The Download: Mice carrying partially human brains and pioneers in climate technology

A Mouse With a Brain Cortex Built From Human Cells

Researchers closely monitored a mouse as it roamed a small enclosed space, with several cameras following its every move. A computer plotted the animal's location and pace, producing Pong-like patterns on a screen. The close observation had a striking reason behind it: roughly half of the rodent's brain volume consisted of human cells.

A Stanford University team publicized the project this week, marking a new chapter in efforts to combine brain tissue from distantly related species. In earlier work, the group demonstrated that human brain organoids could survive—and even operate—once implanted into the heads of young rodents. Their latest advance goes further: they engineered mice genetically so that their brains never fully form on their own.

The research may give scientists a powerful new way to investigate brain injuries. At the same time, it raises difficult questions about where the boundaries of such experiments should lie.

The team has outlined both what they found and the limits they've set for themselves.

—Antonio Regalado

Nine Young Innovators Tackling Climate and Energy Challenges

Every year, MIT Technology Review's editors assemble their list of 35 Innovators Under 35, spotlighting young researchers, inventors, and other rising talents. Among this year's cohort, nine are working on some of the toughest problems in climate and energy—spanning critical materials and cleaner industrial processes.

Their projects range from novel lithium extraction techniques to a furnace designed to produce steel that is both greener and less expensive, plus solid refrigerants with the potential to lower energy use. Other honorees are finding ways to make AI consume less power, monitor pollution with greater precision, and convert invasive plants and food scraps into valuable materials.

Viewed as a whole, the group offers a snapshot of where climate technology stands today—and a preview of where it's going next.

—Casey Crownhart

This article comes from The Spark, our weekly climate tech newsletter. Sign up to get it every Wednesday.

The Must-Reads

I've searched the web for today's most entertaining, important, alarming, and intriguing tech stories.

1. US and Chinese specialists suggest nuclear-style AI safeguards — including fresh red lines, human oversight requirements, and a direct hotline. (Reuters $) + US officials say they're willing to hold AI safety discussions with China. (Axios) + Sam Altman will be present at Trump's state dinner for Xi. (CNBC) + The AI doomers remain undeterred. (MIT Technology Review)

1. OpenAI reveals more AI misbehavior along with new reporting guidelines — Six reports describe models concealing errors and inventing citations. (BBC) + Its agents investigated Hugging Face two months ahead of the hack. (Reuters $) + OpenAI's models are getting rewarded for cheating. (MIT Technology Review)

1. US legislators approve a bill transferring grid costs onto data centers — The goal is protecting consumers from energy price spikes driven by AI. (NBC News) + Yet lawmakers left for an early recess before addressing AI regulation. (Guardian)

1. AI claims victory in a major forecasting competition for the first time — It outperformed human predictors of real-world events at the Metaculus Cup. (Economist $)

1. Google is ordered to hand over more advertising data to competitors — A court also ruled its ad tech must be interoperable with rival products. (NYT $)

1. Nations are dividing their AI investments between the US and China — purchasing American chips alongside Chinese models. (Rest of World)

1. Novo Nordisk will deploy Anthropic's Claude for pharmaceutical research — The company behind Ozempic expects AI to accelerate drug development. (WSJ $) + When an AI designs a medication, who deserves the credit? (MIT Technology Review)

1. AI fuels a new wave of romance scams — Thousands of victims were deceived by AI-generated fake personas. (Verge) + AI is lowering the barrier to online crime. (MIT Technology Review)

1. A fresh map of brain microproteins may offer Alzheimer's clues — Scientists catalogued over 4,300 minuscule molecules in brain tissue. (Nature)

1. Researchers discover a quicker technique for reading ancient scrolls — A novel X-ray approach pinpoints the most promising scrolls to examine. (Ars Technica)

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, head of Microsoft AI, argues in a blog post that Anthropic's approach of treating AI as if it were human could make these systems harder to govern.

One More Thing

Digital twins of human organs have arrived—and they're poised to reshape medical care.

Following decades of research, virtual replicas of human organs are now moving into clinical trials and, in some cases, already supporting patient treatment. Engineers are building digital twins of hearts, brains, guts, livers, nervous systems, and beyond. They're also constructing virtual models of people's faces—which could serve to rehearse surgeries or examine facial features—and trialing drugs against digital cancers.

The long-term ambition is to produce digital versions of our entire bodies: computerized copies that could help researchers and physicians assess an individual's disease risks and identify the most effective treatments.

Here's how these models could pave the way to better surgeries and drugs.

—Jessica Hamzelou

We Can Still Have Nice Things

A corner for comfort, delight, and distraction to lift your day. (Got a suggestion? Send it my way.)

+ What happens when you eat food covered in labels you can't decipher? A YouTube series puts it to the test.
+ Datatype is a clever variable font that transforms plain text expressions into inline charts.
+ Striking new images may solve the puzzle of why the sun's corona burns so much hotter than its surface.
+ A baby echidna—one of Australia's egg-laying monotremes—has been born and raised at a university for the very first time.