Funding for this project was provided by the National Health and Medical Research Council (NHMRC) 1046203 (BVB, AJV) and Melbourne Neuroscience Institute Fellowship (CTN).

<ol>
	<li>Nguyen, C. T. O., Vingrys, A. J., Bui, B. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dietary+omega-3+fatty+acids+and+ganglion+cell+function.">Dietary omega-3 fatty acids and ganglion cell function.</a> Invest Ophthalmol Vis Sci. 49, 3586-3594 (2008).</li><li>Weymouth, A. E., Vingrys, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+electroretinography:+methods+for+extraction+and+interpretation+of+rod+and+cone+responses.">Rodent electroretinography: methods for extraction and interpretation of rod and cone responses.</a> Prog Retin Eye Res. 27, 1-44 (2008).</li><li>Tsai, T. I., Bui, B. V., Vingrys, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+acute+intraocular+pressure+challenge+on+rat+retinal+and+cortical+function.">Effect of acute intraocular pressure challenge on rat retinal and cortical function.</a> Invest Ophthalmol Vis Sci. 55, 1067-1077 (2014).</li><li>Cowey, A., Franzini, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+retinal+origin+of+uncrossed+optic+nerve+fibres+in+rats+and+their+role+in+visual+discrimination.">The retinal origin of uncrossed optic nerve fibres in rats and their role in visual discrimination.</a> Exp Brain Res. 35, 443-455 (1979).</li><li>Weinstein, G. W., Odom, J. V., Cavender, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visually+evoked+potentials+and+electroretinography+in+neurologic+evaluation.">Visually evoked potentials and electroretinography in neurologic evaluation.</a> Neurol Clin. 9, 225-242 (1991).</li><li>Odom, J. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual+evoked+potentials+standard+(2004).">Visual evoked potentials standard (2004).</a> Doc Ophthalmol. 108, 115-123 (2004).</li><li>Ridder, W. H., Nusinowitz, S., Heckenlively, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Causes+of+cataract+development+in+anesthetized+mice.">Causes of cataract development in anesthetized mice.</a> Exp Eye Res. 75, 365-370 (2002).</li><li>Nixon, P. J., Bui, B. V., Armitage, J. A., Vingrys, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+contribution+of+cone+responses+to+rat+electroretinograms.">The contribution of cone responses to rat electroretinograms.</a> Clin Experiment Ophthalmol. 29, 193-196 (2001).</li><li>Bui, B. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+the+electroretinogram+to+understand+how+intraocular+pressure+elevation+affects+the+rat+retina.">Using the electroretinogram to understand how intraocular pressure elevation affects the rat retina.</a> J Ophthalmol. 2013, 262467 (2013).</li><li>Nguyen, C. T., Vingrys, A. J., Bui, B. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dietary+omega-3+fatty+acids+and+ganglion+cell+function.">Dietary omega-3 fatty acids and ganglion cell function.</a> Invest Ophthalmol Vis Sci. 49, 3586-3594 (2008).</li><li>Hood, D. C., Birch, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+quantitative+measure+of+the+electrical+activity+of+human+rod+photoreceptors+using+electroretinography.">A quantitative measure of the electrical activity of human rod photoreceptors using electroretinography.</a> Vis Neurosci. 5, 379-387 (1990).</li><li>Birch, D. G., Hood, D. C., Locke, K. G., Hoffman, D. R., Tzekov, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+electroretinogram+measures+of+phototransduction+in+cone+and+rod+photoreceptors+-+Normal+aging,+progression+with+disease,+and+test-retest+variability.">Quantitative electroretinogram measures of phototransduction in cone and rod photoreceptors - Normal aging, progression with disease, and test-retest variability.</a> Arch Ophthalmol. 120, 1045-1051 (2002).</li><li>Bui, B. V., Vingrys, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+receptoral+responses+in+pigmented+and+albino+guinea-pigs+(Cavia+porcellus).">Development of receptoral responses in pigmented and albino guinea-pigs (Cavia porcellus).</a> Doc Ophthalmol. 99, 151-170 (1999).</li><li>Robson, J. G., Saszik, S. M., Ahmed, J., Frishman, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rod+and+cone+contributions+to+the+a-wave+of+the+electroretinogram+of+the+macaque.">Rod and cone contributions to the a-wave of the electroretinogram of the macaque.</a> J Physiol. 547, 509-530 (2003).</li><li>Severns, M. L., Johnson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+care+and+fitting+of+Naka-Rushton+functions+to+electroretinographic+intensity-response+data.">The care and fitting of Naka-Rushton functions to electroretinographic intensity-response data.</a> Doc Ophthalmol. 85, 135-150 (1993).