Breaking News
May 3, 2019 - Vaping and Smoking May Signal Greater Motivation to Quit
May 3, 2019 - Dementia looks different in brains of Hispanics
May 3, 2019 - Short-Staffed Nursing Homes See Drop In Medicare Ratings
May 3, 2019 - Study of teens with eating disorders explores how substance users differ from non-substance users
May 3, 2019 - Scientists develop new video game that may help in the study of Alzheimer’s
May 3, 2019 - Arc Bio introduces Galileo Pathogen Solution product line at ASM Clinical Virology Symposium
May 3, 2019 - Cornell University study uncovers relationship between starch digestion gene and gut bacteria
May 3, 2019 - How to Safely Use Glucose Meters and Test Strips for Diabetes
May 3, 2019 - Anti-inflammatory drugs ineffective for prevention of Alzheimer’s disease
May 3, 2019 - Study tracks Pennsylvania’s oil and gas waste-disposal practices
May 3, 2019 - Creating a better radiation diagnostic test for astronauts
May 3, 2019 - Vegans are often deficient in these four nutrients
May 3, 2019 - PPDC announces seed grants to develop medical devices for children
May 3, 2019 - Study maps out the frequency and impact of water polo head injuries
May 3, 2019 - Research on Reddit identifies risks associated with unproven treatments for opioid addiction
May 3, 2019 - Good smells may help ease tobacco cravings
May 3, 2019 - Medical financial hardship found to be very common among people in the United States
May 3, 2019 - Researchers develop multimodal system for personalized post-stroke rehabilitation
May 3, 2019 - Study shows significant mortality benefit with CABG over percutaneous coronary intervention
May 3, 2019 - Will gene-editing of human embryos ever be justifiable?
May 3, 2019 - FDA Approves Dengvaxia (dengue vaccine) for the Prevention of Dengue Disease in Endemic Regions
May 3, 2019 - Why Tonsillitis Keeps Coming Back
May 3, 2019 - Fighting the opioid epidemic with data
May 3, 2019 - Maggot sausages may soon be a reality
May 3, 2019 - Deletion of ATDC gene prevents development of pancreatic cancer in mice
May 2, 2019 - Targeted Therapy Promising for Rare Hematologic Cancer
May 2, 2019 - Alzheimer’s disease is a ‘double-prion disorder,’ study shows
May 2, 2019 - Reservoir bugs: How one bacterial menace makes its home in the human stomach
May 2, 2019 - Clinical, Admin Staff From Cardiology Get Sneak Peek at Epic
May 2, 2019 - Depression increases hospital use and mortality in children
May 2, 2019 - Vicon and NOC support CURE International to create first gait lab in Ethiopia
May 2, 2019 - Researchers use 3D printer to make paper organs
May 2, 2019 - Viral infection in utero associated with behavioral abnormalities in offspring
May 2, 2019 - U.S. Teen Opioid Deaths Soaring
May 2, 2019 - Opioid distribution data should be public
May 2, 2019 - In the Spotlight: “I’m learning every single day”
May 2, 2019 - 2019 Schaefer Scholars Announced
May 2, 2019 - Podcast: KHN’s ‘What The Health?’ Bye-Bye, ACA, And Hello ‘Medicare-For-All’?
May 2, 2019 - Study describes new viral molecular evasion mechanism used by cytomegalovirus
May 2, 2019 - SLU study suggests a more equitable way for Medicare reimbursement
May 2, 2019 - Scientists discover first gene involved in lower urinary tract obstruction
May 2, 2019 - Researchers identify 34 genes associated with increased risk of ovarian cancer
May 2, 2019 - Many low-income infants receive formula in the first few days of life, finds study
May 2, 2019 - Global study finds high success rate for hip and knee replacements
May 2, 2019 - Taking depression seriously: What is it?
May 2, 2019 - With Head Injuries Mounting, Will Cities Put Their Feet Down On E-Scooters?
May 2, 2019 - Scientists develop small fluorophores for tracking metabolites in living cells
May 2, 2019 - Study casts new light into how mothers’ and babies’ genes influence birth weight
May 2, 2019 - Researchers uncover new brain mechanisms regulating body weight
May 2, 2019 - Organ-on-chip systems offered to Asia-Pacific regions by Sydney’s AXT
May 2, 2019 - Adoption of new rules drops readmission penalties against safety net hospitals
May 2, 2019 - Kids and teens who consume zero-calorie sweetened beverages do not save calories
May 2, 2019 - Improved procedure for cancer-related erectile dysfunction
May 2, 2019 - Hormone may improve social behavior in autism
May 2, 2019 - Alzheimer’s disease may be caused by infectious proteins called prions
May 2, 2019 - Even Doctors Can’t Navigate Our ‘Broken Health Care System’
May 2, 2019 - Study looks at the impact on criminal persistence of head injuries
May 2, 2019 - Honey ‘as high in sugars as table sugar’
May 2, 2019 - Innovations to U.S. food system could help consumers in choosing healthy foods
May 2, 2019 - FDA Approves Mavyret (glecaprevir and pibrentasvir) as First Treatment for All Genotypes of Hepatitis C in Pediatric Patients
May 2, 2019 - Women underreport prevalence and intensity of their own snoring
May 2, 2019 - Concussion summit focuses on science behind brain injury
May 2, 2019 - Booker’s Argument For Environmental Justice Stays Within The Lines
May 2, 2019 - Cornell research explains increased metastatic cancer risk in diabetics
May 2, 2019 - Mount Sinai study provides fresh insights into cellular pathways that cause cancer
May 2, 2019 - Researchers to study link between prenatal pesticide exposures and childhood ADHD
May 2, 2019 - CoGEN Congress 2019: Speakers’ overviews
May 2, 2019 - A new strategy for managing diabetic macular edema in people with good vision
May 2, 2019 - Sagent Pharmaceuticals Issues Voluntary Nationwide Recall of Ketorolac Tromethamine Injection, USP, 60mg/2mL (30mg per mL) Due to Lack of Sterility Assurance
May 2, 2019 - Screen time associated with behavioral problems in preschoolers
May 2, 2019 - Hormone reduces social impairment in kids with autism | News Center
May 2, 2019 - Researchers synthesize peroxidase-mimicking nanozyme with low cost and superior catalytic activity
May 2, 2019 - Study results of a potential drug to treat Type 2 diabetes in children announced
May 2, 2019 - Multigene test helps doctors to make effective treatment decisions for breast cancer patients
May 2, 2019 - UNC School of Medicine initiative providing unique care to dementia patients
May 2, 2019 - Nestlé Health Science and VHP join forces to launch innovative COPES program for cancer patients
May 2, 2019 - Study examines how our brain generates consciousness and loses it during anesthesia
May 2, 2019 - Transition Support Program May Aid Young Adults With Type 1 Diabetes
May 2, 2019 - Study shows how neutrophils exacerbate atherosclerosis by inducing smooth muscle-cell death
May 2, 2019 - Research reveals complexity of how we make decisions
Early-life stress in mice hinders neuron development, causing attention problems

