. Scientific Frontline

Tuesday, January 28, 2025

Regulatory T Cells Found to Safeguard Brain Health, Memory Formation

Differences in neuronal activation in mice with intact Tregs (left) and depleted Tregs (right). The finding demonstrates that Tregs play a role in ensuring healthy neuronal activity under normal conditions.
Image Credit: Mathis/Benoist Lab

Immune cells called regulatory T cells have long been known for their role in countering inflammation. In the setting of infection, these so-called Tregs restrain the immune system to ensure it doesn’t go into overdrive and mistakenly attack the body’s own organs.

Now scientists at Harvard Medical School have discovered a distinct population of Tregs dwelling in the protective layers of the brains of healthy mice with a repertoire much broader than inflammation control.

The research, published Jan. 28 in Science Immunology, shows that these specialized Tregs not only control access to the inner regions of the brain but also ensure the proper renewal of nerve cells in an area of the brain where short-term memories are formed and stored.

The research, funded in part by the National Institutes of Health, represents an important step toward untangling the complex interplay of immune cells in the brain. If replicated in further animal studies and confirmed in humans, the research could open up new avenues for averting or mitigating disease-fueling inflammation in the brain.

‘Last Ice Area’ in the Arctic could disappear much sooner than previously thought

Photo Credit: Laura Paredis

The Arctic’s “Last Ice Area” (LIA) — a vital habitat for ice-dependent species — might disappear within a decade after the central Arctic Ocean becomes ice-free in summer, which is expected to occur sometime around mid-century, a new study by McGill University researchers using a high-resolution model has found.  

Earlier, lower-resolution models had suggested the LIA might last for several more decades after that point. The stability of this region is crucial for preserving the Arctic ecology, as it provides a suitable habitat for ice-dependent and ice-obligate species, including polar bears, belugas, bowhead whales, walruses, ringed seals, bearded seals and ivory gulls.  

“These findings underscore the urgency of reducing warming to ensure stable projections for the LIA and for critical Arctic habitats,” said Madeleine Fol, lead author of the paper, which was her Master of Science thesis.  

Astrochemists Determined the Ratio of Methane in the Gas and Dust of a Protostar

According to Anton Vasyunin, scientists have obtained important information about the composition of interstellar ice.
Photo Credit: UrFU press service

A team of scientists from the Laboratory of Astrochemical Research at UrFU has for the first time determined the amount of methane in gas and dust in the young star-forming region IRAS 23385+6053. The results of the study are important for understanding the mechanisms of formation of the prebiotically important methane molecule in space. The scientists published a description of the study in The Astrophysical Journal Letters

"Observations in the infrared provide a unique opportunity to simultaneously study interstellar gas and interstellar ice. This is not possible in other wavelength ranges. Thanks to the launch of the new James Webb Space Telescope, the quality of the infrared spectra of star-forming regions has been significantly improved and has made it possible to study the composition of interstellar ice and interstellar gas simultaneously with high precision. To analyze the spectra of the protostar IRAS 23385+6053 obtained from the telescope, we used the ISEAge facility of the Ural Federal University, which allows us to grow and study space ice analogs under conditions of ultra-high vacuum and ultra-low temperatures," said the author of the article, Ruslan Nakibov, a research laboratory assistant at the Laboratory of Astrochemical Research of the Ural Federal University.

Archaeologists find ‘lost’ site depicted in the Bayeux Tapestry

The Bayeux Tapestry, showing King Harold riding to Bosham, where he attends
Photo Credit: Courtesy of University of Exeter

Archaeologists have uncovered evidence that a house in England is the site of the lost residence of Harold, the last Anglo-Saxon King of England.

By reinterpreting previous excavations and conducting new surveys, the team from Newcastle University and the University of Exeter, believe they have located a power center belonging to Harold Godwinson, who was killed in the Battle of Hastings in 1066.

Bosham, on the coast of West Sussex, is depicted twice in the Bayeux Tapestry, which famously narrates the Norman Conquest of England in 1066 when William, Duke of Normandy, challenged Harold for the throne.

