Craving snacks after a meal? It might be food-seeking neurons, not an overactive appetite

The discovery of a circuit in the brain of mice that makes them seek fatty food, even when they are not hungry, could have implications for future understanding of and treatment for human eating disorders.
Photo Credit: Annie Spratt

People who find themselves rummaging around in the refrigerator for a snack not long after they’ve eaten a filling meal might have overactive food-seeking neurons, not an overactive appetite.

UCLA psychologists have discovered a circuit in the brain of mice that makes them crave food and seek it out, even when they are not hungry. When stimulated, this cluster of cells propels mice to forage vigorously and to prefer fatty and pleasurable foods like chocolate over healthier foods like carrots.

People possess the same kinds of cells, and if confirmed in humans, the finding could offer new ways of understanding eating disorders.

The report, published in the journal Nature Communications, is the first to find cells dedicated to food-seeking in a part of the mouse brainstem usually associated with panic, but not with feeding.

“This region we’re studying is called the periaqueductal gray (PAG), and it is in the brainstem, which is very old in evolutionary history and because of that, it is functionally similar between humans and mice,” said corresponding author Avishek Adhikari, a UCLA associate professor of psychology. “Although our findings were a surprise, it makes sense that food-seeking would be rooted in such an ancient part of the brain, since foraging is something all animals need to do.”

Backyard insect inspires invisibility devices, next gen tech

Brochosomes are hollow, nanoscopic, soccer ball-shaped spheroids with through-holes that are produced by the common backyard insect, the leafhopper. Researchers found that the through-holes of these hollow buckyballs help reduce the reflection of light. This is the first biological example showing short wavelength, low-pass antireflection functionality enabled by through-holes and hollow structures.
Image Credit: Lin Wang and Tak-Sing Wong / Pennsylvania State University
(CC BY-NC-ND 4.0 DEED)

Leafhoppers, a common backyard insect, secrete and coat themselves in tiny mysterious particles that could provide both the inspiration and the instructions for next-generation technology, according to a new study led by Penn State researchers. In a first, the team precisely replicated the complex geometry of these particles, called brochosomes, and elucidated a better understanding of how they absorb both visible and ultraviolet light.

This could allow the development of bioinspired optical materials with possible applications ranging from invisible cloaking devices to coatings to more efficiently harvest solar energy, said Tak-Sing Wong, professor of mechanical engineering and biomedical engineering. Wong led the study, which was published in the Proceedings of the National Academy of Sciences (PNAS).

The unique, tiny particles have an unusual soccer ball-like geometry with cavities, and their exact purpose for the insects has been something of a mystery to scientists since the 1950s. In 2017, Wong led the Penn State research team that was the first to create a basic, synthetic version of brochosomes in an effort to better understand their function.

Researchers roll out a more accurate way to estimate genetic risks of disease

Illustration Credit: Ricardo Job-Reese, Broad Communications.

Researchers have developed statistical tools called polygenic risk scores (PRSs) that can estimate individuals’ risk for certain diseases with strong genetic components, such as heart disease or diabetes. However, the data on which PRSs are built is often limited in diversity and scope. As a result, PRSs are less accurate when applied to populations that differ demographically from the PRS training data.

A new scoring approach featured in Cell Genomics and developed by researchers at the Broad Institute of MIT and Harvard and Massachusetts General Hospital (MGH) uses a comprehensive approach to generate more accurate and informative PRSs. Aptly named PRSmix due to its ability to “mix” all previously developed PRSs for a given trait, the approach generates scores that estimate a patient’s genetic disease risk more accurately than PRSs generated from individual studies.

“A major challenge with PRSs is that they’re derived in one population and then unleashed broadly with the assumption that the scores can be generalized,” explained Pradeep Natarajan, the study’s corresponding author. Natarajan is an associate member in Broad's Cardiovascular Disease Initiative and director of preventive cardiology at MGH. “The overall motivation for this work is to better identify individuals who are prematurely at high risk for heritable conditions.”

