Washington, Jan 31 (IANS) The most sensitive patch of skin belongs to the tip of the star-nosed mole snout, a mammalian like us, says a new study.
This organ has a higher proportion of touch-sensitive nerve endings than pain receptors, according to the findings by Diana Bautista and colleagues from the California-Berkeley and Vanderbilt universities.
Touch and pain are closely intertwined sensations. But very little is known about how these sensations are detected in our cells. The study authors turned to a unique species for answers: the star-nosed mole, the journal Public Library of Science ONE reports.
Besides the distinction of being the fastest-eating mammal known, the star-nosed mole also possesses one of the most sensitive tactile organs known in the animal kingdom, according to a California statement.
The star on its nose has the highest density of nerve endings known in any mammalian skin, with over 100,000 fibres in a patch of skin about one cm across. The researchers found these nerve endings significantly enriched in neurons sensitive to light touch, with a lower proportion of neurons that detect and respond to pain.
The novel touch and pain receptors they identified in the mole were also detected in sensory receptors in mice and humans, suggesting that these receptors are likely to be more common across other mammals as well.
The results of the study highlight how examining diverse and highly specialised species can reveal fundamental aspects of biology common across different animals.
Bautista says: "By studying the star-nosed mole we identified candidate genes that may mediate touch and pain. These genes represent new potential targets for the development of much needed drugs and therapies to treat chronic pain."