Whether it’s an overly zealous use of air conditioning or a frigid January morning, you and other mammals have one thing in common: You can sense when it’s cold. But until recently, science had lagged in figuring out just precisely how we know we need an extra sweater.
Now, researchers from the University of Michigan have drilled down into what, exactly, allows us to “detect” that the temperature has dropped — specifically below 60 degrees Fahrenheit.
Using prior research that identified the first cold-sensing receptor protein (in a tiny worm, no less), researchers conducted experiments to examine animals’ behavior in reaction to temperature changes and other stimuli.
In this case, mice that were missing a protein called GluK2 showed no response to icy temperatures, but responded normally to hot, warm and even cool temperatures.
Interestingly, the protein is typically found in the brain, where it acts as an operator — triaging various chemical signals to enable communication between neurons.
But GluK2 is also found in sensory neurons across the peripheral nervous system — outside the brain and spinal cord, in other words — where it takes on its cold-sensing properties, processing temperature cues instead of chemical signals to let us know when we feel cold.
Why does this matter? First, it simply adds to the knowledge base scientists have about thermosensation, in general.
As one example of why it’s relevant: Patients undergoing chemotherapy tend to feel cold in an acute, even painful way — and this could help us understand why.
For now, that’s pretty “cool” on its own — pun intended.