Bu çalışma Avustralya Oftalmik Araştırma Enstitüsü (ORIA) tarafından desteklenmiştir. Biz başlangıçta VEP kayıt tekniğini geliştirmek için bize yardımcı olduğunuz için Prof. Algis Vingrys Dr. Bang Bui, University of Melbourne teşekkür ederim.

Etik Beyanı: hayvanlarla ilgili tüm işlemler Bakım ve Bilimsel Amaçlarla Hayvanların Kullanımı ve Oftalmik ve Vizyon Araştırma Hayvanların Kullanım ARVO Tablosu kılavuzlar için Uygulama Avustralyalı Kanunu&#39;na göre yapılmıştır ve ile kabul edildi Macquarie Üniversitesi Hayvan Etik Kurul. 1. VEP Elektrot İmplantasyonu <ol><li> Bir intraperitonal ketamin enjeksiyonu (75 mg / kg) ve medetomidin (0.5 mg / kg) ile hayvan anestezisi. Anestezi indüksiyonu takiben ameliyat başlamak için bir gösterge olarak çekilme refleksler (tutam testi, korneal ve palpebral refleks, vb) ve bunların yokluğu dikkat: Not. Sürekli ameliyat boyunca hayvanları izlemek ve refleksleri varsa ek anestezik ilaç (kontör başına ilk ketamin dozunun% 10) yönetmek. Yetişkin sıçanlarda (&gt; 12 haftalık) deneylerde kullanılır. </li><li> Cerrahi alanın cildi tıraş.Ameliyat sırasında vücut sıcaklığının muhafaza edilmesi için bir ısıtma pedi (37 ° C) hayvan yerleştirin. Povidon-iyot topikal uygulama sayesinde cildi hazırlayın. Cerrahi dökümlü uygulayın. Genel anestezi altında kornea kuruluğunu önlemek için topikal oftalmik merhem sürün. Steril aletler kullanarak asepsi koruyun. </li><li> Kafa derisinin orta hat üzerinde uzunlamasına bir cilt kesi olun. Kafatasının iyi pozlama elde etmek için bağ dokusu temizleyin. </li><li> Dikkatle, el bregma arkasında 7 mm ve orta hatta 3 mm yanal bir mikro el matkabı kullanarak küçük çapak delik. </li><li> Yaklaşık 0.5 mm&#39;lik bir derinliğe kadar korteksi penetre korteks (bölge 17) içerisine kafatası yoluyla implant vidalı elektrotlar. Bregma orta hat, 3 mm rostral bir referans vida elektrot implante. Vidaları örtmek ve düzeltmek için diş çimento uygulayın (her zaman gerekli değildir). </li><li> Reco hayvan, baş derisini dikin cilde antibiyotik merhem yönetmek ve izinver bir ısınma pad üzerinde anesteziden. Not: Alternatif olarak, elektrotlar maruz sol olabilir, bu cilt, her kayıt yeniden açılması gerekmez böylece. Ameliyattan hemen ancak önceden anestezi kurtarma kesilmesiyle, bir steroid olmayan anti-enflamatuar ilaç (NSAID), (eğer Ameliyat öncesi tatbik) veya bir opioid analjezik uygulayın. Anestezi ve tamamen ayaktan tam iyileşme kadar sürekli hayvanların izleyin. </li><li> Hayvanlar ameliyat öncesi VEP kayıt kurtarmak için en az 1 hafta izin verin. </li></ol> 2. Optik Sinir Enjeksiyon <ol><li> , Hayvan anestezisi cildi hazırlar ve (1.1 ve 1.2) yukarıdaki gibi dökümlü uygulayın. </li><li> Rasgele seçilen bir göz yörüngede üzerinde deri bir 1- 1.5 cm kesi olun. İnce iris makas kullanarak yörünge boşluğuna ulaşmak için deri altı doku açın. Konjonktiva açın ve işletim mikroskop altında Tenon kapsülü anterior. </li><li> Ekstraokuler geri çekinkas ve intraobital gözyaşı bezleri optik sinirin yaklaşık 3 mm uzunluk ortaya çıkarmak. Uzunlamasına bir göz bıçak kullanarak optik sinir etrafında dura ve araknoid madde katmanları açın. </li><li> Dünyanın 2 mm&#39;lik posterior mesafeden optik sinir içine cam pipet yerleştirin. cam mikropipet Hamilton şırınga takılır. </li><li> Yaklaşık 30 saniyelik bir süre boyunca sinir yavaşça - (miyelinasyon üzerinde etkiye sahip değildir% 0.02 Evan Mavisi ile, 1.0 ul 0.4),% 1 lisolesitin enjekte edilir. </li><li> Cilt kesisi dikin. Enfeksiyonu önlemek için antibiyotik merhem sürün. Fellow gözler elektrofizyoloji kayıtları için iç kontroller olarak servis edilebilir. </li><li> Anestezi kurtarmak için bir ısınma pad üzerinde hayvanları yerleştirin. </li></ol> 3. VEP Kaydı <ol><li> Hayvan anestezisi ve 1.1 ve 1.2 olarak cildi hazırlar. Not: anestetiklerin daha düşük doz elektrofizyolojik reco için kullanılabilirrding (ketamin 40 mg / kg ve 0.25 mg / kg medetomidin). </li><li> Karanlık bir odada sıçan yerleştirin ve 5 için karanlığa uyum sağlayacak - 30 dakika. Bazı durumlarda fareler sırasıyla Fotopik VEP kayıtları 8 için uyarlanmış scotopic veya ışık karanlık adapte O / N olabilir. </li><li> Rektal termometre probu ile homoeothermic battaniye sistemi tarafından 37 ± 0.5 ° C&#39;de vücut ısısını korumak. </li><li> % 1.0 tropikamid göz damlaları ile öğrencileri dilate. Erişmek için kafatası üzerindeki deriyi açıp önceden yerleştirilmiş in situ vida elektrotlar. </li><li> Uyarılmış gözün kontralateral görme korteksine ve amplifikatör referans vida üzerine vidayı takın. Zemin olarak kuyruk içine bir iğne elektrot yerleştirin. Tedbir ve 5 kohm