The brain reacts differently to touch depending on context

Photo Credit: Thor Balkhed

The touch of another person may increase levels of the “feelgood” hormone oxytocin. But the context really matters. The situation impacts oxytocin levels not only in the moment, but also later, as is shown by researchers at Linköping University and the University of Skövde.

 An embrace from a parent, a warm hand on your shoulder or a caress from a romantic partner are examples of how touch can strengthen social bonds between people and influence emotions. But although touch and the sense of touch have a very important function, knowledge of how this actually works is still lacking.

Studies in animals have shown that the hormone oxytocin is linked to touch and social bonding. However, many questions remain unanswered when it comes to oxytocin’s role in human social interactions and how this hormone can influence and be influenced by the brain. To study this closer, researchers have examined what happens in the body when we feel a soft touch. India Morrison. 

An unprecedented view of gene regulation

Caption:“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT. 

Video Credit: Melanie Gonick/MIT

Much of the human genome is made of regulatory regions that control which genes are expressed at a given time within a cell. Those regulatory elements can be located near a target gene or up to 2 million base pairs away from the target.

To enable those interactions, the genome loops itself in a 3D structure that brings distant regions close together. Using a new technique, MIT researchers have shown that they can map these interactions with 100 times higher resolution than has previously been possible.

“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT and the senior author of the study. “We are excited to be able to reveal a new layer of 3D structure with our high resolution.”

The researchers’ findings suggest that many genes interact with dozens of different regulatory elements, although further study is needed to determine which of those interactions are the most important to the regulation of a given gene.

T Cells Can Activate Themselves to Fight Tumors

T cells are a type of white blood cell and play a central role in the immune response.
Photo Credit: NIAID.

When you need a bit of motivation, it often has to come from within. New research suggests cancer-fighting immune cells have found a way to do just that.

Scientists at University of California San Diego have discovered a property of T cells that could inspire new anti-tumor therapeutics. Through a previously undescribed form of cell auto-signaling, T cells were shown to activate themselves in peripheral tissues, fueling their ability to attack tumors.

The study, published May 8, 2023 in Immunity, was led by study first author and postdoctoral fellow Yunlong Zhao, PhD, and co-senior authors Enfu Hui, PhD, professor in the School of Biological Sciences at UC San Diego and Jack D. Bui, MD, PhD, professor of pathology at UC San Diego School of Medicine.

T cells are a type of white blood cell that protect against infection and help fight cancer. In the lymph organs, T cells are trained by antigen-presenting cells, which, as their name suggests, present an antigen (a piece of tumor or pathogen) to T cells, stimulating an immune response. 

A new at­las il­lus­trates how the hu­man ret­ina is de­vel­op­ing.

De­tail of a cross-​section of a ret­inal or­ganoid. Dif­fer­ent tis­sue struc­tures are made vis­ible with dif­fer­ent colors.
Pho­to­ Credit: Wahle et al. Nature Bi­o­tech­no­logy 2023

What cell types are found in which hu­man tis­sue, and where? Which genes are act­ive in the in­di­vidual cells, and which pro­teins are found there? An­swers to these ques­tions and more are to be provided by a specialized at­las – in par­tic­u­lar how the dif­fer­ent tis­sues form dur­ing em­bryonic de­vel­op­ment and what causes dis­eases. In cre­at­ing this at­las, re­search­ers aim to map not only tis­sue dir­ectly isol­ated from hu­mans, but also struc­tures called or­ganoids. These are three-​dimensional clumps of tis­sue that are cul­tiv­ated in the labor­at­ory and de­velop in a way sim­ilar to hu­man or­gans, but on a small scale.

“The ad­vant­age of or­ganoids is that we can in­ter­vene in their de­vel­op­ment and test act­ive sub­stances on them, which al­lows us to learn more about healthy tis­sue as well as dis­eases,” ex­plains Bar­bara Treut­lein, Pro­fessor of Quant­it­at­ive De­vel­op­mental Bio­logy at the De­part­ment of Biosys­tems Sci­ence and En­gin­eer­ing at ETH Zurich in Basel.

To help pro­duce such an at­las, Treut­lein, to­gether with re­search­ers from the Uni­ver­sit­ies of Zurich and Basel, has now de­veloped an ap­proach to gather and com­pile a great deal of in­form­a­tion about or­ganoids and their de­vel­op­ment. The re­search team ap­plied this ap­proach to the or­ganoids of the hu­man ret­ina, which they de­rived from stem cells.

