Behavioral and neurochemical sources of variability of circadian period and phase:: studies of circadian rhythms of npy-/- mice
Behavioral and neurochemical sources of variability of circadian period and phase:: studies of circadian rhythms of npy-/- mice
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DOI：
10.1152/ajpregu.00383.2006
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发表时间：
2007-03-01
影响因子：
2.8
通讯作者：
Lall, Gurprit
中科院分区：
文献类型：
--
作者：
Harrington, Mary;Molyneux, Penny;Lall, Gurprit
自由运行节律的周期长度或周期是昼夜节律的关键特征。在这项研究中，我们验证了先前的报告，自发活动模式和转轮访问可以改变昼夜节律周期，我们报告说，这些治疗也增加了动物之间的昼夜节律周期的变异性。我们证明，神经化学物质，神经肽Y（NPY）的损失，废除了这些影响，并减少了个体间的变化，在时钟周期。这些行为和环境的影响，从每日分布的峰值运动活动和从访问一个运行轮，都起到推动平均昼夜周期的值< 24小时。光诱导复位的幅度也改变。当光周期突然从18：6小时的光暗周期（LD 18：6）改变为LD 6：18时，NPY缺乏的小鼠对光周期变化的反应较慢，与对照组相比，它们在延长的黑暗中的活动重新分配，最终采用了延迟的夹带相位角。这些结果支持了这样的假设，即非光的影响昼夜节律周期服务于一个有用的功能时，动物必须响应突然变化的光周期和点的神经肽Y能通路从膝状体间小叶支配视交叉上核作为电路介导这些影响。
The cycle length or period of the free-running rhythm is a key characteristic of circadian rhythms. In this study we verify prior reports that locomotor activity patterns and running wheel access can alter the circadian period, and we report that these treatments also increase variability of the circadian period between animals. We demonstrate that the loss of a neurochemical, neuropeptide Y (NPY), abolishes these influences and reduces the interindividual variability in clock period. These behavioral and environmental influences, from daily distribution of peak locomotor activity and from access to a running wheel, both act to push the mean circadian period to a value < 24 h. Magnitude of light-induced resetting is altered as well. When photoperiod was abruptly changed from a 18:6-h light-dark cycle (LD18:6) to LD6:18, mice deficient in NPY were slower to respond to the change in photoperiod by redistribution of their activity within the prolonged dark and eventually adopted a delayed phase angle of entrainment compared with controls. These results support the hypothesis that nonphotic influences on circadian period serve a useful function when animals must respond to abruptly changing photoperiods and point to the NPYergic pathway from the intergeniculate leaflet innervating the suprachiasmatic nucleus as a circuit mediating these effects.