|Brain: Posteromarginal nucleus|
|File:Medulla spinalis - Substantia grisea - English.svg|
|Medulla spinalis (Rexed lamina I labeled at upper left.)|
The posteromarginal nucleus, Rexed lamina I, is located at the most dorsal aspect of the dorsal horn of the spinal cord. The neurons located here receive input primarily from Lissauer's tract and relay information related to pain and temperature sensation.