Joyce M P, Barr G A
City University of New York, Department of Psychology, Hunter College, NY 10021.
Neuroscience. 1992 Jul;49(1):163-73. doi: 10.1016/0306-4522(92)90084-f.
This study examined cellular activity in the hypothalamus of developing rats in response to cold environmental temperatures. The appearance of the nuclear protein, Fos, in response to cold ambient temperatures in rats three to 35 days of age was used as a marker of neuronal activation. Fos-positive nuclei were first seen in response to cold ambient temperatures in the ventromedial nucleus at three days of age, the paraventricular nucleus at eight days of age, the preoptic-anterior hypothalamus at 10 days of age and the anterior hypothalamic nucleus at 21 days of age. The rectal temperature of the 10-day-old pups dropped by less than half that measured in the nine-day-old pups after 1 h in the cold. It is possible that the activation of neurons in the preoptic-anterior hypothalamus in the 10-day-old animal may contribute to the decreased hypothermia observed in the 10-day-old after 1 h in the cold. The high density of Fos-like immunoreactive-labeled nuclei in the preoptic-anterior hypothalamus in the 10-day-old rats that were exposed to the cold environment indicates increased neuronal activity at this site. The results suggest that, at least in the preoptic-anterior hypothalamus, the appearance of the cellular response to cold ambient temperatures is coincidental with a thermogenic response.
本研究检测了发育中大鼠下丘脑对寒冷环境温度的细胞活性。利用核蛋白Fos在3至35日龄大鼠中对寒冷环境温度的反应，作为神经元激活的标志物。Fos阳性核最早在3日龄的腹内侧核、8日龄的室旁核、10日龄的视前区-下丘脑前部以及21日龄的下丘脑前核中对寒冷环境温度产生反应时被观察到。10日龄幼崽在寒冷环境中1小时后，其直肠温度下降幅度不到9日龄幼崽的一半。10日龄动物视前区-下丘脑前部神经元的激活可能导致10日龄幼崽在寒冷环境中1小时后体温降低幅度减小。暴露于寒冷环境的10日龄大鼠视前区-下丘脑前部中Fos样免疫反应标记核的高密度表明该部位神经元活性增加。结果表明，至少在视前区-下丘脑前部，对寒冷环境温度的细胞反应的出现与产热反应同时发生。
