Scientists find 'pleasure nerves'
Mothers use touch to sooth their babies
Scientists say they understand more about how the body responds to
pleasurable touch.
A team, including scientists from the Unilever company, have identified
a class of nerve fibres in the skin which specifically send pleasure
messages.
And people had to be stroked at a certain speed - 4-5cm per second - to
activate the pleasure sensation.
They say the study, published in Nature Neuroscience, could help
understand how touch sustains human relationships.
For many years, scientists have been trying to understand the mechanisms
behind how the body experiences pain, and the nerves involved in
conveying those messages to the brain.
This is because people can suffer a great deal.
Neuropathy, where the peripheral nervous system is damaged, can be very
painful and sometimes the messaging system goes wrong and people feel
pain even when there is no cause.
Hairy skin
But the researchers involved in this work were looking to understand the
opposite sensation - pleasure.
This research, which also involved experts at the University of
Gothenburg in Sweden and at the University of North Carolina, recorded
nerve responses in 20 people.
They then tested how people responded to having their forearm skin
stroked at a range of different speeds.
They identified "C-tactile" nerve fibres as those stimulated when people
said a touch had been pleasant.
If the stroke was faster or slower than the optimum speed, the touch was
not pleasurable and the nerve fibres were not activated.
The scientists also discovered that the C-tactile nerve fibres are only
present on hairy skin, and are not found on the hand.
Professor Francis McGlone, now based at Unilever after an academic
career where he carried out research into nerve response, says this is
likely to be a deliberate "design".
"We believe this could be Mother Nature's way of ensuring that mixed
messages are not sent to the brain when it is in use as a functional
tool."
He said the speed at which people found arm-stroking pleasurable was the
same as that which a mother uses to comfort a baby, or couples use to
show affection.
Professor McGlone said it was part of the evolutionary mechanism that
sustained relationships between adults, or with children.
"Our primary impulse as humans is procreation, but there are some
mechanisms in place that are associated with behaviour and reward which
are there to ensure relationships continue."
Source: BBC
_________________
Lying to my face again
Suicidal imbecile
Think about it put it on the fault line
What'll it take to get it through to you precious
Over this, why do you wanna throw it away like this
Such a mess, come to this, come to this
Disconnect and self destruct, one bullet at a time
What's your hurry, everyone will have his day to die
If you choose to pull the trigger, should your drama prove sincere,
Do it somewhere far away from here
Subject: Scientists find 'pleasure nerves' 
Sun May 03, 2009 9:10 am
