Summary: Exposure to anesthesia causes lipid clusters to move from an ordered state to a disordered one, then back again. These changes lead to subsequent effects that cause changes in consciousness.
Source: Scripps Research Institute
Surgery would be inconceivable without general anesthesia, so it may come as a surprise that despite its 175-year history of medical use, doctors and scientists have been unable to explain how anesthetics temporarily render patients unconscious.