Distribution of substance P receptor binding in dorsal column nuclei of rat, cat, monkey and human.

In the present study, substance P receptor binding was localized in the dorsal column nuclei (DCN) of the rat, cat, monkey, and human. Bolton-Hunter-labeled [125I]substance P binding was most concentrated in the cell nests of the core region, but was present throughout the DCN of each species. The distribution of substance P receptors may reconcile apparent mismatches between the widespread responsiveness of DCN neurons to substance P and the restricted distribution of substance P containing afferents.