recording of induced seizures through electroencephalography in freely moving rat pups

Recording of Induced Seizures through Electroencephalography in Freely Moving Rat Pups

After the recovery period, house the pup alone to make recordings for about 10 minutes so that the pup may become familiar with the environment. Connect the electrodes to an amplifier, and connect the amplifier to an AD converter attached to a computer. Be careful not to tangle these connections.
Next, on the data acquisition unit, select a sampling rate of at least 10,000 hertz for recording, and check for proper data transmission. Collect a baseline recording. After taking a baseline recording, inject the pup intraperitoneally with kainic acid to induce epileptic seizures. 15 minutes after the injection, observe and record the epileptic discharges.

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All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
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 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 ultraviolet (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&#160;and&#160;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.,&#160;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).</li>
</ol>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<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</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>

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.

<img alt="Figure 1" src="/files/ftp_upload/22886/22886_Figure1.jpg" /> 
Figure 1: Illustration of Surgical Implantation Protocol.&#160;(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 recor...

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

Take a freely moving rat pup implanted with recording electrodes in the hippocampus and a reference electrode in the prefrontal cortex that establishes a baseline signal for comparison.
Connect the electrodes to a data acquisition system to record electrical activity.
Presynaptic neurons release neurotransmitters at synapses, which bind to receptors on postsynaptic neurons. Neurotransmitter binding induces ion influx, altering the membrane potential and generating postsynaptic potentials or PSPs.
The recording electrodes extracellularly capture summed PSPs from a neuronal population as electroencephalogram, or EEG, signals.
Intraperitoneally administer a seizure-inducing neurotoxin that binds to excitatory neurotransmitter receptors on postsynaptic neurons.
The toxin persistently activates the receptors, allowing continuous cation influx. This generates successive PSPs that reach the threshold and continuously trigger action potentials.
The continuous firing of action potentials across neuronal networks results in synchronized bursts of electrical activity termed epileptic seizures.
Monitor the neurotoxin-induced seizure through the EEG patterns.

21 조회수. 자유롭게 움직이는 새끼 쥐에서 뇌파검사를 통한 유도 발작 기록

비디오: 자유롭게 움직이는 새끼 쥐에서 뇌파검사를 통한 유도 발작 기록 - 실험

Application of an Amplitude-integrated EEG Monitor (Cerebral Function Monitor) to Neonates

Amplitude-integrated EEG (aEEG) is an easily accessible technique to monitor the electrocortical activity in preterm and term infants in neonatal intensive care units (NICUs). This method was first used to monitor newborns after asphyxia, providing information about future neurological outcomes. The aEEG is also helpful to select newborns who benefit from cooling. The aEEG monitoring of preterm infants is becoming more widespread, as various studies have shown that neurodevelopmental outcome is related to early aEEG tracings. Here, we demonstrate the application of the aEEG monitoring system and present typical patterns that depend upon gestational age and pathophysiological conditions. Furthermore, we mention pitfalls in the interpretation of the aEEG, as this method requires accurate fixation and localization of the electrodes. Additionally, the raw EEG can be used to detect neonatal seizures or to identify aEEG application problems. In conclusion, aEEG is a safe and generally well-tolerated method for the bedside monitoring of neonatal cerebral function; it can even provide information about long-term outcome.

Application of an Amplitude-integrated EEG Monitor Cerebral Function Monitor to Neonates

Here, we show how to apply amplitude-integrated electroencephalography to monitor cerebral function in neonates.

신생아는 진폭 통합 EEG 모니터 (대뇌 기능 모니터)의 적용

Amplitude-integrated EEG (aEEG) is an easily accessible technique to monitor the electrocortical activity in preterm and term infants in neonatal ...

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의학

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.

자유롭게 이동 Piglets에서 비 침 투 적인 뇌 파 기록

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

신경과학

저비용 EEG와 밀리미터 크기의 코일로 생쥐의 뇌 자극

Low-Cost Electroencephalographic Recording System Combined with a Millimeter-Sized Coil to Transcranially Stimulate the Mouse Brain In Vivo

A low-cost electroencephalographic (EEG) recording system is proposed here to drive transcranial magnetic stimulation (TMS) of the mouse brain in vivo, utilizing a millimeter-sized coil. Using conventional screw electrodes combined with a custom-made, flexible, multielectrode array substrate, multi-site recording can be carried out from the mouse brain. In addition, we explain how a millimeter-sized coil is produced using low-cost equipment usually found in laboratories. Practical procedures for fabricating the flexible multielectrode array substrate and the surgical implantation technique for screw electrodes are also presented, which are necessary to produce low-noise EEG signals. Although the methodology is useful for recording from the brain of any small animal, the present report focuses on electrode implementation in an anesthetized mouse skull. Furthermore, this method can be easily extended to an awake small animal that is connected with tethered cables via a common adapter and fixed with a TMS device to the head during recording.The present version of the EEG-TMS system, which can include a maximum of 32 EEG channels (a device with 16 channels is presented as an example with fewer channels) and one TMS channel device, is described. Additionally, typical results obtained by the application of the EEG-TMS system to anesthetized mice are briefly reported.

저자 스포트라이트: 생체 내에서 쥐 뇌를 경두개골로 자극하기 위해 밀리미터 크기의 코일과 결합된 저비용 뇌파 기록 시스템  

A low-cost electroencephalographic recording system combined with a millimeter-sized coil is proposed to drive transcranial magnetic stimulation of the mouse brain in vivo. Using conventional screw electrodes with a custom-made, flexible, multielectrode array substrate, multi-site recording can be carried out from the mouse brain in response to transcranial magnetic stimulation.

생체 내에서 마우스 뇌를 경두개로 자극하기 위해 밀리미터 크기의 코일과 결합된 저비용 뇌파 기록 시스템

A low-cost electroencephalographic (EEG) recording system is proposed here to drive transcranial magnetic stimulation (TMS) of the mouse brain in vivo, ...

Recording of Induced Seizures through Electroencephalography in Freely Moving Rat Pups

내레이션 대본

Recording of Induced Seizures through Electroencephalography in Freely Moving Rat Pups