Name: simultaneous ex vivo functional testing of two retinas by in vivo electroretinogram system
Uploaded: 2015-05-06T15:00:00
Description: Watch this Scientific Journal Video about Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System at JoVE.com

This work was supported by NIH grants EY019312 and EY021126 (VJK), EY002687 to the Department of Ophthalmology and Visual Sciences at Washington University, and by Research to Prevent Blindness.

All experimental protocols were in accordance with the Guide for the Care and Use of Laboratory Animals and were approved by the institutional Animal Studies Committee at Washington University.
1. Setting Up Perfusion and Specimen Holder
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	<li>Prepare solution for retina perfusion fresh on the day of the experiment. Use distilled and deionized water. Use one of the following three solutions.
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		<li>Prepare Bicarbonate-containing Ames&#8217; solution (1 L): 1 bottle of Ames&#8217; me...

<ol>
	<li>Armington, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Electroretinogram. , (1974).</li><li>Einthoven, W., Jolly, W. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signal+transmission+along+retinal+rods+and+the+origin+of+the+electroretinographic+a-wave.">Signal transmission along retinal rods and the origin of the electroretinographic a-wave.</a> Nature. 223, 201-204 (1969).</li><li>Stockton, R. A., Slaughter, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=B-wave+of+the+electroretinogram.+A+reflection+of+ON+bipolar+cell+activity.">B-wave of the electroretinogram. A reflection of ON bipolar cell activity.</a> J. Gen. Physiol. 93, 101-122 (1989).</li><li>Robson, J. G., Frishman, L. 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T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+responses+to+light+from+cat+pigment+epithelium:+origin+of+the+electroretinogram+c-wave.">Intracellular responses to light from cat pigment epithelium: origin of the electroretinogram c-wave.</a> Nature. 227, 728-730 (1970).</li><li>Wilson, W. S., Shahidullah, M., Millar, 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+bovine+arterially-perfused+eye:+an+in+vitro+method+for+the+study+of+drug+mechanisms+on+IOP,+aqueous+humour+formation+and+uveal+vasculature.">The bovine arterially-perfused eye: an in vitro method for the study of drug mechanisms on IOP, aqueous humour formation and uveal vasculature.</a> Curr. Eye Res. 12, 609-620 (1993).</li><li>Frank, R. N., Dowling, J. 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V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+properties+of+a+new+isolated+rat+retina+preparation.">Electrophysiological properties of a new isolated rat retina preparation.</a> Vision Res. 39, 2165-2177 (1999).</li><li>Hamasaki, D. 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+effect+of+sodium+ion+concentration+on+the+electroretinogram+of+the+isolated+retina+of+the+frog.">The effect of sodium ion concentration on the electroretinogram of the isolated retina of the frog.</a> J. Physiol. 167, 156-168 (1963).</li><li>Luke, M., 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=The+isolated+perfused+bovine+retina--a+sensitive+tool+for+pharmacological+research+on+retinal+function.">The isolated perfused bovine retina--a sensitive tool for pharmacological research on retinal function.</a> Brain Res. Brain Res. Protoc. 16, 27-36 (2005).</li><li>Bastian, B. L., Fain, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+adaptation+in+toad+rods:+requirement+for+an+internal+messenger+which+is+not+calcium.">Light adaptation in toad rods: requirement for an internal messenger which is not calcium.</a> J. Physiol. 297, 493-520 (1979).</li><li>Arden, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltage+gradients+across+the+receptor+layer+of+the+isolated+rat+retina.">Voltage gradients across the receptor layer of the isolated rat retina.</a> J. Physiol. 256, 333-360 (1976).</li><li>Vinberg, F., Kolesnikov, A. V., Kefalov, V. 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Physiol. 567, 923-938 (2005).</li><li>Heikkinen, H., Nymark, S., Koskelainen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+cone+photoresponses+obtained+with+electroretinogram+from+the+isolated+retina.">Mouse cone photoresponses obtained with electroretinogram from the isolated retina.</a> Vision Res. 48, 264-272 (2008).</li><li>Wang, J. S., Kefalov, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+alternative+pathway+mediates+the+mouse+and+human+cone+visual+cycle.">An alternative pathway mediates the mouse and human cone visual cycle.</a> Curr. Biol. 19, 1665-1669 (2009).</li><li>Bolnick, D. A., Walter, A. E., Sillman, 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=Barium+suppresses+slow+PIII+in+perfused+bullfrog+retina.">Barium suppresses slow PIII in perfused bullfrog retina.</a> Vision Res. 19, 1117-1119 (1979).</li><li>Newman, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potassium+conductance+block+by+barium+in+amphibian+Muller+cells.">Potassium conductance block by barium in amphibian Muller cells.</a> Brain Res. 498, 308-314 (1989).</li><li>Oakley, B., Katz, B. J., Xu, Z., Zheng, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+buffering+of+extracellular+potassium+by+Muller+(glial)+cells+in+the+toad+retina.">Spatial buffering of extracellular potassium by Muller (glial) cells in the toad retina.</a> Exp. Eye Res. 55, 539-550 (1992).