A commonly used anesthetic has been found to induce changes associated with Alzheimer’s disease in the brains of laboratory mice, according to a recent report from Massachusetts General Hospital.

Isoflurane, a gas that is regularly used to anesthetize patients before surgery, has been linked with cell death and increased levels of BACE proteins and amyloid-beta plaques in the brain. Both are hallmarks of Alzheimer’s disease, according to researchers. Researchers subjected healthy lab mice to the gas in doses relatively comparable to what humans receive before surgery. Analyses at two-, six- and 12-hour intervals revealed increased levels of BACE in the brain, and analysis at 24 hours found a four-fold increase in BACE levels and a marked increase in amyloid-beta plaques.

General anesthesia before surgery has long been associated with a temporary form of dementia after the patient awakens. Further studies will take place to determine the long-term effects of isoflurane on the human brain, researchers say. Their report appears online in the Annals of Neurology.