[Frontiers in Bioscience 14, 2730-2737, January 1, 2009]

Vision tests in the mouse: Functional phenotyping with electroretinography

Naoyuki Tanimoto1, Regine L. Muehlfriedel1, M. Dominik Fischer1, Edda Fahl1, Peter Humphries2, Martin Biel3, Mathias W. Seeliger1

1Ocular Neurodegeneration Research Group, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen, Schleichstrasse 4/3, D-72076 Tuebingen, Germany, 2 Ocular Genetics Unit, Department of Genetics, Trinity College, Dublin 2, Ireland, 3 Center for Integrated Protein Science CIPS-M and Zentrum fuer Pharmaforschung -Department Pharmazie, Pharmakologie fuer Naturwissenschaften, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstr. 5 -13, D-81377 Muenchen, Germany


1. Abstract
2. Introduction
3. Preparation of mice
4. Recording equipment and settings
5. Recording protocols and interpretations
5.1. Single flash intensity series
5.2. Flicker frequency series
5.3. Cone and rod system contributions
6. Data analysis and presentation
7. Summary and perspective
8. Acknowledgements
9. References


Electroretinography (ERG) is an established diagnostic technique in clinical ophthalmology and provides objective information about retinal function. This technique is also applied in basic research, where animal models of hereditary retinopathies have significantly contributed to our understanding of the composition of ERG responses in general and how retinal degenerative pathologies alter retinal function specifically. Indeed, electrophysiologic assessment of transgenic mice, which are genetically engineered to mimic human mutations that lead to retinal diseases, can be well compared with clinical data. Furthermore, limitations on examinations (e.g. length of measurement, range of light intensity) are much less of a concern when assessing mice compared to human patients. In order to measure and analyze retinal responses properly, several important aspects have to be considered. This paper focuses on these aspects, and shows exemplary ERG data which were obtained from normal wild-type mice and from transgenic mice with specific functional properties, namely Rho-/- (rod opsin knockout, cone function only), and Cnga3-/- (cone CNG channel deficient, rod function only) to illustrate rod and cone system contributions to ERG responses.