이 연구는 호주 안과 연구소 (오리 아)에 의해 지원되었다. 우리는 처음에 VEP 기록 기술을 개발하기 위해 우리를 도와, 교수 Algis Vingrys 박사 빅뱅 부이, 멜버른 대학 감사합니다.

윤리 문 : 동물과 관련된 모든 절차는 관리 및 과학적인 목적을위한 동물의 사용 및 안과 및 비전 연구에서 동물의 사용에 대한 ARVO 방침의 지침 연습 호주 코드에 따라 수행되었으며, 승인했다 맥쿼리 대학의 동물 윤리위원회. 1. VEP 전극 주입 <ol><li> 복강 내 주사 케타민 (75 ㎎ / ㎏) 및 메데 토미 (0.5 밀리그램 / kg)으로 동물을 마취. 마취의 유도에 따라 수술을 시작하는 표시로 철수 반사 (핀치 검사, 각막과 눈꺼풀 반사 등)과 부재을 준수합니다. 수술 내내 계속 동물을 모니터링하고 반사가 존재하는 경우 추가 마취약 (상위 - 업 케타민 당 초기 용량의 10 %)을 관리. 성인 쥐 (&gt; 12주)는 실험에 사용된다. </li><li> 외과 영역의 피부를 면도.수술 중 체온을 유지하기 위해 온난화 패드 (37 ° C)에서 동물을 놓습니다. 포비돈 - 요오드의 국소 응용 프로그램을 통해 피부를 준비합니다. 수술 입체 재단을 적용합니다. 전신 마취하에 각막 건조를 방지하기 위해 국소 안과 연고를 적용합니다. 멸균 악기를 사용하여 무균을 유지한다. </li><li> 헤드 피부의 중간 선에 길이의 피부 절개를합니다. 두개골의 좋은 노출을 달성하기 위해 결합 조직을 취소합니다. </li><li> 조심스럽게, 수동으로 브레 그마 뒤에 7mm과 중간 선에 3mm 측면에서 마이크로 핸드 드릴을 사용하여 작은 버 구멍을 드릴. </li><li> 약 0.5 mm의 깊이로 피질을 관통하는 피질 (영역 (17))에 두개골을 통해 임플란트 나사 전극. 브레 그마로 정중선 3mm의 입쪽에 기준 나사 전극을 이식. 나사를 싸는하고 해결하기 위해 치과 시멘트를 적용합니다 (항상 필요하지 않음). </li><li> RECO하는 동물을 머리의 피부 봉합 피부에 항생제 연고를 관리 허용버전 온난화 패드에 마취에서. 주 : 대안 적으로, 전극이 노출 남아있을 수 있다는 것을 피부에서 각각의 기록 재개 할 필요가없는, 그래서. 수술 전에 즉시하지만 마취 회복의 정지시에, 비 스테로이드 성 항 염증 약물 (NSAID) (아니라면 사전에 동작 투여) 또는 아편 유사 진통제를 투여. 마취 완전히 외래에서 완전히 회복 될 때까지 지속적으로 동물을 모니터링합니다. </li><li> 동물이 수술의 사전 VEP 기록을 복구하는 적어도 일주 허용합니다. </li></ol> 2. 시신경 주입 <ol><li> , 동물을 마취 피부를 준비하고 (1.1 및 1.2) 이상으로 드레이프 적용됩니다. </li><li> 무작위로 선택된 눈의 궤도 위의 피부에 1 - 1.5 cm의 절개를합니다. 미세 홍채 가위를 사용하여 궤도 캐비티에 도달하기 위해 피하 조직을 엽니 다. 결막을 열고 운영 현미경으로 장부의 캡슐을 전방. </li><li> 안구 후퇴근육과 intraobital 눈물 분비는 시신경의 약 3mm 길이를 노출합니다. 길이 방향으로 안과 블레이드를 사용하여 시신경 주위의 경막과 지주막 물질 층을 엽니 다. </li><li> 세계에 2mm 후방의 거리에서 시신경에 유리 피펫을 삽입합니다. 유리 마이크로 피펫은 해밀턴 주사기에 부착된다. </li><li> 약 30 초에 걸쳐 천천히 신경으로 - (수초에 효과가없는 0.02 % 에반 블루와, 1.0 μL, 0.4), 1 % 리소 레시틴을 주입한다. </li><li> 피부 절개 봉합. 