As children we’re all told to drink up our milk to get that vital calcium, which is great for our bones. It turns out that calcium is also great for our ears. Specifically, hair cells in our inner ears. Small projections at the tops of hair cells called stereocilia (pictured false-coloured and very highly magnified) bend when sound passes by. They’re arranged in three rows, connected by linkers at their tips. When the stereocilia bend, the linkers move too. Acting like hinges of a door, the linkers control the opening of channels in the tips of the stereocilia. These channels let in calcium and are present on two of the three rows of stereocilia. When blocked in mice by drugs, the stereocilia (yellow and red) drastically shrank, disturbing the delicate architecture needed for hearing. So it seems calcium doesn’t just help build strong bones but also healthy stereocilia.
Written by Lux Fatimathas
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