (C) Connected female and male pin. (D) Exposed skull. No. 1 presents the reference site, No. 2 presents Bregma, No. 3 and 4 present recording sites, and No. 5 presents Lambda. (E) Electrode implantation. No. 1 presents the reference electrode, No. 3 and 4 present the recording electrode. (F) Recovered rat pup (P9). <a href="http://cloudflare.jove.com/files/ftp_upload/55489/55489fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" src="/files/ftp_upload/55489/55489fig2.jpg" /> 
Figure 2: KA-induced Neonatal Seizure. (A) A representative EEG trace from a P10 rat that was injected with KA (2 mg/kg, i.p.) showed recurrent epileptic burst discharges. (B) Extended view of single cluster-like epileptic discharges from the box in A. (C, D and E) Typical interictal, ictal-tonic, and ictal-clonic traces expanded from the box in B. (F) Summarized data showing the average EEG power (1 min time window) before and after the KA injection (mean &#177;SEM). <a href="http://cloudflare.jove.com/files/ftp_upload/55489/55489fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" src="/files/ftp_upload/55489/55489fig3.jpg" /> 
Figure 3: EEG Recording Set-up. Representative trace recording is shown in freely moving neonatal rat pup. <a href="http://cloudflare.jove.com/files/ftp_upload/55489/55489fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Recording EEG in Freely Moving Neonatal Rats Using a Novel Method at JoVE.com

Recording EEG in Freely Moving Neonatal Rats Using a Novel Method

Here, we introduce a novel technique designed to record electroencephalography (EEG) in freely moving neonatal epileptic pups and describe its procedures, features, and applications. This method allows one to record EEG for more than 1 week.

EEG is a useful method to detect electrical activity in the brain. Moreover, it is a widely used diagnostic tool for various neurological conditions, such ...

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13.2K Views.  South China Normal University. Here, we introduce a novel technique designed to record electroencephalography (EEG) in freely moving neonatal epileptic pups and describe its procedures, features, and applications. This method allows one to record EEG for more than 1 week.

Video: Recording EEG in Freely Moving Neonatal Rats Using a Novel Method

Preterm EEG: A Multimodal Neurophysiological Protocol

Since its introduction in early 1950s, electroencephalography (EEG) has been widely used in the neonatal intensive care units (NICU) for assessment and monitoring of brain function in preterm and term babies. Most common indications are the diagnosis of epileptic seizures, assessment of brain maturity, and recovery from hypoxic-ischemic events. EEG recording techniques and the understanding of neonatal EEG signals have dramatically improved, but these advances have been slow to penetrate through the clinical traditions. The aim of this presentation is to bring theory and practice of advanced EEG recording available for neonatal units. 
In the theoretical part, we will present animations to illustrate how a preterm brain gives rise to spontaneous and evoked EEG activities, both of which are unique to this developmental phase, as well as crucial for a proper brain maturation. Recent animal work has shown that the structural brain development is clearly reflected in early EEG activity. Most important structures in this regard are the growing long range connections and the transient cortical structure, subplate. Sensory stimuli in a preterm baby will generate responses that are seen at a single trial level, and they have underpinnings in the subplate-cortex interaction. This brings neonatal EEG readily into a multimodal study, where EEG is not only recording cortical function, but it also tests subplate function via different sensory modalities. Finally, introduction of clinically suitable dense array EEG caps, as well as amplifiers capable of recording low frequencies, have disclosed multitude of brain activities that have as yet been overlooked.
In the practical part of this video, we show how a multimodal, dense array EEG study is performed in neonatal intensive care unit from a preterm baby in the incubator. The video demonstrates preparation of the baby and incubator, application of the EEG cap, and performance of the sensory stimulations.

This video explains the background theory of the neonatal EEG activity and the sensory responses, followed by a live demonstration of their recording in neonatal intensive care unit.

Since its introduction in early 1950s, electroencephalography (EEG) has been widely used in the neonatal intensive care units (NICU) for assessment and ...

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 ...

Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings

Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with focal epilepsy. This methodology relies on the assumption that seizures originate from the same regions of the brain from which interictal epileptiform discharges (IEDs) emerge. Preclinical models are very useful to find correlates between IED locations and the actual regions underlying seizure initiation in focal epilepsy. Rats have been commonly used in preclinical studies of epilepsy1; hence, there exist a large variety of models for focal epilepsy in this particular species. However, it is challenging to record multichannel EEG and to perform brain source imaging in such a small animal. To overcome this issue, we combine a patented-technology to obtain 32-channel EEG recordings from rodents2 and an MRI probabilistic atlas for brain anatomical structures in Wistar rats to perform brain source imaging. In this video, we introduce the procedures to acquire multichannel EEG from Wistar rats with focal cortical dysplasia, and describe the steps both to define the volume conductor model from the MRI atlas and to uniquely determine the IEDs. Finally, we validate the whole methodology by obtaining brain source images of IEDs and compare them with those obtained at different time frames during the seizure onset.

