14 DAY TRIAL // Are you naturally born Viking? Or do you shiver at the slightest breeze? That's on your genetics. A new research, published in the Journal of Neuroscience, shows that it could be in fact in a single protein.
Some studies had pointed that cold-sensing neurons have specialized functions, with some for painful cold sensations and others just for cooling sensations. But, the team at the University of Southern California has discovered that all the cold sensing neuronal dendrites employ a sole protein called TRPM8, and thus, they can perceive a wide array of cold sensations.
"We all know when we stimulate our teeth with cold we get this distinct cold sensation", said co-author David McKemy. "You get this sharp transient shooting pain and this dulled, aching sensation", McKemy told MSBNC.
"There was a notion that there were neurons called cool fibers and there were others involved in detecting cold pain", he said. Based on other researches, the team expected neurons employing TRPM8 to be characteristic for the pleasant cooling sensation. To check this, the researchers engineered mice so that neuron fibers containing TRPM 8 would shine in a fluorescent green. The cold-sensing fibers were tracked from sensory neurons located in the spine to dendrites in the skin.
"What our study suggests is that even though these neurons express this single protein, it looks like they have diverse functions. Humans appear to share the same mechanism. Nerves that produce TRPM8 account for about 75 % of all cold-sensing neurons", said McKemy.
The researchers suppose there must be other pain specific neurons for cold, like in the case of skin burned in frostbite. "If we understand the basic nuts and bolts of the molecules and neurons and how they detect pain normally, then perhaps we can figure out why we detect pain when we shouldn't", said McKemy.