altında elektrot empedansı korumak. </li><li> Üstün göz izolasyonu 7 sağlamak için göz kapaklarının etrafında cilt üzerinde doğrudan bir mini Ganzfeld uyarıcı yerleştirin. stimülatörü aydınlatma önceden kalibre edilmesi gerekirBir fotometre ile. </li><li> Sırasıyla 1 ve 100 Hz düşük ve yüksek bant-geçiren filtre ayarları ile, 1 Hz frekansta ışığı yanıp aracılığıyla 100 kez fotik uyarımı sunun. Sinyal örnekleme hızı 5 kHz olduğunu. Not: Sinyaller, en az yaklaşık 250 örneklenmelidir - en fazla iki numuneler, her döngü sırasında toplanan sağlamak için 300 Hz. </li><li> Geri cildi dikin ve anestezi kurtarmak için bir ısınma pad üzerinde hayvanları tutmak. Kayıt sürekli bir zaman süresi boyunca, fonksiyonel değişiklikleri izlemek için, ayrı ayrı hayvanlar üzerine kaydedilebilir. </li><li> Son noktada, hayvan euthanize sodyum pentobarbıton (100 mg / kg, ip) aşırı dozda enjeksiyon uygulayın. Kardiyak arrest, solunum durması ve vücut sıcaklığının düşmesi ile ötenazi onaylayın. </li></ol> 4. Doku hazırlanması ve Histoloji <ol><li> Mikroskop altında ötenazi hayvanlardan optik sinirleri çıkarın ve% 1 paraformaldehid O / N doku çözmek. </li> &lt;li&gt; tuz çözeltisi ile iyice doku yıkayın. Otomatik doku işlemci doku davranın ve parafin embed. Bir döner mikrotom kullanılarak - (10 mikron 5) Kesim bölümleri. Not: immünohistokimya çalışması için,% 1 paraformaldehid doku çözmek tuzlu su ile yıkayın ve% 30 sukroz O / N ile kuluçkaya yatmaktadır. Ekim göm doku gömme orta ve Kriyostat kullanarak cryosections yapmak. </li><li> 56 ° C &#39;de bu Luxol (% 95 etanol) O / N olarak% 0.1, hızlı mavi çözelti içinde bölümleri inkübe edin. Daha sonra başka bir 30 saniye için% 70 etanol, 30 saniye için% 0.05 lityum karbonat bölümleri ayırt eder ve. Son olarak, bölümler monte etmeden önce 30 saniye için% 0.1 cresyl mor çözeltisi içinde counterstain. Optik sinir 5 miyelini tanımlamak için hızlı mavi boyama kullanın. </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 nerve. Also, the dura and arachnoid mater should be unwraped longitudinally to avoid any axotomy-like damage to the RGC axons. Evan&#8217;s blue is usually used to facilitate the microinjection, as presence of the dye makes the nerve light blue in colour at the injection site.
The reproducibility of VEP recording is critical for this experiment. Different types of anaesthetics and the depth of anaesthesia can affect the VEP waveforms11. We do not recommend using inhaled isoflurane anaesthesia for the VEP study, as isoflurane can lead to burst suppress on the electroencephalogram response12, probably due to GABAergic activity, resulting in more variable VEP traces13. Combination of ketamine/medetomidine anaesthesia provides stable anaesthesia that can quickly be reversed by administration of an alpha receptor antagonist such as atipamazole (2.5 mg/kg i.p). Body temperature can also have a significant impact on the speed of nerve conduction, especially in demyelinated nerves. Temperature-dependant changes in visual evoked potentials have been observed in rat VEPs and latencies were observed to be significantly longer as body temperature was lowered14,15. Hence, it is important to maintain a uniform body temperature using a homoeothermic blanket system during the VEP recordings.
Also, it is important to understand that the pathogenesis of lysolecithin-induced demyelination differs from that in optic neuritis or multiple sclerosis. Lysolecithin-induced demyelination results from the detergent like action of the toxin upon myelin lipids rather than immune-mediated inflammatory reaction, which is usually seen in the real disease scenarios16. If the study aims to investigate the mechanisms of demyelination/axonal damage in multiple sclerosis, an immune-mediated demyelination model, such as experimental autoimmune encephalomyelitis (EAE)17, should be considered. The advantage of using the toxin-induced demyelination model is that a focal lesion in the optic nerve can be produced and monitored longitudinally. In contrast to the brain lesions, the effects of demyelinated lesions on the optic nerve are more clinically apparent and measureable (lesion size can be accurately determined by VEPs or MRI imaging). Although remyelination in the optic nerve appeared to be not as pronounced as that observed previously in the case of spinal cord18, this optic nerve injection model, in conjunction with the VEP recording technique, is able to provide a superior tool to monitor the process of demyelination and remyelination in vivo, and to potentially evaluate new remyelinating therapies.

