Tzschentke B, Nichelmann M
Humboldt-Universität zu Berlin Institut für Biologie, Germany. barbara=
Ann N Y Acad Sci. 1997 Mar 15;813:87-94. doi: 10.1111/j.1749-6632.1997.tb51677.x.
The aim of the present study was to investigate whether prenatal and postnatal adaptation to different ambient temperatures affects the autonomic (heat production, heat loss, rectal or colonic temperature), behavioral (preferred ambient temperature) and nervous mechanisms (neuronal thermosensitivity of the preoptical area of the anterior hypothalamus) of thermoregulation. The experiments were carried out in postnatal, differently acclimated adult rabbits (60 days at 6-7, 20 and 30 degrees C) and adult rats (3 to 6 weeks at 5 and 21 degrees C) and in differently incubated 1- to 10-day-old Muscovy ducklings and turkeys (last week of incubation at 34.5, 37.5 and 38.5 degrees C). The results of the experiments are summarized as follows: (1) Postnatal acclimation changes the threshold ambient temperature of heat loss and heat production. For example, cold-acclimated rabbits have a lower threshold temperature for evaporative heat loss and thermoregulatory heat production than heat-acclimated ones. (2) Prenatal acclimation changes postnatal thermoregulatory behavior as well as autonomic thermoregulatory mechanisms. Birds incubated at higher (38.5 degrees C) or lower (34.5 degrees C) temperatures than the usual 37.5 degrees C for the last week of embryonic development have higher or lower preferred ambient temperatures during the first 10 days post hatching. Besides this, cold-incubated birds have a higher heat/ production and clonic temperature in the first days post hatching than normally/ incubated or heat-incubated ones. (3) Extracellular recordings from hypothalamic neurons in brain slices from differently acclimated rats have shown that adaptation to different ambient temperatures changes firstly the temperature sensitivity of the hypothalamic neurons and secondly the modulatory action of the neuropeptides bombesin and thyrotropin releasing hormone.
本研究的目的是调查产前和产后对不同环境温度的适应是否会影响体温调节的自主神经机制（产热、散热、直肠或结肠温度）、行为机制（偏好的环境温度）和神经机制（下丘脑前部视前区的神经元热敏感性）。实验在产后经不同环境温度驯化的成年兔（分别在6 - 7℃、20℃和30℃环境中饲养60天）、成年大鼠（分别在5℃和21℃环境中饲养3至6周）以及在不同温度下孵化1至10日龄的番鸭和火鸡（孵化最后一周分别处于34.5℃、37.5℃和38.5℃）身上进行。实验结果总结如下：（1）产后驯化会改变散热和产热的阈值环境温度。例如，冷驯化的兔子比热驯化的兔子蒸发散热和体温调节产热的阈值温度更低。（2）产前驯化会改变产后体温调节行为以及自主神经体温调节机制。在胚胎发育最后一周，孵化温度高于（38.5℃）或低于（34.5℃）通常的37.5℃的鸟类，在孵化后的前10天具有更高或更低的偏好环境温度。除此之外，冷孵化的鸟类在孵化后的头几天比正常孵化或热孵化的鸟类具有更高的产热和结肠温度。（3）对不同环境温度驯化的大鼠脑片下丘脑神经元进行细胞外记录显示，对不同环境温度的适应首先会改变下丘脑神经元的温度敏感性，其次会改变神经肽蛙皮素和促甲状腺激素释放激素的调节作用。