Cranberries provide runners with an all-natural boost, according to new Concordia research

Speed, blood lactate and oxygen levels improve with daily extract consumption
Photo Credit: Rasa Kasparaviciene

Competitive athletes are always looking for an extra edge that can help them improve performance. According to a new study by Concordia researchers published in the journal Physical Activity and Nutrition, they can find one in the common cranberry.

In a series of trials involving trained distance runners, the researchers found that ingesting a cranberry supplement for 28 consecutive days led to noticeable improvements in both performance and muscle fatigue following 1,500-meter time trials. Reoxygenation rates were faster and running speeds improved by 1.5 per cent.

“When it comes to elite athletes, any advantage can make the difference between finishing fifth or on the podium,” says Andreas Bergdahl, an associate professor in the Department of Health, Kinesiology and Applied Physiology and the paper’s senior author.

Greenhouse gas emissions in Global South countries linked with IMF lending policies

New research by sociology professor Matthew Soener links loans from the International Monetary Fund to increased greenhouse gas emissions in Global South countries within several years. 
Photo Credit: Fred Zwicky

Greenhouse gas emissions significantly increase in countries in the Global South within a few years after initially borrowing from the International Monetary Fund using structural loans, but not when more flexible lending conditions are involved. 

However, with countries’ second or subsequent IMF loans, their emissions spike almost immediately, regardless of the lending conditions involved, a recent study suggests.

Structural loans, one of IMF’s two primary lending instruments, specify the precise changes borrowers are required to make to obtain the funds. By contrast, quantitative loans require that borrowers achieve quantifiable benchmarks – such as reducing their deficit by 5%, for example – but give them autonomy in deciding how they accomplish it, said study author Matthew Soener, a professor of sociology at the University of Illinois Urbana-Champaign.

Structural conditions impose coercive market constraints, reforms that pressure borrowers to increase their exports, indirectly raising countries’ greenhouse gas emissions through greater agricultural or manufacturing activities, Soener said.

“As a way to maintain growth and repay that loan, countries might decide, ‘Well, we can export more bananas, forest products or other agricultural products’ – or whatever specialty they might have,” he said. “In doing that, the country might be solving one problem, but they are causing another by increasing their greenhouse gas emissions.” 

Rice researchers develop 3D-printed wood from its own natural components

Researchers at Rice University have unlocked the potential to use 3D printing.
Photo Credit: Gustavo Raskosky/Rice University.

Researchers at Rice University have unlocked the potential to use 3D printing to make sustainable wood structures, offering a greener alternative to traditional manufacturing methods.

Wood has historically been marred by wasteful practices generated during shaping processes, driving up costs and environmental impact. Now researchers in materials science and nanoengineering at Rice have developed an additive-free, water-based ink made of lignin and cellulose, the fundamental building blocks of wood. The ink can be used to produce architecturally intricate wood structures via a 3D printing technique known as direct ink writing.

The work was recently published in the journal Science Advances.

“The ability to create a wood structure directly from its own natural components sets the stage for a more eco-friendly and innovative future,” said Muhammad Rahman, an assistant research professor of materials science and nanoengineering at Rice. “It heralds a new era of sustainable 3D-printed wood construction.”

The implications are far-reaching, potentially revolutionizing industries such as furniture and construction.

Cells harvested from urine may have diagnostic potential for kidney disease, find scientists

Image Credit: AI generated / Gemini Advance

Genes expressed in human cells harvested from urine are remarkably similar to those of the kidney itself, suggesting they could be an important non-invasive source of information on the kidney.

The news offers hope that doctors may one day be able to investigate suspected kidney pathologies without carrying out invasive procedures such as biopsies, raising the tantalizing prospect of earlier and simpler disease detection.

The impact of late detection of kidney disease can be severe and can lead to serious and sometimes life-threatening complications.