Early-life stress in mice hinders neuron development, causing attention problems

Women are roughly twice as likely as men to develop depression, anxiety and other stress-related problems, including difficulty with attention, and new research from Brown University neuroscientists sheds light on the biological reasons why.

Studying mice whose mothers had inadequate supplies to make nests — a model for early-life stress in humans — the researchers found that only female mice developed problems with attention, in part because they had fewer “tuning” neurons in the part of the brain that makes sense of rules and regulating emotions.

The findings were published on Tuesday, Nov. 27, in Cell Reports.

“The million-dollar questions are: What’s driving the development of depression and anxiety symptoms, and co-occurring attentional problems, and why is stress a predisposing factor?” said Kevin Bath, an assistant professor of cognitive, linguistic and psychological sciences at Brown.

“If we can understand the neurobiological mechanisms of how the brain is developing differently as a consequence of early-life stress, using our animal model, then we can better understand what types of things we need to do to get children back on the right course for healthy brain development.”

Early-life stress

To conduct the study, the researchers moved four-day-old mice and their mothers from standard cages to ones where nest-building materials were inadequate. Food and water remained plentiful, but the mothers frequently departed their pups to search for anything that might work as nesting material. Pups therefore received less consistent and more hypervigilant care from their stressed mothers compared to control pups that were never moved from standard cages. After seven days, the mice returned to cages with everything they needed.

