Natural sleep, but not propofol-induced anesthesia preserves spatial and procedural memory consolidation

Propofol-induced anesthesia and natural sleep both inhibit GABA-A-ergic inhibition and induce slow-wave activity. However, sleep actively facilitates memory consolidation, whereas anesthesia may disrupt this process. Nineteen participants undergoing surgery under propofol anesthesia and seventeen participants taking a nap underwent tests involving a hippocampus-dependent spatial memory task and a procedural memory task.

Both tasks showed a decline in performance from pre to post-study in the propofol group, while the sleep group maintained stable performance. Slow oscillations occurred in both non-REM sleep and propofol-induced anesthesia. Nevertheless, only during non-REM sleep were slow oscillations accompanied by increased spindle activity. These findings suggest that propofol anesthesia disrupts memory consolidation, likely due to the absence of spindle coupling that typically mediates the hippocampal-neocortical information transfer necessary for systems memory consolidation.