What are neuritic plaques in Alzheimer disease?

Neuritic plaques, also referred to as senile, dendritic, or amyloid plaques, are a hallmark feature used to diagnose Alzheimer disease during an autopsy.1

These structures consist of deteriorating neuronal material that surrounds deposits of a sticky protein known as amyloid beta (or beta-amyloid). This protein is derived from the amyloid precursor protein, which is a normal component of nerve cells.1

While these plaques are thought to interfere with normal cellular functioning, it remains unclear whether they are a primary cause or a consequence of the disease. Some research suggests that amyloid beta may naturally form plaques in response to infection to entrap microorganisms, leading to theories that Alzheimer disease might be linked to brain infection, with plaque formation becoming excessive or abnormal in affected individuals.1