A Brief Review on Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome

Birds may use the geomagnetic field to find their way around. Behavioral experiments, often with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, although it can adapt to other intensities; (2) it is a “inclination compass,” based on the axial course of the field lines rather than the polarity of the magnetic field; and (3) it is a “inclination compass,” based on the polarity of the magnetic field rather than The Radical Pair-Model of magnetoreception proposes spin-chemical processes in photopigments as the underlying mechanism to explain these properties. The use of radio frequency fields, a diagnostic method for radical pair processes, suggests that a radical pair mechanism is involved in avian magnetoreception: when applied to the geomagnetic field, they disrupted orientation, possibly by interfering with receptive processes. Cryptochrome molecules have been proposed as receptors. Birds’ eyes contain five different forms of cryptochromes. In chickens and robins, the most likely candidate is Cry1a, which is found at the membranes of the discs in the outer segments of the UV-cones. It is enabled by the wavelengths of light that enable birds to use their magnetic compass, according to immunohistochemical studies. The radical pair formed during re-oxidation appears to be the most important for magnetoreception within the cryptochrome photocycle.

Author (s) Details

Roswitha Wiltschko
Fachbereich Biowissenschaften, J.W. Goethe-Universität Frankfurt, Max von Laue Straße 13, D-60438 Frankfurt am Main, Germany.

Wolfgang Wiltschko
Fachbereich Biowissenschaften, J.W. Goethe-Universität Frankfurt, Max von Laue Straße 13, D-60438 Frankfurt am Main, Germany.

View Book :- https://stm.bookpi.org/RRAB-V7/article/view/844

Leave a Reply

Your email address will not be published. Required fields are marked *