The Roots of Autism Are in the...Skin?
The skin is our gateway to the physical world. Below its surface are oodles of nerve fibers relaying different types of messages to the brain. At the ends of the fingertips, for example, fat and fast Aβ nerves help you fish for keys at the bottom of a messy purse, or feel the difference between cotton and polyester. Nearby those big nerves are thinner and slower C-fiber nociceptors, which transmit pain, and others that relay itchiness.
What I didn’t know until this week is that there is yet another type of nerve, found only under hairy skin, that carries information about our social interactions. These nerves, known as C-tactile (CT) afferents, respond to slow, gentle stroking — the soft touch you’d give to a baby’s forehead or a lover’s arm. And some researchers believe that these fibers are crucial for the development of the social brain.
“A hand on the shoulder, a pat on the back — these things anchor and cement social relationships in a meaningful way,” says Francis McGlone, a cognitive neuroscientist at Liverpool John Moores University in the U.K.
In today’s issue of Neuron, McGlone and his colleagues published a commentary reviewing what’s known about these nerves, including some provocative studies suggesting they play a role in autism.
Read more at...