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><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&amp;nbsp;</td><td>Grass</td><td>F-EZM5</td><td></td></tr><tr><td>Screw electrodes&amp;nbsp;</td><td>Micro Fasteners</td><td>M1.0&amp;times;3mm Csk Slot M/T 304 S/S</td><td></td></tr><tr><td>Subdermal needle electrodes&amp;nbsp;</td><td>Grass</td><td>F-E3M-72</td><td></td></tr><tr><td>Rapid Repair&amp;nbsp;</td><td>DeguDent GmbH</td><td></td><td></td></tr><tr><td>Light-emitting diode&amp;nbsp;</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&amp;nbsp;</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&amp;rsquo;s blue&amp;nbsp;</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.

Tekrarlanabilir içi oturumlar VEP izleri Şekil 1&#39;de gösterilmiştir ve N1 gecikme önemli bir gecikme optik sinir enjeksiyonundan sonra görülebilir. Demiyelinizasyonun Kısmi optik sinir lezyonları Luxol hızlı mavi boyama 5 ile histolojik kesitlerde görülebilir. 2 optik sinir merkezinde küçük fokal demiyelinize lezyonu olan temsili bir bölümü göstermektedir. Kesit lezyonun toplam hacmi temsil unutmayın. demiyelinize alan üç boyutlu rekonstrüksiyon kullanarak lezyon hacmini anlamak için sinir her ardışık kesitine üzerinde ölçülebilir. Bizim daha önceki çalışmalarda bu model kullanılarak gecikme gecikme ve lezyon hacmi arasında güçlü bir korelasyon göstermiştir ve tuzlu-enjekte kontrollerde 5 hiçbir VEP gecikme gecikme oldu. Bu flaş aydınlatma aşağıdaki erken VEP bileşenleri daha kararlı olduğuna inanılmaktadır 7 </sup&gt; Ve esas retino-Dirsekli lifleri aracılığı ile birincil görsel korteks uyarma etkilenen. Çalışmamız N1 gecikmesi optik sinir 5 demyelinasyonla güçlü doğrusal bir ilişki olduğunu göstermiştir. Bu nedenle, biz N1 gecikme veri analizi için ve remyelinating tedavilerin etkisini değerlendirirken boyuna VEP izlenmesi için kullanılması gerektiğini tavsiye ediyoruz. VEP genliği, gecikme ile karşılaştırıldığında rağmen daha değişken, optik sinir 6 akson fonksiyonunun daha göstergesidir. Elektroensefalogram bazlı ölçekleme amplitüd analiz 9 için kabul edilebilir. <img alt="Figür 1" src="/files/ftp_upload/52934/52934fig1.jpg" /> Optik sinir enjeksiyonundan sonra Şekil 1. VEP gecikmesi. Temsilci VEP bireysel önce sıçan ve optik sinir mikroenjeksiyon (0.8 ul lisolesitin) 2 gün sonra gelen izler. VEP kayıtları her gün tekrarlandı (intra-sessional izleri göstermek vardırn aynı renkte) Bu VEP kayıt protokolünün tekrarlanabilirliği göstermek için. (Dikey ölçek çubuğu: 10 mV; yatay ölçek çubuğu: 10 milisaniye). <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52934/52934fig1large.jpg" target="_blank">Bu rakamın büyük halini görmek için lütfen buraya tıklayınız.</a> <img alt="Şekil 2" src="/files/ftp_upload/52934/52934fig2.jpg" /> Optik sinirdeki Şekil 2. demeyelinizasyon. Mikroenjeksiyon lisolesitin sonra sıçandan, optik sinirin Örnek kesiti. miyelin bileşeni luxol hızlı mavi ile mavi lekeli. Demiyelinasyon küçük bir fokal lezyonun kesitinin merkezinde görülebilir. Demiyelinize alan üç boyutlu bir ölçekte lezyon hacmini tahmin etmek uzunlamasına seri kesitler üzerinde ölçülebilir. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52934/52934fig2large.jpg" target="_blank">Bu rakamın büyük halini görmek için lütfen buraya tıklayınız.</a>

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.