The Tapestry culminates in Williams’s victory at Hastings, but earlier in the artwork Bosham is shown as the place where Harold enjoys a feast in an extravagant hall before setting sail for France, and again on his return.

A Super-Earth laboratory for searching life elsewhere in the Universe

In green, the habitable zone in the orbit of planet HD 20794.
Image Credit: (Dumusque et al. 2025) © Gabriel Pérez Díaz, SMM (IAC)

Thirty years after the discovery of the first exoplanet, more than 7000 have been discovered in our Galaxy. But there are still billions more to be discovered! At the same time, exoplanetologists have begun to take an interest in their characteristics, with the aim of finding life elsewhere in the Universe. This is the background to the discovery of super-Earth HD 20794 d by an international team including the University of Geneva (UNIGE) and the NCCR PlanetS. The new planet lies in an eccentric orbit, so that it oscillates in and out of its star’s habitable zone. This discovery is the result of 20 years of observations using the best telescopes in the world. The study is published today in the journal Astronomy & Astrophysics.

‘‘Are we alone in the Universe?’’ For thousands of years, this question was confined to philosophy, and it is only very recently that modern science has begun to provide solid hypotheses and evidence to answer it. However, astronomers are making slow progress. Each new discovery, whether theoretical or observational, adds to the edifice by pushing back the limits of knowledge. This was the case with the discovery in 1995 of the first planet orbiting a star other than the Sun, which earned two UNIGE researchers, Michel Mayor and Didier Queloz, the 2019 Physics Nobel Prize.

Nearly thirty years later, astronomers have taken many small steps towards detecting more than 7,000 exoplanets. The current scientific consensus points to the existence of a planetary system for every star in our galaxy. Astronomers are now looking for exoplanets that are easier to characterize or have interesting features to test their hypotheses and consolidate their knowledge. This is the case of planet HD 20794 d, which has just been detected by a team that includes members of the UNIGE Astronomy Department. 

Monday, January 27, 2025

What drives mood swings in bipolar disorder? Study points to a second brain clock

Image Credit: Scientific Frontline

A brain rhythm working in tandem with the body’s natural sleep-wake cycle may explain why bipolar patients alternate between mania and depression, according to new research.

The McGill University-led study published in Science Advances marks a breakthrough in understanding what drives shifts between the two states, something that, according to lead author Kai-Florian Storch, is considered the “holy grail” of bipolar-disorder research.

“Our model offers the first universal mechanism for mood switching or cycling, which operates analogously to the sun and the moon driving spring tides at specific, recurring times,” said Storch, an Associate Professor in McGill’s Department of Psychiatry and a researcher at the Douglas Research Centre.

The findings suggest that regularly occurring mood switches in bipolar disorder patients are controlled by two “clocks”: the biological 24-hour clock, and a second clock that is driven by dopamine-producing neurons that typically influence alertness. A manic or depressed state may arise depending on how these two clocks, which run at different speeds, align at a given time.

A genome-wide atlas of cell morphology reveals gene functions

Human cells imaged using Cell Painting. Cell nuclei are shown in blue, actin filaments in yellow, the endoplasmic reticulum in magenta, golgi bodies in cyan, and mitochondria in green.
Image Credit: Maria Lozada, Neal Lab

Visualizing cells after editing specific genes can help scientists learn new details about the function of those genes. But using microscopy to do this at scale can be challenging, particularly when studying thousands of genes at a time.

Now, researchers at the Broad Institute of MIT and Harvard, along with collaborators at Calico Life Sciences, have developed an approach that brings the power of microscopy imaging to genome-scale CRISPR screens in a scalable way. 

PERISCOPE — which stands for perturbation effect readout in situ via single-cell optical phenotyping — combines two technologies developed by Broad scientists: Cell Painting, which can capture images and key measures of subcellular compartments at scale, and Optical Pooled Screening, which “barcodes” cells and uses CRISPR to systematically turn off individual genes to study their function in those cells. 

