View source for 23. Senile plaques and neurofibrillar degeneration

[[File:Alzheimer - overview.png|thumb|Overview]]'''Staining''': Silver stain (Bielschowsky)

'''Organ''': Brain, hippocampus

'''Description''':

The hippocampus is visible and that’s where the characteristic findings are visible on this slide.

''Senile plaques'' are extracellular deposits of β-amyloid that are surrounded by silver-positive proteins. The amyloids themselves aren’t stained by silver and are therefore pale. These plaques are therefore visible as large black foci with a pale core.

''Neurofibrillary tangles'' are intracellular bundles of hyperphosphorylated ''tau''. These tangles are stained by silver and causes the neurons to be stained black.

'''Diagnosis''': Alzheimer disease (senile plaques, neurofibrillary tangles)[[File:Alzheimer - senile plaques.png|thumb|Senile plaques and amyloid cores]]'''Risk factors:'''

* Genetic factors
* Down syndrome
* Lack of physical activity
* Traumatic brain injury
* Old age

'''Theory''':

Alzheimer’s disease most commonly affects the hippocampus first, and then the frontal and temporal lobes before it becomes a diffuse process.

This slide is overstained, so the characteristic findings are therefore hard to distinguish from background noise.
[[File:Alzheimer - NFTs.png|thumb|These nerve cell bodies are stained black as they contain neurofibrillary tangles|left]]
[[Category:Pathology 2 - Histopathology slides]]