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

Memory problems in those with mild cognitive impairment may begin with problems in visual discrimination and vulnerability to interference — a hopeful discovery in that interventions to improve discriminability and reduce interference may have a flow-on effect to cognition.

Here’s an exciting little study, implying as it does that one particular aspect of information processing underlies much of the cognitive decline in older adults, and that this can be improved through training.

HIV-associated dementia occurs in around 30% of untreated HIV-positive patients. Surprisingly, it also is occasionally found in some patients (2-3%) who are being successfully treated for HIV (and show no signs of AIDS).

My recent reports on brain training for older adults (see, e.g., Review of working memory training programs finds no broader benefit;

Back in 2009, I reported briefly on a large Norwegian study that found that older adults who consumed chocolate, wine, and tea performed significantly better on cognitive tests.

Two years ago, I reported on a clinical trial of a nutrient cocktail called Souvenaid for those with early Alzheimer’s.

Adding to the growing evidence for the long-term cognitive benefits of childhood music training, a new study has found that even a few years of music training in childhood has long-lasting benefits for auditory discrimination.

The study involved 120 healthy older adults (60-79) from Shanghai, who were randomly assigned to one of four groups: one that participated in three sessions of tai chi every week for 40 weeks; another that instead had ‘social interaction’ sessions (‘lively discussions’); another in which partici

I often talk about the importance of attitudes and beliefs for memory and cognition. A new honey bee study provides support for this in relation to the effects of aging on the brain, and suggests that this principle extends across the animal kingdom.

The latest finding from the large, long-running Health, Aging, and Body Composition (Health ABC) Study adds to the evidence that preventing or controlling diabetes helps prevent age-related cognitive decline.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news