Some of Stefan's neurons died as they aged. What type of cell helped digest their remains?

• A. Schwann cells
• B. Astrocytes
• C. Microglia
• D. Oligodendrocytes

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the role of microglia in the nervous system. Microglia are specialized immune cells in the central nervous system (CNS) that act as the primary defense mechanism. They are responsible for clearing out dead neurons, cellular debris, and pathogens through a process called phagocytosis.
2. Step 2: Compare the functions of the other cell types listed in the problem. Schwann cells are involved in the peripheral nervous system and help form the myelin sheath around axons. Astrocytes provide structural and metabolic support to neurons but do not digest dead neurons. Oligodendrocytes form the myelin sheath in the CNS but are not involved in clearing debris.
3. Step 3: Recognize that microglia are uniquely suited for digesting the remains of dead neurons due to their phagocytic activity and immune response capabilities.
4. Step 4: Recall that microglia are activated in response to neuronal damage or aging, and they migrate to the site of injury or cell death to perform their cleanup function.
5. Step 5: Conclude that the correct answer is microglia, as they are the cells responsible for digesting the remains of dead neurons in the CNS.