Berlin 2005 – wissenschaftliches Programm

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AK: Akustik

AK 3: Ultraschall in Biologie und Medizin (Sitzungsorganisation: Robert Lemor, St. Ingbert)

AK 3.1: Hauptvortrag

Samstag, 5. März 2005, 08:30–09:00, TU EB222

Forces that shape cells: Acoustic microscopical investigations into cellular dynamics — •Jürgen Bereiter-Hahn — Johann Wolfgang Goethe-Universität, Zoologisches Institut, 60439 Frankfurt, Germany

The cytoskeleton of animal cells in culture in cooperation with the plasma membrane and its ion channels and transporters controls shape and volume. In fact, cell shape results from a morphodynamic process which is based on cytoskeletal dynamics developing forces which may equilibrate each other yielding almost constant shapes or resulting in different types of shape changes including locomotion. The dynamics of these forces can be visualized, the forces can be measured using ultrasound in the GHz range focused on to the specimen by an acoustic lens. This method for the first time allowed to allocate force development to subcellular areas and to the responsible fibrillar structures on the basis of local impedance changes related to sound velocity. High time resolution is combined with high spatial resolution and very low interaction with the cells under investigation which behave undisturbed. The second basic parameter characterizing the interaction of materials with sound waves is attenuation. This parameter reveals cross linkings between the cytoplasmic fibrils as revealed by a vitro approach which allows synchronous determinations of viscosity, sound velocity and attenuation in a non-destructive manner.