Researchers develop model for how the brain acquires essential omega-3 fatty acids

Step-by-step process of lipid transport across blood-brain barrier.
Illustration Credit: Ethan Tyler from NIH Medical Arts

Researchers at the UCLA David Geffen School of Medicine, the Howard Hughes Medical Institute at UCLA and the National Institutes of Health have developed a zebrafish model that provides new insight into how the brain acquires essential omega-3 fatty acids, including docosahexaenoic acid (DHA) and linolenic acid (ALA). Their findings, published in Nature Communications, have the potential to improve understanding of lipid transport across the blood-brain barrier and of disruptions in this process that can lead to birth defects or neurological conditions. The model may also enable researchers to design drug molecules that are capable of directly reaching the brain.

Omega-3 fatty acids are considered essential because the body cannot make them and must obtain them through foods, such as fish, nuts and seeds. DHA levels are especially high in the brain and important for a healthy nervous system. Infants obtain DHA from breastmilk or formula, and deficiencies of this fatty acid have been linked to problems with learning and memory. To get to the brain, omega-3 fatty acids must pass through the blood-brain barrier via the lipid transporter Mfsd2a, which is essential for normal brain development. Despite its importance, scientists did not know precisely how Mfsd2a transports DHA and other omega-3 fatty acids.

Study sheds light on how the immune system protects the body

Photo Credit: RDNE Stock project

Researchers explore how patients with a rare and severe immunodeficiency were still able to defend themselves normally against viruses, including COVID-19

The first study of humans with a rare immunodeficiency reveals how the immune system protects the body against pathogens known to cause serious diseases, such as tuberculosis and COVID-19. The research involving McGill University, paves the way for new therapies to treat autoimmune diseases, chronic inflammatory diseases, and new approaches to vaccine development.

The immune system responds differently to various types of pathogens, like bacteria, parasites, and viruses. However, scientists are still trying to uncover how this complex network functions together and the processes that can go wrong with immunodeficiencies.

“The immune system plays a vital role in protecting the body from harmful germs that make people ill. It’s made up of a complex network of organs, cells, and proteins – like IRF1 or regulatory factor 1, which is key in the regulation of an early immune response to pathogens,” says co-author of the study David Langlais, an Assistant Professor in the Departments of Human Genetics and Microbiology and Immunology at McGill University.

The evolution of honey bee brains

European honey bee worker. The researchers studied honey bees exhibiting different behaviors: foragers, nurse bees, and queens. Honey bees in general have been a key insect model for better understanding learning and memory for more than 100 years.
Photo Credit: ©2023 Hiroki Kohno

Researchers have proposed a new model for the evolution of higher brain functions and behaviors in the Hymenoptera order of insects. The team compared the Kenyon cells, a type of neuronal cell, in the mushroom bodies (a part of the insect brain involved in learning, memory and sensory integration) of “primitive” sawflies and sophisticated honey bees. They found that three diverse, specialized Kenyon cell subtypes in honey bee brains appear to have evolved from a single, multifunctional Kenyon cell-subtype ancestor. In the future, this research could help us better understand the evolution of some of our own higher brain functions and behaviors.

Are you “busy as a bee,” a “social butterfly” or a “fly on the wall”? There are many ways we compare our behavior to that of insects, and as it turns out there may be more to it than just fun idioms. Studying insects could help us understand not only how their behavior has evolved, but also the behavior of highly evolved animals, including ourselves. Mammalian brains are big and complex, so it is difficult to identify which behaviors and neural and genetic changes have co-developed over time. By comparison, insect brains are much smaller and simpler, making them useful models for study.

Fossil find in California shakes up the natural history of cycad plants

Three-dimensional reconstruction of the whole cone and different views of the same cone scale. Scale bar: cone = 400 microns; cone scales = 200 microns.
Image Credit: Andres Elgorriaga, Brian Atkinson

Cycads, a group of gymnosperms which can resemble miniature palm trees (like the popular sago palm houseplant) were long thought to be “living fossils,” a group that had evolved minimally since the time of the dinosaurs. Now, a well-preserved 80-million-year-old pollen cone discovered in California has rewritten scientific understanding of the plants.

The findings are detailed in a paper by two University of Kansas paleobotanists just published in the journal New Phytologist.