감염을 방지하기 위해 항생제 연고를 적용합니다. 동료의 눈은 전기 생리학 레코딩을위한 내부 통제 역할을 할 수있다. </li><li> 마취에서 회복 온난화 패드에 동물을 놓습니다. </li></ol> 3. VEP 기록 <ol><li> 동물을 마취하고 1.1 및 1.2로 피부를 준비합니다. 참고 : 마취제의 낮은 복용량은 전기 생리 RECO 사용할 수 있습니다rding (케타민 40 ㎎ / ㎏과 0.25 ㎎ / ㎏을 메데 토미). </li><li> 어두운 방에서 쥐를 놓고는 5 어둠에 적응 할 수 - 30 분. 어떤 경우에는 쥐가 각각 포토 픽 VEP 녹음 8 적응 암순응 또는 빛 어두운 적응 O / N이 될 수 있습니다. </li><li> 직장 온도계 프로브 homoeothermic 블랭킷 시스템에 의해 37 ± 0.5 ℃의 체온을 유지한다. </li><li> 1.0 % tropicamide 눈 방울과 학생들을 팽창. 액세스하기 위해 두개골을 통해 피부를 열고 사전 배치 현장 나사 전극에서. </li><li> 자극 눈의 반대편 시각 피질과 앰프에 대한 참조 나사를 통해 나사를 연결합니다. 지상으로 꼬리에 바늘 전극을 삽입합니다. 측정하고 5 kΩ의 아래 전극 임피던스를 유지한다. </li><li> 뛰어난 눈 절연 (7)을 제공하기 위해 눈꺼풀 주위의 피부에 직접 미니 Ganzfeld 자극을 놓습니다. 자극기의 조명이 미리 보정해야광도계에 의해. </li><li> 각각 1 내지 100 Hz의 낮은 및 높은 밴드 패스 필터 설정을 1 Hz의 주파수에서 빛을 깜박 100 회 빛의 자극을 전달한다. 신호 샘플링 레이트는 5 kHz에서이다. 참고 : 신호는 적어도 약 250 샘플링한다 - 더 두 개의 샘플은 각주기 동안 수집되는 것을 보장하기 위해 300 Hz에서. </li><li> 다시 피부를 봉합하고 마취에서 회복하기 온난화 패드에 동물을 유지. 녹화 반복 시간 기간 동안에 기능적 변화를 모니터링하기 위해 각각의 동물에 기록 될 수있다. </li><li> 최종 시점에서, 동물을 안락사 나트륨 펜토 바르비 톤 (100 밀리그램 / kg, IP)의 과다 주사를 관리. 심장 마비, 호흡 정지 및 체온의 감소에 의해 안락사를 확인합니다. </li></ol> 4. 조직 준비 및 조직학 <ol><li> 현미경으로 안락사 동물에서 시신경을 제거하고 1 % 파라 포름 알데히드의 O / N의 조직을 고정합니다. </li> &lt;리&gt; 식염수로 철저하게 조직을 씻으십시오. 자동 조직 프로세서에서 처리하고, 조직을 파라핀에 포함. 회전식 마이크로톰을 사용하여 - (10 μm의 5) 컷 섹션. 참고 : 면역 조직 화학 연구를 들어, 1 % 파라 포름 알데히드에 조직을 고정 식염수로 세척하고 30 % 자당 O / N로 품어. OCT에서 임베드 조직 매체를 포함하고 저온 ​​유지 장치를 사용하여 저온부을합니다. </li><li> 56 ° C에서 같은 룩솔 (95 % 에탄올) O / N으로 0.1 % 빠른 블루 솔루션 섹션을 품어. 다음 다른 30 ​​초 70 % 에탄올을 30 초 동안 0.05 %의 탄산 리튬의 섹션을 차별화하고. 마지막 섹션을 장착하기 전에 30 초 동안 0.1 % 크레 실 바이올렛 용액 Counterstain과. 시신경 5 수초를 식별하기 위해 빠른 파란색 염색을 사용합니다. </li></ol>

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None of the authors have competing interests or conflicting interests.

