[A novel neurotransmitter, DAN, mediates pain sensation in the spinal dorsal horn]

Differential screening-selected gene aberrative in neuroblastoma(DAN) belongs to a novel gene family(DAN family) that includes the head-inducing factor, Cerberus, and dorsaling factor, Gremlin. It has been suggested that DAN family members control diverse processes in growth, development and the cell cycle. Here, we demonstrate that DAN is produced in the small neurons of the dorsal root ganglion(DRG) and transported to the nerve terminals in the spinal dorsal horn in adult rats. Furthermore, intrathecal injection of an antibody to DAN suppressed pain sensations induced by the application of complete Freund's adjuvant and carageenan into the rat hindpaw, and the amount of DAN mRNA in the DRG neurons and of DAN in the spinal dorsal horn were increased in the inflammatory models. These data suggest that DAN in a novel neurotransmitter and/or modulator in the primary sensory nerve fibers for pain sensation.