Penfield’s iconic sensory homunculus depicts the representation of discriminative touch in somatosensory cortex.SUSANNAH WALKER AND FRANCIS MCGLONE
Human skin has two different ways of perceiving its environment: through relatively large, fast discriminative touch nerve fibers that detect objects and through smaller, unmyelinated C fibers that are typically associated with itch or touch. “One is about sensing the world and the other is about feeling,” Susannah Walker of Liverpool Johns Moores University in the U.K. told The Scientist today (November 17) at the Society for Neuroscience (SfN) conference in Washington, DC.
One type of C fiber, known as C-tactile afferents (CTs) is specifically dedicated to the sensation of gentle touch, responding most strongly to strokes around 3 to 10 centimeters/second. In mice, these fibers are found to be most dense on the back and upper extremities, with fewer CTs found on the lower ...