</li><li>Bui, B. V., Fortune, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Origin+of+electroretinogram+amplitude+growth+during+light+adaptation+in+pigmented+rats.">Origin of electroretinogram amplitude growth during light adaptation in pigmented rats.</a> Vis Neurosci. 23, 155-167 (2006).</li><li>Bui, B. V., Fortune, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ganglion+cell+contributions+to+the+rat+full-field+electroretinogram.">Ganglion cell contributions to the rat full-field electroretinogram.</a> J Physiol. 555, 153-173 (2004).</li><li>Tremblay, F., Laroche, R. G., Debecker, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Electroretinographic+Diagnosis+of+the+Incomplete+Form+of+Congenital+Stationary+Night+Blindness.">The Electroretinographic Diagnosis of the Incomplete Form of Congenital Stationary Night Blindness.</a> Vision Res. 35, 2383-2393 (1995).</li><li>Bayer, A. U., Keller, O. N., Ferrari, F., Maag, K. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+of+glaucoma+with+neurodegenerative+diseases+with+apoptotic+cell+death:+Alzheimer's+disease+and+Parkinson's+disease.">Association of glaucoma with neurodegenerative diseases with apoptotic cell death: Alzheimer's disease and Parkinson's disease.</a> Am J Ophthalmol. 133, 135-137 (2002).</li><li>Wostyn, P., Audenaert, K., De Deyn, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+abnormal+high+trans-lamina+cribrosa+pressure+difference:+A+missing+link+between+Alzheimer's+disease+and+glaucoma.">An abnormal high trans-lamina cribrosa pressure difference: A missing link between Alzheimer's disease and glaucoma.</a> Clinical Neurology and Neurosurgery. 110, 753-754 (2008).</li><li>Yucel, Y. H., Zhang, Q. A., Weinreb, R. N., Kaufman, P. L., Gupta, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+retinal+ganglion+cell+loss+on+magno-,+parvo-,+koniocellular+pathways+in+the+lateral+geniculate+nucleus+and+visual+cortex+in+glaucoma.">Effects of retinal ganglion cell loss on magno-, parvo-, koniocellular pathways in the lateral geniculate nucleus and visual cortex in glaucoma.</a> Prog Retin Eye Res. 22, 465-481 (2003).</li><li>Gupta, N., Yucel, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+changes+can+we+expect+in+the+brain+of+glaucoma+patients.">What changes can we expect in the brain of glaucoma patients.</a> Survey of Ophthalmology. 52, 122-126 (2007).</li><li>Kong, Y. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+aging+and+diet+restriction+on+retinal+function+during+and+after+acute+intraocular+pressure+injury.">Impact of aging and diet restriction on retinal function during and after acute intraocular pressure injury.</a> Neurobiol Aging. 33, 1115-1125 (2012).</li><li>Bui, B. V., Sinclair, A. J., Vingrys, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroretinograms+of+albino+and+pigmented+guinea-pigs+(Cavia+porcellus).">Electroretinograms of albino and pigmented guinea-pigs (Cavia porcellus).</a> Aust N Z J Ophthalmol. 26, 98-100 (1998).</li><li>Jobling, A. I., Wan, R., Gentle, A., Bui, B. V., McBrien, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+and+choroidal+TGF-beta+in+the+tree+shrew+model+of+myopia:+isoform+expression,+activation+and+effects+on+function.">Retinal and choroidal TGF-beta in the tree shrew model of myopia: isoform expression, activation and effects on function.</a> Exp Eye Res. 88, 458-466 (2009).</li><li>Robson, J. G., Frishman, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissecting+the+dark-adapted+electroretinogram.">Dissecting the dark-adapted electroretinogram.</a> Doc Ophthalmol. 95, 187-215 (1998).</li><li>Robson, J. G., Frishman, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+rod-driven+a-wave+of+the+dark-adapted+mammalian+electroretinogram.">The rod-driven a-wave of the dark-adapted mammalian electroretinogram.</a> Prog Retin Eye Res. 39, 1-22 (2014).</li><li>Hudnell, H. K., Boyes, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+comparability+of+rat+and+human+visual-evoked+potentials.">The comparability of rat and human visual-evoked potentials.</a> Neurosci Biobehav Rev. 15, 159-164 (1991).</li><li>Charng, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conscious+wireless+electroretinogram+and+visual+evoked+potentials+in+rats.">Conscious wireless electroretinogram and visual evoked potentials in rats.</a> PLoS One. 8, e74172 (2013).</li><li>Hetzler, B. E., Berger, L. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ketamine-Induced+Modification+of+Photic+Evoked-Potentials+in+the+Superior+Colliculus+of+Hooded+Rats.">Ketamine-Induced Modification of Photic Evoked-Potentials in the Superior Colliculus of Hooded Rats.</a> Neuropharmacology. 23, 473-476 (1984).</li></ol>

