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Men experience more brain atrophy with age despite women’s higher Alzheimer’s risk

Women are far more likely than men to end up with Alzheimer’s disease (AD). This may, at least partially, be due to women’s longer average lifespans, but many scientists think there is probably more to the story. It would be easy to surmise that the increased risk is also related to differences in the way men’s and women’s brains change as they age. However, the research thus far has been unclear, as results across different brain regions and methods have been inconsistent.

Now, a new study, published in Proceedings of the National Academy of Sciences, indicates that it’s men who experience greater decline in more regions of the as they age. Researchers involved in the study analyzed 12,638 brain MRIs from 4,726 cognitively healthy participants (at least two scans per person) from the ages of 17–95 to find how age-related changes occurred and whether they differed between men and women.

The results showed that men experienced declines in cortical thickness and in many regions of the brain and a decline in subcortical structures in older age. Meanwhile, women showed greater decline only in a few regions and more ventricular expansion in older adults. So, while differences in brain aging between the sexes are apparent, the cause of increased AD prevalence in women is still a bit mysterious.

A ‘flight simulator’ for the brain reveals how we learn—and why minds sometimes go off course

Every day, your brain makes thousands of decisions under uncertainty. Most of the time, you guess right. When you don’t, you learn. But when the brain’s ability to judge context or assign meaning falters, thoughts and behavior can go astray. In psychiatric disorders ranging from attention-deficit/hyperactivity disorder to schizophrenia, the brain may misjudge how much evidence to gather before acting—or fail to adjust when the rules of the world change based on new information.

“Uncertainty is built into the brain’s wiring,” says Michael Halassa, a professor of neuroscience at Tufts University School of Medicine. “Picture groups of neurons casting votes—some optimistic, some pessimistic. Your decisions reflect the average.” When that balance skews, the brain can misread the world: assigning too much meaning to random events, as in schizophrenia, or becoming stuck in rigid patterns, as in obsessive-compulsive disorder.

Understanding those misfires has long challenged scientists, says Halassa. “The brain speaks the language of single neurons. But fMRI—the tool we use to study brain activity in people—tracks blood flow, not the electrical chatter of individual brain cells.”

Social conflict among strongest predictors of teen mental health concerns, research shows

Approximately 20% of American adolescents experience a mental health disorder each year, a number that has been on the rise. Genetics and life events contribute, but because so many factors are involved, and because their influence can be subtle, it’s been difficult for researchers to generate effective models for predicting who is most at risk for mental health problems.

A new study from researchers at Washington University School of Medicine in St. Louis provides some answers. Published Sept. 15 in Nature Mental Health, it mined an enormous set of data collected from pre-teens and teens across the U.S. and found that social conflicts—particularly family fighting and reputational damage or bullying from peers—were the strongest predictors of near-and long-term mental health issues.

The research also revealed sex differences in how boys and girls experience stress from peer conflict, suggesting that nuance is needed when assessing social stressors in teens.

These Tiny Robots Can Swarm, Adapt, and Heal Themselves

Scientists designed microrobots that use sound to swarm, adapt, and heal themselves — working together like a living organism. The discovery could transform medicine, environmental cleanup, and robotics.

Nature’s Blueprint for Robot Swarms

Animals such as bats, whales, and insects have long relied on sound to communicate and find their way. Drawing inspiration from this, an international group of scientists has developed a model for tiny robots that use sound waves to move and work together in large, coordinated swarms that behave almost intelligently. According to team leader Igor Aronson, Huck Chair Professor of Biomedical Engineering, Chemistry, and Mathematics at Penn State, these robotic collectives could eventually take on challenging missions like exploring disaster areas, cleaning polluted environments, or performing medical procedures inside the human body.

Supercharged vitamin k could help the brain heal itself

Researchers have synthesized enhanced vitamin K analogues that outperform natural vitamin K in promoting neuron growth. The new compounds, which combine vitamin K with retinoic acid, activate the mGluR1 receptor to drive neurogenesis. They also efficiently cross the blood-brain barrier and show stability in vivo. This discovery could pave the way for regenerative treatments for Alzheimer’s and related diseases.

3D-printed microrobots adapt to diverse environments with modular design

Microrobots, small robotic systems that are less than 1 centimeter (cm) in size, could tackle some real-world tasks that cannot be completed by bigger robots. For instance, they could be used to monitor confined spaces and remote natural environments, to deliver drugs or to diagnose diseases or other medical conditions.

Researchers at Seoul National University recently introduced new modular and durable microrobots that can adapt to their surroundings, effectively navigating a range of environments. These , introduced in a paper published in Advanced Materials, can be fabricated using 3D .

“Microrobots, with their insect-like size, are expected to make contributions in fields where conventional robots have struggled to operate,” Won Jun Song, first author of the paper, told Tech Xplore. “However, most microrobots developed to date have been highly specialized, tailored for very specific purposes, making them difficult to deploy across diverse environments and applications. Our goal was to present a new approach toward creating general-purpose microrobots.”

Preventing overhydration: Study uncovers a neural circuit that prompts mice to stop drinking

Identifying the neural mechanisms that support the regulation of vital physiological processes, such as drinking, eating and sleeping, is a long-standing goal within the neuroscience research community. As the disruption of these processes can severely impact people’s health and everyday functioning, uncovering their neural and biological underpinnings is of the utmost importance.

New insights gathered by neuroscientists could ultimately inform the development of more effective interventions designed to regulate vital physiological processes. Thirst and hunger are known to be regulated by homeostatic processes, biological processes that allow the body to maintain internal stability.

Yet behavior can also be anticipatory, which means that animals and humans often adjust their actions (i.e., stop drinking) before the concentration of substances in the blood changes in response to drinking water. The mechanisms through which the brain predicts when it is the right time to stop drinking remain poorly understood.

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