Effects of Volatile Anesthetics on the Circadian Rhythms of Rat Hippocampal Acetylcholine Release and Locomotor Activity

This study revealed that the levels and circadian rhythms of hippocampal ACh release and locomotor activity were more sensitive to isoflurane anesthesia when administered during the dark phase. These findings suggest that anesthesia exerts differential effects on the regulation of circadian rhythms depending on the circadian phase.

http://www.ncbi.nlm.nih.gov/pubmed/23396087