The authors have no disclosures relevant to this work.

O ERG e VEP são medidas objetivas da função visual da retina eo córtex, respectivamente. A vantagem de gravação simultânea é que uma visão mais abrangente de toda a via visual é oferecida. Especificamente, as informações complementares na sua avaliação simultânea poderia fornecer uma definição mais clara do local da lesão na via visual (por exemplo, para distúrbios com sobreposição ERG ainda distinta VEP manifestações 18, quando neuropatia óptica pode co-existir com atrofia cerebral primário 19, 20, ou quando a perda de VEP podem ser confundidos pela manifestação de lesões em vários locais na via visual 21,22). Através da medição do ERG e VEP simultaneamente, um índice do ganho entre a resposta da retina e cortical também pode ser derivada. Isto pode fornecer uma ferramenta útil para detectar alterações patológicas sutis. O protocolo atual permite a medição ERG e VEP em ratos de laboratório comumente usados, mas podem facilmente ser adApted a outras espécies de mamíferos 23-25. ERG e VEP formas de onda a partir de roedores fornecem um substituto razoável pré-clínico para respostas observadas em olhos humanos 26-28. Ao projetar um protocolo de estímulo específico, tanto resposta ERG e VEP pode ser obtida durante uma única sessão de gravação. A Tabela 1 mostra uma progressão nos níveis de luz com a devida consideração do tempo de recuperação entre flashes consecutivos. Este protocolo proporciona um equilíbrio entre a necessidade de maximizar as características sinal-ruído e limitar o tempo de gravação dentro da janela de anestésico é fornecida por uma única dose de cetamina: xilazina. Portanto, esta técnica pode ser útil para uma medida quantitativa objectivo da função visual para pesquisa em fisiologia de base e a doença. Uma avaliação abrangente do sistema visual pode ser alcançado através da avaliação simultaneamente respostas da retina bilaterais e respostas corticais visuais evocados. No entanto, cada técnica também pode ser realizada de forma isolada e monocular em vez de binocularmente para simplificar o procedimento. O protocolo atual descreve sinais escotópicas ERG e VEP escolhidos para isolar a haste da via, dado que os ratos têm uma retina dominada-rod. Se as respostas de luz adaptado são de maior interesse para o estudo, também é possível conduzir sinais ERG e VEP fotópicas por pré-adaptação a um fundo claro. Uma grande limitação desta técnica é a necessidade de realizar o procedimento em condições anestesiados para permitir a colocação do eletrodo estável. No entanto, esta abordagem fornece características robustas de sinal-para-ruído, permitindo a detecção de alterações de tratamento sutis. Devido à pequena amplitude do STR e sua sensibilidade à adaptação à luz, várias etapas devem ser cuidadosamente observados para garantir uma gravação de sucesso desta resposta. Em primeiro lugar, a adaptação ao escuro suficiente precisa ser implementado, que incluiovernight adaptação ao escuro (≥ 8 horas), a colocação do eletrodo sob iluminação vermelha fraca (17,4 cd.m -2, λ max = 600 nm), e adaptação re-escuro após um teste-flash dim (10 min para - 0,52 log cd. SM -2). Além disso, as características de sinal-para-ruído da STR pode ser melhorada pela média ao longo de vários sinais (ou seja, 20 sinais) recolhidas com intervalos curtos inter-estímulos (isto é, 2 seg). Uma das vantagens desta avaliação abrangente de ambos os olhos e córtices é permitir comparação com a gravação contralateral 3. Como tal cuidado, especial deve ser tomado na tomada de eletrodo (ou seja, os mesmos eletrodos de tamanho e em forma), para garantir o mínimo inter-olho e variabilidade inter-cortical. Dada a extensa utilização de ambas as técnicas de ERG e VEP para fornecer em medidas in vivo da via visual e os seus processos relacionados com a doença, seria útil para recolher outra via específica p-rotocols (por exemplo, ON / OFF ou cone sub-tipo específico), e realizar gravações ERG / VEP simultâneas com diferentes modalidades de estímulo (por exemplo, cintilação, teste padrão, dente de serra) para estender a aplicação desta técnica em diagnósticos clínicos. Outra etapa lógica desta aplicação no futuro também seria para gravar o ERG e VEP simultaneamente de consciência 29, os animais livremente em movimento para evitar influências anestésicos sobre a fisiologia neural 30.

