Infections damage our ability to form spatial memories

January 24, 2014

Increased inflammation following an infection impairs the brain's ability to form spatial memories – according to new research. The impairment results from a decrease in glucose metabolism in the brain's memory centre, disrupting the neural circuits involved in learning and memory.

Inflammation has long been linked to disorders of memory like Alzheimer's disease. Severe infections can also impair cognitive function in healthy elderly individuals. The new findings published in the journal Biological Psychiatry help explain why inflammation impairs memory and could spur the development of new drugs targeting the immune system to treat dementia.

In the first trial to image how inflammation impairs human memory, the team at Brighton and Sussex Medical School scanned 20 participants before and after either a benign salty water injection or typhoid vaccination, used to induce inflammation. Positron emission tomography (PET) was used to measure the effects of inflammation on the consumption of glucose in the brain and after each scan participants tested their spatial memory by performing a series of tasks in a virtual reality.

A reduction in within the brain's memory centre, known as the Medial Temporal Lobe (MTL), was seen following inflammation. Participants also performed less well in tasks, an effect that appeared to be directly mediated by the change in MTL metabolism.

"We have known for some time that severe infections can lead to long-term cognitive impairment in the elderly. Infections are also a common trigger for acute decline in function in patients with dementia and Alzheimer's disease," explains Dr Neil Harrison, a Wellcome Trust Intermediate Clinical Fellow at BSMS who led the study. "This study suggests that catching a cold or the flu, which leads to inflammation in the brain, could impair our memory."

Infections are unlikely to cause long-term detrimental impact in the young and healthy but the findings are of great significance in the elderly. The team now plan to investigate the role of inflammation in dementia, including insight into how acute infections such as influenza influence the rate of progression and decline.

"Our findings suggest that the brain's circuits are particularly sensitive to inflammation and help clarify the association between inflammation and decline in dementia," says Dr Harrison. "If we can control levels of , we may be able to reduce the rate of decline in patients' cognition."

Explore further: Junk food can harm memory in a week

More information: Paper: www.biologicalpsychiatryjourna … (14)00019-5/abstract

Related Stories

Junk food can harm memory in a week

December 17, 2013
(Medical Xpress)—Even a short-term diet of junk food can have a detrimental effect on the brain's cognitive ability, according to UNSW research.

Mechanism in Alzheimer's-related memory loss identified

January 19, 2014
Cleveland Clinic researchers have identified a protein in the brain that plays a critical role in the memory loss seen in Alzheimer's patients, according to a study to be published in the journal Nature Neuroscience and posted ...

Study links inflammation in brain to some memory decline

April 13, 2011
High levels of a protein associated with chronic, low-grade inflammation in the brain correlate with aspects of memory decline in otherwise cognitively normal older adults, according to a study led by scientists at the University ...

Underactive thyroid not linked to memory problems

December 30, 2013
(HealthDay)—Hypothyroidism, a condition that causes low or no thyroid hormone production, is not linked to mild dementia or impaired brain function, a new study suggests.

Memory decline may be earliest sign of dementia

July 17, 2013
(AP)—Memory problems that are often dismissed as a normal part of aging may not be so harmless after all.

Chronic inflammation linked to less likelihood of healthy aging

September 16, 2013
Chronic exposure to high levels of interleukin-6 was associated with a significantly lower likelihood of healthy aging, according to a study in CMAJ (Canadian Medical Association Journal).

Recommended for you

To pick a great gift, it's better to give AND receive

July 28, 2017
If it's the thought that makes a gift count, here's a thought that can make your gift count extra: Get a little something for yourself.

Researchers crack the smile, describing three types by muscle movement

July 27, 2017
The smile may be the most common and flexible expression, used to reveal some emotions, cover others and manage social interactions that have kept communities secure and organized for millennia.

Ketamine for depression encouraging, but questions remain around long-term use

July 27, 2017
A world-first systematic review into the safety of ketamine as a treatment for depression, published in the prestigious Lancet Psychiatry, shows the risks of long-term ketamine treatment remain unclear.

Even babies can tell who's the boss, UW research says

July 27, 2017
The charismatic colleague, the natural leader, the life of the party - all are personal qualities that adults recognize instinctively. These socially dominant types, according to repeated studies, also tend to accomplish ...

DREAMers at greater risk for mental health distress

July 27, 2017
Immigrants who came to the United States illegally as small children and who meet the requirements of the Development Relief and Education for Alien Minors Act, more commonly known as DREAMers, are at risk for mental health ...

Negativity, be gone—new online tool can retrain your brain

July 27, 2017
Anxiety and depression can have devastating effects on people's lives. In some cases, the mental disorders lead to isolation, poverty and poor physical health, things that often cascade to future generations.

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.