This video introduces the preparation, recording, and source analysis procedures of high-resolution EEG on sedated rats with a particular preclinical model of focal epilepsy under noninvasive conditions.

Electroencephalogram (EEG) has been traditionally used to determine which brain regions are the most likely candidates for resection in patients with ...

Medicine

Concurrent Recording of Co-localized Electroencephalography and Local Field Potential in Rodent

Although electroencephalography (EEG) is widely used as a non-invasive technique for recording neural activities of the brain, our understanding of the neurogenesis of EEG is still very limited. Local field potentials (LFPs) recorded via a multi-laminar microelectrode can provide a more detailed account of simultaneous neural activity across different cortical layers in the neocortex, but the technique is invasive. Combining EEG and LFP measurements in a pre-clinical model can greatly enhance understanding of the neural mechanisms involved in the generation of EEG signals, and facilitate the derivation of a more realistic and biologically accurate mathematical model of EEG. A simple procedure for acquiring concurrent and co-localized EEG and multi-laminar LFP signals in the anesthetized rodent is presented here. We also investigated whether EEG signals were significantly affected by a burr hole drilled in the skull for the insertion of a microelectrode. Our results suggest that the burr hole has a negligible impact on EEG recordings.

This protocol describes a simple method for concurrent recording of co-localized electroencephalography (EEG) and multi-laminar local field potential in an anesthetized rat. A burr hole drilled in the skull for the insertion of a microelectrode is shown to produce negligible distortion of the EEG signal.

Although electroencephalography (EEG) is widely used as a non-invasive technique for recording neural activities of the brain, our understanding of the ...

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

Noninvasive EEG Recordings from Freely Moving Piglets

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel telemetric electroencephalography system in combination with standard self-adhesive hydrogel electrodes. The piglets are calmed down without the use of sedatives. After their release into the pigpen, the piglets behave normally&#8212;they drink and sleep in the same cycle as their siblings. Their sleep phases are used for the EEG recordings.

Here, we present a protocol to record telemetric electroencephalograms (EEGs) from freely moving piglets directly in the pigpen without the use of a sedative, making it possible to record typical EEG patterns during non-REM sleep, like spindle bursts.

The method allows the recording of high-quality electroencephalograms (EEGs) from freely moving piglets directly in the pigpen. We use a one-channel ...

Electroencephalographic Recording of Epileptic Seizures in Epilepsy-Induced Rats

Source: Soukupov&#225;, M., et al. <a href="https://app.jove.com/v/58455">Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats.</a> J. Vis. Exp. (2018)
This video demonstrates electroencephalographic (EEG) recording of epileptic seizures in epilepsy-induced rats. A rat with electrodes implanted in the ventral hippocampus is connected to the EEG recording system and placed in a plexiglass chamber. The rat is allowed to move freely while the brain activity is recorded to monitor the occurrence of seizures.

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. ...

JoVE Encyclopedia of Experiments

Neurophysiology

Stimulation and Modulation Techniques

Concurrent Electroencephalographic and Local Field Potential Recordings in an Anesthetized Rat

Source: Kang, S., et al. <a href="https://app.jove.com/v/56447">Concurrent Recording of Co-localized Electroencephalography and Local Field Potential in Rodent.</a> J. Vis. Exp. (2017).
This video demonstrates the procedure for concurrent recordings of co-localized electroencephalography (EEG) and local field potentials (LFPs) in an anesthetized rat. The process involves preparing the rat and attaching stimulating electrodes to its whisker pads. An EEG spider electrode is placed on the rat&#39;s skull for surface EEG measurements. At the same time, a multi-channel microelectrode is inserted into a specific brain region through a burr hole in the skull to record neural activity from a localized brain area.

Electrophysiology Techniques

Electroencephalography Recording in a Rat Model of Focal Epilepsy

Source: Bae, J. et al., <a href="https://app.jove.com/v/52700">Brain Source Imaging in Preclinical Rat Models of Focal Epilepsy using High-Resolution EEG Recordings.</a>&#160;J. Vis. Exp. (2015)
This video demonstrates a method for high-resolution EEG recording in a rat model of focal epilepsy. It outlines the steps involved in preparing the rat, connecting a multichannel EEG mini-cap to the rat&#39;s scalp, and recording the EEG to identify seizure-related events characteristic of the epilepsy model.

Recording of Induced Seizures through Electroencephalography in Freely Moving Rat Pups

Source: Huo, Q. et al. <a href="https://app.jove.com/v/55489">Recording EEG in Freely Moving Neonatal Rats Using a Novel Method.</a> J. Vis. Exp. (2017)
The video demonstrates the recording of electroencephalogram (EEG) signals from seizure-induced rat pups. Take a freely moving pup implanted with electrodes connected to a data acquisition system. A neurotoxin is administered to induce epileptic seizures, and the resulting electrical bursting activity is monitored using the EEG signal.