</li><li>Nymark, S., Haldin, C., Tenhu, H., Koskelainen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+for+measuring+free+drug+concentration:+retinal+tissue+as+a+biosensor.">A new method for measuring free drug concentration: retinal tissue as a biosensor.</a> Invest. Ophthalmol. Vis. Sci. 47, 2583-2588 (2006).</li><li>Walter, P., Luke, C., Sickel, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibiotics+and+light+responses+in+superfused+bovine+retina.">Antibiotics and light responses in superfused bovine retina.</a> Cell. Mol. Neurobiol. 19, 87-92 (1999).</li><li>Luke, M., 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=The+safety+profile+of+alkylphosphocholines+in+the+model+of+the+isolated+perfused+vertebrate+retina.">The safety profile of alkylphosphocholines in the model of the isolated perfused vertebrate retina.</a> Graefes Arch. Clin. Exp. Ophthalmol. 248, 511-518 (2010).</li><li>Januschowski, K., 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=Electrophysiological+toxicity+testing+of+VEGF+Trap-Eye+in+an+isolated+perfused+vertebrate+retina+organ+culture+model.">Electrophysiological toxicity testing of VEGF Trap-Eye in an isolated perfused vertebrate retina organ culture model.</a> Acta Ophthalmol. 92, e305-e311 (2014).</li><li>Kolesnikov, A. V., Kefalov, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transretinal+ERG+recordings+from+mouse+retina:+rod+and+cone+photoresponses.">Transretinal ERG recordings from mouse retina: rod and cone photoresponses.</a> J Vis Exp. , (2012).</li><li>Koskelainen, A., Hemila, S., Donner, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+sensitivities+of+short-+and+long-wavelength+sensitive+cone+mechanisms+in+the+frog+retina.">Spectral sensitivities of short- and long-wavelength sensitive cone mechanisms in the frog retina.</a> Acta Physiol. Scand. 152, 115-124 (1994).</li><li>Lyubarsky, A. L., Falsini, B., Pennesi, M. E., Valentini, P., Pugh, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=UV-+and+midwave-sensitive+cone-driven+retinal+responses+of+the+mouse:+a+possible+phenotype+for+coexpression+of+cone+photopigments.">UV- and midwave-sensitive cone-driven retinal responses of the mouse: a possible phenotype for coexpression of cone photopigments.</a> J. Neurosci. 19, 442-455 (1999).</li><li>Lyubarsky, A. L., Daniele, L. L., Pugh, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+candelas+to+photoisomerizations+in+the+mouse+eye+by+rhodopsin+bleaching+in+situ+and+the+light-rearing+dependence+of+the+major+components+of+the+mouse+ERG.">From candelas to photoisomerizations in the mouse eye by rhodopsin bleaching in situ and the light-rearing dependence of the major components of the mouse ERG.</a> Vision Res. 44, 3235-3251 (2004).</li><li>Azevedo, A. W., Rieke, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+protocols+alter+phototransduction:+the+implications+for+retinal+processing+at+visual+threshold.">Experimental protocols alter phototransduction: the implications for retinal processing at visual threshold.</a> J. Neurosci. 31, 3670-3682 (2011).</li><li>Carter-Dawson, L. D., LaVail, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rods+and+cones+in+the+mouse+retina.+I.+Structural+analysis+using+light+and+electron+microscopy.">Rods and cones in the mouse retina. I. Structural analysis using light and electron microscopy.</a> J. Comp. Neurol. 188, 245-262 (1979).</li><li>Fain, G. L., Matthews, H. R., Cornwall, M. C., Koutalos, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptation+in+vertebrate+photoreceptors.">Adaptation in vertebrate photoreceptors.</a> Physiol. Rev. 81, 117-151 (2001).</li><li>Calvert, P. D., Strissel, K. J., Schiesser, W. E., Pugh, E. N., Arshavsky, V. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-driven+translocation+of+signaling+proteins+in+vertebrate+photoreceptors.">Light-driven translocation of signaling proteins in vertebrate photoreceptors.</a> Trends Cell Biol. 16, 560-568 (2006).</li><li>Schneeweis, D. M., Schnapf, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+photovoltage+of+macaque+cone+photoreceptors:+adaptation,+noise,+and+kinetics.">The photovoltage of macaque cone photoreceptors: adaptation, noise, and kinetics.</a> J. Neurosci. 19, 1203-1216 (1999).</li><li>Heikkinen, H., Vinberg, F., Nymark, S., Koskelainen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesopic+background+lights+enhance+dark-adapted+cone+ERG+flash+responses+in+the+intact+mouse+retina:+a+possible+role+for+gap+junctional+decoupling.">Mesopic background lights enhance dark-adapted cone ERG flash responses in the intact mouse retina: a possible role for gap junctional decoupling.</a> J. Neurophysiol. 105, 2309-2318 (2011).</li><li>Gouras, P., MacKay, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+in+amplitude+of+the+human+cone+electroretinogram+with+light+adaptation.">Growth in amplitude of the human cone electroretinogram with light adaptation.</a> Invest. Ophthalmol. Vis. Sci. 30, 625-630 (1989).</li><li>Peachey, N. 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We demonstrate here the critical steps for obtaining high-quality ex vivo ERG recordings simultaneously from two isolated mouse retinas by using in vivo ERG system components together with an ex vivo ERG adapter. In this study we perfused both retinas from the animal with the same solution (either Ames&#8217;, Locke&#8217;s or Ringer) but it is also possible to perfuse each retina with a different solution e.g., for drug testing purposes. The most important steps for obtaining high qua...

