The Rexed laminae comprise a system of ten layers of

grey matter Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil ( dendrites and unmyelinated axons), glial cells ( astrocytes and oligodendrocytes), synapses, and capillaries. Grey matter is ...

(I–X), identified in the early 1950s by Bror Rexed to label portions of the grey columns of the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

. Similar to

Brodmann area A Brodmann area is a region of the cerebral cortex, in the human or other primate brain, defined by its cytoarchitecture, or histological structure and organization of cells. History Brodmann areas were originally defined and numbered by th ...

s, they are defined by their cellular structure rather than by their location, but the location still remains reasonably consistent.

Laminae

Posterior grey column The posterior grey column (posterior cornu, dorsal horn, spinal dorsal horn, posterior horn, sensory horn) of the spinal cord is one of the three grey columns of the spinal cord. It receives several types of sensory information from the body, inc ...

: I–VI ** Lamina I: marginal nucleus of spinal cord or posteromarginal nucleus ** Lamina II: substantia gelatinosa of Rolando ** Laminae III and IV: nucleus proprius ** Lamina V: Neck of the dorsal horn. Neurons within lamina V are mainly involved in processing sensory afferent stimuli from cutaneous, muscle and joint mechanical nociceptors as well as visceral nociceptors. This layer is home to wide dynamic range tract neurons, interneurons and propriospinal neurons. Viscerosomatic pain signal convergence often occurs in this lamina due to the presence of wide dynamic range tract neurons resulting in pain referral. ** Lamina VI: Base of the dorsal horn. No nociceptive input occurs here, instead this lamina receives input from large-diameter fibres innervating muscles and joints and from muscle spindles which are sensitive to innocuous joint movement and muscle stretch to feed forward this information to the cerebellum where it can modulate muscle tone accordingly. * Lateral grey column: VII and X ** Lamina VII: intermediomedial nucleus, intermediolateral nucleus, posterior thoracic nucleus in the thoracic and upper lumbar region ** Lamina X: an area of grey matter surrounding the

central canal The central canal (also known as spinal foramen or ependymal canal) is the cerebrospinal fluid-filled space that runs through the spinal cord. The central canal lies below and is connected to the ventricular system of the brain, from which it ...

. * Anterior grey column: VIII–IX ** Lamina VIII: motor

interneurons Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons. I ...

; Commissural nucleus ** Lamina IX: hypaxial (body wall muscles), lateral (in limb regions) and medial (back muscles)

motor neurons A motor neuron (or motoneuron or efferent neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly ...

, also phrenic and spinal accessory nuclei at cervical levels, and Onuf's nucleus in the sacral region

References

{{Authority control Spinal cord