Heart Strings - Rat/Mouse Chimeras - Listening Web - Burning the Stomach
Breedlove, S
https://www.sciencenews.org/article/heart-brain-mental-health
The heart plays a hidden role in our mental health
By Laura Sanders
Everyone knows that the brain influences the heart.
Stressful thoughts can set the heart pounding, sometimes with such deep force that we worry people can hear it. Anxiety can trigger the irregular skittering of atrial fibrillation. In more extreme and rarer cases, emotional turmoil from a shock — the death of a loved one, a cancer diagnosis, an intense argument — can trigger a syndrome that mimics a heart attack.
But not everyone knows that the heart talks back.
Subscribe to Science News
Powerful signals travel from the heart to the brain, affecting our perceptions, decisions and mental health. And the heart is not alone in talking back. Other organs also send mysterious signals to the brain in ways that scientists are just beginning to tease apart.
A bodywide perspective that seeks to understand our biology and behavior is relatively new, leaving lots of big, basic questions. The complexities of brain-body interactions are “only matched by our ignorance of their organization,” says Peter Strick, a neuroscientist at the University of Pittsburgh.
Exploring the relationships between the heart, other organs and the brain isn’t just fascinating anatomy. A deeper understanding of how we sense and use signals from inside our bodies — a growing field called interoception — may point to new treatments for disorders such as anxiety.
“We have forgotten that interactions with the internal world are probably as important as interactions with the external world,” says cognitive neuroscientist Catherine Tallon-Baudry of École Normale Supérieure in Paris.
© Society for Science & the Public 2000–2024.
--------------------
Rat neurons thrive in a mouse brain world, testing ‘nature versus nurture’
By Angie Voyles Askham
Some questions about neurons, such as how they give rise to behavior, are tricky to answer when those cells are embedded within their natural milieu.
“Is residence in a nervous system sufficient to allow synapses to form?” says Kristin Baldwin, professor of genetics and development at Columbia University. “Are synapses that we can see sufficient to allow communication? And is synaptic communication sufficient to actually endow an animal with a set of behaviors that would be appropriate for it?”
The best way to answer those questions is to put the cells in a new environment where their extrinsic and intrinsic influences can be teased apart, says Xin Jin, assistant professor of neuroscience at the Scripps Research Institute.
For a long time, Jin says, that new environment was the unnatural setting of a petri dish. But two new studies that make use of chimeric mice—animals with both mouse and rat cells in their brain—point to another option: One demonstrates how rat stem cells can restore a mouse’s ability to smell, whereas the other shows how rat stem cells can give rise to a forebrain in mice that would otherwise lack one. The studies were published last month in Cell. Because rat brains are larger than mouse brains and develop at a different rate, the chimeras enable researchers to probe the competing forces of a cell’s intrinsic programming and its external environment.
The work opens up doors for new research and the ability to explore the origins of species-specific cellular behaviors, says Jin, who was not involved in either study.
“It’s sort of a fundamental ‘nature versus nurture,’” says Baldwin, who led one of the new studies.
© 2024 Simons Foundation
--------------------
https://www.sciencenews.org/article/burn-stomach-lining-ghrelin-weight-loss
Burning the stomach lining reduces the ‘hunger hormone’ and cuts weight
By Meghan Rosen
An experimental weight loss procedure cranks up the heat to dial down hunger.
Blasting a patch of patients’ stomach lining with thermal energy curbed hunger and cut pounds, researchers reported in a small pilot study to be presented at the annual Digestive Disease Week meeting on May 19 in Washington, D.C.
Called gastric fundus mucosal ablation, the procedure relies on an endoscope, a thin tube that can be threaded down the throat. It takes less than an hour and doesn’t require hospitalization. “The advantage of this is that it’s a relatively straightforward procedure,” says Cleveland Clinic surgical endoscopist Matthew Kroh, who was not involved with the work. Side effects, which included mild nausea and cramping, are minimal, one study author said in a news conference on May 8.
That’s a big difference from bariatric surgery, considered the gold standard treatment for obesity, which includes many techniques to restrict stomach size or affect food absorption. Patients can be hospitalized for days and take weeks to recover. Obese people often avoid these treatments because they don’t want to endure surgery, Kroh says.
The new procedure could one day offer an easier option — if the results hold up in larger groups of patients. “There’s potential,” Kroh says, “but I think we have to be cautious.”
The trial included 10 women, so the method is still at the proof-of-concept stage. On average, the women lost nearly 8 percent of their body weight, some 19 pounds, over six months. That’s less than patients typically see from bariatric surgery or pharmaceutical treatments like the anti-obesity drug Wegovy (SN 12/13/23).
© Society for Science & the Public 2000–2024.
--------------------
https://www.nytimes.com/2024/05/16/science/spider-web-microphone-silk.html
The Itsy Bitsy Spider Inspired a Microphone
By Jordan Pearson
Engineers and scientists have an enduring fascination with spider silk. Similar to typical worm silk that makes for comfy bedsheets, but much tougher, the material has inspired the invention of lighter and more breathable body armor and materials that could make airplane components stronger without adding weight. Researchers are even using examples drawn from spider webs to design sensitive microphones that can one day be used to treat hearing loss and deafness and to improve other listening devices.
Spiders use their webs like enormous external eardrums. A team of scientists from Binghamton University and Cornell University reported in 2022 that webs allow arachnids to detect sound from 10 feet away.
When you hear a sound through your ear, what you’re really experiencing are changes in air pressure that cause your eardrum to vibrate. This is how microphones work: by mimicking the human ear and vibrating in response to pressure.
Instead of vibrating when hit by a wave of pressure like a stick hitting a drumhead, they move with the flow of the air being displaced. Air is a fluid medium “like honey,” said Ronald Miles, a professor of mechanical engineering at Binghamton. Humans navigate this environment without noticing much resistance, but silk fibers are buffeted about by the velocity of the viscous forces in air.
Dr. Miles couldn’t help but wonder if this principle could lead to a new kind of microphone.
“Humans are kind of arrogant animals,” he said. “They make devices that work like they do.” But he wondered about building a device to be more like a spider and sense “sound with the motion of the air.”
© 2024 The New York Times Company
--------------------