Area of brain resistant to NFTs in Alzheimer’s disease:
**Core Concept**
Neurofibrillary tangles (NFTs) are a hallmark pathological feature of Alzheimer's disease, composed of hyperphosphorylated tau protein. The distribution and resistance of brain regions to NFT formation are crucial in understanding the pathophysiology of Alzheimer's disease.
**Why the Correct Answer is Right**
The area of the brain resistant to NFTs in Alzheimer's disease is the **hippocampal subfield CA1**. This region is relatively spared from NFT formation due to the presence of a unique molecular mechanism involving the enzyme **cyclooxygenase-2 (COX-2)**, which is involved in the regulation of tau phosphorylation. The hippocampal subfield CA1 is also characterized by a higher expression of **tau phosphatase enzymes**, such as protein phosphatase 2A (PP2A), which dephosphorylate and prevent the aggregation of tau protein.
**Why Each Wrong Option is Incorrect**
* **Option A:** The **cingulate gyrus** is involved in various higher-order cognitive functions and is often affected by Alzheimer's disease pathology, including NFT formation.
* **Option B:** The **basal ganglia** are a group of subcortical structures involved in motor control and cognition, but they are not resistant to NFT formation in Alzheimer's disease.
* **Option C:** The **cerebellum** is a critical structure involved in motor coordination and learning, but it is not resistant to NFT formation in Alzheimer's disease.
**Clinical Pearl / High-Yield Fact**
The hippocampal subfield CA1 is an important region for memory formation and is relatively spared from NFT formation in Alzheimer's disease. This region is often used as a biomarker for early Alzheimer's disease diagnosis and progression.
**Correct Answer:** C