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Brain circuit controlling compulsive behavior mapped

Researchers at Karolinska Institutet in Sweden have identified a brain circuit that can drive repetitive and compulsive behaviors in mice, even when natural rewards such as food or social contact are available. The study has been published in the journal Science Advances and may contribute to increased knowledge about obsessive-compulsive disorder and addiction.

Both animals and humans can become stuck in certain behaviors, but exactly how this is regulated in the brain has been unknown. Now, researchers have been able to show that a specific nerve circuit in the brain can put behaviors into a kind of “repeat mode,” where mice continue to perform the same actions over and over again, even when there is no longer any reward.

The researchers investigated a that runs from the , part of the brain’s reward system, to a region in the hypothalamus, which in turn is connected to the , an area that processes unpleasant experiences. By activating this circuit using optogenetics, a method in which are controlled by light, the researchers were able to induce a negative state in mice that led to repetitive behaviors such as digging and sniffing—even when food or other rewards were available.

Airborne sensors map ammonia plumes in California’s Imperial Valley

A recent study led by scientists at NASA’s Jet Propulsion Laboratory in Southern California and the nonprofit Aerospace Corporation shows how high-resolution maps of ground-level ammonia plumes can be generated with airborne sensors, highlighting a way to better track the gas.

A key chemical ingredient of fine particulate matter—tiny particles in the air known to be harmful when inhaled—ammonia can be released through agricultural activities such as livestock farming and geothermal power generation as well as natural geothermal processes. Because it’s not systematically monitored, many sources of the pungent gas go undetected.

Published in Atmospheric Chemistry and Physics, the study focuses on a series of 2023 research flights that covered the Imperial Valley to the southeast of the Salton Sea in inland Southern California, as well as the Eastern Coachella Valley to its northwest. Prior satellite-based research has identified the Imperial Valley as a prolific source of gaseous ammonia.

Soft robot powered by edible pneumatic battery and actuator

Using common kitchen ingredients such as citric acid and sodium bicarbonate, scientists have created an edible pneumatic battery and valve system to power soft robots.

Soft, biodegradable robots are used in various fields, such as and targeted drug delivery, and are designed to completely disappear after performing their tasks. However, the main problem with them is that they rely on conventional batteries (such as lithium), which are toxic and non-biodegradable. And until now, no successful system has been developed that can provide repeated, self-sustained motion using only edible materials.

In a new paper published in the journal Advanced Science, researchers from Dario Floreano’s Laboratory of Intelligent Systems at EPFL in Switzerland describe how they developed a fully edible power source (), a valve system (controller), and an actuator (the robot’s muscle).

Species in crisis: Critically endangered penguins are directly competing with fishing boats

A new study led by the University of St Andrews has found that critically endangered African penguins (Spheniscus demersus) are significantly more likely to forage in the same areas as commercial fishing vessels during years of low fish abundance, increasing competition for food and adding pressure to a species already in crisis.

Published in the Journal of Applied Ecology, the research introduces a novel metric called “overlap intensity” which for the first time measures not just the extent of shared space between and fishing vessels, but how many penguins are actually affected by this overlap.

The African penguin population has plummeted by nearly 80% in the past three decades, in part due to competition with the local fishery targeting sardines and anchovies, a key prey for the penguins.

Urolithin A nudges aging immune cells toward a youthful profile in 28 days

An international research team focused on aging reports that urolithin A at 1,000 mg per day shifted human immune profiles toward a more naive-like, less exhausted CD8+ state and increased fatty acid oxidation capacity, with additional functional gains.

Urolithin A is a metabolite produced by gut bacteria after breaking down ellagic acid from certain foods, such as pomegranates and walnuts. While produced naturally through microbial digestion, it is in much smaller quantities than available as a supplement or used in the study.

Aging bodies face reduced production of mature T cells, shrinking naive T cell pools and chronic low-grade inflammation. Mitochondrial dysfunction and waning autophagy sit at the core of these shifts, with mitophagy failure linked to immune dysregulation and disease.

Unusual days signal rising migraine risk

Harvard Medical School researchers report that higher day-to-day “trigger surprisal” scores were associated with migraine attacks over the next 12 and 24 hours. In this cohort, higher surprisal scores aligned with greater odds of a headache attack, even after accounting for recent headache history and fluctuations in daily experience.

Migraine management often revolves around trying to identify and control conditions that might trigger them. From food and drink and to physiological and psychological stressors, it is a crowded landscape of potential trigger suspects. Individuals attempting to match attack timing to these suspected triggers rely on memory and a self-selected list of candidates rather than controlled experimental designs.

In the study, “Information-Theoretic Trigger Surprisal and Future Headache Activity,” published in JAMA Network Open, researchers conducted a to evaluate the association between surprise and future attacks.

Fighting poverty may require cultural wisdom, not just cash

Most poverty-fighting efforts focus on meeting basic material needs, such as food and shelter. But this overlooks the psychological and cultural factors that shape how people take action in their lives.

University of Michigan researchers found that psychosocial programs designed to support women’s agency in Niger, West Africa, were effective in promoting women’s economic empowerment when grounded in local values—such as social harmony, respectfulness and collective progress—but not a Western-style program grounded in individual ambition.

The new study highlights how culturally attuned approaches to empowerment can offer a powerful pathway for reducing . The research, published in the latest issue of Proceedings of the National Academy of Sciences, introduces a “culturally wise” approach: psychosocial programs that honor diverse worldviews and community values.

New lightweight polymer film can prevent corrosion

MIT researchers have developed a lightweight polymer film that is nearly impenetrable to gas molecules, raising the possibility that it could be used as a protective coating to prevent solar cells and other infrastructure from corrosion, and to slow the aging of packaged food and medicines.

The polymer, which can be applied as a film mere nanometers thick, completely repels nitrogen and other gases, as far as can be detected by laboratory equipment, the researchers found. That degree of impermeability has never been seen before in any polymer, and rivals the impermeability of molecularly-thin crystalline materials such as graphene.

“Our polymer is quite unusual. It’s obviously produced from a solution-phase polymerization reaction, but the product behaves like graphene, which is gas-impermeable because it’s a perfect crystal. However, when you examine this material, one would never confuse it with a perfect crystal,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT.

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