Magnetoception
From Wikipedia, the free encyclopedia
Magnetoception (or "magnetoreception") is the ability to detect changes in a magnetic field to perceive direction or altitude and has even been postulated as a method for animals to develop regional maps. It is most commonly observed in birds, though it has also been observed in many other animals including honeybees and turtles. Researchers have identified a probable sensor in pigeons: a small (dwarf), heavily innervated region of the skull, which contains biological magnetite. Humans have a similar magnetite deposit in the ethmoid bone of the nose, and there is some evidence this gives humans some magnetoception. [1][2][3]
Although there is no dispute that a magnetic sense exists in many avians (it is essential to the navigational abilities of migratory birds), it is a controversial and not well-understood phenomenon. Certain types of bacteria (magnetotactic bacteria) and fungi [4]are also known to sense the flux direction, these contain organelles known as magnetosomes for this purpose. In bees, it has been observed that magnetite is embedded across the cellular membrane of a small group of neurons; the theory is that when the magnetite aligns with the Earth's magnetic field, induction causes a current to cross the membrane which depolarizes the cell.
[edit] See also
[edit] References
- ^ Do humans have a compass in their nose?. Retrieved on 2008-01-02.
- ^ The Human Compass. Retrieved on 2008-01-02.
- ^ Carrubba S, Frilot C, Chesson AL, Marino AA (2007). "Evidence of a nonlinear human magnetic sense". Neuroscience 144 (1): 356–67. doi: . PMID 17069982.
- ^ Pazur A, Schimek C,Galland P (2007) Magnetoreception in microorganisms and fungi. Central European Journal of Biology 2(4): 597 [1]
[edit] External links
- The Gift of Magnetic Vision — Implantation of a magnet in a human finger to explore artificial magnetoception
- ABC Dr Karl - Magnetic Sixth Sense
- Evidence of a nonlinear human magnetic sense
- Modulation of spike frequencies by varying the ambient magnetic field and magnetite candidates in bees (Apis mellifera)
- The Physics and Neurobiology of Magnetoreception (Nature Reviews Neuroscience)