Electroretinogram (ERG) is a well-established technique that can be used to record the electrical activity of the retina triggered by light. The ERG signal is generated mainly by voltage changes caused by radial currents (along the axis of photoreceptors and bipolar cells) flowing in the resistive extracellular space of the retina. The first ERG signal was recorded in 1865 by Holmgren from the surface of a fish eye1. Einthoven and Jolly 19082 divided the ERG response to the onset of light into three different waves, called a-, b-, and c-waves, that are now known to reflect mainly the activity of photoreceptors, ON bipolar cells, and pigment epithelium cells, respectively3-8. ERG can be recorded from the eyes of anesthetized animals or humans (in vivo), from isolated eye preparation9, across isolated intact retina (ex vivo)3,10-15 or across specific retina layers with microelectrodes (local ERG)4,16. Of these, in vivo ERG is currently the most widely used method to assess retinal function. It is a noninvasive technique that can be used for diagnostic purposes or to follow the progression of retinal diseases in animals or patients. However, in vivo ERG recordings produce a complicated signal with several overlapping components, often contaminated by extraocular physiological noise (e.g., breathing and cardiac activity).
Local ERG can be used to record the signal across specific layers of the retina but it is the most invasive and has the lowest signal-to-noise ratio (SNR) as compared to the other ERG recording configurations. Local ERG is also technically demanding and requires expensive equipment (e.g., microscope and micromanipulators). Transretinal ERG from the intact, isolated retina (ex vivo ERG) offers a compromise between in vivo and local ERG methods allowing stable and high SNR recordings from intact retinas of animals or humans17. Recently, this method has been used successfully to study rod and cone photoreceptor function in mammalian, primate and human retinas18-20. In addition, due to absence of pigment epithelium in the ex vivo retina, the positive c-wave component of the ERG signal is removed and a prominent negative slow PIII component is revealed in the ex vivo recordings. The slow PIII component has been shown to originate from the activity of M&#252;ller glia cells in the retina21-23. Thus, ex vivo ERG method could also be used to study M&#252;ller cells in the intact retina. Several studies have also shown that ex vivo ERG recordings could be used to measure concentration of pharmacological agents around the retina24 and test the safety and efficacy of drugs25-27.
Multiple commercial in vivo systems are available and used in many laboratories that do not necessarily have extensive electrophysiology background. In contrast, ex vivo devices have not been available until recently17 and as a result only very few laboratories are currently taking advantage of this powerful technique. It would be beneficial to make ex vivo ERG recordings available to more laboratories in order to advance our knowledge about retinal physiology and pathology, and to develop new therapies for blinding diseases. We demonstrate here a simple and affordable ex vivo ERG device17 and show how it can be used in combination with several commercially available in vivo ERG systems to record rod- and cone-mediated signaling (a- and b-waves) and the function of M&#252;ller cells (slow PIII) from intact wild-type mouse retinas.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>In vivo ERG system</td>
			<td>OcuScience</td>
			<td>HMsERG</td>
			<td><a href="http://www.ocuscience.us/id77.html">www.ocuscience.us/id77.html</a></td>
		</tr>
		<tr>
			<td>In vivo ERG system</td>
			<td>LKC Technologies</td>
			<td>UTAS-E 3000</td>