Medição do eletrorretinograma (ERG) e visual potencial evocado (VEP) fornecem avaliações quantitativas úteis da integridade da via visual. O ERG mede as respostas eléctricas do retina para a estimulação pela luz, enquanto o VEP mede a integridade funcional correspondente das vias visuais da retina para o córtex visual primário seguindo o mesmo evento de luz. Este manuscrito descreve um protocolo para a gravação e análise das respostas do ERG e VEP em um modelo de laboratório comumente usado, o rato. O ERG fornece um índice da integridade funcional de um número de classes principais de células da retina quantificando resposta elétrica bruta da retina para um flash de luz. Uma série coordenada de fluxos iônicos iniciado pelo aparecimento de luz e compensar, produzir mudanças detectáveis ​​na tensão que pode ser medido por meio de eletrodos de superfície colocados fora do olho. A forma de onda resultante representa a combinação de um SEries de componentes bem definidas, diferindo na amplitude, tempo e frequência. Um corpo substancial de investigação tem demonstrado que estes componentes são relativamente bem conservada entre muitos retina de vertebrados e que os componentes podem ser separados uns dos outros. Ao seleccionar criteriosamente as condições de estímulo (stimulus flash, fundo, intervalo interstimulus) e escolher características específicas da forma de onda composta para analisar se pode ter a certeza de voltar uma medida de um grupo específico de células da retina 1,2. Estas características são a base da utilidade e, portanto, as aplicações difundidas do ERG como uma medida não-invasiva da função retina. Este manuscrito incide sobre a metodologia para a medição do ERG e analisar suas características para retornar informações sobre alguns dos principais classes de células na retina, nomeadamente fotorreceptores (o componente PIII), células bipolares (o componente PII) e células ganglionares da retina (o positivo limiar de resposta escotópica ou pstr). <p class= &quot;Jove_content&quot;&gt; O VEP proporciona um ensaio da resposta cortical à luz; primeiro proveniente da retina e posteriormente comunicadas em série através do nervo óptico, trato óptico, tálamo (núcleo geniculado lateral, LGN) e radiação óptica para a área do córtex V1 3. Em roedores, a maioria (90-95%) de fibras do nervo óptico de cada olho decussate 4 e inervam o cérebro médio contralateral. Ao contrário do ERG, é como ainda não é possível atribuir diferentes componentes da VEP às classes de células específicas, 5 muda, assim, em qualquer lugar ao longo da via visual pode afetar a forma de onda VEP. No entanto, o VEP é uma medida não-invasivo útil do desempenho visual e integridade da via visual. A VEP, quando usado em conjunto com o ERG, pode proporcionar uma avaliação mais completa do sistema visual (ou seja, a retina / via visual). registos de ERG e VEP pode ser realizada de forma isolada ou em combinação, dependendo da aplicação. A metodologia descrita neste artigo permite a avaliação simultânea de eletrofisiologia visual evocado retina e cortical de ambos os olhos e ambos os hemisférios em ratos anestesiados. Esta é uma maneira útil para avaliar de forma mais abrangente a função da retina e os efeitos a montante que as mudanças na função da retina pode ter em função cortical evocado visual.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Alligator clip</td>
			<td>generic brand</td>
			<td>HM3022</td>
			<td>Stainless steel 26 mm clip for connecting VEP screw electrodes to cables</td>
		</tr>
		<tr>
			<td>Bioamplifier</td>
			<td>ADInstruments</td>
			<td>ML 135</td>
			<td>For amplifying ERG and VEP signals</td>
		</tr>
		<tr>
			<td>Carboxymethylcellulose sodium 1.0%</td>
			<td>Allergan</td>
			<td>CAS 0009000-11-7</td>
			<td>Viscous fluid for improving signal quality of the active ERG electrode</td>
		</tr>
		<tr>
			<td>Carprofen 0.5%</td>
			<td>Pfizer Animal Health Group</td>
			<td>CAS 53716-49-7</td>
			<td>Proprietary name: Rimadyl injectable (50 mg/mL). For post-surgery analgesia, diluted to 0.5% (5 mg/mL) in normal saline</td>
		</tr>
		<tr>
			<td>Chlorhexadine 0.5%</td>
			<td>Orion Laboratories</td>
			<td>27411, 80085</td>
			<td>For disinfecting surgical instruments</td>
		</tr>
		<tr>
			<td>Circulating water bath</td>
			<td>Lauda-K&#246;nigshoffen</td>
			<td>MGW Lauda</td>
			<td>For maintaining body temperature of the anesthetized animal during surgery and electrophysiological recordings</td>
		</tr>
		<tr>
			<td>Dental amalgam</td>
			<td>DeguDent GmbH</td>
			<td>64020024</td>
			<td>For encasing the electrode-skull assembly to make it more robust</td>
		</tr>
		<tr>
			<td>Dental burr</td>
			<td>Storz Instruments, Bausch and Lomb</td>
			<td>#E0824A</td>
			<td>A miniature drill head of ~0.7mm diameter for making a small hole in the skull over each hemisphere to implant VEP screws</td>
		</tr>
		<tr>
			<td>Drill</td>
			<td>Bosch</td>
			<td>Dremel 300 series</td>
			<td>An automatic drill for trepanning</td>
		</tr>
		<tr>
			<td>Electrode lead</td>
			<td>Grass Telefactor&#160;</td>
			<td>F-E2-30</td>
			<td>Platinum cables for connecting silver wire electrodes to the amplifier</td>
