Functional Populations Among Interneurons in the Dorsal Horn

The superficial dorsal horn of the spinal cord receives input from primary sensory neurons conveying information that is perceived as pain and itch. The vast majority of neurons in this area are interneurons, which form circuits that are essential for the behavioral expression of these percepts. The classes of neuron involved in these circuits and their functions are poorly understood, although recent studies have developed categorization schemes that account for most of these cells. This chapter highlights the important methodologies for identifying interneuron populations in the dorsal horn and discusses these populations in the light of their predicted functions.