Wiggling Whiskers for a Living?

At first glance it sounds like another pork barrel government waste of money. Research grants to wiggle rat and mouse whiskers?

Connections from touch receptors that translate touch into brain signals to the brain are mapped in a precise reflection of the layout of your skin over your body. One thing different is that areas sensitive to touch like your fingertips and your lips have many more connections than relatively insensitive areas like your back.

When you explore the environment with touch you probably reach out and grab something and then move it around in your hands. This is active touch carried out by a couple of your organs of touch; your hands. In particular, primarily the finger tips on your hands.

As a brain scientist I ask what the signals are that the thousands of receptors are transmitting to the brain from those fingertips. How does the brain recognize an object and the object’s properties from those signals?

The example of you exploring an object with your hands is surprisingly complex. How may a brain scientist control the stimulus to the fingers in such a precise manner that they’re able to come up with the precise, preferably mathematical, translation between stimulus and signal? This is where whiskers come in.

Whiskers (technically vibrissae) are part of the sensory organs of touch that enable rodents like rats and mice to get around and explore their surroundings. Each whisker is attached at its root to a vibrissa follicle that contains the receptors that translate whisker movement into brain signals.

Each follicle is located at a point on the rodent’s snout so that the group of more than 30 whiskers and each side of the rodent’s face forms an array that works as a unit for exploring the environment in much the same way as your fingers and thumb make up an array of five on each of your hands.

The cool thing is that the scientist is able to very precisely control how a whisker is stimulated right down to about a one micron movement. And they may control other parameters like which direction the whisker is moved. Finally, the anatomy of the connections within the whisker system in rodents is very well defined. I will post more about this last very important point in the near future.

In sum, wiggling whiskers enables us to learn a lot about the brain and touch. Expect future postings here on research in this area.