"You Gotta Scratch That Itch"

Alisa Kanganis

AP Biology

January 2, 2018

Current Event 13

“You Gotta Scratch That Itch”

Hopkin, Karen. “You Gotta Scratch That Itch.” Scientific American, 19 Dec. 2018, www.scientificamerican.com/podcast/episode/you-gotta-scratch-that-itch/.

We are all familiar with itching, but do we really know why we feel itchy and why we feel the urge to scratch it? Yang-Gan Sun of the Chinese Academy of Sciences sought to answer this question. Typically, itching is caused by allergic reactions to the environment, insect bites, medication, and skin conditions. However, when the itching gets out of hand, we can scratch so much that we damage our skin. Sun pointed out that “Effective treatment for chronic itch is still lacking. This is largely due to our limited knowledge about the neural mechanism of itch.” While scientists have discovered most about the signal carried from the spinal cord to the skin, we know very little about how the information is processed in the brain. Therefore, Sun decided to conduct an experiment that exposes mice to histamine, which triggers itching. While doing so, the Tac1-expressing neurons in the periaqueductal gray of the brain lit up, indicating the these neurons are responsible for making animals itchy. When these neurons were eliminated, Sun and his colleagues noticed itching was greatly reduced among the mice.

This discovery is very important for people who suffer from chronic itching diseases. Now that a specific set of neurons, the Tac1, is known to be responsible for itching, it is possible that these neurons can be eliminated in humans in order to reduce itchiness. Not only will this reduce the uncomfortable sensation of being constantly itchy, but will also help people refrain from scratching themselves so frequently that it causes damage to their skin.

While I enjoyed reading Karen Hopkins article about itches, I do have a few suggestions for her. I appreciate the fact that the article is concise and written in simple terms so it is easy to understand, but I wish the author included more detail. For instance, how exactly can neurons be eliminated and does this process yield any negative effects? I would have also liked to learn more about how Sun and his team are going to use this newfound information to treat human patients. Regardless, I found this article to be very interesting as I had never truly indulged myself in the science of itching before now.