The optic nerve is very susceptible to mechanical damage. Optic nerve crush injury over a duration of 1 s can lead to about 75% loss of RGC over a period of 2 weeks10. Therefore, extreme care is required while performing the surgical procedures. According to the authors&#8217; experience, it is much better to adapt a blunt dissection approach to expose and make way through the tissues around the optic nerve along the orientation of the nerve, rather than penetrating in a perpendicular orientation to the optic ...

Optic neuritis is one of the most common form of optic neuropathy, causing complete or partial loss of vision1. Histologically, it is featured by inflammatory demyelination, retinal ganglion cell axonal loss and varying degrees of remyelination in the optic nerve2. Optic neuritis is usually the manifest onset of multiple sclerosis. The visual evoked potential (VEP) is a non-invasive tool for investigating the function of the visual system. It reflects the post-retinal function from the retina to the primary visual cortex and is affected in many optic nerve disease conditions3. The VEP has been predominantly used in optic neuritis patients to assess the integrity of the visual pathway4. 
The latency of VEP, which reflects the velocity of signal conduction along the visual pathway, is considered to be an accurate measurement of the level of myelin associated changes in the optic nerve5; while the amplitude of VEP is believed to be closely correlated with axonal damage of the retinal ganglion cells (RGC)6. This hypothesis has been fairly well established using the rat model of lysolecithin-induced optic nerve demyelination5. 
Here, we explicate a comprehensive protocol of optic nerve microinjection technique in rodents, which can minimise the surgical manipulation-related damage to the nerve per se as well as to the adjacent tissues such as extraocular muscles and blood vessels. Also, the skull electrode implantation surgery has been described for VEP recording in animals7. The VEP recordings can be repeatedly carried out on animals over a period of time to assess demyelination/remyelination related changes as well as impact on axonal integrity in the optic nerve.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Ketamine 100 mg/ml (Ketamil)</td>
			<td>Troy Laboratories</td>
			<td>AC 116</td>
			<td></td>
		</tr>
		<tr>
			<td>Medetomidine 1 mg/ml (Domitor)</td>
			<td>Pfizer</td>
			<td>sc-204073</td>
			<td></td>
		</tr>
		<tr>
			<td>Tropicamide 1.0% (Mydriacyl)</td>
			<td>Alcon</td>
			<td>sc-202371</td>
			<td></td>
		</tr>
		<tr>
			<td>Homoeothermic blanket system</td>
			<td>Harvard Apparatus</td>
			<td>NC9203819</td>
			<td></td>
		</tr>
		<tr>
			<td>Impedance meter&#160;</td>
			<td>Grass</td>
			<td>F-EZM5</td>
			<td></td>
		</tr>
		<tr>
			<td>Screw electrodes&#160;</td>
			<td>Micro Fasteners</td>
			<td>M1.0&#215;3mm Csk Slot M/T 304 S/S</td>
			<td></td>
		</tr>
		<tr>
			<td>Subdermal needle electrodes&#160;</td>
			<td>Grass</td>
			<td>F-E3M-72</td>
			<td></td>
		</tr>
		<tr>
			<td>Rapid Repair&#160;</td>
			<td>DeguDent GmbH</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Light-emitting diode&#160;</td>
			<td>Nichia</td>
			<td>NSPG300A</td>
			<td></td>
		</tr>
		<tr>
			<td>Bioamplifier</td>
			<td>CWE, Inc.</td>
			<td>BMA-400</td>
			<td></td>
		</tr>
		<tr>
			<td>CED system</td>
			<td>Cambridge Electronic Design, Ltd.</td>
			<td>Power1401</td>
			<td></td>
		</tr>
		<tr>
			<td>Hamilton syringe&#160;</td>
			<td>Hamilton</td>
			<td>87930</td>
			<td></td>
		</tr>
		<tr>
			<td>Lysolecithin</td>
			<td>Sigma</td>
			<td>L4129</td>
			<td></td>
		</tr>
		<tr>
			<td>Evan&#8217;s blue&#160;</td>
			<td>Sigma</td>
			<td>E2129</td>
			<td></td>
		</tr>
	</tbody>
</table>

visual evoked potential recording in a rat model of experimental optic nerve demyelination