The new technique lets scientists study the effects of perturbing over 20,000 genes on hundreds of image-based cellular features. Generating data with this method is more than 10 times less expensive than comparable high-dimensional approaches such as high-throughput single-cell RNA sequencing and can be adapted to study a wide variety of cell types. In Nature Methods, the researchers applied PERISCOPE to execute three whole-genome CRISPR screens to create an open-source atlas of cell morphology.

FAU Engineering Develops New Weapon against Harmful Algal Blooms

Photo Credit: Tom Fisk

As harmful algal blooms (HABs) continue to spread across the globe, urgent research is needed to address this growing threat. Studies in Italy, China, and the Atlantic basin have shown that many water bodies have high nitrogen-to-phosphorus ratios, making phosphorus a key factor that drives these blooms. This highlights the critical need for more effective phosphorus management strategies to curb the rise of HABs and protect our ecosystems.

Recently, there’s been a growing interest in finding useful ways to repurpose troublesome algal biomass, which could be turned into valuable products like bioplastics, biofertilizers, and biofuels. Researchers have already explored using algal biomass to create materials that can help clean up things such as heavy metals, rare earth metals, dyes, and even capture CO2 and harmful volatile organic compounds from the air.

However, few studies have looked into how algal biomass, especially cyanobacteria, also known as blue-green algae, can be used to create materials that remove phosphate from water.

Now, researchers from the College of Engineering and Computer Science at Florida Atlantic University, have filled that gap by transforming cyanobacterial biomass, which is typically a hazardous waste, into custom-made adsorbent materials that can pull harmful phosphorus out of water. A d sorbent materials are substances that can attract and hold molecules or particles such as gases, liquids, or dissolved solids on their surface. Unlike a b sorbent materials that soak up substances into their structure, a d sorbents capture molecules on the outside surface, forming a thin layer.

How mites have survived for millions of years

oribatid mite Platynothrus peltifer
Image Credit: Gemini (AI)

An international research team has discovered various mechanisms in asexual mites that generate genetic diversity and thus ensure survival

In collaboration with colleagues from international partner institutions, researchers at the University of Cologne have investigated the asexual reproduction of oribatid mites using genome sequencing techniques. They show that the key to evolution without sex in oribatid mites may lie in the independent evolution of their two chromosome copies – a phenomenon known as the ‘Meselson effect’. The research team identified various mechanisms that may contribute to the genetic diversity of the chromosome sets, potentially enabling the long-term persistence of the mite.

Like humans, oribatid mites possess two sets of chromosomes. However, the asexual oribatid mite Platynothrus peltifer reproduces parthenogenetically: Mothers produce daughters from unfertilized eggs, resulting in a population consisting entirely of females. Using single-individual sequencing, the researchers analysed the accumulated differences between the chromosome copies for the first time and evaluated their significance for the mite’s survival. The study titled ‘Chromosome-scale genome dynamics reveal signatures of independent haplotype evolution in the ancient asexual mite Platynothrus peltifer’, funded by the German Research Foundation (DFG), was published in Science Advances.

Nerve Stimulation: the Brain is Not Always Listening

A small device worn on the body can stimulate the nervous system via electrodes on the ear.
Image Credit: Courtesy of Technische Universität Wien

Nerve stimulation can help with various diseases. However, this only works well if the body's own rhythms are taken into account, says a study by TU Wien (Vienna).

It doesn't always have to be medication. Some health problems, from chronic pain and inflammation to neurological diseases, can also be treated by nerve stimulation, for example with the help of electrodes that are attached to the ear and activate the vagus nerve. This method is sometimes referred to as an ‘electric pill’.

However, vagus nerve stimulation does not always work the way it is supposed to. A study conducted by TU Wien (Vienna) in cooperation with the Vienna Private Clinic now shows how this can be improved: Experiments demonstrate that the effect is very good when the electrical stimulation is synchronized with the body's natural rhythms – the actual heartbeat and breathing.

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