“Cycads aren’t well-known but make up a significant part of plant diversity, accounting for around 25% of all gymnosperms,” said lead author Andres Elgorriaga, postdoctoral researcher with the KU Department of Ecology & Evolutionary Biology and KU Biodiversity Institute and Natural History Museum3. “Cycads are plants that have thick stems and short stature, with thick, palm-like leaves on top. They produce cones like pine cones and are related to other seed-bearing plants that also don’t produce flowers, like Ginkgo and the monkey puzzle tree. But they’re also highly endangered, with the highest level of endangerment among all plant groups. Trafficking of cycads also is a significant issue.”

iDNA from flies to track native species across Western Australian wheatbelt

Carrion Fly
Photo Credit: Ian Lindsay

Researchers from Curtin University have collected iDNA from flies to track the movements of Australia’s native species across the Western Australian wheatbelt, with hopes to improve future conservation efforts in the region.

Published in the Journal Conservation Biology, the research team found that native animals, such as the echidna, numbat, woylie and chuditch, were predominantly located in conservation reserves and not across the wider wheatbelt landscape, compared to invasive species like foxes and feral cats which were found across all areas.

Senior researcher and co-author Associate Professor Bill Bateman, from Curtin’s School of Molecular and Life Sciences, said native mammal populations were declining at alarming rates and there was an urgent need to monitor and protect their wellbeing.

“It is essential to monitor the distribution and movements of animals so we can identify which populations are most at risk, which ones are declining, and which ones are on the brink of extinction. Tracking wildlife through alternative techniques, such as camera trapping and audio recording, can be difficult, costly and take several weeks to gather data,” Associate Professor Bateman said.

The Trumpet biocomputing platform heralds a new path for medicine

A biocomputing chip made of bacteria.
Image Credit: College of Biological Sciences / University of Minnesota

From early detection and internal treatment of diseases to futuristic applications like augmenting human memory, biological computing, or biocomputing, it has the potential to revolutionize medicine and computers. Traditional computer hardware is limited in its ability to interface with living organs, which has constrained the development of medical devices. Computerized implants require a constant supply of electricity, they can cause scarring in soft tissue that makes them unusable and they cannot heal themselves the way organisms can. Through the use of biological molecules such as DNA or proteins, biocomputing has the potential to overcome these limitations.

Biocomputing is typically done either with live cells or with non-living, enzyme-free molecules. Live cells can feed themselves and can heal, but it can be difficult to redirect cells from their ordinary functions towards computation. Non-living molecules solve some of the problems of live cells, but have weak output signals and are difficult to fine-tune and regulate. 

Targeting mitochondria and related protein suggest new therapeutic strategy for treating Lou Gehrig's disease (ALS)

Researchers have discovered a receptor, sigma-1 receptor (green), and a protein, ATAD3A (red),  that are associated with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease.
Image Credit: Yamanaka Laboratory

Researchers at Nagoya University in Japan have discovered a receptor, sigma-1 receptor, and a protein, ATAD3A, that are associated with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease. Since there are drugs that specifically target the receptor, their findings suggest a new therapeutic strategy. They published the study in the journal Neurobiology of Disease. 

ALS causes degeneration of motor neurons and the resulting muscle atrophy. Some of this degeneration is the result of the dysfunction of mitochondria, the energy-generating organelles of the body. This dysfunction causes a lack of energy in neurons resulting in the characteristic symptoms of the disease.   

The integrity of the mitochondria-associated membrane (MAM) is important for the stability of the mitochondria. The MAM is especially important during the processes of division of mitochondria (called fission) and mitochondria fusing together (called fusion). Several proteins, including enzymes, are associated with these processes and accumulate in the MAM.  

Study unlocks potential breakthrough in Type 1 diabetes treatment

Omid Veiseh and Boram Kim. Kim is holding a medical-grade catheter similar to ones used in the study experiments.
Photo Credit: Gustavo Raskosky/Rice University

For the over 8 million people around the globe living with Type 1 diabetes, getting a host immune system to tolerate the presence of implanted insulin-secreting cells could be life-changing.

Rice University bioengineer Omid Veiseh and collaborators identified new biomaterial formulations that could help turn the page on Type 1 diabetes treatment, opening the door to a more sustainable, long-term, self-regulating way to handle the disease.

To do so, they developed a new screening technique that involves tagging each biomaterial formulation in a library of hundreds with a unique “barcode” before implanting them in live subjects.

