Breaking News
April 26, 2019 - The Inflamed Brain | NIH News in Health
April 26, 2019 - Stress-free training may enhance surgical skill
April 26, 2019 - Newsom: California Leads On Prescription Drugs
April 26, 2019 - Exploring novel strategies to heal damage after a heart attack
April 26, 2019 - Small army of tiny robots can remove dental plaque
April 26, 2019 - Cellular communication in emotion-processing brain region motivates us to keep eating tasty food
April 26, 2019 - Greater spousal life satisfaction associated with lower mortality risk
April 26, 2019 - Genetic mutations in brain development lead to discovery of rare genetic diseases
April 26, 2019 - Speech-Based Algorithm Helps ID Posttraumatic Stress Disorder
April 26, 2019 - First birth via robot-assisted uterus transplant
April 26, 2019 - CircRNAs bind to dsRNA-activated protein kinase which is linked to innate immunity
April 26, 2019 - MR Solutions wins third Queen’s Award
April 26, 2019 - Study details how optimism can bias prognosis in serious illness
April 26, 2019 - Vascular surgery after firearm injury linked with higher morbidity and mortality
April 26, 2019 - New findings about aggressive blood cancer may help develop drugs with less harmful side effects
April 26, 2019 - People with intense feelings of responsibility susceptible to developing OCD, anxiety
April 26, 2019 - Despite expansion of insurance coverage for depression, treatment rates are lower than expected
April 26, 2019 - Huge Malaria vaccine trial in Malawi
April 26, 2019 - Can Obesity Shrink Your Brain?
April 26, 2019 - This oral appliance could help you (and your partner) sleep better
April 26, 2019 - Myelination deficits cause abnormal hypersocial behavior associated with Williams syndrome
April 26, 2019 - New sepsis detector uses photonics to make accurate diagnosis in less than thirty minutes
April 26, 2019 - New study describes process to diagnose rare genetic diseases in record time
April 26, 2019 - Scientists and patients gather in Vancouver to discuss about Stevens-Johnson syndrome
April 26, 2019 - Advance in breakthrough cancer treatment eliminates serious side effects
April 26, 2019 - Discovery about cold sensing could pave way for new pain relief drugs
April 26, 2019 - Children often turn to sugary drinks instead of water
April 26, 2019 - Genome analysis shows the combined effect of many genes on cognitive traits
April 26, 2019 - Patients Caught In Middle Of Fight Between Health Care Behemoths
April 26, 2019 - Drug overdoses among adolescents and young adults on the rise
April 26, 2019 - Implementing a Paperless QC Micro Laboratory”
April 25, 2019 - Obesity linked to a reduction in gray matter
April 25, 2019 - Smart assistants could help combat opioid crisis
April 25, 2019 - Diagnostic stewardship strategy reduces inappropriate testing
April 25, 2019 - Three-antibiotic cocktail eradicates ‘persister’ Lyme bacteria in mouse model
April 25, 2019 - Study investigates how early blindness shapes sound processing
April 25, 2019 - Outcomes Worse for Cancer Patients Seen at Noncancer EDs
April 25, 2019 - Link found between temperament of high-risk infants and obesity
April 25, 2019 - Al Letson explores ties between journalists and doctors at Medicine and the Muse symposium
April 25, 2019 - New mobile phone game can detect people at risk of Alzheimer’s
April 25, 2019 - Scientists discover trigger region for absence epileptic seizures
April 25, 2019 - Stretchy wearable patch can do a health check while you work out
April 25, 2019 - Exercise activates brain circuits associated with memory in older adults
April 25, 2019 - Veggies, Fruits and Grains Keep Your Heart Pumping
April 25, 2019 - Healthy meal kits can boost children’s long-term health
April 25, 2019 - Designing an inexpensive surgical headlight: A Q&A with a Stanford surgeon
April 25, 2019 - States Weigh Banning A Widely Used Pesticide Even Though EPA Won’t
April 25, 2019 - Integrator complex proteins are crucial for healthy brain development in fruit flies, study finds
April 25, 2019 - Device converts brain signals into speech, offering hope for patients
April 25, 2019 - Measles vaccination rates are a ‘public health time bomb’
April 25, 2019 - Maths made easier for scientists students who shun the subject wins award
April 25, 2019 - Researchers decode how cancer drug works in brains of Parkinson’s disease patients
April 25, 2019 - Smarter Brain Cancer Trial Comes to Columbia
April 25, 2019 - Researchers Seek Sage Advice Of Elders On Aging Issues
April 25, 2019 - New chemical synthesis strategy leads to identification of novel, simpler derivatives
April 25, 2019 - Vanderbilt investigators discover link between vascular biology and eye disease
April 25, 2019 - Feces transplantation is effective and provides economic benefits
April 25, 2019 - Eisenhower Health first in Southern California to offer new lung valve treatment for COPD/emphysema
April 25, 2019 - Johns Hopkins researchers uncover role of neurotransmitter in the spread of aggressive cancers
April 25, 2019 - Porvair Sciences offers highly effective P3 microplate for biological sample clean-up
April 25, 2019 - Air pollution increases risk for respiratory hospitalization among childhood cancer survivors
April 25, 2019 - We are sitting more! How bad is that?
April 25, 2019 - Majority of stroke survivors not screened for osteoporosis, despite increased risk
April 25, 2019 - ADHD Screening: MedlinePlus Lab Test Information
April 25, 2019 - Cellular alterations increase vulnerability of obese and diabetic individuals to infection
April 25, 2019 - Association Insurance Pushes On Despite Court Ruling
April 25, 2019 - Traditional and e-cigarette users may be more receptive to smoking cessation interventions
April 25, 2019 - Delving into tumor’s cellular lineage may offer clues for customized therapies
April 25, 2019 - Two studies uncover brain mechanisms underlying decision making process
April 25, 2019 - Cardiometabolic Risk Better ID’d in Children Reclassified to Higher BP
April 25, 2019 - How the obesity epidemic is taking a toll on our bones and joints
April 25, 2019 - E-cigarettes contaminated with dangerous microbial toxins
April 25, 2019 - Researchers document specific characteristics of storefront tobacco advertisements
April 25, 2019 - Oncotype DX-guided treatment could reduce cost for breast cancer care, study suggests
April 25, 2019 - Predicting whether a patient will benefit from chemotherapy
April 25, 2019 - New review highlights how lifestyle affects our genes
April 25, 2019 - Study provides evidence that blood tests can detect Alzheimer’s risk
April 25, 2019 - Computer program mimics natural speech using brain signals from epilepsy patients
April 25, 2019 - Physicians turning to antibiotic alternatives for long-term acne treatment
April 25, 2019 - Preschool Is Prime Time to Teach Healthy Lifestyle Habits
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