Nichelmann M, Tzschentke B
Humboldt-Universität zu Berlin, Germany.
Ann N Y Acad Sci. 1997 Mar 15;813:78-86. doi: 10.1111/j.1749-6632.1997.tb51676.x.
In contrast to the well-known thermoregulatory processes in the postnatal period the ontogeny of the thermoregulatory effector system as well as the central nervous control elements in the prenatal period is underinvestigated. Because of this, the aim of this paper is to characterize the development of thermoregulatory mechanisms in the embryonic period of one avian species, the Muscovy duck, Cairina moschata. The experiments were carried out in three series. In the first the influence of low ambient temperatures on call producing activity was investigated, in the second the oxygen consumption of single or pooled embryos was measured in the temperature range between 34.0 and 40.5 degrees C and in the last oxygen consumption, colonic temperature and preferred temperature were examined in birds incubated in reduced temperatures (34.5 degrees C) during the last 7 days before hatching. The results of experiments led to the conclusion, that (1) some days before hatching temperature perception is very well developed, (2) endothermic reactions occur in the last quarter of embryonic development, (3) the thermoregulatory setpoint is adjustable during the perinatal period. Altogether, embryos of the Muscovy duck show in the last days of incubation typical endothermic reactions. They activate the heat production as well as the heat loss mechanisms to control the body temperature. Besides this, when vocalization is used, behavioral thermoregulatory mechanisms support the autonomic reactions.
与出生后时期广为人知的体温调节过程形成对比的是，产前时期体温调节效应系统以及中枢神经控制元件的个体发生情况研究不足。因此，本文的目的是描述一种鸟类——番鸭（Cairina moschata）胚胎期体温调节机制的发育情况。实验分三个系列进行。第一个系列研究低环境温度对鸣叫产生活动的影响；第二个系列在34.0至40.5摄氏度的温度范围内测量单个或多个胚胎的耗氧量；最后一个系列在孵化前最后7天处于较低温度（34.5摄氏度）环境下孵化的雏鸟中检测耗氧量、结肠温度和偏好温度。实验结果得出以下结论：（1）孵化前几天温度感知发育良好；（2）胚胎发育的最后四分之一阶段会出现产热反应；（3）围产期体温调节设定点是可调节的。总体而言，番鸭胚胎在孵化的最后几天表现出典型的产热反应。它们激活产热以及散热机制来控制体温。除此之外，当使用鸣叫时，行为体温调节机制会辅助自主反应。
