Gray matter and white matter both exist in the brain and spinal cord. Gray matter, named for its pinkish-gray hue, contains axon terminals, neural cell bodies, and all nerve synapses. This form of brain tissue is prevalent in the cerebellum, cerebrum and brainstem, also forming a butterfly-shaped portion of the central spinal cord. White matter, on the other hand, is comprised of axon bundles that are coated with myelin, a mix of proteins and lipids, that protects the axons and aids in conducting nerve signals between the brain and the rest of the body.