The navigational abilities of night-migratory songbirds, travelling alone over thousands of kilometres, are absolutely staggering. The successful completion of these magnificent voyages depends crucially on the birds’ ability to sense the Earth’s magnetic field. Exactly how this magnetic sense works is largely a mystery: the experimental evidence suggests something extraordinary. The birds’ magnetic compass sensor seems to rely on coherent quantum phenomena that indirectly allow magnetic interactions a million times smaller than kBT (Boltzmann’s constant multiplied by temperature) to be detected in biological tissue. Together with our collaborators, we aim to discover the detailed mechanism of animal magnetoreception.
The primary magnetoreceptor is believed to be cryptochrome, a blue-light photoreceptor protein found in a variety of cell types in the avian retina. Photo-induced electron transfer within the protein produces pairs of radicals in which the unpaired electron spins are in a coherent superposition, far removed from equilibrium. As a consequence, and because the radical recombination reactions conserve spin, weak magnetic interactions can affect the yield of a conformation of the protein that could act as a signalling state.
For more information, see our recent review: Hore & Mouritsen, Ann. Rev. Biophys. 45 (2016) 299-344, which includes a tutorial on the radical pair mechanism.
Quantum effects in magnetoreception. DARPA, QuBE program. 2010-2014.
ChemNav – Magnetic sensing by molecules, birds and devices. ERC Advanced Grant. 2013-2018.
Cryptochrome-based magnetic sensing. AFOSR. 2014-2019.
Magnetic field effects on Drosophila melanogaster cryptochrome. EMF Biological Research Trust. 2015-2019.
QuantumBirds – Radical pair-based magnetic sensing in migratory birds. ERC Synergy Grant. 2019-2025.
Christiane Timmel, Stuart Mackenzie, David Manolopoulos, Justin Benesch (Department of Chemistry, Oxford)
Henrik Mouritsen, Karl-Wilhelm Koch, Ilia Solov'yov (University of Oldenburg)
Stefan Weber, Erik Schleicher (University of Freiburg)