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to monitor the disease course in the follow-up period. Changes in the VEP parameters closely correlate with pathological damage in the optic nerve. This protocol provides a detailed description about the rodent model of optic nerve microinjection, in which a partial demyelination lesion is produced in the optic nerve. VEP recording techniques are also discussed. Using skull implanted electrodes, we are able to acquire reproducible intra-session and between-session VEP traces. VEPs can be recorded on individual animals over a period of time to assess the functional changes in the optic nerve longitudinally. The optic nerve demyelination model, in conjunction with the VEP recording protocol, provides a tool to investigate the disease processes associated with demyelination and remyelination, and can potentially be employed to evaluate the effects of new remyelinating drugs or neuroprotective therapies.

재현성 인트라 셔널 VEP 트레이스는도 1에 도시되어 있으며 대기 N1에서 상당한 지연은 시신경 주입 후에 알 수있다. 탈수 초화의 부분 시신경 병변 룩솔 패스트 블루 염색법을 이용하여 조직 학적 5 절에서 발견 될 수있다. 2 시신경의 중심에 작은 초점 탈수 초 병변 대표적인 부분을 도시한다. 단면은 병변의 총 부피를 대표하지 않습니다. 탈?...

Watch this Scientific Journal Video about Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination at JoVE.com

Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination

Focal demyelination is induced in the optic nerve using lysolecithin microinjection. Visual evoked potentials are recorded via skull electrodes implanted over the visual cortex to examine the signal conduction along the visual pathway in vivo. This protocol details the surgical procedures underlying electrode implantation and optic nerve microinjection.

실험 시신경의 탈수 초화의 쥐 모델에서 시각 유발 전위 기록

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to ...

visual-evoked-potential-recording-rat-model-experimental-optic-nerve

Research

JoVE Journal

Neuroscience

12.1K 조회수.  Macquarie University. Focal demyelination is induced in the optic nerve using lysolecithin microinjection. Visual evoked potentials are recorded via skull electrodes implanted over the visual cortex to examine the signal conduction along the visual pathway in vivo. This protocol details the surgical procedures underlying electrode implantation and optic nerve microinjection. 

비디오: Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination

Optic Nerve Transection: A Model of Adult Neuron Apoptosis in the Central Nervous System

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. 
The optic nerve can be accessed within the orbit of the eye and completely transected (axotomized), cutting the axons of the entire RGC population. Optic nerve 
transection is a reproducible model of apoptotic neuronal cell death in the adult CNS 1-4. This model is particularly attractive because the vitreous
 chamber of the eye acts as a capsule for drug delivery to the retina, permitting experimental manipulations via intraocular injections. The diffusion of chemicals 
through the vitreous fluid ensures that they act upon the entire RGC population. Moreover, RGCs can be selectively transfected by applying short interfering RNAs 
(siRNAs), plasmids, or viral vectors to the cut end of the optic nerve 5-7 or injecting vectors into their target, the superior colliculus 8. 
This allows researchers to study apoptotic mechanisms in the desired neuronal population without confounding effects on other bystander neurons or surrounding glia. 
An additional benefit is the ease and accuracy with which cell survival can be quantified after injury. The retina is a flat, layered tissue and RGCs are localized in 
the innermost layer, the ganglion cell layer. The survival of RGCs can be tracked over time by applying a fluorescent tracer (3% Fluorogold) to the cut end of the 
optic nerve at the time of axotomy, or by injecting the tracer into the superior colliculus (RGC target) one week prior to axotomy. The tracer is retrogradely transported, labeling 
the entire RGC population. Because the ganglion cell layer is a monolayer (one cell thick), RGC densities can be quantified in flat-mounted tissue, without the need 
for stereology. Optic nerve transection leads to the apoptotic death of 90% of injured RGCs within 14 days postaxotomy 9-11. RGC apoptosis has a 
characteristic time-course whereby cell death is delayed 3-4 days postaxotomy, after which the cells rapidly degenerate. This provides a time window for 
experimental manipulations directed against pathways involved in apoptosis.

