Senile plaques in Alzeihmer’s diseasae are rich in-
**Core Concept**
Alzheimer's disease is a neurodegenerative disorder characterized by the accumulation of **amyloid-beta peptides** and **tau protein** in the brain, leading to neuronal damage and death. The underlying pharmacological principle involves the imbalance of **cholinergic** and **aminergic** neurotransmission.
**Why the Correct Answer is Right**
The correct answer is related to the composition of senile plaques, which are a hallmark of Alzheimer's disease. Senile plaques are rich in **amyloid-beta peptides**, specifically **Aβ42**, which is a fragment of the **amyloid precursor protein (APP)**. The deposition of amyloid-beta peptides is thought to be a key event in the pathogenesis of Alzheimer's disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while **tau protein** is indeed involved in Alzheimer's disease, it is primarily associated with **neurofibrillary tangles**, not senile plaques.
**Option B:** This option is incorrect because **alpha-synuclein** is more closely associated with **Parkinson's disease**.
**Option D:** This option is incorrect because **huntintin** is associated with **Huntington's disease**.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that Alzheimer's disease is characterized by the presence of both **amyloid-beta plaques** and **neurofibrillary tangles**, and that **early diagnosis** is crucial for effective management.
**Correct Answer:** D. Amyloid beta peptides