title: Chemical compass model of avian magnetoreception.
abstract: Approximately 50 species, including birds, mammals, reptiles, amphibians, fish, crustaceans and insects, are known to use the Earth's magnetic field for orientation and navigation. Birds in particular have been intensively studied, but the biophysical mechanisms that underlie the avian magnetic compass are still poorly understood. One proposal, based on magnetically sensitive free radical reactions, is gaining support despite the fact that no chemical reaction in vitro has been shown to respond to magnetic fields as weak as the Earth's ( approximately 50 muT) or to be sensitive to the direction of such a field. Here we use spectroscopic observation of a carotenoid-porphyrin-fullerene model system to demonstrate that the lifetime of a photochemically formed radical pair is changed by application of < or =50 microT magnetic fields, and to measure the anisotropic chemical response that is essential for its operation as a chemical compass sensor. These experiments establish the feasibility of chemical magnetoreception and give insight into the structural and dynamic design features required for optimal detection of the direction of the Earth's magnetic field.
authors.affiliation: Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, UK.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Maeda
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Henbest
authors.forename: Filippo
authors.initials: F
authors.lastname: Cintolesi
authors.forename: Ilya
authors.initials: I
authors.lastname: Kuprov
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Rodgers
authors.forename: Paul A
authors.initials: PA
authors.lastname: Liddell
authors.forename: Devens
authors.initials: D
authors.lastname: Gust
authors.forename: Christiane R
authors.initials: CR
authors.lastname: Timmel
authors.forename: P J
authors.initials: PJ
authors.lastname: Hore
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D016880:Anisotropy; D001717:Birds / Q000502:physiology*; D018534:Earth, Planet; D008280:Magnetics; D008954:Models, Biological; D009949:Orientation / Q000502:physiology*; D013481:Superoxides / Q000378:metabolism
chemical_list: D013481:Superoxides