Having A Bad Hair Day?

The detection of movement and vibrations is critical to most species. Whether you’re a mammal, reptile or a fish you have hairs that amplify the motion and convert it to an electrical signal in the brain. To make this work, each hair has a little bundle of organelles on the end, rather like a brush.
We use these little brushes to listen to endless political debates and we know our heads are spinning from these by more little brushes, which normally help us to maintain our equilibrium.
Fish have their little brushes hidden along their lateral line, which makes them very sensitive to variations in water movement. Very useful for proper shoaling behavior, but doesn’t help in paying attention to political debates, not that it matters to most fish as they have very short memories, which would probably make their vote predicable should they ever get registered.
If our hair bundles are going to work well for us, we want them to give us a clear signal when the volume is very low, but turn it down when the volume is very high. In other words we need them to be non-linear. Too much of a good thing and we may get them mussed up leaving us with a ringing in the ears.
Those little hair bundles have to be very versatile depending on the their location and end-use. A recent paper by   Ó Maoiléidigh et al published in the proceedings of the National Academy of Science has used a simple mechanical model that behaves in a similar fashion to hair bundles (1). The key is that the response can be widely varied by altering the loading of parts of the model in an analogous manner to the variation of situations that hair bundles find themselves occupying.
Now we know how we are using similar technology to fish or frogs are we going to shoal to the polls or sit stubbornly on our own pad and croak?

  1. http://www.pnas.org/content/early/2012/01/17/1120298109.full.pdf+html

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