Medulla spinalis - Substantia grisea
The Rexed laminae comprise a system of ten layers of grey matter (I-X), identified in the early 1950s by Bror Rexed to label portions of the gray columns of the spinal cord. 
Similar to Brodmann areas, they are defined by their cellular structure rather than by their location, but the location still remains reasonably consistent.
- ^ Rexed B (1952). "The cytoarchitectonic organization of the spinal cord in the cat.". J Comp Neurol 96 (3): 414–95. doi:10.1002/cne.900960303. PMID 14946260.
- ^ Rexed B (1954). "A cytoarchitectonic atlas of the spinal cord in the cat.". J Comp Neurol 100 (2): 297–379. doi:10.1002/cne.901000205. PMID 13163236.
- ^ a b c Blumenfeld, Hal (2010). Neuroanatomy through Clinical Cases. Sunderland, MA: Sinauer Associates.