Learning from leprosy’s nerve damage
Since ancient times, societies have feared and sometimes cast out people with leprosy, an infectious disease characterized by skin lesions and a gradual loss of feeling in the limbs. Researchers have now teased out some of the earliest steps in the irreversible nerve damage characteristic of the disease. It turns out that the bacterium that causes leprosy directly damages a protective sheathing, made of the protein myelin, around many nerve cells.
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The myelin sheath is produced by so-called Schwann cells. The leprosy-causing bacterium–known as Mycobacterium leprae–can attach to all Schwann cells but it can grow only inside those that are not making myelin at the time.