In male mice, a long dose of a common anesthesia gas seems to lower levels of brain proteins that help burn fat for energy, and this effect lasts up to a week after the anesthesia wears off.

Giving mice a drug called fenofibrate before anesthesia might boost brain proteins that help burn fat for energy — like turning up the brain’s fuel-burning system for several days after the procedure.

In mice, a drug called fenofibrate helps protect the brain after anesthesia, but only if the brain can burn fat for energy — when another drug blocks fat burning, the protection goes away.