The study identified a specific population of neurons that transmit mechanical itch from the spinal cord to the parabrachial nucleus (PBN) in the brain, and separate populations of neurons in the PBN relay mechanical and chemical itch. The study also found that mechanical and chemical itch are transmitted by separate ascending pathways to the PBN, where they engage separate populations of FoxP2+ neurons to drive scratching behavior. Additionally, the study suggests that both mechanical and chemical itch pathways are recruited together in pathological itch.