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How does gray matter differ from white matter in the central nervous system?

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Diagram of a human figure showing the full nervous system, including the brain, spinal cord, and branching peripheral nerves throughout the body, with labels for each part. — human nervous system The conduction of electrochemical stimuli from sensory receptors in the human nervous system occurs via organized groups of specialized cells, consisting largely of neurons, various neural support cells, and tracts of nerve fibers.

In the central nervous system (CNS), gray matter and white matter are distinguished primarily by their cellular composition and functional roles.1

Gray matter is composed of large concentrations of neurons, including cell bodies, dendrites, and synapses. It serves as the site for processing information and coordinating responses. Within the spinal cord, gray matter is organized into distinct cellular layers known as laminae that receive sensory input and house motor neurons.12
White matter consists mainly of bundles of myelinated axons. These fibers are covered in myelin, an insulating sheath that facilitates rapid signal transmission. White matter acts as the communication network, relaying signals along tracts between different areas of the brain and spinal cord.13

These tissues are supported by neuroglia, such as astrocytes and oligodendrocytes, which are distributed differently throughout these regions to maintain the neuronal environment and support signal conduction.4