Nav: Home

Long-term stress erodes memory

March 01, 2016

Sustained stress erodes memory, and the immune system plays a key role in the cognitive impairment, according to a new study from researchers at The Ohio State University.

The work in mice could one day lead to treatment for repeated, long-term mental assault such as that sustained by bullying victims, soldiers and those who report to beastly bosses, the researchers say.

"This is chronic stress. It's not just the stress of giving a talk or meeting someone new," said lead researcher Jonathan Godbout, associate professor of neuroscience at Ohio State.

This is the first study of its kind to establish the relationship between short-term memory and prolonged stress. In the case of the mice, that meant repeat visits from a larger, nasty intruder mouse.

Mice that were repeatedly exposed to the aggressive intruder had a hard time recalling where the escape hole was in a maze they'd mastered prior to the stressful period.

"The stressed mice didn't recall it. The mice that weren't stressed, they really remembered it," Godbout said.

They also had measurable changes in their brains, including evidence of inflammation brought on by the immune system's response to the outside pressure. This was associated with the presence of immune cells, called macrophages, in the brain of the stressed mice.

The research team was able to pin the short-term memory loss on the inflammation, and on the immune system.

Their work, which appears in The Journal of Neuroscience, builds on previous research substantiating the connections between chronic stress and lasting anxiety.

The impact on memory and confirmation that the brain inflammation is caused by the immune system are important new discoveries, Godbout said.

"It's possible we could identify targets that we can treat pharmacologically or behaviorally," he said.

It could be that there are ways to interrupt the inflammation, said John Sheridan, who worked on the study and is associate director of Ohio State's Institute for Behavioral Medicine Research.

The mice used in the study are exposed to repeated social defeat - basically dominance by an alpha mouse - that aims to mimic chronic psychosocial stress experienced by humans.

Researchers at Ohio State seek to uncover the secrets behind stress and cognitive and mood problems with a long-range goal of finding ways to help those who are anxious, depressed and suffer from lasting problems, including post-traumatic stress disorder.

This new research focused on the hippocampus, a hub of memory and emotional response.

The researchers found that the stressed mice had trouble with spatial memory that resolved within 28 days. They found that the mice displayed social avoidance, which measures depressive-like behavior, that continued after four weeks of monitoring.

And they were able to measure deficits in the development of new neurons 10 days and 28 days after the prolonged stress ended.

When they gave the mice a chemical that inhibited inflammation, neither the brain-cell problem nor the depressive symptoms went away. But the memory loss and inflammatory macrophages did disappear.

And that led them to conclude that the post-stress memory trouble is directly linked to inflammation - and the immune system - rather than to other damage to the brain. That type of information can pave the way for immune-based treatments, Godbout said.

"Stress releases immune cells from the bone marrow and those cells can traffic to brain areas associated with neuronal activation in response to stress," Sheridan said. "They're being called to the brain, to the center of memory."
-end-
The researchers' work was supported by the National Institutes of Health, the National Institute of Aging and the National Institute of Dental and Craniofacial Research.

Other Ohio State researchers who worked on the study were Daniel McKim, Anzela Niraula, Andrew Tarr and Eric Wohleb.

CONTACTS: Jonathan Godbout, 614-293-3456; Jonathan.Godbout@osumc.edu John Sheridan, 614-293-3571; John.Sheridan@osumc.edu

Written by: Misti Crane, 614-292-5220; Crane.11@osu.edu

Ohio State University

Related Immune System Articles:

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.
Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.
COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.
Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.
Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.
Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.
Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.
How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.
Immune system upgrade
Theoretically, our immune system could detect and kill cancer cells.
Using the immune system as a defence against cancer
Research published today in the British Journal of Cancer has found that a naturally occurring molecule and a component of the immune system that can successfully target and kill cancer cells, can also encourage immunity against cancer resurgence.
More Immune System News and Immune System Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.