Senile plaques (syn. neuritic plaques, senile druse, braindruse) are extracellular deposits of beta amyloid in the gray matter of the brain. Degenerative neural structures and an abundance of microglia and astrocytes can be associated with senile plaque deposits. These deposits can also be a byproduct of senescence or biological aging. However, large numbers of senile plaques and neurofibrillary tangles are characteristic features of Alzheimer's disease. Abnormal neurites in senile plaques are composed primarily of paired helical filaments, a component of neurofibrillary tangles. The plaques are variable in shape and size, but are on average 50 µm in size. In Alzheimer's disease they are primarily composed of beta amyloid peptides. These polypeptides tend to aggregate and are believed to be neurotoxic.
Read more about Senile Plaques: History, Formation and Description, Identification, Disease, Occurrence, Research, See Also
Famous quotes containing the word senile:
“I think I noticed once
T’was morning one sole street-lamp still bright-lit,
Which, with a senile grin, like an old dunce,
Vied the blue sky, and tried to rival it....”
—Philip Larkin (1922–1986)