Deneysel Optik Sinir demyelinizasyon bir Rat Modelinde Görsel Uyarılmış Potansiyel Kayıt

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

Universidad San Sebastian

Research

JoVE Journal

Neuroscience

12.2K Görüntüleme.  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. 

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

Single-unit In vivo Recordings from the Optic Chiasm of Rat

Information about the visual world is transmitted to the brain in sequences of action potentials in retinal ganglion cell axons that make up the optic nerve. In vivo recordings of ganglion cell spike trains in several animal models have revealed much of what is known about how the early visual system processes and encodes visual information. However, such recordings have been rare in one of the most common animal models, the rat, possibly owing to difficulty in detecting spikes fired by small diameter axons. The many retinal disease models involving rats motivate a need for characterizing the functional properties of ganglion cells without disturbing the eye, as with intraocular or in vitro recordings. Here, we demonstrate a method for recording ganglion cell spike trains from the optic chiasm of the anesthetized rat. We first show how to fabricate tungsten-in-glass electrodes that can pick up electrical activity from single ganglion cell axons in rat. The electrodes outperform all commercial ones that we have tried. We then illustrate our custom-designed stereotaxic system for in vivo visual neurophysiology experiments and our procedures for animal preparation and reliable and stable electrode placement in the optic chiasm.

Single-unit In vivo Recordings from the Optic Chiasm of Rat

Retinal ganglion cells transmit visual information from the eye to the brain with sequences of action potentials. Here, we demonstrate how to record the action potentials of single ganglion cells in vivo from anesthetized rats.

Tek birim In vivo</emSıçan, optik kiazma> Kayıtlar

Information about the visual world is transmitted to the brain in sequences of action potentials in retinal ganglion cell axons that make up the optic ...

Nörobilim

Implantation and Recording of Wireless Electroretinogram and Visual Evoked Potential in Conscious Rats

The full-field electroretinogram (ERG) and visual evoked potential (VEP) are useful tools to assess retinal and visual pathway integrity in both laboratory and clinical settings. Currently, preclinical ERG and VEP measurements are performed with anesthesia to ensure stable electrode placements. However, the very presence of anesthesia has been shown to contaminate normal physiological responses. To overcome these anesthesia confounds, we develop a novel platform to assay ERG and VEP in conscious rats. Electrodes are surgically implanted sub-conjunctivally on the eye to assay the ERG and epidurally over the visual cortex to measure the VEP. A range of amplitude and sensitivity/timing parameters are assayed for both the ERG and VEP at increasing luminous energies. The ERG and VEP signals are shown to be stable and repeatable for at least 4 weeks post surgical implantation. This ability to record ERG and VEP signals without anesthesia confounds in the preclinical setting should provide superior translation to clinical data.

