Which abnormal structures are indicators of Alzheimer's disease?

• A. Neurofibrillary tangles and synaptic dendrites
• B. Amyloid plaques and neurofibrillary tangles
• C. Protein synthesis and cell membranes
• D. Neuroglial cells and neurotransmitter vesicles

Answer: (B)

The presence of amyloid plaques and neurofibrillary tangles is recognized as key pathological features that indicate Alzheimer's disease. Amyloid plaques are composed of beta-amyloid peptides that aggregate and form sticky clumps outside neurons, disrupting cell communication and triggering neuroinflammation. Neurofibrillary tangles, on the other hand, are intracellular accumulations of hyperphosphorylated tau protein, which leads to the collapse of the neuron’s structural framework and ultimately cell death. The accumulation of these two abnormal structures disrupts cognitive function and is central to the progression of Alzheimer's disease, making their identification critical in diagnosing this neurodegenerative condition.

The other options do not accurately reflect key indicators of Alzheimer's disease. While protein synthesis and cell membranes are fundamental aspects of cell biology, they are not specific markers for Alzheimer's pathology. Neuroglial cells and neurotransmitter vesicles play important roles in neuronal function and support but are not considered abnormal structures resulting from Alzheimer's. Similarly, synaptic dendrites, although essential for nerve communication, are not identified as direct indicators of the disease.