Substantia gelatinosa:

cross-section of the spinal cord with circle indicating the general location of the substantia gelatinosa.

area of the posterior horn of the spinal cord where fibers carrying pain and temperature information from the body synapse on other fibers that will carry such information up to the brain.

Read more: Know your brain - Spinal cord

Watch this 2-Minute Neuroscience video to learn more about the spinal cord.