My wife and I love the fall season. We love the colors, Halloween, county fairs and the wonderful change in temperature. We have already transitioned our home into fall mode and broke out our decorations. Perhaps this will encourage the weather to cooperate, and we will see our first cold snap soon.
I look forward to the day that I walk outside and feel that wonderful chill, but have you ever wondered exactly how you feel the change?
Simple answers satisfy most, but science loves to seek the full truth and discover all the details to our simple questions. This past week in my courses at Paris Junior College, we have been investigating the details of why we and other animals must take in oxygen and exhale carbon dioxide.
Everyone knows you need to breathe to live, but far fewer of us actually know why. For the scientifically-minded individual, stopping at the answer “to live” is not satisfying at all and it offers no real explanation. You may also know that you can feel when fall has indeed arrived when you walk out in the morning to 60 degrees, but how did that happen?
Dr. Shawn Xu of the University of Michigan is a lead researcher, working with a team of other researchers, which published an article in the journal “Cell” in late August. Their work was titled “A Cold-Sensing Receptor Encoded by a Glutamate Receptor Gene.” They had discovered the gene and protein involved in your ability to sense that it is cold.
Science already knew that peripheral nerves in your skin respond to changes in external temperature and then relay this information to your brain so that you can respond accordingly. The details of how the nerves know are what Dr. Xu and colleagues worked on. They kept asking questions and were not satisfied with the simple answer of “nerves in your skin feel it.”
The team found that the gene involved was one that is shared across species. We call this “conserved” in biology. A great many of the genes that control the basic functions of life exist in everything from bacteria to blue whales. You might imagine that a gene responsible for letting a species know the temperature had dropped would be one of these highly conserved genes in life.
The very cool thing about their research is that they tested it, as all good scientists do. The team knocked out the suspected “cold” gene in C. elegans worms and the worms stopped responding to the cold as if they could no longer feel that it was cold. The worms with the active gene all avoided the cold by curling up, but the knock-out worms just kept swimming. They did the same thing in mice basically and got the same results, indicating that the gene was indeed a key to kicking off the signal that allows a species to know that it is cold out.
Now we know more about the details of how we know fall is here.