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Sleep deprivation increases levels of the synaptic density marker SV2A in the human brain

The synaptic homeostasis hypothesis posits that sleep is essential for restoring cerebral equilibrium by downscaling synaptic connections that progressively strengthen and accumulate metabolic costs during wakefulness. While previously supported only by preclinical animal models, a recent study provides direct in vivo evidence of this mechanism in humans. Researchers evaluated 40 volunteers, half of whom underwent 28 hours of continuous sleep deprivation, utilizing Positron Emission Tomography (PET) to quantify levels of the SV2A protein, a reliable biomarker for synaptic density. The findings revealed that prolonged wakefulness significantly elevated SV2A levels across multiple brain regions, most notably in the hippocampus and thalamus. Furthermore, during a subsequent two-hour recovery sleep period, these elevated SV2A levels were strongly correlated with enhanced slow-wave activity, a primary electrophysiological marker of deep sleep and homeostatic sleep pressure. These results validate the synaptic homeostasis hypothesis in humans, demonstrating a measurable biological link between sleep deprivation, the accumulation of neural connections, and the restorative drive for deep, slow-wave sleep.


The synaptic homeostasis hypothesis (SHY) [14] posits that wakefulness promotes synaptic potentiation due to environmental interactions and learning [5]. The strengthening of connections during waking elevates energy consumption, results in the accumulation of proteins and receptors that compete for the limited anatomical space in the skull and diminishes the signal-to-noise ratios in the neuronal network, ultimately saturating the capacity for learning. Sleep allows for synaptic down-selection, preserving energy and network efficiency. While the SHY has been supported by anatomical and molecular studies in animals, human evidence has remained limited due to the invasive nature of most techniques for quantifying synaptic strength.

Studies in animals indicate that anatomical or molecular markers of synaptic strength increase during wake and decline during sleep [6]. Firing rates in rodents indicate increased cortical excitability during wakefulness and decreased cortical excitability during sleep. In humans, cortical excitability is an indirect measure of plasticity. Findings from studies using transcranial magnetic stimulation (TMS) translated the findings from the above-mentioned rodent studies (reviewed in [7]). However, some in-vitro and in-vivo studies of synaptic strength in animals reveal opposite results, which may be due to differences in the type of marker, examined brain regions, cortical layers, or housing of animals (reviewed in [8]).

Synaptic vesicle glycoprotein 2A (SV2A) [9] is an integral membrane protein located on synaptic vesicles. Recent advances in PET imaging with tracers such as [¹⁸F]SynVesT-1 enable the noninvasive measurement of SV2A binding in the living human brain [10,11], allowing new opportunities to examine state-dependent synaptic changes. However, whether this reflects presynaptic terminal number, vesicle complement, SV2A expression per vesicle, or excitatory/inhibitory-synapse composition cannot be resolved with in vivo imaging. While SV2A availability is commonly interpreted as a proxy measure of synaptic density, we refer to it here as ‘SV2A-indexed synaptic density’ to reflect this interpretation while acknowledging its underlying biological ambiguity.

Sugar-coated nanoparticles show promise for treating most aggressive form of brain cancer

Researchers at Oregon State University have potentially found a new way to treat the most aggressive form of brain cancer, glioblastoma, whose two-year survival rate is less than 30%.

The study, led by Oleh Taratula, Olena Taratula and Yoon Tae Goo of the OSU College of Pharmacy, addresses what they describe as the two most persistent obstacles to effective glioblastoma treatment: delivering therapeutic agents through the blood-brain barrier, the cell network that acts as a security checkpoint between the bloodstream and the central nervous system, and then getting those agents to preferentially target tumors.

In research published in the Journal of Controlled Release, the scientists demonstrate the novel treatment technique in a mouse model. They loaded lipid nanoparticles with genetic material that promotes tumor suppression, then coated the nanoparticles with a type of sugar. The result was a 50% median increase in glioblastoma survival time.

New effort will get genome sequences for entire Endangered Species list

The US Endangered Species Act compels the government to identify species at risk of extinction and devise plans to restore populations and the habitats they depend on. It has seen some spectacular successes, such as the restoration of the bald eagle to much of its original range. But over 2,300 plant and animal populations remain on the list, requiring ongoing government intervention.

On Thursday, it was announced that all of those species would see their genomes sequenced and tissue samples preserved to aid future conservation efforts. The work will be done by a partnership between two unexpected parties. One is the US government, which has generally attempted to undercut the Endangered Species Act as part of its anti-regulatory efforts. It is joined by Colossal Biosciences, a biotech company that has a controversial take on what actually constitutes a species.

Colossal has always said it had a conservation focus, but its headline-grabbing efforts have been directed toward restoring species that have been driven to extinction. It intends to do that by developing a combination of gene editing and reproductive technologies that it expects it can profitably license. But its dire wolf announcement, in which only a tiny handful of genetic changes were edited in to grey wolves, have raised some questions about its seriousness regarding these efforts.

Cloud Atlas: A Sextet Of Artistic Genius, Daring Imagination And Profound, Multi-Layered Meaning

Fourteen years ago, I walked into a theater not knowing the film would haunt me.

I saw it on Saturday. Then I went back on Sunday.

#CloudAtlas is profound, artistic, brave, and brilliant, all at once. Six stories, six instruments, one piece of harmony moving through centuries. Comedy and tragedy. Drama and even farce. Past and future, unfolding at the same time.

Here is what stayed with me. The film refuses to hand you its meaning. It hides the treasure, scatters the clues, then makes you earn it. Most viewers will dismiss it for exactly that reason. The patient few get rewarded.

