The human brain's color, in its living state, is predominantly white, black, and red-pinkish due to its composition and blood flow. The colors seen in preserved or deceased brains are different due to the absence of blood and oxygen.
Brain Color Breakdown
-
White Matter: The white color comes from myelin, a fatty substance that insulates nerve fibers (axons). This insulation allows for faster and more efficient transmission of electrical signals.
-
Gray Matter: The gray color comes from the neuronal cell bodies and dendrites, which lack the extensive myelination of axons.
-
Black: Certain regions, particularly those rich in neuromelanin (a pigment related to dopamine production), such as the substantia nigra, appear black. This is more apparent in older individuals.
-
Red-Pinkish: This color is due to the blood supply flowing through the brain's vessels. An active, living brain requires a constant supply of oxygenated blood, which imparts a pinkish hue.
Color Variations and Deceased Brains
The "gray matter" description is somewhat misleading, as a healthy, living brain isn't simply gray. Brains seen in movies or medical illustrations are often presented in shades of gray, white, and yellowish-brown because they have been preserved (e.g., with formaldehyde) or are no longer receiving blood flow. This process alters the natural color.
Summary
The brain's color is determined by the interplay of its components (myelin, neurons), the presence of pigments, and, crucially, blood flow. A living brain displays a range of colors from white and gray to pinkish-red, while preserved brains tend to appear in more muted tones.
