Animals' Ultimate Sensory Tool: How Do Whiskers Really Work?

Whiskers are more than just a facial enhancement for mammals. Aside from its 'cute' feature, it is more than functional than it looks.

Whiskers serve a very important role in mammals' sensory functions. Originally, sensory signals are sent to the brain through the follicle - the small spherical or vase-like base of the whisker made up of group of cells- and not through the whisker itself. Whiskers simply provide additional sensory input to the follicle, similar to antennae on insects.

A group of researchers from Northwestern University conducted a study on understanding the follicles' sensory setup and how whiskers actually work.

Typically, research on mammals were done experimentally in laboratories. Scientists from the Northwestern University decided to develop a mechanical simulation exploring the biological transmission instead of actually using a real animal.

According to them, the process cannot be measured experimentally by slicing the follicle open as it will damage its biological component and will miss the main purpose of the research. By developing their very first mechanical simulation, understanding how whiskers work and its relation to human touch was made possible.

Experimental data gathering through anatomical observation of rats

The study was further made possible through anatomical observation of rats. Rats are known to be good at navigating places using their sense of touch and especially how their senses magnify in dark places. The Northwestern team believed that using rats will provide more accurate results due to its common whisking behavior. They highlighted that although the observation and data collection was done with rats, findings will likely apply to other mammals as well.

The simulation illustrated how the follicle bends into an 'S' shaped-profile, whether it touches an object or something external passively touches it. In conclusion, the simulation model depicts consistency in its shape and form under both conditions, and once touched, the sensor cells transmit information to the brain.

Mitra Hartmann, senior author of the study, said that they could not have done the study without experts from different scientific fields like mechanical engineers, a neuroscientist and a civil engineer. In addition, John Rudnicki contributed his knowledge of beam theory- commonly used in geology such as the bending of sediment layers and tectonic plates - in analyzing how the whisker contribute to stimulation of the follicle.

Lastly, researchers stressed how the simplified simulation model of the whiskers also shed light on human's sense of touch.

Human sense of touch simplified by whisker simulation

While the human sense of touch is more complicated than whiskers, Hartmann believed that their simulation model provided new insights into the human's nature of touch. She made comparison of how it was simpler to understand the nature of touch through whiskers than of human hands, given that the sensory neurons in our fingers are too receptive and way more complex.

Given that the human touch has multiple hotspots making it impossible to know in just a day, the insight gotten from whiskers simulation paves way into understanding it in a