Newswise — Every day, hundreds of thousands of people undergo general anesthesia, trusting they’ll drift into unconsciousness and wake safely after surgery. Yet despite decades of use, scientists still don’t fully understand how anesthetic drugs reshape the brain’s electrical activity to produce unconsciousness.

Studying the brain’s response to anesthesia has been difficult: in living humans, there’s no safe way to study the brain cell by cell, and in animals, the drugs act on many different brain regions at once, making it hard to isolate where the effects arise.

Now, UCLA researchers have shown for the first time that human stem cell-derived brain assembloids — tiny, three-dimensional models that recreate simplified human brain circuits — can reproduce the electrical changes seen during general anesthesia. Their findings were just published in the British Journal of Anaesthesia.

A small protein known as p11 may play a much broader role in cellular signaling than previously thought. Researchers at Karolinska institutet have now shown that p11 interacts with numerous receptors targeted by commonly used medicines, opening new possibilities for treating conditions such as pain, inflammation and depression. The research is published in the journal Science Advances.

“Cells communicate through complicated molecular networks, with most modern drugs acting by tuning these signals on or off. Our study identifies a key protein modulating signal transduction across G protein-coupled receptors, the largest receptor family in mammals. Decoding these signaling networks is essential to advance receptor biology and drive the development of next-generation therapies,” says Marcus Saarinen at the Department of Clinical Neuroscience and the lead author of the study.