Major basic protein is secreted by?
**Core Concept**
Major basic protein (MBP) is a component of the myelin sheath surrounding nerve fibers, and it plays a crucial role in maintaining the structural integrity and function of the myelin sheath.
**Why the Correct Answer is Right**
MBP is a type of extracellular matrix protein that is secreted by oligodendrocytes, the myelinating cells of the central nervous system. Oligodendrocytes are responsible for wrapping the myelin sheath around axons, and MBP is one of the key proteins that helps to stabilize the myelin structure. The correct answer is associated with the oligodendrocytes' function in the central nervous system.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because MBP is not secreted by astrocytes, which are involved in providing support and nutrients to neurons.
**Option B:** Incorrect because MBP is not secreted by neurons themselves, but rather by the glial cells that support them.
**Option C:** Incorrect because MBP is not secreted by microglia, which are involved in immune responses within the central nervous system.
**Clinical Pearl / High-Yield Fact**
MBP is a marker of oligodendrocyte function and is often used in research and diagnostic tests to study demyelinating diseases such as multiple sclerosis.
**Correct Answer:** C. Oligodendrocytes.