Optic Nerve transection is a widely used model of adult CNS injury. Ninety percent of retinal ganglion cells (RGCs) whose axons are completely transected (axotomy) die within 14 days after axotomy. This model is easily amenable to experimental manipulations and highly reproducible.

시신경의 절개 : 중추 신경계에서 신경 세포의 Apoptosis 성인의 모델

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. 
The optic nerve can be ...

연구

신경과학

Methods for Experimental Manipulations after Optic Nerve Transection in the Mammalian CNS

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. The optic nerve can be accessed within the orbit of the eye and completely transected (axotomized), cutting the axons of the entire RGC population. Optic nerve transection is a reproducible model of apoptotic neuronal cell death in the adult CNS 1-4. This model is particularly attractive because the vitreous chamber of the eye acts as a capsule for drug delivery to the retina, permitting experimental manipulations via intraocular injections. The diffusion of chemicals through the vitreous fluid ensures that they act upon the entire RGC population. Viral vectors, plasmids or short interfering RNAs (siRNAs) can also be delivered to the vitreous chamber in order to infect or transfect retinal cells 5-12. The high tropism of Adeno-Associated Virus (AAV) vectors is beneficial to target RGCs, with an infection rate approaching 90% of cells near the injection site 6, 7, 13-15. Moreover, RGCs can be selectively transfected by applying siRNAs, plasmids, or viral vectors to the cut end of the optic nerve 16-19 or injecting vectors into their target the superior colliculus 10. This allows researchers to study apoptotic mechanisms in the injured neuronal population without confounding effects on other bystander neurons or surrounding glia. RGC apoptosis has a characteristic time-course whereby cell death is delayed 3-4 days postaxotomy, after which the cells rapidly degenerate. This provides a window for experimental manipulations directed against pathways involved in apoptosis. Manipulations that directly target RGCs from the transected optic nerve stump are performed at the time of axotomy, immediately after cutting the nerve. In contrast, when substances are delivered via an intraocular route, they can be injected prior to surgery or within the first 3 days after surgery, preceding the initiation of apoptosis in axotomized RGCs. In the present article, we demonstrate several methods for experimental manipulations after optic nerve transection.

Optic Nerve transection is a widely used model of adult CNS injury. This model is ideal for performing a number of experimental manipulations that target the retina globally or directly target the injured neuronal population of retinal ganglion cells.

포유류의 CNS에서 시신경의 절개 후 실험에 대한 노는 방법

Retinal ganglion cells (RGCs) are CNS neurons that output visual information from the retina to the brain, via the optic nerve. The optic nerve can be ...

An Optic Nerve Crush Injury Murine Model to Study Retinal Ganglion Cell Survival

Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible vision loss. Examples of such diseases in human include traumatic optic neuropathy and optic nerve degeneration in glaucoma. It is characterized by typical changes in the optic nerve head, progressive optic nerve degeneration, and loss of retinal ganglion cells, if uncontrolled, leading to vision loss and blindness.
The optic nerve crush (ONC) injury mouse model is an important experimental disease model for traumatic optic neuropathy, glaucoma, etc. In this model, the crush injury to the optic nerve leads to gradual retinal ganglion cells apoptosis. This disease model can be used to study the general processes and mechanisms of neuronal death and survival, which is essential for the development of therapeutic measures. In addition, pharmacological and molecular approaches can be used in this model to identify and test potential therapeutic reagents to treat different types of optic neuropathy.
Here, we provide a step by step demonstration of (I) Baseline retrograde labeling of retinal ganglion cells (RGCs) at day 1, (II) Optic nerve crush injury at day 4, (III) Harvest the retinae and analyze RGC survival at day 11, and (IV) Representative result.

