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Magnetoreception in an Avian Brain in Part Mediated by Inner Ear Lagena

2011; Elsevier BV; Volume: 21; Issue: 5 Linguagem: Inglês

10.1016/j.cub.2011.01.058

1879-0445

Le‐Qing Wu, J. David Dickman,

Magnetic and Electromagnetic Effects

Many animals use the Earth's geomagnetic field for orientation and navigation, but the neural mechanisms underlying that ability remain enigmatic [1Lohmann K.J. Q&A: Animal behaviour: Magnetic-field perception.Nature. 2010; 464: 1140-1142Crossref PubMed Scopus (103) Google Scholar, 2Wiltschko W. Wiltschko R. Magnetic orientation and magnetoreception in birds and other animals.J. Comp. Physiol. A Neuroethol. Sens. Neural Behav. Physiol. 2005; 191: 675-693Crossref PubMed Scopus (373) Google Scholar]. Support for at least two avian magnetoreceptors exists, including magnetically activated photochemicals in the retina [3Möller A. Sagasser S. Wiltschko W. Schierwater B. Retinal cryptochrome in a migratory passerine bird: A possible transducer for the avian magnetic compass.Naturwissenschaften. 2004; 91: 585-588Crossref PubMed Scopus (138) Google Scholar, 4Ritz T. Wiltschko R. Hore P.J. Rodgers C.T. Stapput K. Thalau P. Timmel C.R. Wiltschko W. Magnetic compass of birds is based on a molecule with optimal directional sensitivity.Biophys. J. 2009; 96: 3451-3457Abstract Full Text Full Text PDF PubMed Scopus (218) Google Scholar] and ferrimagnetic particles in the beak [5Fleissner G. Stahl B. Thalau P. Falkenberg G. Fleissner G. A novel concept of Fe-mineral-based magnetoreception: Histological and physicochemical data from the upper beak of homing pigeons.Naturwissenschaften. 2007; 94: 631-642Crossref PubMed Scopus (118) Google Scholar, 6Wiltschko R. Schiffner I. Fuhrmann P. Wiltschko W. The role of the magnetite-based receptors in the beak in pigeon homing.Curr. Biol. 2010; 20: 1534-1538Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar]. The possibility of a third magnetoreceptor in the inner ear lagena organs has been suggested [7Harada Y. Taniguchi M. Namatame H. Iida A. Magnetic materials in otoliths of bird and fish lagena and their function.Acta Otolaryngol. 2001; 121: 590-595Crossref PubMed Scopus (44) Google Scholar]. The brain must process magnetic receptor information to derive constructs representing directional heading and geosurface location. Here, we used the c-Fos transcription factor, a marker for activated neurons [8Heimovics S.A. Riters L.V. Breeding-context-dependent relationships between song and cFOS labeling within social behavior brain regions in male European starlings (Sturnus vulgaris).Horm. Behav. 2006; 50: 726-735Crossref PubMed Scopus (43) Google Scholar], to discover where in the brain computations related to a specific set of magnetic field stimulations occur. We found that neural activations in discrete brain loci known to be involved in orientation, spatial memory, and navigation may constitute a major magnetoreception pathway in birds. We also found, through ablation studies, that much of the observed pathway appears to receive magnetic information from the pigeon lagena receptor organs.