FUNCTIONAL-ANALYSIS OF CIRCADIAN PACEMAKERS IN NOCTURNAL RODENTS .4. ENTRAINMENT - PACEMAKER AS CLOCK
FUNCTIONAL-ANALYSIS OF CIRCADIAN PACEMAKERS IN NOCTURNAL RODENTS .4. ENTRAINMENT - PACEMAKER AS CLOCK
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DOI：
10.1007/bf01417859
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发表时间：
1976-01-01
期刊：
影响因子：
--
通讯作者：
DAAN, S
中科院分区：
文献类型：
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作者：
PITTENDRIGH, CS;DAAN, S
在使用1或2个光脉冲/周期的实验中测试夜间啮齿动物[金黄仓鼠、小家鼠、白足鼠和马尼拉鼠]的昼夜节律起搏器的非参数夹带模型。Mesocricetus auratus和P. leucopus夹带到涉及1个脉冲（15“或60”）/周期的时间表。相位角差（ψ）在节律和光周期之间的变化取决于起搏周期（τ）。和光周期（T）。由于对τ的后效应，白足拟杆菌的夹带是不稳定的。由光脉冲产生。与拟暗果蝇相比，果蝇受时间限制的时间周期更接近24 h。常常不能运送到T = 23和T = 25小时只能用两种τ的相当大的个体间差异来解释。和PRC [相位响应曲线]。在2个脉冲/周期的情况下，相位关系与骨骼光周期的预测相匹配，最长可达约14小时。增加不对称性迫使动物进入相位跳跃，从而使活动从较短的间隔转变为较长的间隔。这些在仓鼠中被准确地预测，但是它们发生在比在P. leucopus中预测的长得多的光周期。该模型，使用一个严格固定的物种。和PRC，不足以解释夹带。τ中的变化和PRC形状，限制了预测的有效性。从实验和预测之间的协议，从完整的和骨架的光周期和行为之间的密切对应关系，短光信号的非参数夹带在自然界中的夜间啮齿动物节律的夹带有一个主要的份额。具有可变τ的人工起搏器的计算机模拟使用PRC。这些心脏起搏器的昼夜节律特性使. psi保持不变。对τ中的不稳定性敏感。when. hivin..τ的接近24小时。分析对. psi的贡献-保护与季节性变化的光周期，相对于黄昏（夜间动物）或黎明（白天动物）的活动阶段是保守的。夜间起搏器行为对这种类型的. psi的三个贡献-注意到了保护：PRC振幅增大，PRC不对称，延迟部分的斜率比超前部分的斜率陡，DD自由运行周期短。光的参数效应，不能通过模型追踪，并且在完全光周期中有效防止跳跃，被注意到了。参数效应通过τ的变化来证明。光照强度为LL。试图区分的功能，必要的夹带发生，时间流逝测量或本地时间识别的生物钟。
The non-parametric entrainment model of circadian pacemakers of nocturnal rodents [Mesocricetus auratus, Mus musculus, Peromyscus leucopus and P. maniculatus] is tested in experiments using 1 or 2 light pulses/cycle. Mesocricetus auratus and P. leucopus entrain to zeitgebers involving 1 pulse (15'' or 60'')/cycle. The phase angle differences (.psi.) between rhythm and light cycle depend on the pacemaker period (.tau.) and light cycle period (T). Entrainment of P. leucopus is unstable due to the after effects on .tau. created by the light pulse. The limiting values of zeitgeber period to which the animals entrain are much closer to 24 h than in Drosophila pseudoobscura. Frequent failures to entrain to T = 23 and T = 25 h are only explained by considerable interindividual variation in both .tau. and PRC [phase response curve]. With 2 pulses/cycle, the phase relationships match predictions for skeleton photoperiods up to about 14 h. Increasing asymmetry forces animals into a phase jump, so that activity shifts from the shorter to the longer interval. These are accurately predicted in the hamster, but they occur at much longer photoperiods than predicted in P. leucopus. The model, using a rigidly fixed species .tau. and PRC, is inadequate to explain entrainment. Variations in .tau. and PRC-shape, restricts the validity of the predictions. From agreement between experiment and prediction, from the close correspondence between complete and skeleton photoperiods and from behavior, non-parametric entrainment by short light signals has a major share in the entrainment of nocturnal rodent rhythms in nature. Computer simulations of artificial pacemakers with variable .tau. and PRC are used. The very circadian nature of these pacemakers conserves .psi. sensitive to instabilities in .tau. when .hivin..tau. is close to 24 h. To analyze the contributions to .psi.-conservation with seasonally changing photoperiod, the activity phase with respect to dusk (nocturnal animals) or to dawn (diurnal animals) was conserved. Three contributions of nocturnal pacemaker behavior to this type of .psi.-conservation were noted: increased amplitude of the PRC, asymmetry in the PRC, such that the slope of the delay-part is steeper than the slope of the advance-part, and a short freerunning period in DD. Parametric effects of light, not traceable by the model, and effective in preventing in complete photoperiods the .psi.-jump, were noted. Parametric effects are demonstrated by the change of .tau. with light intensity in LL. An attempt is made to distinguish the features of circadian clocks necessary for entrainment to occur, for time lapse measurement or for local time identification.