Drawing comparing a normal aged brain (left) and the brain of a person with Alzheimer's. Characteristics that separate the two are pointed out.
Microscopy of a cell with neurofibrillary tangles (marked by arrows).
Stages of atrophy in Alzheimer's.
Diagram of how microtubules disintegrate with Alzheimer's disease
A normal brain on the left and a late-stage Alzheimer's brain on the right
Overview of RNA interference.
In Alzheimer's disease, changes in tau protein lead to the disintegration of microtubules in brain cells.
Histopathologic images of Alzheimer's disease, in the CA3 area of the hippocampus, showing an amyloid plaque (top right), neurofibrillary tangles (bottom left), and granulovacuolar degeneration bodies (bottom center)
PET scan of the brain of a person with Alzheimer's disease showing a loss of function in the temporal lobe
Cognitive tests such as the Mini–Mental State Examination (MMSE) can help in the diagnosis of Alzheimer's disease. In this test instructions are given to copy drawings like the one shown, remember some words, read, and subtract numbers serially.
Intellectual activities such as playing chess or regular social interaction have been linked to a reduced risk of Alzheimer's disease in epidemiological studies, although no causal relationship has been found.
Three-dimensional molecular model of donepezil, an acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease symptoms
Molecular structure of memantine, a medication approved for advanced Alzheimer's disease symptoms
Alois Alzheimer's patient Auguste Deter in 1902. Hers was the first described case of what became known as Alzheimer's disease.
Self-portrait of artist William Utermohlen, created after Alzheimer's disease diagnosis

Neurofibrillary tangles (NFTs) are aggregates of hyperphosphorylated tau protein that are most commonly known as a primary biomarker of Alzheimer's disease.

- Neurofibrillary tangle

The disease process is largely associated with amyloid plaques, neurofibrillary tangles, and loss of neuronal connections in the brain.

- Alzheimer's disease
Drawing comparing a normal aged brain (left) and the brain of a person with Alzheimer's. Characteristics that separate the two are pointed out.

4 related topics with Alpha

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Diagram of a normal microtubule and one affected by tauopathy

Tauopathy

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Diagram of a normal microtubule and one affected by tauopathy
Diagram of a normal microtubule and one affected by tauopathy
Abnormal accumulation of tau protein in neuronal cell bodies (arrow) and neuronal extensions (arrowhead) in the neocortex of a patient who died with Alzheimer's disease. The bar = 25 microns (0.025 millimeters).

Tauopathy belongs to a class of neurodegenerative diseases involving the aggregation of tau protein into neurofibrillary or gliofibrillary tangles (Neurofibrillary tangle) in the human brain.

(These aggregations are also called paired helical filaments.) The mechanism of tangle formation is not well understood, and whether tangles are a primary cause of Alzheimer's disease or play a peripheral role is unknown.

Amyloid beta immunostaining showing amyloid plaques (brown).

Amyloid plaques

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Amyloid plaques (also known as neuritic plaques, Aβ plaques or senile plaques) are extracellular deposits of the amyloid beta (Aβ) protein mainly in the grey matter of the brain.

Amyloid plaques (also known as neuritic plaques, Aβ plaques or senile plaques) are extracellular deposits of the amyloid beta (Aβ) protein mainly in the grey matter of the brain.

Amyloid beta immunostaining showing amyloid plaques (brown).
Two amyloid plaques from the brain of a patient with Alzheimer's disease. In this photomicrograph, neurites are darkly stained with the Naoumenko-Feigin silver method, and the pink elements (including the plaque cores) are stained with the periodic acid-Schiff (PAS) counterstain. The bar is 20 microns (0.02 mm) in length.

Some plaques occur in the brain as a result of senescence (aging), but large numbers of plaques and neurofibrillary tangles are characteristic features of Alzheimer's disease.

Neurons were grown in tissue culture and stained with antibody to MAP2 protein in green and MAP tau in red using the immunofluorescence technique. MAP2 is found only in dendrites and perikarya, while tau is found not only in the dendrites and perikarya but also in axons. As a result, axons appear red while the dendrites and perikarya appear yellow, due to superimposition of the red and green signals. DNA is shown in blue using the DAPI stain which highlights the nuclei. Image courtesy EnCor Biotechnology Inc.

Tau protein

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The tau proteins (abbreviated from tubulin associated unit ) are a group of six highly soluble protein isoforms produced by alternative splicing from the gene MAPT (microtubule-associated protein tau).

The tau proteins (abbreviated from tubulin associated unit ) are a group of six highly soluble protein isoforms produced by alternative splicing from the gene MAPT (microtubule-associated protein tau).

Neurons were grown in tissue culture and stained with antibody to MAP2 protein in green and MAP tau in red using the immunofluorescence technique. MAP2 is found only in dendrites and perikarya, while tau is found not only in the dendrites and perikarya but also in axons. As a result, axons appear red while the dendrites and perikarya appear yellow, due to superimposition of the red and green signals. DNA is shown in blue using the DAPI stain which highlights the nuclei. Image courtesy EnCor Biotechnology Inc.

Pathologies and dementias of the nervous system such as Alzheimer's disease and Parkinson's disease are associated with tau proteins that have become hyperphosphorylated insoluble aggregates called neurofibrillary tangles.

Image of a man diagnosed with dementia in the 1800s

Dementia

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Disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease.

Disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease.

Image of a man diagnosed with dementia in the 1800s
Image of a man diagnosed with dementia in the 1800s
A drawing of a woman diagnosed with dementia
A drawing of an old man diagnosed with senile dementia
Brain atrophy in severe Alzheimer's
Donepezil
Deaths per million persons in 2012 due to dementia
Disability-adjusted life year for Alzheimer and other dementias per 100,000 inhabitants in 2004.
Woman with dementia being cared for at home in Ethiopia

However, the most common cause is Alzheimer's disease, a neurodegenerative disorder.

High proportions of viral-associated proteins in amyloid plaques or neurofibrillary tangles (NFTs) confirm the involvement of HSV-1 in Alzheimer's disease pathology.