Berlin 2005 – scientific programme

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AKB: Biologische Physik

AKB 100: Poster Session I

AKB 100.71: Poster

Saturday, March 5, 2005, 16:45–18:45, Poster TU D

Retinal Glial Cells as Living Optical Fibers — •K. Franze^1,2, S. Schinkinger¹, K. Travis¹, A. Reichenbach², and J. Guck¹ — ¹Abteilung Physik Weicher Materie, Universität Leipzig — ²PFI für Hirnforschung, Universität Leipzig

Vision is one of our most important senses. The cells responsible for converting light into electrical impulses are the photoreceptor cells (PRs). However, due to the sequence of evolution, the vertebrate retina is the "wrong way round": in order for light to reach the PRs, it must first pass through several retinal layers of different types of cells. Especially under low-light conditions additional structures are required which guarantee optimal utilization of the light. These structures ideally span the entire thickness of the retina and guide the light through all of the cell layers to the PRs. Only the so-called Müller cells, the principal retinal glial cells, have this ability. Furthermore, these cells contact every single PR.

In the present work, the light guiding properties of individual Müller cells were studied. Cells were aligned in a two-beam IR laser trap, additional visible light was sent through the cells, and the light guiding efficiency of the cells for visible light was measured. These measurements unambiguously demonstrate the light guidance function of Müller cells. The observed intensity dependent transmittance might serve as a protective mechanism of the inverted retina against photo damage of the PRs.