A light-dependent magnetoreception mechanism insensitive to light intensity and polarization
Abstract
Billions of migratory birds navigate thousands of kilometres every year aided by a magnetic compass sense, the biophysical mechanism of which is unclear. One leading hypothesis is that absorption of light by specialized photoreceptors in the retina produces short-lived chemical intermediates known as radical pairs whose chemistry is sensitive to tiny magnetic interactions. A potentially serious but largely ignored obstacle to this theory is how directional information derived from the Earth's magnetic field can be separated from the much stronger variations in the intensity and polarization of the incident light. Here we propose a simple solution in which these extraneous effects are cancelled by taking the ratio of the signals from two neighbouring populations of magnetoreceptors. Geometric and biological arguments are used to derive a set of conditions that make this possible. We argue that one likely location of the magnetoreceptor molecules would be in association with ordered opsin dimers in the membrane discs of the outer segments of double-cone photoreceptor cells.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2017
- Source ID
- 10.1098/rsif.2017.0405
Entities
People
- Henrik Mouritsen
- Peter Hore
- Susannah Worster
Organizations
- Air Force Office of Scientific Research
- FP7 Ideas: European Research Council
- German Research Foundation
- University of Oldenburg
- University of Oxford
- Volkswagen Foundation