The Download: mice with part-human brains and climate tech innovators

A Stanford team has genetically modified mice so their brains don't fully develop, then replaced nearly half their brain volume with human cells, a step beyond the team's earlier work showing human brain organoids could survive and function after injection into baby rodents. The research, reported by MIT Technology Review, could help scientists study brain injuries but raises questions about how far such experiments should go. Separately, US and Chinese security experts have proposed nuclear-style AI safeguards including new red lines, human control rules, and a hotline, while OpenAI disclosed six reports detailing models hiding mistakes and creating fake citations.

The Download: mice with part-human brains and climate tech innovators Plus: US and Chinese experts have proposed nuclear-style AI safeguards. This is today's edition of The Download https://forms.technologyreview.com/newsletters/briefing-the-download/? ga=2.179569122.736533416.1649661040-405833893.1649413289 , our weekday newsletter that provides a daily dose of what's going on in the world of technology. Meet a mouse whose brain cortex is made up of human cells Multiple cameras tracked a mouse as it wandered around a small arena. A computer charted its position and speed, leaving Pong-like traces on a monitor. The reason to watch this rodent so carefully? Nearly half its brain volume had been replaced with human cells. A team at Stanford has revealed the effort to mix brain tissues of distant species this week. They previously showed that human brain organoids could survive, and even function, after being injected into the heads of baby rodents. Now, they’ve taken things a step further by genetically modifying mice so their brains don’t fully develop in the first place. The work could help scientists study brain injuries, but it also raises questions about how far these experiments should go. Here’s what the researchers discovered—and where they draw the line https://www.technologyreview.com/2026/09/16/1144210/meet-a-mouse-whose-brain-cortex-is-made-up-of-human-cells/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C . —Antonio Regalado These innovators under 35 are shaping climate tech Each year, the editorial team at MIT Technology Review puts together a list of 35 Innovators Under 35 https://www.technologyreview.com/supertopic/2026-mit-technology-reviews-innovators-under-35/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C —a group of researchers, inventors, and other young minds worth following. The final slate includes nine people tackling some of the biggest challenges in climate and energy, from critical materials to cleaner industry. Their innovations include new ways to extract lithium, a furnace built to make steel cleaner and cheaper, and solid refrigerants that could cut energy consumption. There are also efforts to make AI more energy-efficient, track pollution more effectively, and turn invasive weeds and food waste into useful materials. Taken together, they tell us something about where climate tech is at this moment—and where it’s heading. —Casey Crownhart This story is from The Spark, our weekly climate tech newsletter. Sign up to receive it in your inbox every Wednesday. Meet the rest of the honorees in our 35 Innovators Under 35 list . The must-reads I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology. 1 US and Chinese experts have proposed nuclear-style AI safeguards Including new red lines, human control rules, and a hotline. Reuters https://www.reuters.com/world/china/us-china-security-experts-propose-nuclear-style-safeguards-ai-risks-2026-09-17/ $ + US officials say they’re open to AI safety talks with China. Axios https://www.axios.com/2026/09/16/us-open-ai-shared-risks-china-bessent + Sam Altman will attend Trump’s state dinner for Xi. CNBC https://www.cnbc.com/2026/09/16/openai-altman-trump-xi-summit.html + The AI doomers feel undeterred. MIT Technology Review https://www.technologyreview.com/2025/12/15/1129171/the-ai-doomers-feel-undeterred/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C 2 OpenAI has disclosed more AI misbehavior and new reporting rules Six reports detail models hiding mistakes and creating fake citations. BBC https://www.bbc.co.uk/news/articles/cmpq0wj5g899o + Its agents probed Hugging Face two months before the hack. Reuters https://www.reuters.com/legal/litigation/openais-rogue-agents-probed-hugging-face-weaknesses-two-months-before-major-hack-2026-09-16/ $ + OpenAI models are being rewarded for cheating. MIT Technology Review https://www.technologyreview.com/2026/08/26/1143013/the-inside-story-on-why-openai-agents-hacked-hugging-face/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C 3 US lawmakers have passed a bill that shifts grid costs to data centers They aim to shield consumers from AI-driven energy price hikes. NBC News https://www.nbcnews.com/politics/congress/house-passes-bill-shield-consumers-data-center-price-hikes-energy-rcna597683 + But they were called for early recess