Abstract:
The idea of ameliorating jetlag with drugs has received considerable attention. Melatonin has been found to reduce feelings of jetlag in people after transatlantic flights. In hamsters, injections of triazolam, a benzodiazepine, increase the rate of adjustment of activity rhythms to an 8 h advance of the light-dark (LD) cycle. But melatonin can make people drowsy and triazolam often induces hamsters to run in their wheels. Therefore, it is not clear whether these chemicals exert their chronotypic effects by acting directly on circadian pacemakers or because they first alter behavioural states. Non-photic behavioural events (for instance, social interactions) are capable of entraining rhythms and causing phase shifts. Thus, it is possible that behavioural events alone could alter the rate of adjustment to new LD cycles. To investigate this possibility, we studied the rate of re-entrainment of hamsters in a testing paradigm similar to that used with triazolam. We found that the rate of adjustment could be more than doubled simply by making the animals active on a single occasion in the middle of their normal rest period, immediately after the shift in the LD cycle.
摘要:
用药物改善时差的想法受到了相当多的关注。已发现褪黑激素可以减少跨大西洋飞行后人们的时差感觉。在仓鼠中,注射三唑仑,苯二氮卓类药物,将活动节奏的调整速率提高到明暗(LD)周期的8小时。但是褪黑激素会使人昏昏欲睡,三唑仑通常会诱导仓鼠在轮子上奔跑。因此,目前尚不清楚这些化学物质是通过直接作用于昼夜节律起搏器,还是因为它们首先改变了行为状态而发挥了它们的慢性效应。非光行为事件(例如,社交互动)能够夹带节奏并引起相移。因此,行为事件本身可能会改变对新LD周期的调整率。为了调查这种可能性,我们在类似于三唑仑的测试范式中研究了仓鼠的再夹带率。我们发现,只需让动物在正常休息时间的中间活动一次,调整速度就可以增加一倍以上,在LD周期移位后立即。