		</tr>
		<tr>
			<td>Faraday Cage</td>
			<td>custom-made</td>
			<td></td>
			<td>Ensures light proof to maintain dark adaptation. Encloses the Ganzfeld setup to improve signal to noise ratio</td>
		</tr>
		<tr>
			<td>Gauze swabs</td>
			<td>Multigate Medical Products Pty Ltd</td>
			<td>57-100B</td>
			<td>For drying the surgical incision and exposed skull surface during surgery</td>
		</tr>
		<tr>
			<td>Ganzfeld integrating sphere</td>
			<td>Photometric Solutions International</td>
			<td></td>
			<td>Custom designed light stimulator: 36 mm diameter, 13 cm aperture size</td>
		</tr>
		<tr>
			<td>Velcro</td>
			<td>VELCRO Australia Pty Ltd</td>
			<td>VELCRO Brand Reusable Wrap</td>
			<td>Hook-and-loop fastener to secure the electrodes and the animal on the recording platform</td>
		</tr>
		<tr>
			<td>Isoflurane 99.9%</td>
			<td>Abbott Australasia Pty Ltd</td>
			<td>CAS 26675-46-7</td>
			<td>Proprietary Name: Isoflo(TM) Inhalation anaaesthetic. Pharmaceutical-grade inhalation anesthetic mixed with oxygen gas for VEP electrode implant surgery</td>
		</tr>
		<tr>
			<td>Ketamine&#160;</td>
			<td>Troy Laboratories</td>
			<td>Ilium Ketamil</td>
			<td>Proprietary name: Ketamil Injection, Brand: Ilium. Pharmaceutical-grade anesthetic for electrophysiological recording</td>
		</tr>
		<tr>
			<td>Luxeon LEDs</td>
			<td>Phillips Lighting Co.</td>
			<td></td>
			<td>For light stimulation twenty 5 watt and one 1 watt LEDs.</td>
		</tr>
		<tr>
			<td>Micromanipulator</td>
			<td>Harvard Apparatus</td>
			<td>BS4 50-2625</td>
			<td>Holds the ERG active electrode during recordings</td>
		</tr>
		<tr>
			<td>Needle electrode</td>
			<td>Grass Telefactor&#160;</td>
			<td>F-E2-30</td>
			<td>Subcutaneously inserted in the tail to serve as the ground electrode for both the ERG and VEP</td>
		</tr>
		<tr>
			<td>Phenylephrine 2.5% minims&#160;</td>
			<td>Bausch and Lomb</td>
			<td>CAS 61-76-7</td>
			<td>Instilled with Tropicamide to achieve maximal dilation for ERG recording</td>
		</tr>
		<tr>
			<td>Povidone iodine 10%</td>
			<td>Sanofi-Aventis</td>
			<td>CAS 25655-41-8</td>
			<td>Proprietory name: Betadine, Antiseptic to prepare the shaved skin for surgery 10%, 500 mL</td>
		</tr>
		<tr>
			<td>Powerlab data acquisition system</td>
			<td>ADInstruments</td>
			<td>ML 785</td>
			<td>Controls the LEDs</td>
		</tr>
		<tr>
			<td>Proxymetacaine 0.5%</td>
			<td>Alcon Laboratories&#160;</td>
			<td>CAS 5875-06-9</td>
			<td>For corneal anaesthesia during ERG recordings</td>
		</tr>
		<tr>
			<td>Saline solution</td>
			<td>Gelflex</td>
			<td></td>
			<td>Non-injectable, for electroplating silver wire electrodes</td>
		</tr>
		<tr>
			<td>Scope Software</td>
			<td>ADInstruments</td>
			<td>version 3.7.6</td>
			<td>Simultaneously triggers the stimulus via the Powerlab system and collects data</td>
		</tr>
		<tr>
			<td>Silver (fine round wire)</td>
			<td>A&#38;E metal</td>
			<td>0.3 mm</td>
			<td>Used to make active and inactive ERG electrodes, and the inactive VEP electrode</td>
		</tr>
		<tr>
			<td>Stainless streel screws&#160;</td>
			<td>MicroFasterners</td>
			<td></td>
			<td>0.7 mm shaft diameter, 3 mm in length to be implanted over the primary visual cortex and serve as the active VEP electrodes</td>
		</tr>
		<tr>
			<td>Stereotaxic frame</td>
			<td>David Kopf</td>
			<td>Model 900</td>
			<td>A small animal stereotaxic instrument for locating the primary visual cortices according to Paxinos &#38; Watson&#39;s 2007 rat brain atlas coordinates</td>
		</tr>
		<tr>
			<td>Surgical blade</td>
			<td>Swann-Morton Ltd.</td>
			<td>0206</td>
			<td>For incising the area of skin overlaying the primary visual cortex to implant the VEP electrodes</td>
		</tr>
		<tr>
			<td>Suture</td>
			<td>Shanghai Pudong Jinhuan Medical Products Co.,Ltd</td>
			<td></td>
			<td>3-0 silk braided suture non-absorbable, for skin retraction during VEP electrode implantation surgery</td>
		</tr>
		<tr>
			<td>Tobramycine eye ointment 0.3%</td>
			<td>Alcon Laboratories&#160;</td>
			<td>CAS 32986-56-4</td>
			<td>Proprietary name: Tobrex. Prophylactic antibiotic ointment applied around the skin wound after surgery</td>
		</tr>
		<tr>
			<td>Tropicamide 0.5%</td>
			<td>Alcon Laboratories&#160;</td>
			<td>CAS 1508-75-4</td>
			<td>Proprietary name: 0.5% Mydriacyl eye drop, Instilled to achieve mydriasis for ERG recording</td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Troy Laboratories</td>
			<td>Ilium Xylazil-100</td>
			<td>Pharmaceutical-grade anesthetic for electrophysiological recording</td>
		</tr>
		<tr>
			<td>Pipette tip&#160;</td>
			<td>Eppendorf Pty Ltd</td>
			<td>0030 073.169</td>
			<td>Eppendorf epTIPS 100 - 5000 mL, for custom-made electrodes</td>
		</tr>
		<tr>
			<td>Microsoft Office Excel</td>
			<td>Microsoft</td>
			<td>version 2010</td>
			<td>spreadsheet software for data analysis</td>
		</tr>
		<tr>
			<td>Lethabarb Euthanazia Injection</td>
			<td>Virbac (Australia) Pty Ltd</td>
			<td>LETHA450</td>
			<td>325 mg/mL pentobarbital sodium for rapid euthanazia</td>
		</tr>
	</tbody>
</table>

