Increased photic sensitivity for phase resetting but not melatonin suppression in Siberian hamsters under short photoperiods.
Increased photic sensitivity for phase resetting but not melatonin suppression in Siberian hamsters under short photoperiods.
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DOI：
10.1016/j.yhbeh.2014.01.002
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发表时间：
2014-03
影响因子：
3.5
通讯作者：
Gorman, M. R.
中科院分区：
文献类型：
--
作者：
Glickman, G. L.;Harrison, E. M.;Elliott, J. A.;Gorman, M. R.
光调节各种行为和生理过程，包括活动节律和激素分泌模式。一天中光照比例（光周期）的季节性变化进一步调节这些功能。最近，短（SP）与长的日子（LP）被发现显着增加光敏感性的相移在叙利亚仓鼠。据我们所知，光周期对光敏感性的影响尚未在其他啮齿动物中研究，也不知道它们是否适用于其他昼夜节律反应。我们测试是否光相移和褪黑激素抑制不同西伯利亚仓鼠保持LP或SP。选择光照度进行管理，并确定活动的变化。通过在4个对数单位光子密度范围内的光脉冲，在单独的一组动物中检查褪黑激素抑制的光敏感性，通过RIA测定脉冲后血浆褪黑激素水平。相移和褪黑激素的抑制是更大的LP和SP在较高的辐照度。较低的辐照度条件下，在LP的相移阈值以下，但不SP。褪黑激素的抑制不随光周期变化，半饱和常数拟合S形曲线是相似的LP和SP。因此，光周期调制的光敏感性相移是保守的两个仓鼠属。光周期对光相移和褪黑激素抑制的影响的解离表明敏感性的调制发生在共同的视网膜输入途径的下游。了解这种可塑性的机制基础可能会产生优化光疗实践的治疗目标。
Light regulates a variety of behavioral and physiological processes, including activity rhythms and hormone secretory patterns. Seasonal changes in the proportion of light in a day (photoperiod) further modulate those functions. Recently, short (SP) versus long days (LP) were found to markedly increase light sensitivity for phase shifting in Syrian hamsters. To our knowledge, photoperiod effects on light sensitivity have not been studied in other rodents nor is it known if they generalize to other circadian responses. We tested whether photic phase shifting and melatonin suppression vary in Siberian hamsters maintained under LP or SP. Select irradiances of light were administered, and shifts in activity were determined. Photic sensitivity for melatonin suppression was examined in a separate group of animals via pulses of light across a 4 log-unit photon density range, with post-pulse plasma melatonin levels determined via RIA. Phase shifting and melatonin suppression were greater at higher irradiances for both LP and SP. The lower irradiance condition was below threshold for phase shifts in LP but not SP. Melatonin suppression did not vary by photoperiod, and the half saturation constant for fitted sigmoid curves was similar under LP and SP. Thus, photoperiodic modulation of light sensitivity for phase shifting is conserved across two hamster genera. The dissociation of photoperiod effects on photic phase shifting and melatonin suppression suggests modulation of sensitivity occurs downstream of the common retinal input pathway. Understanding the mechanistic basis for this plasticity may yield therapeutic targets for optimizing light therapy practices.
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DOI：
10.1530/revreprod/3.1.13
发表时间：
1998-01-01
期刊：
REVIEWS OF REPRODUCTION
影响因子：
--
作者：
Arendt, J
通讯作者：
Arendt, J
影响因子：
3.5
作者：
Evans, Jennifer A.;Elliott, Jeffrey A.;Gorman, Michael R.
通讯作者：
Gorman, Michael R.
DOI：
10.1007/s00359-004-0522-7
发表时间：
2004-08-01
影响因子：
2.1
作者：
Gorman, MR;Elliott, JA
通讯作者：
Elliott, JA
影响因子：
2.5
作者：
HOFFMANN, K;ILLNEROVA, H;VANECEK, J
通讯作者：
VANECEK, J
影响因子：
4.1
作者：
LERCHL, A;SCHLATT, S
通讯作者：
SCHLATT, S