Alzheimer’s is defined as a degenerative brain disorder characterized by plaques (deposits made from a protein called beta amyloid) and tangles (made from a protein called tau) in the brain. The exact role of plaques and tangles is still under investigation.
Researchers have found other abnormalities in Alzheimer’s brains: some areas of the brain may shrink, connections among neurons may be lost, and blood flow patterns and levels of various chemicals may be unusual. These and other abnormalities may contribute to memory loss.
Scientists are still working to understand the causes of Alzheimer’s. Variations in three genes cause inherited, early onset (or young onset) Alzheimer’s. But the majority of Alzheimer’s cases are not inherited, and are considered to be late (after age 65) onset.
The factors that contribute to these sporadic late onset cases are unclear, and many diagnosed with Alzheimer’s have other conditions that may contribute to memory loss. The biggest risk factor for late onset Alzheimer’s is aging.
Tangled Neuron Posts:
Alzheimer's Research at a Crossroads: a new conference report
Amyloid Inhibitors for Alzheimer’s: Less Promising Than Thought?
Detecting Alzheimer’s and Other Memory Disorders Before Symptoms Appear: The FDDNP-PET Scan
The Alzheimer's Answer: a new book
The Myth of Alzheimer’s?
Enbrel – an Alzheimer’s “Miracle” and Irresponsible Reporting
David Shenk's Talk on Alzheimer's at the Early Memory Loss Forum
Education, Cognitive Reserve and Alzheimer's
The Alzheimer’s Research Registry
Participating in Alzheimer's Clinical Trials in Sun City, Arizona
Folate, Folic Acid and Alzheimer's
Dr. Rudolph Tanzi's Talk on Alzheimer's Genetics and Treatments
Chlamydia Pneumoniae and Alzheimer's
Alzheimer's Risk Factors, Genetics, Family History and Prevention, Part 1
Cognitive Rehabilitation For People With Alzheimer's and Dementia
A Growing Awareness of Early Onset Alzheimer's
Herpes Simplex Virus Type 1 and Alzheimer's
Head Injuries And Alzheimer's
Cholesterol, Statins and Alzheimer's: Part 1 of 3
Cholesterol, Statins and Alzheimer’s, Part 2 of 3
Cholesterol, Statins and Alzheimer's: Part 3 of 3
Alzheimer's, Ulcerative Colitis and the Poetry of Donald Rumsfeld
Alzheimer's, Tangles and Tau
SORL1: New Alzheimer's Gene
Dreaming About A Cure, Talking About Care: Part 1 of 4 - Is Alzheimer's Really A Disease?
Dreaming About A Cure, Talking About Care: Part 2 of 4 - More Care, Less "Cure"?
Dreaming About A Cure, Talking About Care: Part 3 of 4 - The Fantasy of "Cure"
Dreaming About A Cure, Talking About Care: Part 4 of 4 - New Ideas for Care and Cure
Diabetes and Alzheimer’s
Antipsychotic Medications and Alzheimer's
Antipsychotic Medicines and Alzheimer's, continued
Calcium Channel Blockers and Alzheimer's
Can Insulin-Degrading Enzyme Drain Beta Amyloid From Alzheimer's Brains?
Stress, Depression and Alzheimer's, Part 1
Stress, Depression and Alzheimer's, Part 2
Beta Amyloid in Alzheimer's and CAA: Dr. Jekyll or Mr. Hyde?
Hormones, Alzheimer's and the Fountain of Youth
The Wisconsin Registry for Alzheimer's Prevention
Cerebral Amyloid Angiopathy and Alzheimer's Disease: Evil Twins?
The APOE Gene, Alzheimer's and Dementia
Do cerebral emboli cause Alzheimer's and vascular dementia?
The MTHFR gene and Alzheimer's
Can loss of sense of smell predict Alzheimer's?
Alzheimer's Foundation of America
U.S. National Institute on Aging Information on Alzheimer’s
Fisher Center for Alzheimer’s Research
Alzheimer’s Disease International
MedlinePlus Alzheimer’s Page
Alzheimer’s Association Information on Alzheimer’s in African-Americans
Caregiver.com Alzheimer’s Information
Alzheimer Society (Canada) Information about Alzheimer’s Research
Los Angeles Times article on Alzheimer’s Research [free registration required]
Summary of article discussing synapse loss and other changes in Alzheimer’s brains