PHASE-CONTROL OF ULTRADIAN FEEDING RHYTHMS IN THE COMMON VOLE (MICROTUS-ARVALIS) - THE ROLES OF LIGHT AND THE CIRCADIAN SYSTEM
PHASE-CONTROL OF ULTRADIAN FEEDING RHYTHMS IN THE COMMON VOLE (MICROTUS-ARVALIS) - THE ROLES OF LIGHT AND THE CIRCADIAN SYSTEM
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DOI：
10.1177/074873049300800205
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发表时间：
1993-06-01
影响因子：
3.5
通讯作者：
VANDERLEEST, F
中科院分区：
文献类型：
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作者：
GERKEMA, MP;DAAN, S;VANDERLEEST, F
在它们极端的(2-3小时)摄食节律中，普通田鼠每天都表现出个体内的同步性，以及种群成员之间的个体间同步性，即使是在遥远的距离。这项研究解决的问题是如何重新设定超常节奏，这是实现这种同步的前提条件。普通田鼠受到短明暗周期(1小时黑暗，光照在0.7-2.5小时之间变化)，T周期(昼夜范围内的长明暗周期-16小时黑暗和3-13小时光照)，不同昼夜和超常阶段的光脉冲(15分钟)，以及在饮用水中添加D2O(25%)。在损毁视交叉上核后，短光暗周期和D2O也被应用于没有昼夜节律性的田鼠。在这些实验中，检验了关于超常节律性同步的四个假说：(I)通过对光的直接反应进行同步；(Ii)通过具有多个触发器的昼夜节律系统同步，在这里被称为‘齿轮’，每个触发器控制一个传统的摄食回合；以及(iii和iv)通过昼夜节律系统的同步，这将重置超昼夜节律振荡器，并且(Iii)直接起源于昼夜节律起搏器，或者(Iv)通过公开的昼夜活动节律来调节。短的光-暗周期不能在昼夜节律或非昼夜节律的田鼠中捕获超常节律；光脉冲不会引起相移；在极端的T周期中，不能证明与光的稳定的相位关系。因此，假设I被拒绝了。昼夜节律周期(Tau)的变化是由光脉冲的后效、不同T周期中的夹带和向饮用水中添加D2O产生的。Tau的这些变化并没有导致极端时期的平行变化，更不用说成比例的变化了。这排除了假设II。无论是在T周期实验中，还是在对昼夜节律田鼠的D2O实验中，超短线田鼠的摄食阶段都锁定在昼夜活动的结束，而不是起搏器最显著的标志-昼夜活动的开始。在这些实验的基础上，我们得出结论，超常夹带的最有可能的机制是一个光不敏感的超常振荡器，通过昼夜节律起搏器控制的活动阶段的终止来重置每天黎明，而昼夜节律起搏器本身也被光暗周期所缠绕。无论是昼夜节律的田鼠还是非昼夜节律的田鼠，投喂D2O都不会延长其摄食节律的周期。在生物节律中，这种对氘的不敏感是异常的。
In their ultradian (2- to 3-hr) feeding rhythm, common voles show intraindividual synchrony from day to day, as well as interindividual synchrony between members of the population, even at remote distances. This study addresses the question of how resetting of the ultradian rhythm, a prerequisite for such synchronization, is achieved. Common voles were subjected to short light-dark cycles (1 hr darkness with light varying between 0.7 and 2.5 hr); to T cycles (long light-dark cycles in the circadian range-16 hr darkness and 3-13 hr light); to light pulses (15 min) during different circadian and ultradian phases; and to addition of D2O to the drinking water (25%). Short light-dark cycles and D2O were also applied to voles without circadian rhythmicity, after lesions of the suprachiasmatic nuclei.In these experiments, four hypotheses on synchronization of ultradian rhythmicity were tested: (I) synchronization by a direct response to light; (II) synchronization via the circadian system with multiple triggers, here called ''cogs,'' each controlling a single ultradian feeding bout; and (III and IV) synchronization via the circadian system with a single ''cog,'' which resets an ultradian oscillator and either (III) originates directly from the circadian pacemaker, or (IV) is mediated via the overt circadian activity rhythm.Short light-dark cycles failed to entrain ultradian rhythms, either in circadian-rhythmic or in non-circadian-rhythmic voles; light pulses did not cause phase shifts; and in extreme T cycles no stable phase relationship with light could be demonstrated. Thus, Hypothesis I was rejected. Changes in the circadian period (tau) were generated ak aftereffects of light pulses, by entrainment in various T cycles, and by the addition of D2O to the drinking water. These changes in tau did not lead to parallel, let alone proportional, changes in the ultradian period. This excluded Hypothesis II. Both in T-cycle experiments and in the D2O experiments with circadian-rhythmic voles, the phase of ultradian feeding bouts was locked to the end of circadian activity rather than to the most prominent marker of the pacemaker, the onset of circadian activity. This was not expected under Hypothesis III, but was consistent with entrainment via activity (Hypothesis IV).On the basis of these experiments, we conclude that the most likely mechanism of ultradian entrainment is that of a light-insensitive ultradian oscillator, reset every dawn by the termination of the activity phase controlled by the circadian pacemaker, which is itself entrained by the light-dark cycle. Neither in circadian-rhythmic nor in non-circadian-rhythmic voles was the period of the feeding rhythm lengthened by administration of D2O. This insensitivity to deuterium is exceptional among biological rhythms.