Bath, who is affiliated with Brown’s Carney Institute for Brain Science, said the condition was designed to reflect common early-life stresses faced by children — growing up in a home with a single parent who works multiple jobs, for example. Previous work has shown that nearly 60 percent of individuals will experience at least one significant stress in childhood, he added.

The team found that when the mouse pups reared by stressed mothers reached adulthood at two months old, the female mice found it difficult to adapt their behavior to changing circumstances. The researchers taught the mice to find a treat in a small container with a specific odor and texture. Once they learned to find a treat in containers that smelled one way, the researchers would change the setup and hide the food in containers with a different odor, Bath said.

This is called rule-reversal learning, Bath said, and relies upon a specific form of cognitive flexibility and attention — similar to how children learn different rules for behavior at home versus school, he added.

The female mice that experienced stress in early life took far longer to learn this new setup than the control females and made more mistakes along the way. The stressed males learned the new rules at the same rate as the control mice.

To understand the neurological factors for the learning impairment, the researchers looked in the orbitofrontal cortex — the part of the brain responsible for decision-making, specifically related to making sense of emotions and following rules — of the early-life stress and control mice. They found fewer parvalbumin interneurons, which help tune the activity of other neurons, in that area in the stressed female mice than the other mice. Other important decision-making areas of the brain had normal levels of tuning neurons.

Interestingly, Bath said, research from other labs has found decreased numbers of parvalbumin interneurons in the orbitofrontal cortex of clinically depressed patients.

The team confirmed the importance of those neurons for rule-reversal learning using optogenetics — a technique that allows scientists to control specific cells using light — to selectively turn off the parvalbumin interneurons in several brain regions, including the orbitofrontal cortex. Turning off the parvalbumin interneurons in the orbitofrontal cortex also hindered rule-reversal learning.

Further research

Bath said the researchers don’t yet know exactly what about the early-life stress model causes the difference in brain development. It could be the mothers’ parenting behaviors, or stress hormones in breast milk. The team is conducting more research on the mice using a drug that blocks a stress hormone to explore those questions.

Prior research from the same researchers on mice with early-life stress found that only female mice had depression-like symptoms, but male mice had problems with spatial reasoning and the part of the brain region responsible for fear-based learning matured much faster.

“It seems that the brains of both males and females are developing differently as a consequence of this altered parenting style,” Bath said. “Females are taking a hit in terms of emotion and attentional processing, whereas the males are taking a hit in terms of spatial reasoning skills.”

He added that his team will conduct more research to understand the reasons for the differences by sex. Possible explanations include differences in sensitivity of specific populations of neurons due to early hormonal changes or sex-specific genes, slightly different brain maturation timelines or different maternal care for male and female pups.

After Bath understands the mouse model, the goal is to learn what kind of interventions or medications can reverse or decrease the impact of early-life stress on neurobiological and behavioral outcomes. Ultimately, his hope is understanding how to help children get back on the right course of brain development after, or during, extremely stressful experiences.

“Can we provide some intervention in these children to basically decrease the levels of stress they are feeling or the amount of instability that they’re sensing, which could be the driving factor to shift the developmental program of the brain?” Bath said. “Early-life stress isn’t breaking the brain so much as pushing it on a different course of development.”

He believes that, for instance, growing up in a war zone causes the brain to develop such that a child has the best chance to detect danger and survive in that environment, but that these traits are harmful instead of beneficial when the child ends up in a classroom instead.

In addition to his work developing animal models to study early-life stress, Bath is assisting in research led by Dima Amso, an assistant professor of cognitive, linguistic and psychological sciences and Bath’s spouse. That work, a collaboration between brain science and Middle East studies experts at Brown, focuses on how scholarship and science might best focus aid to refugee children from Syria and, perhaps, around the world. One specific goal is to see how best to provide resources for Syrian refugees to reduce the children’s risk for developing depression, anxiety, attention problems and PTSD later in life.

Source:

https://news.brown.edu/articles/2018/11/stress

Tagged with:

About author

Related Articles