The team led by University of Manchester scientists measured the levels of approximately 20,000 genes in each cellular sediment sample of urine using a technique called transcriptomics.

The British Heart Foundation-funded study benefited from access to the world's largest collection of human kidney samples collected after surgery or kidney biopsy conducted before transplantation, known as the Human Kidney Tissue Resource, at The University of Manchester.

They extracted both DNA and RNA from each sample and connected information from their analysis, together with data from previous large-scale analyses of blood pressure (called genome-wide association studies), using sophisticated computational methods.

Inflammatory bowel disease after a stem cell transplant

Additional genetic testing could make bone marrow donations even safer.
Image Credit: Gerd Altmann

A stem cell donation saves a leukemia sufferer’s life. Five years later, the patient develops a chronic inflammatory bowel disease that occurs very rarely following a transplant. Researchers from the University of Basel and University Hospital Basel have studied the case and are calling for more extensive genetic analyses in bone marrow donors.

In many forms of blood cancer, a transplant of blood stem cells is the only chance of a cure. This procedure involves first eliminating the patient’s degenerated blood stem cells and then building up their immune system again with stem cells from a donor.

So that the new immune system doesn’t turn against the recipient’s body, a series of tissue markers must match the recipient and donor. This criterion is investigated as standard. Now, a research team led by Professors Petr Hrúz from Clarunis (University Digestive Health Care Center Basel) and Mike Recher from the University of Basel and University Hospital Basel has shown that it would also be sensible to carry out a more extensive genetic analysis.

Writing in the Journal of Clinical Immunology, the team describes the case of a man who developed a chronic inflammatory bowel disease (Crohn’s disease) five years after receiving a blood stem cell transplant for leukemia. Genetic analysis revealed that a mutation had been transplanted along with the blood stem cells from the donor. This mutation affected the operation of a factor called TIM-3, a key regulator of the immune system. The donor, on the other hand, was and remains in apparently good health.

There are large accumulations of plastics in the ocean, even outside so-called garbage patch

Neuston net towed on the side of the German RV SONNE, collecting surface-floating plastic samples when crossing the North Pacific Ocean.
Photo Credit: Philipp Klöckner / UFZ

When plastic ends up in the ocean, it gradually weathers and disintegrates into small particles. If marine animals ingest these particles, their health can be severely affected. Large accumulations of plastic can therefore disrupt the biological balance of marine ecosystems. But which areas are particularly affected? In a recent study, a research team from the Helmholtz Centre for Environmental Research (UFZ), in collaboration with the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), has found large quantities of plastic waste and microplastics in a remote marine protected area in the Pacific Ocean. These quantities were similar to those found in one of the world’s largest known garbage patches. The researchers highlight that plastics are distributed much more widely than expected. The entire ocean ecosystem is threatened. They therefore call for the global emissions of plastics into the ocean to be stopped as quickly as possible. The study has been published in Environmental Science & Technology.

New research deepens our understanding of pescatarians

(L-R)
Postgraduate researcher Maja Cullen, teaching assistant and researcher Devon Docherty, and Dr Carol Jasper
Photo Credit: Courtesy of University of Stirling

New research has deepened our understanding of why pescatarians choose to eat fish but not the meat of land animals.

The perceived distance between marine life and participants in the study was a key factor, researchers in the University of Stirling’s Division of Psychology found.

The team, consisting of Maja Cullen, Devon Docherty and Dr Carol Jasper, used the construal-level theory of psychological distance to investigate further how this distance is created and how this might be experienced.

The theory argues that we interpret people, animals, objects or situations differently depending on how much we know about them.

Dr Carol Jasper, co-author of the study, said: “When we do not know much about someone or something we think of it in more abstract and general terms because we lack information.

“For our sample of pescatarians, this meant that they felt less emotionally connected to marine animals than they felt to land animals with whom we share some more obvious similarities.