The posterolateral tract contains centrally projecting axons from dorsal root ganglion cells carrying peripheral pain and temperature information (location, intensity and quality).

These axons enter the spinal column and penetrate the grey matter of the dorsal horn, where they synapse on second-order neurons in either the substantia gelatinosa of Rolando or the nucleus proprius.

After this, the 3rd order neuron fibers traverse the internal capsule and the corona radiata, ultimately synapsing in the post central gyrus (somatosensory cortex).

The location of this synapse is dependent upon the somatotopic organisation of the somatosensory cortex, it can be estimated according to the position on the 'somatosensory homunculus' The posterolateral tract consists of fine fibers which do not receive their myelin sheaths until toward the close of fetal life.

This article incorporates text in the public domain from page 762 of the 20th edition of Gray's Anatomy (1918) 2° (Spinomesencephalic tract → Superior colliculus of Midbrain tectum)