(a) The effect of feeding schedule on daily rhythm before and after isoflurane anaesthesia. After manipulating RF, mice were divided into five groups: control group (feeding throughout the entire day, from ZT0 to ZT24, n = 8), Night-Feeding group (feeding during nighttime, from ZT12 to ZT24, n = 8), Day-Feeding group (feeding during daytime, from ZT0 to ZT12, n = 8), Night-Feeding + Anes group (feeding during nighttime from ZT12 to ZT24 and receive isoflurane on D0, n = 8), and Day-Feeding + Anes group (feeding during daytime from ZT0 to ZT12 and receive isoflurane on D0, n = 8). (b) The effect of feeding schedule on post-anaesthetic fear memory at D7, D10, D14. After manipulating RF, mice were divided into six groups: Control group (feeding throughout the entire day, from ZT0 to ZT24, n = 8), Control + Anes group (feeding throughout the entire day, from ZT0 to ZT24 and receive isoflurane on D0, n = 8), Night-Feeding group (feeding during nighttime, from ZT12 to ZT24, n = 8), and Day-Feeding group (feeding during daytime, from ZT0 to ZT12, n = 8), Night-Feeding + Anes group (feeding during nighttime from ZT12 to ZT24 and receive isoflurane on D0, n = 8), Day-Feeding + Anes group (feeding during daytime from ZT0 to ZT12 and receive isoflurane on D0, n = 8).