A adolescent was bitten by a stray dog. To rule out rabies in the animal, brain tissue sample was taken. Which of the pa of brain tissue should be taken to see the characteristic Negri bodies?
## Core Concept
The question tests knowledge of **rabies diagnosis** and the specific neuropathological features associated with the disease. Rabies is a viral infection that affects the central nervous system (CNS), and its diagnosis can be confirmed by the presence of characteristic **Negri bodies** in brain tissue.
## Why the Correct Answer is Right
Negri bodies are **eosinophilic, cytoplasmic inclusions** found in the neurons of animals infected with rabies. They are a hallmark of the disease and are used as a diagnostic criterion. These bodies are most commonly found in the **hippocampus, cerebellum, and cerebral cortex**. Among the options provided, the **cerebellum** is a correct location where Negri bodies can be identified, making it a suitable site for brain tissue sampling to diagnose rabies.
## Why Each Wrong Option is Incorrect
- **Option A:** While certain neuropathological changes can occur in the brainstem, it is not the primary or preferred site for identifying Negri bodies.
- **Option B:** The cerebral cortex can be involved, but it is not as specific or sensitive for Negri body identification as the cerebellum.
- **Option D:** The spinal cord is not typically used for the diagnosis of rabies through Negri body identification.
## Clinical Pearl / High-Yield Fact
A key point to remember is that **Negri bodies are found in the neurons of the cerebellum, hippocampus, and cerebral cortex**. When diagnosing rabies, especially in animals, a brain tissue sample from these areas can be critical. It's also important to note that the absence of Negri bodies does not entirely rule out rabies, as they may not be present in all cases, and other diagnostic methods like PCR may be needed.
## Correct Answer: C. Cerebellum