Gray matter (substantia grisea) Last edited and medically reviewed by Alaric Steinmetz on 12.10.2023 Synonyms Substantia grisea The Brain and Spinal cord are divided into gray matter (substantia grisea) and white matter (substantia alba). The gray matter contains cell bodies, which are also called perikarya.Imaging Enlarge Gray matter in the brain (for example, marked by two red arrows) on an axial MDEFT MRI sequence.