Substantia gelatinosa of Rolando

Substantia gelatinosa of Rolando (SGR) (or gelatinous substance of the posterior horn), is a part of the spinal column. It forms the apex of the posterior grey column, one of three grey columns in the spinal cord. It is a v-shaped, translucent mass of neuroglia containing neuroglia cells and small neurons. Its gelatinous appearance derives from abundant neuropil with few myelinated fibers. It spans the entire spinal cord, extending into the medulla oblongata as the spinal trigeminal nucleus. Named after Luigi Rolando, it corresponds to Rexed lamina II.