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Researchers pinpoint a gene marker for neurons sensitive to gentle touch
such as grooming.
By Edyta Zielinska
February 1, 2013
The gentle touch that calms pets can be traced to a genetically single,
genetically tractable neuron, researchers from the California Institute of
Technology reported this week (January 30) in
Researchers have known that a specific subset of neurons,
sometimes called CT afferents, were responsible for conveying pleasant or
anxiety-producing senses. But no one had found the molecular marker for
these nerves, nor been able to link them directly to behavior. By creating a
window into a living mouse and genetically labeling the neurons they
suspected were involved, researchers were able to see specific neurons light
up when then mouse was stroked with a paintbrush.
In a second
experiment, the researchers activated mice�s pleasant-touch nerves with a
drug and placed them in a chamber with a specific smell and look. The
investigators also injected the same mice with saline and placed them in an
adjacent room with a different smell and look. After these training
sessions, they let the mice choose between the the two chambers and saw that
the animals consistently favored the room in which they had associated with
the positive touch sensation.
The findings �imply that social touch
is not simply nice, but that it has calming power in the context of
something less-than-wonderful,� India Morrison, a neuroscientist at the
University of Gothenburg in Sweden, told ScienceNOW.
(Read more about
pleasant touch in our September 2012 feature �Pleasant
to the Touch.�)