Where Alzheimer's starts and how it spreads

A new study involving 96 older adults initially free of dementia at the time of enrollment, of whom 12 subsequently developed mild Alzheimer’s, has clarified three fundamental issues about Alzheimer's: where it starts, why it starts there, and how it spreads.

Specifically, it begins in the lateral entorhinal cortex (LEC), a gateway to the hippocampus. Over time, Alzheimer's spreads from the LEC directly to other areas of the cerebral cortex, in particular the parietal cortex. It’s thought that it spreads by compromising the function of neurons in the LEC, which then compromises the integrity of neurons in adjoining areas.

Mouse models comparing the effects of elevated levels of tau in the LEC with elevated levels of APP, and with elevated levels of both, found that LEC dysfunction occurred only in the mice with high levels of both tau and APP. The LEC normally accumulates tau, making it more vulnerable to the accumulation of APP.

http://www.eurekalert.org/pub_releases/2013-12/cumc-ssw121713.php

[3582] Khan, U. A., Liu L., Provenzano F. A., Berman D. E., Profaci C. P., Sloan R., et al.
(2014).  Molecular drivers and cortical spread of lateral entorhinal cortex dysfunction in preclinical Alzheimer's disease.
Nature Neuroscience. 17(2), 304 - 311.

Related News

While everyone agrees that amyloid-beta protein is part of the problem, not everyone agrees that amyloid plaques are the cause (or one of them) of Alzheimer’s. Other forms of amyloid-beta have been pointed to, including floating clumps called oligomers or ADDLs.

A few months ago, I reported on an exciting finding that

The American Academy of Neurology has updated its guidelines on when people with dementia should stop driving.

Another gene has been identified that appears to increase risk of Alzheimer’s. The gene, MTHFD1L, is located on chromosome six.

Previous research has found that unexplained weight loss is an early sign of Alzheimer's.

Amnestic mild cognitive impairment often leads to Alzheimer's disease, but what predicts aMCI?

A pilot study involving 21 institutionalized individuals with moderate-to-severe Alzheimer’s found that, although drinking two 4-oz glasses of apple juice daily for a month produced no change in the Dementia Rating Scale or in the Activities of Daily Living measure, there was a significant (27%)

A pilot study involving 10 patients with moderate Alzheimer's disease, of whom half were randomly assigned to the treatment, has found that two weeks of receiving daily (25 minute) periods of repetitive transcranial magnetic stimulation to the prefrontal

A study involving outpatients with early stage Alzheimer’s found that their performance on some computerized tests of executive function and visual attention, including a simulated driving task, improved significantly after three months of taking

A study involving 54 older adults (66-76) and 58 younger adults (18-35) challenges the idea that age itself causes people to become more risk-averse and to make poorer decisions.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news
Error | About memory

Error

The website encountered an unexpected error. Please try again later.