Bees with chemically-induced jet lag are giving clues on how best to help patients recover from the effects of anaesthetics.
Dr Guy Warman, from the University of Auckland, and colleagues, report their findings this week in the Proceedings of the National Academy of Sciences.
"We've provided the science to explain why when you wake up from anaesthetics you feel like that no time has passed," says Warman.
"The reason for that is that your biological clock has shifted at a fundamental molecular level."
Jet lag can affect not just the timing of your sleep but your mood, immune system and even wound healing.
It is well established that the majority of people given anaesthetics report afterwards feeling no time has passed. But, says Warman, it's not clear whether this is a case of amnesia or chemically induced jet lag disturbing the biological clock.
The perfect animal to help answer this question, he says, is the honey bee.
"Scientists say they have a continuously-consulted biological clock," says Warman.
Bees visit flowers only at times when the flower produce nectar and they navigate by knowing where the Sun is in the sky at any time of the day.
"By looking at their behaviour you can determine what time of the day they think it is," says Warman.
In a series of experiments involving thousands of bees, Warman and colleagues looked at the normal behaviour of bees, the effect of anaesthesia on their time perception and on their biological clock.
The researchers gave the bees the common anaesthetic isoflurane in the morning and woke them up after about 6 hours.
Warman and colleagues used RFIDs to track the bees as they visited food sources and used radar to track their flight paths, specifically their angle of orientation with respect to the Sun.
The bees' floral visits and orientation suggested they had an altered perception of time, says Warman.
"They wake up from their anaesthetic and think it's much earlier in the day than it is," he says. "They don't have the perception that 6 hours have passed."
In a separate molecular analysis, the researchers showed the bees' biological clock, based on circadian clock genes, had shifted by 3 to 4 hours during the anaesthetic.
"They had jet lag," says Warman. "It's like waking up in Sydney time when you are actually on Auckland time."
The researchers found that this only occurred when anaesthetic was given during the day.
"When you have anaesthetic at night you don't get that phase-shifting effect," says Warman.
He says the findings suggest that light could be used to help patients recover from anaesthesia just as it helps people recover from jet lag.
"Light in the morning shifts you to an earlier time zone and light in the evening shifts you to a later time zone," says Warman. "That's why it can be hard to get up on a Monday morning if you've slept in on a Saturday and Sunday morning."
He says anaesthesia-induced jetlag could similarly be reduced by shining high-intensity light at patients' eyes during anaesthesia.