Dresden 2009 – scientific programme

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BP: Fachverband Biologische Physik

BP 14: Neuronal and Sensory Systems

BP 14.9: Talk

Wednesday, March 25, 2009, 16:30–16:45, HÜL 186

Magnetoreception mechanisms in birds - towards the discovery of the sixth sense — •Ilia Solov'yov and Walter Greiner — Frankfurt Institute for Advanced Studies, Goethe University, Frankfurt am Main, Germany

Many birds are able to orient themselves accurately when the sky is not visible (e.g. covered with clouds). This requires non-visual sources of information. Many studies have established that birds are sensitive to the Earth's magnetic field. European robins, pigeons and other bird species use the geomagnetic field as a compass, and are also sensitive to slight temporal and spatial variation in the magnetic field that is potentially useful for determining location.

We study a putative avian magnetoreception mechanism, which is based on the interaction of two iron minerals (magnetite and maghemite) experimentally observed in subcellular compartments within sensory dendrites of the upper beak of several bird species. The iron minerals in the beak form platelets of crystalline maghemite and clusters of magnetite nanoparticles. We develop a theoretical model [1] to quantitatively describe the interaction between the iron-mineral containing particles, and demonstrate that depending on the external magnetic field the external pull or push to the magnetite clusters may reach a value of 0.4 pN. This might be principally sufficient to excite specific mechanoreceptive membrane channels leading to different nerve signals and causing a certain orientational behavior of the bird.

[1] I. Solov'yov and W. Greiner, Biophys. J. 93, 1493 (2007)