What happens to the brain in Alzheimer’s

Disease?

The lobes of the Human Brain

Figure from Gray 728 Public Domain

What is Alzheimer’s Disease?

Alzheimer’s disease is an irreversible, progressive brain disease .

It seems that abnormal deposits of proteins form amyloid plaques and tau tangles throughout the brain. These affects the ability of the neurons to function and communicate with each other, and eventually they die.

The lobes of the Human Brain

Image from :http://www.alz.org/braintour/alzheimers_changes.asp

Alzheimer’s disease changes the whole brain

There is a loss of nervous tissue. Over time, the brain shrinks dramatically, affecting nearly all its functions.

Normal brain

Brain with advanced Alzheimer

Comparing normal brain and brain with Alzheimer

Image from :http://www.alz.org/braintour/alzheimers_changes.asp

Which brain functions are affected?

The cortex shrivels up, damaging areas involved in thinking, planning and remembering.

Shrinkage is especially severe in the hippocampus, an area of the cortex involved in formation of new memories.

Cortex

Hippocampus

Early Stage

Alzheimer’s Disease Symptoms in the Early Stage

oShort-term memory lossoDifficulty performing familiar tasksoDisorientation oIncreasing problems with planning and managingoTrouble with languageoRapid, unpredictable mood swingsoLack of motivationoChanges in sleep

Middle Stage

Alzheimer’s Disease Symptoms in the Middle Stage

oDifficulty completing everyday tasks, such as getting dressed, going to bathroom, or preparing mealsoHallucinationsoStrong feelings of paranoia and anger oWandering

Later Stages

Alzheimer’s Disease Symptoms in the Later Stages

oInability to communicate with or recognize other peopleoInability to walkoDifficulty swallowingoInability to smileoInability to care for himself or herself at all

Image from:http://www.alz.org/braintour/plaques_tangles.asp

Amyloid plaques

Amyloid plaques are found in the spaces between the brain’s nerve cells. Plaques consist of largely insoluble deposits of an apparently toxic protein peptide, or fragment, called beta-amyloid.

Amyloid plaques

Image from:http://www.wellsphere.com/alzheimer-s-dementia-article/plaques-and-tangles-in-the-alzheimer-8217-s-brain-which-one-is-most-to-blame-for-alzheimer-8217-s-disease/1358255

Tangles

Neurofibrillary tangles are insoluble twisted fibers found inside the brain's cells.These tangles consist primarily of a protein called tau, which forms part of a structure called a microtubule. In Alzheimer's disease the tau protein is abnormal and the microtubule structures collapse.Nutrients and other essential supplies can no longer move through the cells, which eventually die

Image from:http://www.shutterstock.com/s/neurotransmitter/search.html#id=166154162&src=lYW8iAgPMJJ_XBIg3bOPQQ-1-2

Neurotransmitters

Another problem is a reduction in the levels of certain neurotransmitters . The so-called cholinergic neurons in the brain produce acetylcholine, a neurotransmitter crucial to memory and learning.

These neurons are plentiful in the hippocampus and the cerebral cortex—the two regions of the brain most ravaged by Alzheimer's disease.

http://en.wikipedia.org/wiki/Human_brainhttp://www.nia.nih.gov/alzheimers/publication/part-2-what-happens-brain-ad/hallmarks-adhttp://www.nia.nih.gov/alzheimers/topics/alzheimers-basicshttp://www.alz.org/braintour/alzheimers_changes.asphttp://www.brightfocus.org/alzheimers/about/understanding/plaques-and-tangles.htmlhttp://www.healthcommunities.com/alzheimers-disease/plaques-and-tangles_jhmwp.shtmlhttp://www.wellsphere.com/alzheimer-s-dementia-article/plaques-and-tangles-in-the-alzheimer-8217-s-brain-which-one-is-most-to-blame-for-alzheimer-8217-s-disease/1358255http://www.shutterstock.com/s/neurotransmitter/search.html#id=166154162&src=lYW8iAgPMJJ_XBIg3bOPQQ-1-2http://www.webmd.com/alzheimers/guide/alzheimers-disease-symptoms

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