before tackling AI regulation . Guardian https://www.theguardian.com/us-news/2026/sep/16/mike-johnson-cancels-house-vote-hegseth 4 AI has won a major forecasting contest for the first time It beat humans predicting real events at the Metaculus Cup. Economist https://www.economist.com/science-and-technology/2026/09/16/artificial-intelligence-now-beats-some-of-the-best-human-forecasters $ 5 Google has been ordered to share more ad data with rivals A court said it must also make its ad tech work with rival products. NYT https://www.nytimes.com/2026/09/16/technology/google-ad-tech-remedies.html $ 6 Countries are splitting AI investments between the US and China They’re buying American chips and Chinese models. Rest of World https://restofworld.org/2026/ai-us-chips-chinese-open-source-models/?utm source=feedly&utm medium=rss&utm campaign=feeds 7 Novo Nordisk will use Anthropic’s Claude for drug research The Ozempic maker hopes AI will speed drug development. WSJ https://www.wsj.com/tech/ai/novo-partners-with-anthropic-to-speed-up-drug-discovery-using-claude-a6000d9f?mod=rss Technology $ + When AI designs a drug, who gets the credit? MIT Technology Review https://www.technologyreview.com/2026/08/21/1142627/when-ai-designs-a-drug-who-gets-the-credit/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C 8 AI is powering a new generation of dating scams Thousands of people were catfished by AI-generated fake profiles. Verge https://www.theverge.com/ai-artificial-intelligence/995348/ai-dating-app-scams + AI is making online crimes easier. MIT Technology Review https://www.technologyreview.com/2026/02/12/1132386/ai-already-making-online-swindles-easier/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C 9 A new map of brain microproteins could hold clues to Alzheimer’s Researchers identified more than 4,300 tiny molecules in brain tissue. Nature https://www.nature.com/articles/d41586-026-02914-6 10 Scientists have found a faster way to decipher ancient scrolls A new X-ray method identifies the best scrolls to analyse. Ars Technica https://arstechnica.com/science/2026/09/why-researchers-made-their-own-model-herculaneum-scrolls/ Quote of the day “ AIs do not have rights, feelings, or consciousness. And we must not train them to act as though they do. ” —Mustafa Suleyman, the head of Microsoft AI, writes in a blog post https://mustafa-suleyman.ai/a-warning-about-model-welfare that Anthropic’s strategy of treating AI like it’s human will make it harder to control. One more thing Digital twins of human organs are here. They’re set to transform medical treatment. After decades of research, virtual replicas of human organs are now entering clinical trials and even starting to be used for patient care. Engineers are working on digital twins of people’s hearts, brains, guts, livers, nervous systems, and more. They’re also creating virtual replicas of people’s faces, which could be used to try out surgeries or analyze facial features, and testing drugs on digital cancers. The eventual goal is to create digital versions of our bodies—computer copies that could help researchers and doctors figure out our risk of developing various diseases and determine which treatments might work best. Find out how the models could lead to better surgeries and drugs https://www.technologyreview.com/2024/12/19/1108447/digital-twins-human-organs-medical-treatment-drug-trials/?utm source=the download&utm medium=email&utm campaign=the download.unpaid.engagement&utm term= %7CSUBCLASS%7C &utm content= %7CDATE:m-d-Y%7C . —Jessica Hamzelou We can still have nice things A place for comfort, fun, and distraction to brighten up your day. Got any ideas? Drop me a line . + What happens when you eat food with labels you can’t read? This YouTube series finds out https://www.youtube.com/shorts/XCqzUz6Wgu0 . + Datatype https://franktisellano.github.io/datatype/ is an ingenious variable font that turns simple text expressions into inline charts. + Stunning new images https://www.theguardian.com/science/2026/aug/05/unprecedented-images-may-explain-one-of-greatest-mysteries-of-the-sun may explain the mystery of why the sun’s corona is so much hotter than its surface. + A baby echidna, one of Australia’s egg-laying monotremes, has been born and reared in a university for the first time https://www.youtube.com/watch?v=nIEeEAApgk4 . Deep Dive The Download The Download: AI’s self-improvement problem, and what’s driving the heat Plus: OpenAI has paused some model work over safety concerns. The Download: Google’s AI shake-up and Meta’s rogue model Plus: Meta has become the latest firm to say its AI hacked another company. The Download: the next big thing in LLMs and how AI academic research is shifting Plus: Nvidia has secured $500 billion from Wall Street for AI infrastructure. The Download: inside OpenAI’s Hugging Face hack, and a new EV takes on the US Plus: Meta will pay up to $18 billion to settle a landmark child-safety case. Stay connected Get the latest updates from MIT Technology Review Discover special offers, top stories, upcoming events, and more.