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.

O ERG uma onda (&gt; -1,38 log cd.sm -2), b-ondas (&gt; - 4,99 log cd.sm -2) STRs (&lt;- 4,99 log cd.sm -2) e os PEVs (&gt; - 0,52 cd.sm log -2) foram gravadas simultaneamente (Figura 1 e 3). No flashes muito fraca, a STR positivo (pstr) é visto em cerca de 110 milissegundos após o flash, e uma STR negativo (NSTR) a cerca de 220 ​​ms (Figuras 1 e 2). Um ERG com um grande da onda b, picos entre 50 a 100 ms após o início de um flash moderada que podem ser analisados ​​para a sua resposta PII (Figuras 1 e 2). Neste energia estímulo, o negativo de uma onda antes do pico é insignificante. A energias luminosas brilhantes a deformação negativa da onda torna-se mais proeminente que pode ser quantificado com a resposta PIII (Figura 2). A forma de onda escotópica VEP mostra uma resposta negativa (P1N1; 15-70 janela mseg) seguido de<html> um desvio positivo (N1P2; 30 - 100 ms) (Figuras 3 e 4). <img alt="figura 1" src="/files/ftp_upload/54158/54158fig1.jpg" /> Figura 1. Grupo Média ERG formas de onda. O ERG altera com o aumento da intensidade do estímulo. Os números à esquerda da forma de onda indicar a exposição luminosa utilizada para induzir a forma de onda. Observe as diferentes escalas de amplitude e tempo para cada painel. A energias luminosas de intensidade da luz das componentes positiva e negativa da resposta escotópica limiar pode ser provocada (pStr, NSTR). Como energias estímulo ficar mais brilhante, a um e b-onda de resposta pode ser testada, e um paradigma-flash emparelhado permite que a resposta cone a ser medido. <a href="https://www.jove.com/files/ftp_upload/54158/54158fig1large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> pload / 54158 / 54158fig2.jpg &quot;/&gt; Figura 2. Análise. (A) A função de fotorreceptores Rod ERG pode ser ensaiada usando um PIII para modelar a uma onda. A-ondas na cd.sm 1,22 e 1,52 log -2 (círculos não preenchidas, ○) estão aptos como um conjunto com um PIII (linhas cinzentas, Equação 1) a 90% do mínimo que retorna Rm PIII (amplitude saturado, mV) S (sensibilidade, m 2 .s -1 .cd -3) e os parâmetros de TD (atraso de temporização, ms). (B) a função da célula bipolar haste (média ± SEM) pode ser ensaiada através da modelação da série resposta intensidade da haste PII (círculos não preenchidos ○) com uma função de Naka-Rushton (linha cinza). Isso retorna V max (amplitude saturado, mV), k (1 / sensibilidade, ingresse cd sm -2) e n (inclinação). Função de células ganglionares (C) Retinal é ensaiada em energias luminosas fracas e quantificados por pstr pico de amplitude (pstr amp) e tempo (pstr-lo </sub&gt;). (D) a função das células bipolar Cone é provocada com um paradigma-flash emparelhado quantificada por cone PII pico de amplitude (cone PII amp) e tempo (cone PII-lo). <a href="https://www.jove.com/files/ftp_upload/54158/54158fig2large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> <img alt="Figura 3" src="/files/ftp_upload/54158/54158fig3.jpg" /> Figura 3. Grupo Média VEP formas de onda. A forma da onda de VEP altera com o aumento da energia estímulo. Os números à esquerda da forma de onda indicam a exposição luminosa utilizada para induzir a forma de onda. <a href="https://www.jove.com/files/ftp_upload/54158/54158fig3large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> <img alt="Figura 4" src="/files/ftp_upload/54158/54158fig4.jpg" /> Figure 4. Análise VEP e função Response Intensidade. (A) Análise Amplitude da VEP é tomado como pico à calha (P1N1) e através de pico amplitudes (N1P2). Os tempos implícitos (ele) destas respostas também é retornado (P1-lo, N1-lo, P2-lo). (B) A amplitude VEP P1N1 (média ± SEM) aumenta com o aumento da energia estímulo. <a href="https://www.jove.com/files/ftp_upload/54158/54158fig4large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior esta figura.</a>

Watch this Scientific Journal Video about Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats at JoVE.com

Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats

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

Gravação simultânea de Eletrorretinografia e potenciais evocados visuais em ratos anestesiados

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

simultaneous-recording-electroretinography-visual-evoked-potentials

Nanyang Technological University

Research

JoVE Journal

Neuroscience

12.2K visualizações.  University of Melbourne. This protocol describes simultaneous measurement of electroretinogram and visual evoked potentials in anesthetized rats. 

Vídeo: Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats

Recording Large-scale Neuronal Ensembles with Silicon Probes in the Anesthetized Rat

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of behaviors from the spiking activity of its neurons. One of the most effective methods to monitor spiking activity from a large number of neurons in multiple local neuronal circuits simultaneously is by using silicon electrode arrays1-3.
Action potentials produce large transmembrane voltage changes in the vicinity of cell somata. These output signals can be measured by placing a conductor in close proximity of a neuron. If there are many active (spiking) neurons in the vicinity of the tip, the electrode records combined signal from all of them, where contribution of a single neuron is weighted by its 'electrical distance'. Silicon probes are ideal recording electrodes to monitor multiple neurons because of a large number of recording sites (+64) and a small volume. Furthermore, multiple sites can be arranged over a distance of millimeters, thus allowing for the simultaneous recordings of neuronal activity in the various cortical layers or in multiple cortical columns (Fig. 1). Importantly, the geometrically precise distribution of the recording sites also allows for the determination of the spatial relationship of the isolated single neurons4. Here, we describe an acute, large-scale neuronal recording from the left and right forelimb somatosensory cortex simultaneously in an anesthetized rat with silicon probes (Fig. 2).

