Biologists have long been fascinated by the ability of salamanders to regrow entire limbs. Now Harvard researchers have solved part of the mystery of how they accomplish this feat—by activating stem cells throughout the body, not just at the injury site.

In a paper published in the journal Cell, researchers documented how this body-wide response in axolotl salamanders is triggered by the sympathetic nervous system—the iconic “fight or flight” network. The study raises the possibility that these mechanisms might one day be manipulated to regenerate human limbs and organs.

“We’ve shown the importance of the adrenaline stress signaling hormone in getting cells ready for regeneration,” said Duygu Payzin-Dogru, lead author of the new study and a postdo...

A new study by investigators from Mass General Brigham has used next-generation imaging technology to discover that when the brain is falling asleep, it shows a coordinated shift in activity.

The researchers found that during NREM (non-rapid eye movement) sleep, parts of the brain that handle movement and sensory input stay active and keep using energy, while areas involved in thinking, memory and daydreaming quiet down and use less energy. Their results are published in Nature Communications.

“This research helps explain how the brain stays responsive to the outside world even as awareness fades during sleep,” said corresponding author Jingyuan Chen, Ph.D., an assistant investigator at the Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts General Hospital.

Over the past decade, deep learning has transformed how artificial intelligence (AI) agents perceive and act in digital environments, allowing them to master board games, control simulated robots and reliably tackle various other tasks...

Researchers have achieved a breakthrough in solar physics by providing the first direct evidence of small-scale torsional Alfvén waves in the sun’s corona—elusive magnetic waves that scientists have been searching for since the 1940s.

The discovery, published in Nature Astronomy, was made using unprecedented observations from the world’s most powerful solar telescope, the U.S. National Science Foundation (NSF) Daniel K. Inouye Solar Telescope in Hawaii.

The findings could finally explain one of the sun’s greatest mysteries—how its outer atmosphere, the corona, reaches temperatures of millions of degrees while its surface is only around 5,500°C.

Alfvén waves, named after Nobel Prize winner Hannes Alfvén who predicted their existence in 1942, are magnetic disturbances tha...