Clusters of iron-rich cells in the upper beak of pigeons are macrophages not magnetosensitive neurons

@article{Treiber2012ClustersOI,
  title={Clusters of iron-rich cells in the upper beak of pigeons are macrophages not magnetosensitive neurons},
  author={Christoph Daniel Treiber and Marion Claudia Salzer and Johannes Riegler and Nathaniel B. Edelman and Cristina Sugar and Martin W. Breuss and Paul Pichler and Herv{\'e} Cadiou and Martin Saunders and Mark F. Lythgoe and Jeremy A. Shaw and David Anthony Keays},
  journal={Nature},
  year={2012},
  volume={484},
  pages={367-370}
}
Understanding the molecular and cellular mechanisms that mediate magnetosensation in vertebrates is a formidable scientific problem. One hypothesis is that magnetic information is transduced into neuronal impulses by using a magnetite-based magnetoreceptor. Previous studies claim to have identified a magnetic sense system in the pigeon, common to avian species, which consists of magnetite-containing trigeminal afferents located at six specific loci in the rostral subepidermis of the beak. These… 
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Prussian blue technique is prone to yield false negative results in magnetoreception research
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