Extracellular recordings of neuronal activity using silicon probes in the anesthetized rat will be described. This technique allows information to be obtained across multiple brain areas from more than 100 neurons simultaneously. It provides information with single cell resolution about neuronal ensembles dynamics in multiple local circuits.

Gravação em grande escala Ensembles Neuronal com Sondas Silício na rato anestesiado

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of ...

Neurociência

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation

One of the central tasks in retinal neuroscience is to understand the circuitry of retinal neurons and how those connections are responsible for shaping the signals transmitted to the brain. Photons are detected in the retina by rod and cone photoreceptors, which convert that energy into an electrical signal, transmitting it to other retinal neurons, where it is processed and communicated to central targets in the brain via the optic nerve. Important early insights into retinal circuitry and visual processing came from the histological studies of Cajal1,2 and, later, from electrophysiological recordings of the spiking activity of retinal ganglion cells - the output cells of the retina3,4.
A detailed understanding of visual processing in the retina requires an understanding of the signaling at each step in the pathway from photoreceptor to retinal ganglion cell. However, many retinal cell types are buried deep in the tissue and therefore relatively inaccessible for electrophysiological recording. This limitation can be overcome by working with vertical slices, in which cells residing within each of the retinal layers are clearly visible and accessible for electrophysiological recording.
Here, we describe a method for making vertical sections of retinas from larval tiger salamanders (Ambystoma tigrinum). While this preparation was originally developed for recordings with sharp microelectrodes5,6, we describe a method for dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells in which we manipulate the photoreceptor's membrane potential while simultaneously recording post-synaptic responses in horizontal or bipolar cells. The photoreceptors of the tiger salamander are considerably larger than those of mammalian species, making this an ideal preparation in which to undertake this technically challenging experimental approach. These experiments are described with an eye toward probing the signaling properties of the synaptic ribbon - a specialized synaptic structure found in a only a handful of neurons, including rod and cone photoreceptors, that is well suited for maintaining a high rate of tonic neurotransmitter release7,8 - and how it contributes to the unique signaling properties of this first retinal synapse.

We describe the preparation of thin retinal slices from aquatic tiger salamanders (Ambystoma tigrinum) and explain how we use these slices to study synaptic processing in the retina by obtaining dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells.

Gravações Whole-cell simultâneas de fotorreceptores e os neurônios de segunda ordem em um anfíbio Retinal Slice Preparação

One of the central tasks in retinal neuroscience  is to understand the circuitry of retinal neurons and how those connections are  responsible for shaping ...

Simultaneous Electrophysiological Recording and Calcium Imaging of Suprachiasmatic Nucleus Neurons

Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in regulating the intracellular calcium concentration. Changing environmental conditions, such as the light-dark cycle, can modify neuronal and neural network activity and the expression of a family of circadian clock genes within the suprachiasmatic nucleus (SCN), the location of the master circadian clock in the mammalian brain. Excitatory synaptic transmission leads to an increase in the postsynaptic Ca2+ concentration that is believed to activate the signaling pathways that shifts the rhythmic expression of circadian clock genes. Hypothalamic slices containing the SCN were patch clamped using microelectrodes filled with an internal solution containing the calcium indicator bis-fura-2. After a seal was formed between the microelectrode and the SCN neuronal membrane, the membrane was ruptured using gentle suction and the calcium probe diffused into the neuron filling both the soma and dendrites. Quantitative ratiometric measurements of the intracellular calcium concentration were recorded simultaneously with membrane potential or current. Using these methods it is possible to study the role of changes of the intracellular calcium concentration produced by synaptic activity and action potential firing of individual neurons. In this presentation we demonstrate the methods to simultaneously record electrophysiological activity along with intracellular calcium from individual SCN neurons maintained in brain slices.

Procedures are described to perform simultaneous recordings of membrane potential or current and changes of intracellular calcium concentration. Suprachiasmatic nucleus neurons are filled with the calcium indicator bis-fura-2 using a patch clamp electrode in the whole cell patch clamp configuration.

Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in ...

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological effects. Specifically, by creating a transient interference with the normal activity of a target region and measuring changes in an electrophysiological signal, we can establish a causal link between the stimulated brain area or network and the electrophysiological signal that we record. If target brain areas are functionally defined with prior fMRI scan, TMS could be used to link the fMRI activations with evoked potentials recorded. However, conducting such experiments presents significant technical challenges given the high amplitude artifacts introduced into the EEG signal by the magnetic pulse, and the difficulty to successfully target areas that were functionally defined by fMRI. Here we describe a methodology for combining these three common tools: TMS, EEG, and fMRI. We explain how to guide the stimulator&#39;s coil to the desired target area using anatomical or functional MRI data, how to record EEG during concurrent TMS, how to design an ERP study suitable for EEG-TMS combination and how to extract reliable ERP from the recorded data. We will provide representative results from a previously published study, in which fMRI-guided TMS was used concurrently with EEG to show that the face-selective N1 and the body-selective N1 component of the ERP are associated with distinct neural networks in extrastriate cortex. This method allows us to combine the high spatial resolution of fMRI with the high temporal resolution of TMS and EEG and therefore obtain a comprehensive understanding of the neural basis of various cognitive processes.