We show surgical implantation and Recording procedures to measure visual electrophysiological signals from the eye (electroretinogram) and brain (visual evoked potential) in conscious rats, which is more analogous to the human condition where recordings are conducted without anesthesia confounds.

Bilinçli Sıçanlarda implantasyon ve Kablosuz Elektroretinogram Recording ve Görsel Uyarılmış Potansiyel

The full-field electroretinogram (ERG) and visual evoked potential (VEP) are useful tools to assess retinal and visual pathway integrity in both ...

Davranış

Rat Model of Photochemically-Induced Posterior Ischemic Optic Neuropathy

Posterior Ischemic optic neuropathy (PION) is a sight-devastating disease in clinical practice. However, its pathogenesis and natural history have&#160;remained poorly understood. Recently, we developed a reliable, reproducible animal model of PION and tested the treatment effect of some neurotrophic factors in this model1. The purpose of this video is to demonstrate our photochemically induced model of posterior ischemic optic neuropathy, and to evaluate its effects with retrograde labeling of retinal ganglion cells. Following surgical exposure of the posterior optic nerve, a photosensitizing dye, erythrosin B, is intravenously injected and a laser beam is focused onto the optic nerve surface. Photochemical interaction of erythrosin B and the laser during irradiation damages the vascular endothelium, prompting microvascular occlusion mediated by platelet thrombosis and edematous compression. The resulting ischemic injury yields a gradual but pronounced retinal ganglion cell dieback, owing to a loss of axonal input - a remote, injury-induced and clinically relevant outcome. Thus, this model provides a novel platform to study the pathophysiologic course of PION,&#160;and can be further optimized for testing therapeutic approaches for optic neuropathies as well as other CNS ischemic diseases.

The goal of this protocol is to photochemically induce ischemic injury to the posterior optic nerve in rat. This model is critical to studies of the pathophysiology of posterior ischemic optic neuropathy, and therapeutic approaches for this and other optic neuropathies, as well as of other CNS ischemic diseases.

Fotokimyasal Bağlı Posterior İskemik Optik Nöropati Rat Modeli

Posterior Ischemic optic neuropathy (PION) is a sight-devastating disease in clinical practice. However, its pathogenesis and natural history ...

Tıp

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.

Elektroretinografi Eşzamanlı Kayıt ve Anestezi Sıçanlar Görsel Uyarılmış Potansiyeller

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

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.

Görsel uyarılmış potansiyel kayıtları bir kuru Non-invaziv çok kanallı kullanarak farelerde EEG sensör kafa derisi

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 ...

In Vivo Methods to Assess Retinal Ganglion Cell and Optic Nerve Function and Structure in Large Animals

The optic nerve collects axons signals from the retinal ganglion cells and transmits visual signal to the brain. Large animal models of optic nerve injury are essential for translating novel therapeutic strategies from rodent models to clinical application due to their closer similarities to humans in size and anatomy. Here we describe some in vivo methods to evaluate the function and structure of the retinal ganglion cells (RGCs) and optic nerve (ON) in large animals, including visual evoked potential (VEP), pattern electroretinogram (PERG) and optical coherence tomography (OCT). Both goat and non-human primate were employed in this study. By presenting these in vivo methods step by step, we hope to increase experimental reproducibility among different labs and facilitate the usage of large animal models of optic neuropathies.

In Vivo Methods to Assess Retinal Ganglion Cell and Optic Nerve Function and Structure in Large Animals

Here we demostrate several in vivo tests (flash visual evoked potential, pattern electroretinogram and optic coherence tomography) in goat and rhesus macaque to understand the structure and function of the optic nerve and its neurons.

In Vivo Büyük Hayvanlarda Retina Ganglion Hücre ve Optik Sinir Fonksiyonu ve Yapısını Değerlendirme Yöntemleri

The optic nerve collects axons signals from the retinal ganglion cells and transmits visual signal to the brain. Large animal models of optic nerve injury ...

