Negri bodies are not found in which part of CNS?
**Core Concept**
Negri bodies are characteristic intracytoplasmic inclusions found in the neurons of individuals infected with rabies virus. They are composed of viral nucleocapsid proteins and are a hallmark of rabies infection.
**Why the Correct Answer is Right**
Negri bodies are typically found in the neurons of the hippocampus, cerebellum, and brainstem, but they are not typically found in the spinal cord. This is because the rabies virus tends to replicate and cause damage in the central nervous system (CNS) regions that are rich in neurons, such as the hippocampus and cerebellum. The spinal cord, on the other hand, is primarily composed of glial cells and motor neurons, which are less commonly affected by the rabies virus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Negri bodies are indeed found in the hippocampus, which is a region of the CNS affected by rabies virus.
**Option B:** This option is incorrect because Negri bodies are also found in the cerebellum, which is another region of the CNS affected by rabies virus.
**Option C:** This option is incorrect because Negri bodies are found in the brainstem, which is a region of the CNS affected by rabies virus.
**Clinical Pearl / High-Yield Fact**
It's worth noting that while Negri bodies are a classic finding in rabies, they can be difficult to detect in peripheral nerves and may not be present in all cases of rabies. A diagnosis of rabies is typically made based on clinical presentation, laboratory tests, and histopathological examination.
**Correct Answer: D. Spinal cord.**