Course/Module 8/Lesson 15

Lesson 15

Biogenic Magnetite in the Human Brain

The Inner Compass

⏱ 0:41
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Audio Narration

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"You have actual magnetic crystals inside your head. And your body builds them on purpose."
Key Terms
  • Magnetite (Fe3O4): A naturally occurring magnetic mineral.
  • Biogenic: Produced by a living organism rather than by geologic processes.
  • Ferrimagnetic: A type of magnetism used in compasses and data storage.
  • Single-domain crystal: A crystal that behaves as one single, strong magnet.

In 1992, Joseph Kirschvink proved that the human brain contains roughly 5 million magnetite crystals per gram. In 2018, Bauer showed that these crystals are twice as concentrated in the brainstem as anywhere else in the brain — exactly where the neuromelanin-dense SN and LC are located. We have even found four gene modules in humans that are ancestral descendants of the system bacteria use to make 'magnetosomes'. Your brain isn't just processing signals; it is physically built to respond to magnetic fields.

BRAINSTEM MAGNETITE

Key Takeaways

  • ◈ The human brain contains millions of biogenic magnetite crystals.
  • ◈ Concentration is highest in the neuromelanin-dense brainstem.
  • ◈ This system evolved from ancient bacterial 'magneto-sensors'.
Collapse Check — Reflection

Apply Your Intelligence

If you have magnets in your brain, what does that mean for your relationship to the Earth's magnetic field?

Next: How do the melanin and the magnets work together? That is the cascade.
Module Overview