This paper describes a method for collecting and analyzing electroencephalography (EEG) data during concurrent transcranial magnetic stimulation (TMS) guided by activations revealed with functional magnetic resonance imaging (fMRI). A method for TMS artifact removal and extraction of event related potentials is described as well as considerations in paradigm design and experimental setup.

Extraindo potenciais evocados visuais de dados EEG gravado durante fMRI-guiada Estimulação Magnética Transcraniana

Transcranial Magnetic Stimulation (TMS) is an effective method for establishing a causal link between a cortical area and cognitive/neurophysiological ...

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise from extra-retinal sources. Ex vivo ERG provides an efficient method to dissect the function of retinal cells directly from an intact isolated retina of animals or donor eyes. In addition, ex vivo ERG can be used to test the efficacy and safety of potential therapeutic agents on retina tissue from animals or humans. We show here how commercially available in vivo ERG systems can be used to conduct ex vivo ERG recordings from isolated mouse retinas. We combine the light stimulation, electronic and heating units of a standard in vivo system with custom-designed specimen holder, gravity-controlled perfusion system and electromagnetic noise shielding to record low-noise ex vivo ERG signals simultaneously from two retinas with the acquisition software included in commercial in vivo systems. Further, we demonstrate how to use this method in combination with pharmacological treatments that remove specific ERG components in order to dissect the function of certain retinal cell types.

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System

Ex vivo ERG can be used to record electrical activity of retinal cells directly from isolated intact retinas of animals or humans. We demonstrate here how common in vivo ERG systems can be adapted for ex vivo ERG recordings in order to dissect the electrical activity of retinal cells.

Simultâneo<em&gt; Ex vivo</em&gt; Teste Funcional de Dois retinas por<em&gt; In vivo</em&gt; Sistema Eletrorretinograma

An In vivo electroretinogram (ERG) signal is composed of several overlapping components originating from different retinal cell types, as well as noise ...

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.

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.

Visual Gravação Potencial Evocado em um modelo de rato de Experimental Nervo Óptico desmielinização

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 ...

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the pathophysiological basis of these diseases, it is necessary to precisely characterize in which way the processing of information is disturbed between the different neuronal parts of the circuit. Using extracellular in vivo electrophysiological recordings, it is possible to accurately delineate neuronal activity within a neuronal network. The application of this method has several advantages over alternative techniques, e.g., functional magnetic resonance imaging and calcium imaging, as it allows a unique temporal and spatial resolution and does not rely on genetically engineered organisms. However, the use of extracellular in vivo recordings is limited since it is an invasive technique that cannot be universally applied. In this article, a simple and easy to use method is presented with which it is possible to simultaneously record extracellular potentials such as local field potentials and multiunit activity at multiple sites of a network. It is detailed how a precise targeting of subcortical nuclei can be achieved using a combination of stereotactic surgery and online analysis of multi-unit recordings. Thus, it is demonstrated, how a complete network such as the hyperdirect cortico-basal ganglia loop can be studied in anesthetized animals in vivo.

Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats

In this study, the methodology is presented on how to perform multi-site in vivo electrophysiological recordings from the hyperdirect pathway under urethane anesthesia.

Agudo<em&gt; In Vivo</em&gt; Gravações eletrofisiológicas de Potenciais de campo locais e atividade de múltiplas unidades a partir do caminho hiperdiretivo em ratos anestesiados

Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the ...

Chronic Transcranial Electrical Stimulation and Intracortical Recording in Rats

Transcranial electrical stimulation (TES) is a powerful and relatively simple approach to diffusely influence brain activity either randomly or in a closed-loop event-triggered manner. Although many studies are focusing on the possible benefits and side-effects of TES in healthy and pathologic brains, there are still many fundamental open questions regarding the mechanism of action of the stimulation. Therefore, there is a clear need for a robust and reproducible method to test the acute and the chronic effects of TES in rodents. TES can be combined with regular behavioral, electrophysiological, and imaging techniques to investigate neuronal networks in vivo. The implantation of transcranial stimulation electrodes does not impose extra constraints on the experimental design while it offers a versatile, flexible tool to manipulate brain activity. Here we provide a detailed, step-by-step protocol to fabricate and implant transcranial stimulation electrodes to influence brain activity in a temporally constrained manner for months.

This detailed protocol describes transcranial stimulation electrode placement on the temporal bone in order to investigate the short- and long-term effects of transcranial electrical stimulation in freely moving rats.

Estimulação elétrica transcraniana crônica e gravação Intracortical em ratos

Transcranial electrical stimulation (TES) is a powerful and relatively simple approach to diffusely influence brain activity either randomly or in a ...

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.

Gravações de potenciais evocadas visuais em ratos usando um não-invasivo seco multi-canal do couro cabeludo Sensor de EEG

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 ...

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;

Padrões morfológicos do potencial evocado cortical Visual específico do estímulo

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

Gravação simultânea de Eletrorretinografia e potenciais evocados visuais em ratos anestesiados

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