Topographical EEG Recordings of Visual Evoked Potentials in Mice using Multichannel Thin-film Electrodes

Visual evoked potentials (VEP) allow the characterization of visual function in preclinical mouse models. Various methods exist to measure VEPs in mice, from non-invasive EEG, subcutaneous single-electrodes, and ECoG to fully invasive intracortical multichannel visual cortex recordings. It can be useful to acquire a global, topographical EEG-level characterization of visual responses previous to local intracortical microelectrode measurements in acute experimental settings. For example, one use case is&#160;to assess global cross-modal changes in VEP topography in deafness models before studying its effects on a local intracortical level. Multichannel epicranial EEG is a robust method to acquire such an overview measure of cortical visual activity.&#160;Multichannel epicranial EEG provides comparable results through a standardized, consistent approach to, for example, identify cross-modal, pathological, or age-related changes in cortical visual function. The current study presents a method to obtain the topographical distribution of flash-evoked VEPs with a 32-channel thin-film EEG electrode array in anesthetized mice. Combined with analysis in the time and frequency domain, this approach allows fast characterization and screening of the topography and basic visual properties of mouse cortical visual function, which can be combined with various acute experimental settings.

<meta charset="utf8"></head><body>Çok Kanallı İnce Film Elektrotlar Kullanılarak Farelerde Görsel Uyarılmış Potansiyellerin Topografik EEG Kayıtları

The present protocol describes a simple procedure to acquire and analyze the topography of epicranial visual evoked potentials with 32-multichannel thin-film electrodes in the mouse.

Çok Kanallı İnce Film Elektrotlar Kullanılarak Farelerde Görsel Uyarılmış Potansiyellerin Topografik EEG Kayıtları

Visual evoked potentials (VEP) allow the characterization of visual function in preclinical mouse models. Various methods exist to measure VEPs in mice, ...

Inducing Local Demyelination in the Optic Nerve Using Lysolecithin

Source: You, Y. et al., <a href="https://app-jove-com.bdigitaluss.remotexs.co/v/52934">Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination.</a> J. Vis. Exp. (2015)
This video demonstrates the procedure of surgically accessing the optic nerve in an anesthetized animal and precisely delivering lysolecithin to induce focal demyelination, creating neuropathological conditions for further study.

Lisolesitin kullanılarak optik sinirde lokal demiyelinizasyonun indüklenmesi

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

JoVE Encyclopedia of Experiments

Neuropathology

Epilepsy and Seizure Disorders

Preparing a Rat Model to Assess Visual Pathway Integrity Using an Electrophysiology Setup

Source: Nguyen, C. T. et al., <a href="https://app-jove-com.bdigitaluss.remotexs.co/v/54158">Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats.</a>&#160;J. Vis. Exp. (2016)
This video demonstrates the preparation of a rat model to study retinal health and visual pathway integrity. Visual evoked potential and electroretinography reference and active electrodes are connected to the rat, followed by aligning the platform with the rat in front of the Ganzfeld bowl for even retinal illumination and closing the Faraday cage to avoid external interference.

Bir Elektrofizyoloji Kurulumu Kullanarak Görsel Yol Bütünlüğünü Değerlendirmek için Bir Sıçan Modeli Hazırlama

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

Deneysel Optik Sinir demyelinizasyon bir Rat Modelinde Görsel Uyarılmış Potansiyel Kayıt

Özet

Daha Fazla Video Keşfet

Bu videodaki bölümler

Tek birim In vivo Kayıtlar

Bilinçli Sıçanlarda implantasyon ve Kablosuz Elektroretinogram Recording ve Görsel Uyarılmış Potansiyel

Fotokimyasal Bağlı Posterior İskemik Optik Nöropati Rat Modeli

Elektroretinografi Eşzamanlı Kayıt ve Anestezi Sıçanlar Görsel Uyarılmış Potansiyeller

Görsel uyarılmış potansiyel kayıtları bir kuru Non-invaziv çok kanallı kullanarak farelerde EEG sensör kafa derisi

In Vivo Büyük Hayvanlarda Retina Ganglion Hücre ve Optik Sinir Fonksiyonu ve Yapısını Değerlendirme Yöntemleri

Çok Kanallı İnce Film Elektrotlar Kullanılarak Farelerde Görsel Uyarılmış Potansiyellerin Topografik EEG Kayıtları

Çok Kanallı İnce Film Elektrotlar Kullanılarak Farelerde Görsel Uyarılmış Potansiyellerin Topografik EEG Kayıtları

Lisolesitin kullanılarak optik sinirde lokal demiyelinizasyonun indüklenmesi

Bir Elektrofizyoloji Kurulumu Kullanarak Görsel Yol Bütünlüğünü Değerlendirmek için Bir Sıçan Modeli Hazırlama