YOU don't need us to tell you that certain types of touch - massage and stroking - can be pleasurable. Nerves dedicated to creating these feelings have been identified and artificially stimulated in mice, leading to hope that the work could aid the development of drugs that relieve pain or stress.
Some nerves rapidly tranit sensations of touch or pain to the brain, but others work much more slowly. These C-tactile fibres, as they are known in humans, are found under hairy skin and respond to stroking.
David Anderson at the California Institute of Technology in Pasadena and colleagues used calcium imaging to identify similar bundles of nerves in mice.
When the mice were in a special chamber, the team injected them with a chemical that activated these nerves. Afterwards, the mice visited the chamber almost twice as often as they had before, suggesting that they enjoyed the experience and wanted more (Nature, DOI: 10.1038/nature11810).
A drug that evokes a similar response in humans could boost the beneficial effects of skin-to-skin contact such as massage in rehabilitation or for psychiatric conditions, says Johan Weserg at the University of Gothenburg in Sweden.
Interactions involving stroking are common among many mammals, particularly in nurturing, and removing this contact can impair development. "For the first time we are getting a neurological basis for these phenomena," says Francis McGlone at Liverpool John Moores University in the UK.
