Nerve cell bodies that form the thinking part of the brain and spinal cord are called what?

• A. White Matter
• B. Grey Matter
• C. Nerve Cells
• D. Neurons

Answer: (B)

In the CNS, gray matter is the region that contains the neuron cell bodies, their dendrites, and synapses, where information processing happens. The color comes from the lack of myelin around these cells, unlike white matter, which is made mainly of myelinated axons that connect different gray matter areas. The thinking portions of the brain and spinal cord—the cerebral cortex and the spinal cord’s gray matter regions—are built primarily from these neuron cell bodies, so the tissue is described as gray matter. While nerve cells or neurons refer to the cells themselves, the question asks for the tissue that houses their bodies, which is gray matter.