That gentle touch would mean nothing without protein
Receptivity to touch develops early in life, with the first caresses that mothers lavish on newborns. Now, scientists claim to have cracked the mystery of the "gentle touch".
Researchers from University of California San Francisco (UCSF), have identified the exact subset of nerve cells responsible for communicating gentle touch to the brains of larvae of drosophila, the fruit fly. The cells have been called class III neurons.
They also uncovered a particular protein called NOMPC, found abundantly at the spiky ends of the nerves, which appears to be critical for sensing gentle touch in flies, the journal Nature reports.
The team discovered that without this key molecule, flies are insensitive to any amount of eyelash stroking. If NOMPC is inserted into neurons that cannot sense gentle touch, even those neurons wake to the sense of touch, according to a statement from the UCSF.
A newborn fruit fly larva, when tickled with a freshly plucked eyelash, will respond by altering its movement - an observation that has helped UCSF scientists uncover the molecular basis of gentle touch, one of the least well understood of our senses.
"NOMPC is sufficient to confer sensitivity to gentle touch," said Yuh Nung Jan, professor of physiology, biochemistry and biophysics and a Howard Hughes Medical Institute investigator at UCSF.
Jan led the study with his wife Lily Jan, his counterpart and a Howard Hughes Medical Institute investigator.
The work sheds light on a poorly understood yet fundamental sense through which humans experience the world and derive pleasure and comfort.