This protocol shows how to retrogradely label retinal ganglion cells, and how to subsequently make an optic nerve crush injury in order to analyze retinal ganglion cell survival and apoptosis. It is an experimental disease model for different types of optic neuropathy, including glaucoma.

망막 신경절 세포의 생존을 공부 시신경의 호감 상해 Murine 모델

Injury to the optic nerve can lead to axonal degeneration, followed by a gradual death of retinal ganglion cells (RGCs), which results in irreversible ...

Determination of Mitochondrial Membrane Potential and Reactive Oxygen Species in Live Rat Cortical Neurons

Mitochondrial membrane potential (&Delta;&Psi;m) is critical for maintaining the physiological function of the respiratory chain to generate ATP. A significant loss of &Delta;&Psi;m renders cells depleted of energy with subsequent death. Reactive oxygen species (ROS) are important signaling molecules, but their accumulation in pathological conditions leads to oxidative stress. The two major sources of ROS in cells are environmental toxins and the process of oxidative phosphorylation. Mitochondrial dysfunction and oxidative stress have been implicated in the pathophysiology of many diseases; therefore, the ability to determine &Delta;&Psi;m and ROS can provide important clues about the physiological status of the cell and the function of the mitochondria. 
Several fluorescent probes (Rhodamine 123, TMRM, TMRE, JC-1) can be used to determine &Delta;&psi;m in a variety of cell types, and many fluorescence indicators (Dihydroethidium, Dihydrorhodamine 123, H2DCF-DA) can be used to determine ROS. Nearly all of the available fluorescence probes used to assess &Delta;&Psi;m or ROS are single-wavelength indicators, which increase or decrease their fluorescence intensity proportional to a stimulus that increases or decreases the levels of &Delta;&Psi;m or ROS. Thus, it is imperative to measure the fluorescence intensity of these probes at the baseline level and after the application of a specific stimulus. This allows one to determine the percentage of change in fluorescence intensity between the baseline level and a stimulus. This change in fluorescence intensity reflects the change in relative levels of &Delta;&Psi;m or ROS. In this video, we demonstrate how to apply the fluorescence indicator, TMRM, in rat cortical neurons to determine the percentage change in TMRM fluorescence intensity between the baseline level and after applying FCCP, a mitochondrial uncoupler. The lower levels of TMRM fluorescence resulting from FCCP treatment reflect the depolarization of mitochondrial membrane potential. We also show how to apply the fluorescence probe H2DCF-DA to assess the level of ROS in cortical neurons, first at baseline and then after application of H2O2. This protocol (with minor modifications) can be also used to determine changes in &#x2206;&#x03A8;m and ROS in different cell types and in neurons isolated from other brain regions.

We demonstrate application of the fluorescence indicator, TMRM, in cortical neurons to determine the relative changes in TMRM fluorescence intensity before and after application of a specific stimulus. We also show application of the fluorescence probe H2DCF-DA to assess the relative level of reactive oxygen species in cortical neurons.

라이브 랫 두피 뉴런에서 Mitochondrial 분리막 잠재력과 반응 산소 종의 결정

Mitochondrial membrane potential (&Delta;&Psi;m) is critical for maintaining the physiological function of the respiratory chain to generate ATP.  A ...

Minimally-invasive Technique for Injection into Rat Optic Nerve

The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads.

Direct injection into the rat optic nerve is useful for regenerative research. We demonstrate a minimally-invasive technique for direct injection into a rat optic nerve that does not involve opening the skull. Using this method, surgical complications are minimized and recovery is more rapid.

쥐 시신경에 주입을위한 최소 침습 기술

The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central ...

Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats

The electroretinogram (ERG) and visual evoked potential (VEP) are commonly used to assess the integrity of the visual pathway. The ERG measures the electrical responses of the retina to light stimulation, while the VEP measures the corresponding functional integrity of the visual pathways from the retina to the primary visual cortex following the same light event. The ERG waveform can be broken down into components that reflect responses from different retinal neuronal and glial cell classes. The early components of the VEP waveform represent the integrity of the optic nerve and higher cortical centers. These recordings can be conducted in isolation or together, depending on the application. The methodology described in this paper allows simultaneous assessment of retinal and cortical visual evoked electrophysiology from both eyes and both hemispheres. This is a useful way to more comprehensively assess retinal function and the upstream effects that changes in retinal function can have on visual evoked cortical function.

