Cats do their sensing at the base of their whiskers, which is hidden inside a small follicle, and researchers have just found out a lot about how this process works.
A fresh study published in PLOS Computational Biology explored a new mechanical simulation of how whisker sensing works.
In combination with anatomical observations of rats, this simulation demonstrates that the tip of the whiskers gets bent into an ‘S’ shape when it is touched – and this ‘S’ shape then pulls and pushes particular sensor cells to send signals to the brain to notify it about what is happening.
Mitra Hartmann, a biomedical engineering professor at Northwestern University had the following to say:
“The part of the whisker that triggers touch sensors is hidden inside the follicle, so it’s incredibly difficult to study.”
“By developing new simulations, we can gain insights into biological processes that cannot be directly measured experimentally.”
And while the model is a simplified version of reality, and does not use a full set of data from the rat whiskers, it gives us some deep insights into how whiskers function to sense an animal’s surroundings.
The study gathered knowledge from various scientific fields, including continuum mechanics and neuroscience.
Part of the mechanical model involved the use of the beam theory, which is often applied in engineering and geology in order to understand how bending materials or entire tectonic plates might interact with one another.
In this case, beam theory was used for the interaction of the whisker and its follicle.
The team found that the change in the shape of the whisker – in many ways “just a deformable beam interacting with springs” – was likely to be the same whether it was actively pressing against something or passively being touched by something else.
Yifu Luo, a mechanical engineer from Northwestern University said:
“Our model demonstrates consistency in the whisker deformation profile between passive touch and active whisking.”
“In other words, the same group of sensory cells will respond when the whisker is deflected in the same direction under both conditions. This result suggests that some types of experiments to study active whisking can be done in an anesthetized animal.”
A Genius New Simulation Has Revealed More on How Whiskers Actually Work
Whiskers on cats and other mammals aren't covered with sensors. Instead, the sensing is done at the base of the whisker, hidden inside a small follicle, and s…https://t.co/VTreiv5OhL https://t.co/Od5tNrPXlA
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And while this research only studied rats in terms of actual biology, the team believe their findings will apply to all animals with whiskers to a degree, even though there will probably also be differences.
For example, rats use their whiskers much more as local scanners than cats do.
Furthermore, the study could additionally help the development of manmade whiskers to be used in the field of robotics. They can act as fine-tuned detectors of what’s around an animal, operating in different frequencies, and that is an incredibly helpful mechanic to copy.
The researchers also believe that studies into human touch will benefit from these findings as well.
There is still lots to be found out about how we interact with the world through this particular sense, and the ‘S’ bend produced by whiskers could be seen as new insight into understanding it.
“The sense of touch is incredibly important to nearly everything we do in the world, yet it is very difficult to study touch using hands,” Hartmann said. “Whiskers provide a simplified model to understand the complex, mysterious nature of touch.”
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