Alzheimer's Disease

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Alzheimer's Disease

• Amyloid Protein Aggregation Formation
• By Keiley Sivakumaran

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What is the disease?

• Alzheimer's is a degenerative disease that
  attacks nerves cell in several regions of the
  brain
• The condition predominantly affects the cerebral
  cortex and hippocampus of the brain, which both
  disintegrate as the disease advances.
• A typical progression of AD can result in memory
  loss, decreased judgment and reasoning skills,
  personality and language changes and, eventually,
  the inability to carry out simple everyday tasks
  or recognize family members.
• The microscopic changes that occur in the brain
  of a person with AD were first noted by German
  neurologist Alois Alzheimer in 1906 and called
  the changes he observed plaques and tangles.
• Neurotic plaques associated by amyloid
  accumulation and neurofibrillary tangles arethe
  two most significant physical findings in the
  cells of brains affected by Alzheimer's disease..
  Another significant factor in Alzheimer's disease
  is the greatly reduced presence of acetylcholine
  in the cerebral cortex.

http//www.futuredynamicadvantage.com/braingraphic
s/humanbrain.gif
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What causes Alzheimer's?

• There is no known real reason, some
  possibilities
• Neurotransmitters
• Neurofibrillary Tangles
• Plaques

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Neurotransmitters

• One type of neurotransmitter, acetylcholine, is
  critical in the process of forming memories and
  is used by neurons in the hippocampus and
  cerebral cortex regions of the brain.
• These areas are highly affected by AD. Most
  neurotransmitter research has been focused on
  acetylcholine due to the large drop in its level
  in patients with AD.
• Acetylcholine has been found to drop 90 in
  people with AD.
• However, other neurotransmitters, such as
  serotonin, somatostatin and noradrenaline are
  also lower than normal in people with AD.

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• http//grove.ufl.edu/clp3144/Neuro20NolenF2_8.gi
  f

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Neurofibrillary Tangles

• Neurofibrillary tangles consist of insoluble
  twisted fibers that are found inside of the
  brain's cells. They primarily consist of a
  protein called tau, which forms part of a
  structure called a microtubule.
• The microtubule helps transport nutrients and
  other important substances from one part of the
  nerve cell to another. In Alzheimer's disease,
  however, the tau protein is abnormal and the
  microtubule structures collapse.
• Neurofibrillary tangles have been described as
  looking like a rope tied in knots.

http//www.anuan.net/Pictures/tangle.gif
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Neurofibrillary Tangles
http//www.ahaf.org/alzdis/about/plaques_tanglesBo
rder.jpg
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Plaques

• Unlike neurofibrillary tangles, plaques occur
  outside the neuron.
• One of the hallmarks of Alzheimer's disease is
  the accumulation of amyloid plaques between nerve
  cells (neurons) in the brain. Amyloid is a
  general term for protein fragments that the body
  produces normally. Beta-amyloid is a fragment of
  a protein that is snipped from another protein
  called amyloid precursor protein (APP).
• In a healthy brain, these protein fragments
  would be broken down and eliminated. In
  Alzheimer's disease, the fragments accumulate to
  form hard, insoluble plaques.
• It is unknown whether these deposits are due to
  excess production or whether the enzymes that
  usually break it down are not functioning
  properly.
• Neuritic plaques appear in excessive numbers in
  the cerebral cortex of the brain. The protein
  called beta amyloid occupies the center of these
  plaques. Surrounding the protein are fragments of
  deteriorating neurons, especially those that
  produce acetylcholine (ACh).

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http//whyfiles.org/117alzheimer/images/toshi_t_p.
jpg

• Here's what the culprits look like in actual
  brain tissue.
• Healthy neurons are marked in red tangles and
  plaques are in blue.

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http//www.bloodrootproducts.com/images/brain.jpg