Breaking News
February 22, 2019 - Successful testing of multi-organ “human-on-a-chip” could replace animals as test subjects
February 22, 2019 - Analysis of cervical precancer shows decline in two strains of HPV
February 22, 2019 - Sugary stent eases suturing of blood vessels
February 22, 2019 - From surgery to psychiatry: A medical student reevaluates his motivations
February 22, 2019 - Is New App From Feds Your Answer To Navigating Medicare Coverage? Yes And No
February 22, 2019 - New pacemakers powered by heartbeats could reduce need for surgery
February 22, 2019 - The United States records highest drug overdose death rates
February 22, 2019 - Phase 1 data reinforce safety profile of new drug for treating Duchenne muscular dystrophy
February 22, 2019 - Vitamin D supplementation less effective in the presence of obesity, shows study
February 22, 2019 - Sarepta Announces FDA Acceptance of Golodirsen (SRP-4053) New Drug Application for Patients with Duchenne Muscular Dystrophy Amenable to Skipping Exon 53
February 22, 2019 - An institutional effort to reduce the amount of opioids prescribed following lumbar surgery
February 22, 2019 - Failure to take statins leads to higher mortality rates | News Center
February 22, 2019 - New study explains why some patients report phantom sensations after limb amputation
February 22, 2019 - First motor-controlled heart valves implanted by Mainz University Medical Center
February 22, 2019 - Novel preclinical model mimics persistent interneuron loss seen in preterm infants
February 22, 2019 - Global health burden of glaucoma has increased, study reveals
February 22, 2019 - A holistic approach key to minimize treatment complexity in patients with interstitial lung disease
February 22, 2019 - 1 in 10 middle-aged Chinese adults are at high risk for heart disease, finds study
February 22, 2019 - More than half a million breast cancer patient’s lives saved by improvements in treatment
February 22, 2019 - Study finds no evidence that tougher policies prevent teenage cannabis use
February 22, 2019 - New blood test detects genetic disorders in fetuses
February 22, 2019 - Lower Self-Perception Observed in Children With Amblyopia
February 22, 2019 - Up to 15 percent of children have sleep apnea, yet 90 percent go undiagnosed
February 22, 2019 - Rare pulmonary defect prompts parents’ nationwide search for answers | News Center
February 22, 2019 - Lesbian and bisexual women at greater risk of being overweight, study finds
February 22, 2019 - UQ research may explain why vitamin D is essential for brain health
February 22, 2019 - Heart Attacks Rising Among Younger Women
February 22, 2019 - How your smartphone is affecting your relationship
February 22, 2019 - Orthopaedic surgeon receives prestigious award, $10 million grant | News Center
February 22, 2019 - New sepsis test could save thousands of lives
February 22, 2019 - Cervical cancer could be eradicated by 2100
February 21, 2019 - Sustained smoking cessation can lower risk of seropositive RA
February 21, 2019 - Thousands with chronic UTIs are not receiving the treatment they need
February 21, 2019 - Are teens getting high on social media? The surprising study seeking the pot-Instagram link
February 21, 2019 - Stanford expands biobank services | News Center
February 21, 2019 - Scientists identify link between drinking contexts and early onset intoxication among adolescents
February 21, 2019 - Strong social support may reduce cardiovascular disease risk in postmenopausal women
February 21, 2019 - Rapid expansion of interventions could prevent up to 13 million cases of cervical cancer within 50 years
February 21, 2019 - Motif Bio Receives Complete Response Letter From The FDA
February 21, 2019 - Researchers map previously unknown disease in children
February 21, 2019 - A skeptical look at popular diets: Going gluten-free
February 21, 2019 - Podcast: KHN’s ‘What The Health?’ How Safe Are Your Supplements?
February 21, 2019 - Factors associated with increased risk of developing surgical site infections
February 21, 2019 - Anticipatory signals in eye movements can help measure attentive capacity, learning with greater precision
February 21, 2019 - Study explores daily exposure to indoor air pollutants
February 21, 2019 - Evening exercise does not negatively affect sleep, may also reduce hunger
February 21, 2019 - Artificial intelligence technique can be used to identify alcohol misuse in trauma setting
February 21, 2019 - Overweight, obesity in adolescence associated with increased risk of renal cancer later in life
February 21, 2019 - BGU develops new AI platform for monitoring and predicting ALS progression
February 21, 2019 - Researchers discover a new promising target to improve HIV vaccines
February 21, 2019 - Brief Anesthesia in Infancy Does Not Mar Neurodevelopment
February 21, 2019 - Gaming system helps with autism diagnosis
February 21, 2019 - Heart Disease: Six Things Women Should Know
February 21, 2019 - More States Say Doctors Must Offer Overdose Reversal Drug Along With Opioids
February 21, 2019 - Researchers explore case studies focused on industries that kill more people than employed
February 21, 2019 - Only half of GP practice buildings are fit for purpose
February 21, 2019 - Intense exercise, fasting and hormones can enhance waste-protein removal, study shows
February 21, 2019 - Scientists can monitor brain activity to predict epileptic seizures few minutes in advance
February 21, 2019 - Study quantifies hepatic and intestinal mRNA expression of Ugt isoforms in rats
February 21, 2019 - ‘Apple-Shaped’ Body? ‘Pear-Shaped’? Your Genes May Tell
February 21, 2019 - Can we repair the brain? The promise of stem cell technologies for treating Parkinson’s disease
February 21, 2019 - Trump Plan To Beat HIV Hits Rough Road In Rural America
February 21, 2019 - PENTAX Medical introduces new electrosurgical and argon plasma coagulation platforms
February 21, 2019 - Trump plan to beat HIV hits rough road in rural America
February 21, 2019 - Eating blueberries every day could help decrease blood pressure
February 21, 2019 - ‘No Second Chances’ report calls for new measures to combat cardiovascular disease in Australia
February 21, 2019 - Mayo clinic researchers discuss local case studies of leprosy
February 21, 2019 - Scientists demonstrate key role of salt in allergic immune reactions
February 21, 2019 - Experts propose revising the criteria for diagnosis of Parkinson’s disease
February 21, 2019 - The med student and the machine
February 21, 2019 - Hey, Hey! Ho, Ho! Is Striking For School Nurses The Way To Go?
February 21, 2019 - Latest research encourages children to move out and learn through physical activity
February 21, 2019 - Proper oral hygiene and regular visits to dentist can promote heart health
February 21, 2019 - New, versatile technique for remote control of transplanted cells in Parkinson’s
February 21, 2019 - Why melanoma tumors in the brain may be worse?
February 21, 2019 - New project aims to improve lung disease care in Appalachia
February 21, 2019 - Drug increases melanin production in some people with albinism
February 21, 2019 - Over 1 in 3 adults miss the mark on protein, finds study
February 21, 2019 - CymaBay Therapeutics Announces Seladelpar Granted Breakthrough Therapy Designation by the FDA for the Treatment of Primary Biliary Cholangitis
February 21, 2019 - A correlation between obesity and income has only developed in the past 30 years
Early-life stress in mice hinders neuron development, causing attention problems

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

image_pdfDownload PDFimage_print

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