Substantia gelatinosa of Rolando

The apex of the posterior horn of the gray matter of the spinal cord is capped by a V-shaped or crescentic mass of translucent, gelatinous neuroglia, termed the substantia gelatinosa of Rolando (or SGR) (or gelatinous substance of posterior horn of spinal cord), which contains both neuroglia cells, and small nerve cells. The gelatinous appearance is due to a very low concentration of myelinated fibers.

It is named after Luigi Rolando.

It corresponds to Rexed lamina II & III.

Function
The substantia gelatinosa is one point (the nucleus proprius being the other) where first order neurons of the spinothalamic tract synapse.

Many μ- and к-opioid receptors, presynaptic and postsynaptic, are found on these nerve cells; they can be targeted to manage pain of distal origin.

C fibers terminate at this layer. Thus the cell bodies located here are part of the neural pathway conveying slowly conducting, poorly localized pain sensation. However, some A delta fibers (carrying fast, localized pain sensation) also terminate in the substantia gelatinosa, mostly via axons passing through the area of the nucleus proprius. So there is cross talk between the two pain pathways.