This protocol describes simultaneous measurement of electroretinogram and visual evoked potentials in anesthetized rats.

전위도의 동시 녹화 및 마취 된 흰쥐의 비주얼 사건 관련 전위

The electroretinogram (ERG) and visual evoked potential (VEP) are commonly used to assess the integrity of the visual pathway. The ERG measures the ...

Partial Optic Nerve Transection in Rats: A Model Established with a New Operative Approach to Assess Secondary Degeneration of Retinal Ganglion Cells

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection is considered a useful and reproducible model. Compared with other optic nerve injury models used commonly for assessing secondary degeneration, e.g. complete optic nerve transection and optic nerve crush models, the partial optic nerve transection model is superior as it distinguishes primary from secondary degeneration in situ. Therefore, it serves as an excellent tool for evaluating secondary degeneration. This study describes a novel operative approach of partial optic nerve transection by directly accessing the area of the retrobulbar optic nerve through the orbital lateral wall of the eyeball. Moreover, we present a newly designed, low cost surgical instrument to assist with transection. As demonstrated by the representative results in distinguishing the boundary of primary and secondary injury areas, the new approach and instrument ensures high efficiency and stability of the model by providing adequate space for surgical operation. This in turn makes it easy to separate the meningeal sheath and ophthalmic vessels from the optic nerve before transection. An additional benefit is that this space-saving operative approach improves the investigators&#39; ability to administer drugs, carriers, or selective RGC tracers to the stump of the partially transected optic nerve, allowing the exploration of mechanisms behind secondary injury in RGCs, in a new way.

Secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. This study describes an innovative operative approach for partial optic nerve transection. The use of this space-saving operative approach extends the model's application range, and allows exploration of secondary injury mechanisms in RGCs in a new way.

쥐에 있는 부분 시 신경 Transection: 망막 신경 절 세포의 2 차 변성을 평가 하기 위해 새로운 수술 방식으로 설립 모델

Previous studies have shown that the secondary degeneration of retinal ganglion cells (RGCs) occurs commonly in glaucoma. Partial optic nerve transection ...

Visual Evoked Potential Recordings in Mice Using a Dry Non-invasive Multi-channel Scalp EEG Sensor

For scalp EEG research environments with laboratory mice, we designed a dry-type 16 channel EEG sensor which is non-invasive, deformable, and re-usable because of the plunger-spring-barrel structural facet and mechanical strengths resulting from metal materials. The whole process for acquiring the VEP responses in vivo from a mouse consists of four steps: (1) sensor assembly, (2) animal preparation, (3) VEP measurement, and (4) signal processing. This paper presents representative measurements of VEP responses from multiple mice with a submicro-voltage signal resolution and sub-hundred millisecond temporal resolution. Although the proposed method is safer and more convenient compared to other previously reported animal EEG acquiring methods, there are remaining issues including how to enhance the signal-to-noise ratio and how to apply this technique with freely moving animals. The proposed method utilizes easily available resources and shows a repetitive VEP response with a satisfactory signal quality. Therefore, this method could be utilized for longitudinal experimental studies and reliable translational research exploiting non-invasive paradigms.

We designed a dry-type 16 channel EEG sensor which is non-invasive, deformable, and re-usable. This paper describes the whole process from manufacturing the proposed EEG electrode to signal processing of visual evoked potential (VEP) signals measured on a mouse scalp using a dry non-invasive multi-channel EEG sensor.

드라이 비-침략 적 멀티 채널을 사용 하 여 마우스에 비주얼 갖는 잠재적인 녹음 두 피 뇌 파 센서

For scalp EEG research environments with laboratory mice, we designed a dry-type 16 channel EEG sensor which is non-invasive, deformable, and re-usable ...

