. Scientific Frontline

Sunday, January 1, 2023

Good and bad feelings for brain stem serotonin

An illustration of the facial expression changes in mice following stimulation and inhibition of the median raphe nucleus
Image Credit: Yu Ohmura

New insights into the opposing actions of serotonin-producing nerve fibers in mice could lead to drugs for treating addictions and major depression.

Scientists in Japan have identified a nerve pathway involved in the processing of rewarding and distressing stimuli and situations in mice.

The new pathway, originating in a bundle of brain stem nerve fibers called the median raphe nucleus, acts in opposition to a previously identified reward/aversion pathway that originates in the nearby dorsal raphe nucleus. The findings, published by scientists at Hokkaido University and Kyoto University with their colleagues in the journal Nature Communications, could have implications for developing drug treatments for various mental disorders, including addictions and major depression.

Previous studies had already revealed that activating serotonin-producing nerve fibers from the dorsal raphe nucleus in the brain stem of mice leads to the pleasurable feeling associated with reward. However, selective serotonin reuptake inhibitors (SSRIs), antidepressant drugs that increase serotonin levels in the brain, fail to exert clear feelings of reward and to treat the loss of ability to feel pleasure associated with depression. This suggests that there are other serotonin-producing nerve pathways in the brain associated with the feelings of reward and aversion.

A glimpse of a cell’s sense of touch

Confocal image of the presomitic mesoderm of a zebrafish embryo. N-cadherin adhesion molecules are shown (they appear black because the image is inverted). This shows the cell borders.
Image Credit: Campàs Lab

A research team at the Cluster of Excellence Physics of Life of TU Dresden and the University of California, Santa Barbara, reveals how cells sense their mechanical environment as they build tissues during embryogenesis.

Building tissues and organs is one of the most complex and essential tasks that cells must accomplish during embryogenesis. In this collective task, cells communicate through a variety of communication methods, including biochemical signals - similar to a cell's sense of smell - and mechanical cues - the cell's sense of touch. Researchers in a variety of disciplines have been fascinated by cell communication for decades. Professor Otger Campàs together with his colleagues from the Physics of Life (PoL) Cluster of Excellence at Technische Universität Dresden and from the University of California Santa Barbara (UCSB) have now been able to unravel another mystery surrounding the question of how cells use their sense of touch to make vital decisions during embryogenesis. Their paper has now been published in the journal Nature Materials.

Russian Scientists Learned to Create Analogues of Space Ice

Astronomers from Ural Federal University have grown ice in a vacuum installation.
Photo Credit: Aldebaran S

Employees of the Ural Federal University's Youth Research Laboratory of Astrochemical Research grew the first samples of interstellar ice analogs and for the first time obtained test infrared spectra of these ices (the quality of the spectra is not inferior to those obtained in foreign laboratories). Obtaining analogues of interstellar ice in the laboratories is important because it will help to analyze data from telescopes, in particular James Webb (JWST), and to determine the chemical composition of interstellar ice and its structure in space.

"Until a year ago, experiments to obtain spectra of interstellar ice analogs were conducted only abroad. Now we can conduct them in Russia as well. The quality of the obtained spectra is not inferior to those obtained in foreign laboratories. It is also important to note that one of the key elements of our experimental setup, the turbomolecular pump, is made in Russia," Anton Vasyunin, Head of the Scientific Laboratory for Astrochemical Research at UrFU, commented on the results.

Interstellar ice forms in the cold formation regions of stars and planets from atoms and molecules that freeze at low temperatures from gas on the surface of microscopic cosmic dust particles. Studies of interstellar ice are necessary to understand the chemical evolution of the galaxy and to find answers to fundamental questions, in particular about the origin of life in the universe.

Tuesday, December 20, 2022

Network neuroscience theory best predictor of intelligence

U. of I. Professor Aron Barbey, pictured, and co-author Evan Anderson found that taking into account the features of the whole brain – rather than focusing on individual regions or networks – allows the most accurate predictions of intelligence.     
Photo Credit: Fred Zwicky

Scientists have labored for decades to understand how brain structure and functional connectivity drive intelligence. Researchers report a new analysis offers the clearest picture yet of how various brain regions and neural networks contribute to a person’s problem-solving ability in a variety of contexts, a trait known as general intelligence, researchers report.

They detail their findings in the journal Human Brain Mapping.

The study used “connectome-based predictive modeling” to compare five theories about how the brain gives rise to intelligence, said Aron Barbey, a professor of psychology, bioengineering and neuroscience at the University of Illinois Urbana-Champaign who led the new work with first author Evan Anderson, now a researcher for Ball Aerospace and Technologies Corp. working at the Air Force Research Laboratory.

“To understand the remarkable cognitive abilities that underlie intelligence, neuroscientists look to their biological foundations in the brain,” Barbey said. “Modern theories attempt to explain how our capacity for problem-solving is enabled by the brain’s information-processing architecture.”

Antimalarial Drug Proves Ineffective at Saving Children’s Lives

A drug used for the initial treatment of malaria failed to improve child survival in real world circumstances.
Photo Credit: Matthis Kleeb, Swiss TPH

Rectal artesunate, a promising antimalarial drug, has no beneficial effect on the survival of young children with severe malaria when used as an emergency treatment in resource-constrained settings. These are the results of a large-scale study conducted by the Swiss Tropical and Public Health Institute and local partners in three African countries.

