How chronic stress accelerates Alzheimer's disease

March 14, 2013, Umea University
The figure shows the proportion of AD mice with normal and impaired memory in each treatment group respectively. A substantial increase in the number of mice with impaired memory function was found after chronically elevated levels of allopregnanolone in comparison to placebo treatment.

Why does chronic stress lead to increased risk for dementia? The answer may lie in the elevation of stress steroids that is seen in the brain during stress, Sara K. Bengtsson suggests in the thesis she is defending at Umeå University in Sweden on March 22.

These stress steroids can inhibit the general brain activity. Allopregnanolon is one of them, and the doctoral thesis shows that chronically elevated levels of allopregnanolone accelerated the disease development in two transgenic Alzheimer . The Alzheimer mice responded with impaired learning and memory. They had also increased brain levels of beta-amyloids, i.e. the proteins that form plaques in Alzheimer's disease.

The thesis also demonstrates that high levels of beta-amyloids corresponded to dysfunction among brain synapses. This was seen after a period of chronically elevated levels of allopregnanolon, but not after . The effects were identified early in the disease development when the animals normally have intact memory function. A similar acceleration of AD in humans could mean the difference between living self-sufficiently at home and living with requirements of professional care.

Sara K. Bengtsson was born in Malmö, Sweden, and completed her pre-university graduation in Ystad. Professionally, Sara K. Bengtsson has worked in various fields and in 2008 she completed her Master's degree in medicine with a major in biomedicine at Umeå University, Sweden, where she now is a postgraduate student at the Department of Clinical Sciences, division of .

On Friday, March 22nd, Sara K. Bengtsson, Department of Clinical Sciences, Umeå University, is publicly defending her thesis with the title "Stress steroids as accelerators of Alzheimer's disease." Effects of chronically elevated levels of allopregnanolone in transgenic AD models.

Explore further: Drugs targeting blood vessels may be candidates for treating Alzheimer's

More information: Read the thesis or abstract at: urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-66572

Related Stories

Drugs targeting blood vessels may be candidates for treating Alzheimer's

March 7, 2013
(Medical Xpress)—University of British Columbia researchers have successfully normalized the production of blood vessels in the brain of mice with Alzheimer's disease (AD) by immunizing them with amyloid beta, a protein ...

Stress may increase risk for Alzheimer's disease

May 26, 2011
Stress promotes neuropathological changes that are also seen in Alzheimer's disease. Scientists from the Max Planck Institute of Psychiatry in Munich have discovered that the increased release of stress hormones in rats leads ...

Scientists study link between amyloid beta peptide levels and Alzheimer's disease

March 20, 2012
The effects of the bacterial endotoxin lipopolysaccharide (LPS) has been found to elevate amyloid beta (Aβ) peptide levels in the brain, leading to short-term deficits in learning.

Clue to cause of Alzheimer's dementia found in brain samples

October 22, 2012
Researchers at Washington University School of Medicine in St. Louis have found a key difference in the brains of people with Alzheimer's disease and those who are cognitively normal but still have brain plaques that characterize ...

Recommended for you

Rocky start for Alzheimer's drug research in 2018

January 19, 2018
The year 2018, barely underway, has already dealt a series of disheartening blows to the quest for an Alzheimer's cure.

Alzheimer's disease: Neuronal loss very limited

January 17, 2018
Frequently encountered in the elderly, Alzheimer's is considered a neurodegenerative disease, which means that it is accompanied by a significant, progressive loss of neurons and their nerve endings, or synapses. A joint ...

Anxiety: An early indicator of Alzheimer's disease?

January 12, 2018
A new study suggests an association between elevated amyloid beta levels and the worsening of anxiety symptoms. The findings support the hypothesis that neuropsychiatric symptoms could represent the early manifestation of ...

One of the most promising drugs for Alzheimer's disease fails in clinical trials

January 11, 2018
To the roughly 400 clinical trials that have tested some experimental treatment for Alzheimer's disease and come up short, we can now add three more.

Different disease types associated with distinct amyloid-beta prion strains found in Alzheimer's patients

January 9, 2018
An international team of researchers has found different disease type associations with distinct amyloid-beta prion strains in the brains of dead Alzheimer's patients. In their paper published in Proceedings of the National ...

Advances in brain imaging settle debate over spread of key protein in Alzheimer's

January 5, 2018
Recent advances in brain imaging have enabled scientists to show for the first time that a key protein which causes nerve cell death spreads throughout the brain in Alzheimer's disease - and hence that blocking its spread ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.