According to the study in Nature Biomedical Engineering, using one of the alginate formulations to encapsulate human insulin-secreting islet cells provided long-term blood sugar level control in diabetic mice. Catheters coated with two other high-performing materials did not clog up.

“This work was motivated by a major unmet need,” said Veiseh, a Rice assistant professor of bioengineering and Cancer Prevention and Research Institute of Texas scholar. “In Type 1 diabetes patients, the body’s immune system attacks the insulin-producing cells of the pancreas. As those cells are killed off, the patient loses the ability to regulate their blood glucose.”

Researchers get the drop on new frog species

The Litoria naispela juvenile mimics bird droppings.
Photo Credit: Steve Richards

Five new species of frogs, including one with camouflage that makes it look like bird droppings, have been described by Australian scientists.

Scientists from Griffith University, Queensland Museum and South Australian Museum recently described the five species of treefrogs from Papua New Guinea.

Griffith University scientist Dr Paul Oliver, a joint appointee with Queensland Museum, said the new species highlighted the remarkable and poorly understood diversity of New Guinea frogs.

“These small tree frogs lay their eggs out of the water, typically on leaves, quite different to your typical treefrog, which lay their eggs directly into water,” Dr Oliver said.

How wiggly spaghetti guard the genome

The image shows an artistic impression of the rocky scaffold structure of the nuclear pore complex filled with intrinsically disordered nucleoporins in the central channel depicted as seaweeds. In this work, the viewer dives into the dark hole of the nuclear pore complex to shine light on the disordered nucleoporins.
Illustration Credit: ©: Sara Mingu

Tiny pores in the cell nucleus play an essential role for healthy aging by protecting and preserving the genetic material. A team from the Department of Theoretical Biophysics at the Max Planck Institute of Biophysics in Frankfurt am Main and the Synthetic Biophysics of Protein Disorder group at Johannes Gutenberg University Mainz (JGU) has literally filled a hole in the understanding of the structure and function of these nuclear pores. The scientists found out how intrinsically disordered proteins in the center of the pore can form a spaghetti-like mobile barrier that is permeable for important cellular factors but blocks viruses or other pathogens.

Human cells shield their genetic material inside the cell nucleus, protected by the nuclear membrane. As the control center of the cell, the nucleus must be able to exchange important messenger molecules, metabolites or proteins with the rest of the cell. About 2,000 pores are therefore built into the nuclear membrane, each consisting of about 1,000 proteins.

Membrane proteins of cyanobacteria and higher organisms are structurally highly similar

SynDLP, the dynamin-like protein of the cyanobacterium Synechocystis, forms highly ordered oligomeric structures that bind to membranes.
Illustration Credit: ©: Lucas Gewehr, Dirk Schneider

The cells of living organisms are equipped with proteins that are involved in the shaping and remodeling of cellular membranes, thereby performing important tasks. The cell membrane encloses the cell interior, but is constantly remodeled, for example, due to membrane budding, invagination, or fusion processes. This also involves various proteins that were long assumed to be present exclusively or predominantly in higher organisms. In the past 10 to 20 years, however, proteins have been identified or predicted to be present also in simple organisms that do not possess a nucleus. In a research collaboration, a protein involved in membrane remodeling in cyanobacteria has now been described for the first time. The existence of such a bacterial protein was suspected, but proof was still pending. The studied protein is likely a bacterial representative of a similar protein found in higher organisms such as animals and plants.

Predators decrease prey disease levels but also population size

Microscope image showing a phantom midge larva (genus Chaoborus), top left, preying on a Daphnia dentifera water flea, bottom right. Chaoborus is a fierce predator with a complex “catching basket” on its head for quickly trapping small crustaceans like water fleas.
Photo Credit: Meghan Duffy, University of Michigan.

Nature documentaries will tell you that lions, cheetahs, wolves and other top predators target the weakest or slowest animals and that this culling benefits prey herds, whether it’s antelope in Africa or elk in Wyoming.

This idea has been widely accepted by biologists for many years and was formalized in 2003 as the healthy herds hypothesis. It proposes that predators can help prey populations by picking off the sick and injured and leaving healthy, strong animals to reproduce.

The healthy herds hypothesis has even been used to suggest that manipulating predator numbers to protect prey might be a useful conservation strategy. Even so, hard evidence supporting the hypothesis is scarce, and in recent years many of its assumptions and predictions have been questioned.

