Health Institute Carlos III

The Karolinska Institute has awarded the Nobel Prize in Medicine or Physiology to Karl Deisseroth, Peter Hegemann, and Georg Nagel for their discoveries regarding light-activated ion channels and optogenetics. This method, which makes it possible to activate or deactivate individual neurons in a living brain, “is currently used in laboratories around the world to unravel the mysteries of the brain,” the institute announced. 

The Atmosphere Watch analysis, published by the Copernicus Atmosphere Monitoring Service, shows how, in 2026, air pollution has crossed borders and caused nearly 40 per cent of the world’s population to be exposed to high levels of tropospheric ozone. This pollutant is produced when other harmful compounds react with sunlight and high temperatures. The report highlights the massive wildfires in France, Spain and Belgium this summer, which generated significant smoke transport, affecting air quality thousands of kilometres away. Furthermore, across Europe as a whole, successive heatwaves between June and August led to an increase in ozone emissions from local sources, resulting in the health protection limit values being exceeded.  

A team of Spanish researchers has investigated the early stages of metastatic cells taking hold in target organs and has discovered that there is a transitional stage during which these ‘metastatic seeds’ are particularly vulnerable. They have also demonstrated in mice and in human samples that these micrometastases can be eliminated using three drugs, two of which are already approved for other indications. The study is published in the journal Cancer Cell.

A pilot trial assessed the feasibility and acceptability of reducing the consumption of ultra-processed foods in the diets of patients with major depressive disorder. The study, which involved twenty participants from the United States, has been published in the journal JAMA Psychiatry and shows that scores for depression and anxiety were lower during the period of reduced consumption of ultra-processed foods than during the period of their usual diet. According to the authors, this is an exploratory study – in the form of a Research Letter – and, “at best, it generates hypotheses”.

A US-based team with Spanish participation has successfully transplanted cortical organoids—self-organizing fragments of lab-grown human brain tissue—into modified mice lacking most of their cerebral cortex, the brain layer responsible for functions ranging from cognition and language to attention and decision-making. The research, published in the journal Nature, shows that the human tissue survived, grew, and developed functional connections with the mice's brains and, extending beyond that, with the spinal cord. According to the authors, this could help generate new models for studying disease-related alterations in human brain circuits.

A study led by the Carlos III Health Institute (ISCIII) shows that, between 2013 and 2018, on days when fires were recorded, there was an increase in A&E admissions for respiratory problems in nine Spanish provinces. At a briefing organised by SMC Spain, Cristina Linares and Julio Díaz, the study’s authors and researchers at the ISCIII, explained the implications of the research and called for a surveillance plan, alongside the monitoring of these harmful particles and compounds, in the face of increasingly severe wildfires.

A team from the United States exposed pregnant mice to a mild inflammatory agent so that their offspring would develop brain and behavioural changes similar to those seen in autism spectrum disorder. When these offspring reached adulthood, the researchers administered a dose of rapamycin — an immunosuppressant — and found that several of these changes improved for a few hours, including cerebral hyperactivity, the risk of seizures, sensory hypersensitivity, repetitive behaviours and abnormal organisation of the brain’s functional network. The authors, whose work is published in Nature Communications, emphasise in a press release that these effects are temporary and that repeated administration loses its efficacy. Furthermore, they point out that rapamycin’s high potential for toxicity and the fact that the study was conducted on mice rule out its widespread use in humans.

The range of CRISPR tools for genome editing can extend beyond nature-inspired designs thanks to proteins designed using artificial intelligence. A new study by Nobel laureate Jennifer Doudna’s team, published in Science, describes the design of synthetic RNA-guided nucleases, with sequences substantially different from those found in nature, which match or exceed the activity of their natural counterparts whilst offering novel properties.

A new study reveals that the proportion of adults with dementia has risen significantly in Mexico, Peru and Puerto Rico over the last two decades, rising from one in ten older adults to almost one in six; a trend that runs counter to that seen in the US and other wealthy countries. Rates remained stable in Cuba and the Dominican Republic. The authors urge investment in prevention, dementia screening and care infrastructure. The study is published in JAMA Neurology.

The latest reports from the European Centre for Disease Prevention and Control (ECDC) indicate a rise in bacterial sexually transmitted infections (STIs) across Europe. In 2024, notifications of gonorrhoea and syphilis, along with congenital syphilis, reached their highest levels in more than a decade, reflecting sustained transmission across multiple countries. Gonorrhoea has increased by more than 300 % over the past 10 years, with Spain among the countries with the highest rates, while syphilis has risen by around 100 %, with Spain also ranking second highest. Men who have sex with men are the most affected population group for both infections. Congenital syphilis increased by almost 250 %, described as “one of the most concerning findings” by two ECDC experts during the briefing presenting the results. Possible contributing factors include reduced condom use, an increase in sexual partners, as well as higher levels of testing.