Institute for Ophthalmic Research

Head

Prof. Dr. rer. nat. Thomas Euler

Contact

Otfried-Mueller-Strasse 25
72076 Tuebingen

thomas [dot] euler [at] cin [dot] uni-tuebingen [dot] de

Mission statement

Visual information processing occupies a substantial part of our brain. It starts in the retina, which not only converts the incoming stream of photons into electrical signals, but also performs a first analysis of the observed scene. The retina extracts information such as contrast, brightness and „color”, as well as more complex stimulus features, including edges, motion and its direction. Even some initial clues about object segregation may be computed in the retina. In short, the retina is a sophisticated image processor. The retina’s processing capabilities depend on about 70 types of neurons organized in various microcircuits. Our work is aimed at unraveling the function and organization of retinal microcircuits and a better understanding of the underlying computational rules.

Because the retina is a part of the brain that can be easily isolated and remains fully functional, in vitro, for hours, it represents an excellent model system for studying neuronal processing at both the cellular and the network level. In contrast to other parts of the brain, the in vitro retina can be provided with physiological stimuli – patterns of light – while observing the processing of these stimuli at intermediate levels in interneurons as well as at the level of the retina’s output neurons, the ganglion cells.

To study retinal processing we use a combination of electrical and optical recording techniques. The latter allows the intact, light-sensitive tissue to be visualized at a high spatial resolution and local signals to be measured in dendrites. In the retina, most dendrites are thin and entangled with each other, such that they usually cannot be accessed by recording electrodes. However, the ability to measure local dendritic activity is important for understanding neuronal processing. This is crucial for the retina, since many retinal interneurons lack dedicated output structures – such as an explicit axon – and instead use their dendrites both for receiving inputs and forming output synapses.

Selected publications

Dedek K, Breuninger T, Pérez de Sevilla Müller L, Maxeiner S, Schultz K, Janssen-Bienhold U, Willecke K, Euler T, Weiler R. A novel type of interplexiform amacrine cell in the mouse retina.
Eur J Neurosci, 2009; 30(2):217-28

Schlichtenbrede FC., Mittmann W, Rensch F, vom Hagen F, Jonas JB, Euler T. Toxicity
Assessment of intravitreal Triamcinolone and Bevacizumab in an retinal explant mouse model using Two-Photon Microscopy.
Invest Ophthalmol Vis Sci, 2009;doi:10.1167/iovs.08-3078

Euler T, Hausselt SE, Margolis DJ, Breuninger T, Castell X, Detwiler PB, Denk W.
Eyecup scope-optical recordings of light stimulus-evoked fluorescence signals in the retina.
Pflügers Arch, 2009; 457:1393-1414

Euler T, Hausselt SE.
Direction Selective Cells.
In: Vision I, The Senses – A Comprehensive Reference (Masland RH, Albright TD, eds), 2008, pp 413-422. San Diego: Academic Press.

Hausselt SE, Euler T, Detwiler PB, Denk W. A Dendrite-Autonomous Mechanism
for Direction Selectivity in Retinal Starburst Amacrine Cells.
PLoS Biol, 2007;5:e185

More information

http://www.cin.uni-tuebingen.de