In a study published online April 26 in the journal Ecology, a University of Michigan-led research team used a pint-sized predator-prey-parasite system inside 20-gallon water tanks to test the healthy herds hypothesis.

This killer protein causes pancreatic cancer

Mouse pancreas cells with high levels of the protein SRSF1; CSHL Professor Adrian Krainer found that mice with high levels of SRFS1 tend to exhibit intraepithelial neoplasia—a known precursor to the most common form of pancreatic cancer.
Image Credit: Cold Spring Harbor Laboratory

Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer. It’s also one of the deadliest. More than 90% of PDAC patients die within five years of diagnosis. Usually, by the time the cancer is identified, it has already spread.

“PDAC is often found too late for treatments like chemotherapy and surgery to be very effective,” Cold Spring Harbor Laboratory (CSHL) Professor Adrian Krainer says. “But if we can clearly understand the underlying genetic mechanisms of PDAC, this might lead to earlier diagnoses and new types of therapies.”

Krainer and CSHL Postdoc Ledong Wan partnered with CSHL Professor David Tuveson to explore the role of a genetic process called RNA splicing in pancreatic cancer. RNA splicing helps DNA deliver instructions to cells for protein production. The team zeroed in on a splicing-regulator protein called SRSF1. They found that high levels of SRSF1 cause inflammation, or pancreatitis. This jumpstarts PDAC tumor development.

Near-universal T cell immunity towards a broad range of bacteria

Neutralizing the bacterially derived cytotoxic bomb: the pneumococci lie in the background, an array of macrophages and dendritic cells are arranged around the central image of a T cell. Rows of TCRs interacting with the identified pneumolysin epitope bound to HLA (white) cross the length and breadth of the artwork, emphasizing their centrality in the immune response.
Illustration Credit: Dr. Erica Tandori.

Typically, T cells of the immune system respond to a specific feature (antigen) of a microbe, thereby generating protective immunity. As reported in the journal Immunity, an international team of scientists have discovered an exception to this rule. Namely, a group of divergent bacterial pathogens, including pneumococci, all share a small highly conserved protein sequence, which is both presented and recognized by human T cells in a conserved population-wide manner.

The study set out to understand immune mechanisms that protect against pneumococcus, a bacterial pathobiont that can reside harmlessly in the upper respiratory mucosae but can also cause infectious disease, especially in infants and older adults, which can range from middle ear and sinus infections to pneumococcal pneumonia and invasive bloodstream infections.

Most currently used pneumococcal polysaccharide-based conjugate vaccines (PCVs) are effective against 10–13 serotypes, but growing serotype replacement becomes a problem.

COVID-19 vaccine appears more effective if received around midday

A new study led by Washington University School of Medicine in St. Louis suggests that circadian rhythm — the natural cycle of physical and other changes our bodies go through in a 24-hour period — may affect the body’s response to the COVID-19 vaccine. The research suggests that vaccines given around the middle of the day may prevent more infections than those given at other times.
Image Credit: Scientific Frontline

A study from Washington University School of Medicine in St. Louis indicates that the COVID-19 mRNA vaccine may be more effective at preventing infections if doses are given around the middle of the day rather than at other times. The researchers believe circadian rhythm — the natural cycle of physical and other changes our bodies go through in a 24-hour period — may affect the body’s response to the vaccine.

Further, they found that the correlation was strongest in children and teenagers, as well as adults over age 50.

The study is published April 25 in The Journal of Clinical Investigation.

Horses living in groups are better at following human indications than horses living in individual paddocks

An illustration and photo of the research situation.
Photo Credit: Océane Liehrmann

Wild horses live in complex social groups and can move an average distance of 9–16 kilometers in a day, and cover areas up to 40 km2 in one summer. In contrast, domestic horses are kept in enclosures and groups varying in size and even in individual stalls or small paddocks.

Horses living in bigger fields or pastures are more active – they are free to move according to their needs and, for example, to look for shade or shelter against wind and rain. When living in a group, horses can fulfil their social needs, interact in complex ways with many individuals, and have enough space to avoid unwanted interactions.

“It has been observed in earlier studies that horses with access to a pasture with other horses showed better learning performance and were less aggressive towards humans than horses kept in individual stables. Therefore, we wanted to explore whether horses’ social and physical environment affect their responsiveness to human indications,” says the lead author of the study, Doctoral Researcher Océane Liehrmann from the Department of Biology at the University of Turku, Finland.