			<td><a href="http://www.lkc.com/products/UTAS/bigshot.html">www.lkc.com/products/UTAS/bigshot.html</a></td>
		</tr>
		<tr>
			<td>Ex vivo adapter</td>
			<td>OcuScience</td>
			<td>Ex VIVO ERG adapter</td>
			<td><a href="http://www.ocuscience.us/id107.html">www.ocuscience.us/id107.html</a></td>
		</tr>
		<tr>
			<td>Dissection microscope</td>
			<td>North Central Instruments</td>
			<td>Leica M80</td>
			<td><a href="http://www.ncimicro.com/store/ListProduct.asp?bSub=T&amp;idCategory=27">May use any brand</a></td>
		</tr>
		<tr>
			<td>IR emitter</td>
			<td>Opto Diode Corp.</td>
			<td>OD-50L</td>
			<td><a href="http://www.optodiode.com/">www.optodiode.com</a></td>
		</tr>
		<tr>
			<td>Prowler Night Vision Scopes</td>
			<td>B.E. Meyers Electro Optics</td>
			<td>D4300-I</td>
			<td>Military grade product.</td>
		</tr>
		<tr>
			<td>Red filter</td>
			<td>Rosco Laboratories</td>
			<td>Roscolux #27 Medium Red</td>
			<td>May be used instead of IR system</td>
		</tr>
		<tr>
			<td>Red head light</td>
			<td>OcuScience</td>
			<td>ERGX011</td>
			<td><a href="http://www.ocuscience.us/catalog/i29.html">www.ocuscience.us/catalog/i29.html</a></td>
		</tr>
		<tr>
			<td>Microscissors</td>
			<td>WPI, Inc.</td>
			<td>500086</td>
			<td><a href="http://www.wpiinc.com/">www.wpiinc.com/</a></td>
		</tr>
		<tr>
			<td>Dumont tweezers #5</td>
			<td>WPI, Inc.</td>
			<td>14101</td>
			<td></td>
		</tr>
		<tr>
			<td>Razor blades</td>
			<td>Electron Microscopy Sciences</td>
			<td>72000</td>
			<td><a href="http://www.emsdiasum.com/">www.emsdiasum.com</a></td>
		</tr>
		<tr>
			<td>Scale</td>
			<td>Metler Toledo</td>
			<td>AB54-S/FACT</td>
			<td><a href="http://www.sigmaaldrich.com/">May use any brand</a></td>
		</tr>
		<tr>
			<td>pH meter and electrode</td>
			<td>Beckman Coulter</td>
			<td>pHI 350</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sigma-Aldrich</td>
			<td>S7653</td>
			<td><a href="http://www.sigmaaldrich.com/">May use any brand</a></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Sigma-Aldrich</td>
			<td>60129</td>
			<td><a href="http://www.sigmaaldrich.com/">May use any brand</a></td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Sigma-Aldrich</td>
			<td>63020</td>
			<td>1.0 M solution</td>
		</tr>
		<tr>
			<td>CaCl2</td>
			<td>Sigma-Aldrich</td>
			<td>21114</td>
			<td>1.0 M solution</td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sigma-Aldrich</td>
			<td>431788</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Sigma-Aldrich</td>
			<td>H3375</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>Sodium Bicarbonate</td>
			<td>Sigma-Aldrich</td>
			<td>S6297</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>Ames medium</td>
			<td>Sigma-Aldrich</td>
			<td>A1420</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>BaCl2</td>
			<td>Sigma-Aldrich</td>
			<td>B0750</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>DL-AP4</td>
			<td>Tocris Bioscience</td>
			<td>101</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>Succinic acid disodium salt</td>
			<td>Sigma-Aldrich</td>
			<td>224731</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>L-Glutamic acid</td>
			<td>Sigma-Aldrich</td>
			<td>G2834</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>D-(+)-Glucose</td>
			<td>Sigma-Aldrich</td>
			<td>G7528</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>Leibovitz culture medium L-15</td>
			<td>Sigma-Aldrich</td>
			<td>L4386</td>
			<td>May use any brand</td>
		</tr>
		<tr>
			<td>MEM vitamins</td>
			<td>Sigma-Aldrich</td>
			<td>M6895</td>
			<td></td>
		</tr>
		<tr>
			<td>MEM amino acids</td>
			<td>Sigma-Aldrich</td>
			<td>M5550</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbogen</td>
			<td>Airgas</td>
			<td>UN3156</td>
			<td>5% CO2</td>
		</tr>
	</tbody>
</table>

