Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 13: Photobiophysics
BP 13.3: Talk
Tuesday, March 27, 2007, 13:00–13:15, H44
Light Guidance by Living Cells — •Kristian Franze1,2, Jens Grosche1, Serguei Skatchkov3, Stefan Schinkinger2, Detlev Schild4, Ortrud Uckermann1, Kort Travis2, Andreas Reichenbach1, and Jochen Guck2 — 1Paul-Flechsig-Institute of Brain Research, Universität Leipzig — 2Soft Matter Physics, Universität Leipzig — 3CMBN, Universidad Central de Caribe, Bayamon, USA — 4DFG Research Center, Universität Göttingen
While cells are mostly transparent they are phase objects that differ in shape and refractive index. Any image that is projected through layers of cells will normally be distorted by refraction, reflection, and scattering. Strangely, the retina of the vertebrate eye is inverted with respect to its optical function and light must pass through several tissue layers before reaching the light-sensitive photoreceptor cells, with each photon having a chance of being scattered. Here we report how nature has optimized this apparently unfavourable situation. We investigated the optical properties of retinal tissue and individual Müller cells, which are radial glial cells spanning the entire thickness of the retina. We found that these cells act as optical fibers and guide light that would otherwise be scattered from the retinal surface to the photoreceptor cells. Their parallel arrangement in the retina is reminiscent of fiber-optic plates used for low-distortion image transfer. Thus, Müller cells seem to mediate the image transfer through the vertebrate retina with minimal distortion and low loss. This finding explains a fundamental feature of the inverted retina as an optical system and it ascribes a new function to glial cells.