Rat Model of Widespread Cerebral Cortical Demyelination Induced by an Intracerebral Injection of Pro-Inflammatory Cytokines

Multiple sclerosis (MS) is the most common immune-mediated disease of the central nervous system (CNS) and progressively leads to physical disability and death, caused by white matter lesions in the spinal cord and cerebellum, as well as by demyelination in grey matter. Whilst conventional models of experimental allergic encephalomyelitis are suitable for the investigation of the cell-mediated inflammation in the spinal and cerebellar white matter, they fail to address grey matter pathologies. Here, we present the experimental protocol for a novel rat model of cortical demyelination allowing the investigation of the pathological and molecular mechanisms leading to cortical lesions. The demyelination is induced by an immunization with low-dose myelin oligodendrocyte glycoprotein (MOG) in an incomplete Freund&#39;s adjuvant followed by a catheter-mediated intracerebral delivery of pro-inflammatory cytokines. The catheter, moreover, enables multiple rounds of demyelination without causing injection-induced trauma, as well as the intracerebral delivery of potential therapeutic drugs undergoing a preclinical investigation. The method is also ethically favorable as animal pain and distress or disability are controlled and relatively minimal. The expected timeframe for the implementation of the entire protocol is around 8 - 10 weeks.

The protocol presented here allows the reproduction of a widespread grey matter demyelination of both cortical hemispheres in adult male Dark Agouti rats. The method comprises of intracerebral implantation of a catheter, subclinical immunization against myelin oligodendrocyte glycoprotein, and intracerebral injection of a pro-inflammatory cytokine mixture through the implanted catheter.

프로 염증 성 사이토카인의 인트레이스렐 주입에 의해 유도된 광범위한 대뇌 피질 탈량의 쥐 모델

Multiple sclerosis (MS) is the most common immune-mediated disease of the central nervous system (CNS) and progressively leads to physical disability and ...

Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns

This paper presents a methodology for the recording and analysis of cortical visual evoked potentials (CVEPs) in response to various visual stimuli using 128-channel high-density electroencephalography (EEG). The specific aim of the described stimuli and analyses is to examine whether it is feasible to replicate previously reported CVEP morphological patterns elicited by an apparent motion stimulus, designed to simultaneously stimulate both ventral and dorsal central visual networks, using object and motion stimuli designed to separately stimulate ventral and dorsal visual cortical networks.&#160; Four visual paradigms are presented: 1. Randomized visual objects with consistent temporal presentation. 2. Randomized visual objects with inconsistent temporal presentation (or jitter).&#160; 3. Visual motion via a radial field of coherent central dot motion without jitter.&#160; 4. Visual motion via a radial field of coherent central dot motion with jitter.&#160; These four paradigms are presented in a pseudo-randomized order for each participant.&#160; Jitter is introduced in order to view how possible anticipatory-related effects may affect the morphology of the object-onset and motion-onset CVEP response.&#160; EEG data analyses are described in detail, including steps of data exportation from and importation to signal processing platforms, bad channel identification&#160;and removal, artifact rejection, averaging, and categorization of average CVEP morphological pattern type based upon latency ranges of component peaks. Representative data show that the methodological approach is indeed sensitive in eliciting differential object-onset and motion-onset CVEP morphological patterns and may, therefore, be useful in addressing the larger research aim. Given the high temporal resolution of EEG and the possible application of high-density EEG in source localization analyses, this protocol is ideal for the investigation of distinct CVEP morphological patterns and the underlying neural mechanisms which generate these differential responses.&#160; &#160; &#160;&#160;

In this paper, we present a protocol to investigate differential cortical visual evoked potential morphological patterns through stimulation of ventral and dorsal networks using high-density EEG. Visual object and motion stimulus paradigms, with and without temporal jitter, are described. Visual evoked potential morphological analyses are also outlined.&#160;&#160;

자극 특이적 피질 시각적 자극 잠재적 인 형태 학적 패턴을 불러 일으켰다

This paper presents a methodology for the recording and analysis of cortical visual evoked potentials (CVEPs) in response to various visual stimuli using ...