Pohl H
Max-Planck-Institut für Verhaltensphysiologie, Andechs, Germany.
Physiol Behav. 1994 May;55(5):803-10. doi: 10.1016/0031-9384(94)90063-9.
Changes in entrainment properties of the circadian pacemaking system with respect to changes in reproductive state and molt were investigated in the male domestic canary (Serinus canaria). In two experiments canaries were subjected to three and two similar sequences of light regimens, respectively, during 1 year. Locomotor activity, feeding, and vocalization were simultaneously recorded. Only birds showing complete postnuptial wing feather molt and related changes in behavior (vocalization) expressed differences in the ability of their circadian system to entrain to low-amplitude light/dark (LD) cycles with periods (T) > 24 h. It is suggested that changes in the organization of the circadian system, including differences in entrainment properties, are associated with the state of photorefractoriness and related functions (testicular regression, postnuptial molt). Regardless of the molt status, over 90% of the birds that were arrhythmic in constant light (LL) entrained to low-amplitude LD cycles with T 25.5 h (Experiment 1) or T 25.0 h (Experiment 2). Birds that did not entrain or were relatively entrained with the respective light regimes were (with one exception) rhythmic in LL. It is therefore likely that the occurrence of arrhythmia in LL facilitates entrainment to low-amplitude light cycles.
在家养雄性金丝雀（Serinus canaria）中，研究了昼夜节律起搏系统的夹带特性随生殖状态和换羽变化的情况。在两项实验中，金丝雀在1年的时间里分别接受了三种和两种相似的光照方案序列。同时记录了运动活动、进食和鸣叫情况。只有那些显示出完全的婚后翅羽换羽以及行为（鸣叫）相关变化的鸟类，其昼夜节律系统对周期（T）>24小时的低振幅光/暗（LD）循环的夹带能力才表现出差异。研究表明，昼夜节律系统组织的变化，包括夹带特性的差异，与光不应性状态及相关功能（睾丸退化、婚后换羽）有关。无论换羽状态如何，在持续光照（LL）下无节律的鸟类中，超过90%能被T为25.5小时（实验1）或T为25.0小时（实验2）的低振幅LD循环所夹带。未被夹带或相对被各自光照方案夹带的鸟类（有一个例外）在LL中是有节律的。因此，LL中出现心律失常可能有助于对低振幅光周期的夹带。
