In Alzheimer's disease, neurofibrillary tangles are composed of abnormally phosphorylated forms of which protein?
- A Alpha-synuclein
- B TDP-43
- C Tau (microtubule-associated protein) ✓
- D Huntingtin
Correct answer: C. Tau (microtubule-associated protein)
Explanation
Neurofibrillary tangles (NFTs) in Alzheimer's disease consist of paired helical filaments (PHFs) of hyperphosphorylated tau protein. Normally, tau stabilises microtubules; hyperphosphorylation causes it to dissociate and aggregate intraneuronally. NFT burden correlates better with cognitive decline than amyloid plaque burden (Braak staging). Alpha-synuclein forms Lewy bodies (Parkinson's/DLB); TDP-43 inclusions characterise ALS/FTD; huntingtin aggregates occur in Huntington's disease.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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