Movies are like music. We can all listen to the same tune, yet not all of us actually hear it. That is the real test of great #Storytelling, and few films dare to be this challenging.

So I gave it a verdict. A number I have handed to almost nothing else in all my years of reviewing film.

Can Mind-Reading Tech Help People Hear Better?

From Vishal Choudhari, PhD, and the lab of Nima Mesgarani, PhD, at Columbia University’s Zuckerman Institute: A new tech monitors the brain to detect who you are listening to. It then amplifies that voice and quiets other voices nearby. Brain surgery patients recently tested the system in hospitals. They heard two overlapping conversations, one on each side. The volunteers then tried to focus on only one conversation. One video here shows a man listening to the overlapping conversations. Researchers ask him to focus on the conversation on his right. Controlled by his brain activity, the system adjusts the volume. In another experiment, he again focuses his attention on the right. The system notices, amplifying a conversation about bread. Then, researchers ask him to switch to the left conversation. The mind reading system turns about another conversation, about repairs. In a different experience, a volunteer can freely choose what to listen to. He starts on the right. A graph appears, showing the system monitoring his brain activity. What happens when he switches from right to left? The system spots his shift in attention and adjusts the volume. Scientists asked volunteers about the experience. “In the second section, what I was listening to was louder, and the other thing was quieter. And in the first section, they were both equally loud. That’s super dope.” “I think if you could really implement it in the hearing aids, if this is the goal, I think it would be really helpful to just be able to have someone who is hard of hearing be able to kind of pinpoint exactly the conversation they want to have, especially if you’re in a location with a lot of people.” “Well I just keep thinking about about Uncle Aaron. Can you imagine if this technology existed in a world that he could access it? He might actually live a much more peaceful… life.”

New bacteria-based cooling material could help electronics and EV batteries run cooler

Next-generation electronic devices like newer computers and other high-power devices require more energy to run. When they are working hard, the intense heat they generate can limit their performance and reliability. That’s why scientists are trying to find better and more sustainable materials to help cool devices down.

Weinan Xu, an assistant professor in the Department of Materials Science and Engineering at the University of Tennessee, Knoxville, has developed a novel concept for the fabrication and processing of thermal interface materials based on synergistic microbial biosynthesis, which is a way of making useful materials with the help of microbes like bacteria.

Thermal interface materials are specialized substances inserted between electronic and cooling devices to eliminate tiny air pockets so heat can move out of the device faster. By changing how the bacteria are grown and how the material is processed, the material’s ability to move heat, known as thermal conductivity, can be adjusted.

How ‘peacemakers’ of the immune system could unlock long-term disease remission

“Peacemaker” immune cells could help treat diseases ranging from type 1 diabetes to neurodegeneration by restoring immune tolerance, according to a new paper in Frontiers in Science.

From cancer, diabetes and chronic infections to cardiovascular, neurodegenerative and reproductive conditions, inflammation is increasingly cited as a driver of a broad range of diseases. Immune cells called regulatory T cells (Tregs)—originally defined as “suppressor” cells that stop other immune cells from attacking the body—are being explored as “living drugs” that could eventually be adapted to target many diseases with an inflammatory component.

Such an approach, which aims to tailor Treg therapies to specific diseases and tissues, could support more precise control of immune responses. In autoimmune diseases and transplant rejection, Tregs could even help shift treatment from broad immunosuppression, which brings myriad risks, toward restored immune tolerance and longer-term disease control.

Turning low-value diamond dust into high-performance quantum materials

Diamonds have long been coveted for their beauty. Their dazzling color and clarity make them perfect candidates for luxury jewelry. However, it’s their other unique characteristics, including their hardness, thermal conductivity and chemical resistance, that make diamonds suitable for various applications in industry and advanced technologies.

At the quantum scale, carefully engineered diamonds can behave like tiny sensors—able to ‘feel’ magnetic signals from nearby molecules. In simple terms, they can pick up incredibly faint signals that would otherwise be invisible to conventional instruments. This capability could help us detect contaminants in water, identify disease biomarkers and monitor chemical processes in real time.

The project strengthens one of Australia’s most important international science partnerships, bringing together complementary expertise in quantum materials, advanced manufacturing and characterization to accelerate the development of next-generation sensing technologies.

X-ray snapshots reveal how viral shells change shape as they dry out

When viruses travel through the air in tiny droplets, they can quickly start to dry out. Yet many viruses remain infectious after rehydration—something that is still not fully understood. Now, an international team of researchers has directly observed at the European XFEL how the protein shells of viruses can change shape during dehydration, offering new clues to viral resilience and opening new possibilities for virology research. The results, published in Light: Science & Applications, lay the groundwork for potential applications in virology and public health and can, for instance, help develop antiviral strategies.

At the SPB/SFX instrument of the European XFEL, Abhishek Mall from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg (MPSD) and his colleagues explored the structural dynamics of the protein shells—called capsids—that enclose the genetic material of viruses. Specifically, they examined the behavior of capsids of the bacteriophage MS2 under conditions of dehydration. MS2 is an icosahedral, i.e., shaped by 20 triangular surfaces that form a sphere, single-stranded RNA virus that infects the bacterium Escherichia coli and is widely used as a model system in virology.

The capsid’s design is critical for protecting the viral genome and helping the virus interact with host cells. However, viruses are often confronted with environments that challenge their structural integrity, for example through dehydration. Theoretical studies have long suggested that capsids may undergo low-energy “buckling transitions”—sudden changes in shape—to adapt to such stresses, but direct experimental evidence has been lacking.

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