All over your body, you have special nerve pathways that transmit different types of information from your skin. For example, you don't confuse softness with temperature because different nerves are responsible for each type of sensation. Many of these nerves connect at the spinal cord before being transmitted to the brain, where they are processed. But since we don't feel a mechanical itch on our skin all the time, even when we have things like clothes pressing against it, there must be something gating the signal to the brain. The researchers decided to test a particular protein called neuropeptide Y, or NPY, which has a number of functions in the brain such as reducing anxiety or pain and controlling epileptic seizures. But NPY is also found in the spine, and researchers knew little about what it does there.