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.

We recorded flash responses from dark-adapted wild-type (WT) C57BL/6 mouse retinas by following the experimental protocols described above and illustrated in Figure 1 by using different standard perfusion solutions (Figure 2). The response waveforms and kinetics as well as sensitivity of rod photoreceptors appeared similar in Ames&#8217; and Locke&#8217;s media (Figure 2A and B). On the other hand, under HEPES-buffered Ringer solution (no bicarbonate or ...

Watch this Scientific Journal Video about Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System at JoVE.com

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.

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 ...

Research

JoVE Journal

Neuroscience

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

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In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice

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Two-photon imaging is a powerful tool for the in vivo analysis of neuronal circuits in the mammalian brain. However, a limited number of in vivo imaging ...

Ex Vivo Pressurized Hippocampal Capillary-Parenchymal Arteriole Preparation for Functional Study

From subtle behavioral alterations to late-stage dementia, vascular cognitive impairment typically develops following cerebral ischemia. Stroke and ...

Transpupillary Two-Photon In Vivo Imaging of the Mouse Retina

The retina transforms light signals from the environment into electrical signals that are propagated to the brain. Diseases of the retina are prevalent ...

Optimizing the Setup and Conditions for Ex Vivo Electroretinogram to Study Retina Function in Small and Large Eyes

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Measurements of retinal neuronal light responses are critical to investigating the physiology of the healthy retina, determining pathological changes in ...