Rectal artesunate (RAS) proves ineffective at saving the lives of young children suffering from severe malaria, according to the results of a new study. A viewpoint about these findings was published in The Lancet Infectious Diseases.

The study, which investigated a large-scale roll-out of RAS in the Democratic Republic of the Congo, Nigeria and Uganda, found that when used as an emergency treatment under real-world conditions, RAS did not improve the odds of survival for young children with severe malaria.

Diving birds are more prone to extinction, says new study

Diving birds like puffins are highly adapted for their environment, but that means they can't adapt so well to changing conditions.
Photo Credit: Michael Blum

Diving birds like penguins, puffins and cormorants may be more prone to extinction than non-diving birds, according to a new study by the Milner Centre for Evolution at the University of Bath. The authors suggest this is because they are highly specialized and therefore less able to adapt to changing environments than other birds.

The ability to dive is quite rare in birds, with less than a third of the 727 species of water bird using this way of hunting for food.

Evolutionary scientists Joshua Tyler and Dr Jane Younger studied of the evolution of diving in modern waterbirds to investigate how diving impacted: the physical characteristics of the birds (morphology); how the species evolved to increase diversity (rate of speciation); and how prone the species were to extinction.

The study, published in Proceedings of the Royal Society B, found that diving evolved independently 14 times, and that once a group had evolved the ability to dive, subsequent evolution didn’t reverse this trait.

The researchers found that body size amongst the diving birds had evolved differently depending on the type of diving they did.

More stable states for quantum computers

The properties of gralmonium qubits are dominated by a tiny constriction of only 20 nanometers, which acts like a magnifying glass for microscopic material defects.
Illustration Credit: Dennis Rieger, KIT

Quantum computers are considered the computers of the future. A and O are quantum bits (qubits), the smallest computing unit of quantum computers. Since they not only have two states, but also states in between, qubits process more information in less time. Maintaining such a condition longer is difficult, however, and depends in particular on the material properties. A KIT research team has now produced qubits that are 100 times more sensitive to material defects - a crucial step to eradicate them. The team published the results in the journal Nature Materials.

Quantum computers can process large amounts of data faster because they perform many calculation steps in parallel. The information carrier of the quantum computer is the qubit. With qubits there is not only the information "0" and "1", but also values in between. The difficulty at the moment, however, is to produce qubits that are small enough and can be switched quickly enough to perform quantum calculations. Superconducting circuits are a promising option here. Superconductors are materials that have no electrical resistance at extremely low temperatures and therefore conduct electrical current without loss. This is crucial to maintain the quantum state of the qubits and to connect them efficiently.

Technique for tracking resistant cancer cells could lead to new treatments for relapsing breast cancer patients

Breast cancer cells
Image Credit: Anne Weston - Francis Crick Institute (CC BY-NC 4.0)

Tumors are complex entities made up of many types of cells, including cancer cells and normal cells. But even within a single tumor there are a diverse range of cancer cells – and this is one reason why standard therapies fail.

When a tumor is treated with anti-cancer drugs, cancer cells that are susceptible to the drug die, the tumor shrinks and the therapy appears to be successful. But in reality, a small number of cancer cells in the tumor may be able to survive the treatment and regrow, often more persistently, causing a relapse.

In a study published in eLife, scientists from Professor Greg Hannon’s IMAXT lab at the Cancer Research UK Cambridge Institute at the University of Cambridge have developed a new technique for identifying the different types of cells in a tumor. Their method – developed in mouse tumors – allows them to track the cells during treatment, seeing which types of cells die and which survive.

The IMAXT team was previously awarded £20 million by Cancer Grand Challenges, funded by Cancer Research UK.

Developing antibiotics that target multiple-drug-resistant bacteria

The sphaerimicin analogs (SPMs) inhibit the activity of MraY, and hence the replication of bacteria, with different degrees of effectiveness. The potency of the analog increases as the IC50 decrease Illustration Credit: Takeshi Nakaya, et al. Nature Communications. December 20, 2022

Researchers have designed and synthesized analogs of a new antibiotic that is effective against multidrug-resistant bacteria, opening a new front in the fight against these infections.

Antibiotics are vital drugs in the treatment of a number of bacterial diseases. However, due to continuing overuse and misuse, the number of bacteria strains that are resistant to multiple antibiotics is increasing, affecting millions of people worldwide. The development of new antibacterial compounds that target multiple drug resistant bacteria is also an active field of research so that this growing issue can be controlled.

A team led by Professor Satoshi Ichikawa at Hokkaido University has been working on the development of new antibacterial. Their most recent research, published in the journal Nature Communications, details the development of a highly effective antibacterial compound that is effective against the most common multidrug-resistant bacteria.

Polarity proteins shape efficient “breathing” pores in grasses

One of the two “compass proteins” (POLAR, in pink) orients the future cell division. In grey there are cell outlines on the developing leaf.
Image Credit: ZVG / Courtesy of Michael T. Raissig

A research group at the University of Bern is studying how plants "breathe". They have gained new insights into how grasses develop efficient "breathing pores" on their leaves. If important landmark components in this development process are missing, the gas exchange between plant and atmosphere is impaired. The findings are also important regarding climate change.

Grasses have "respiratory pores" (called stomata) that open and close to regulate the uptake of carbon dioxide for photosynthesis on the one hand and water loss through transpiration on the other. Unlike many other plants, stomata in grasses form lateral "helper cells". Thanks to these cells, the stomata of grasses can open and close more quickly, which optimizes plant-atmosphere gas exchange and thus saves water.

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