Primary afferent neurons mediating itch sensation

Using sophisticated genetic approaches, the peripheral neuronal mechanisms of itch have been uncovered at an unprecedented pace over the last 2 decades in mice. Although questions regarding the translatability of these observations to nonhuman and human primates exist, these discoveries provided important insights motivating experiments in higher species. In this chapter, we will summarize findings regarding the peripheral neuronal mechanisms underlying the sensation of itch in different species, highlighting commonalities and differences that have been observed. The goal of this summary is not only to provide an overview of our current knowledge but also to highlight aspects that need clarification. In particular, the peripheral neuronal code of itch and harmonization of functional and transcriptional classifications of primary afferent neurons remain unresolved.