Functional conections between right & left hypothalamus in thermcregulation.

本研究通过测量麻醉大鼠在单侧POAH加温和电刺激或单侧腹部皮肤热刺激时的爪部皮肤血管舒缩活动和冷引起的后腿肌肉颤动，来探讨麻醉大鼠中枢神经温度调节的偏侧性。单侧POAH加温引起双侧血管扩张，但同侧血管扩张总是发生在较低的下丘脑阈值温度或比对侧更强。在寒冷环境中(5ﾟC)，一侧受热时双后腿的颤动被同时抑制，而当受热停止时，双后腿的颤动又同时出现。这些结果表明，不同的温度调节效应器由POAH的每一侧以不同的方式调节。在接下来的一系列实验中，可能会在左…之间直接交换温度调节控制信息用细胞外记录局部温度变化和电刺激对侧视前区和下丘脑前区单单位活动的方法，检测乌拉坦麻醉大鼠多侧和右侧视前区和下丘脑前部(POAH)的单位活动。123个神经元中的24个被对侧刺激促进，20个被抑制；没有一个是反向激活的。在测试的82个神经元中，有27个是热敏感的，20个是冷敏感的：一个神经元的温度敏感性与它对对侧刺激的反应没有明显的相关性。当刺激和记录部位都在POAH的前半部时，对侧刺激的反应发生率最高(60%)。在矢状面正中横断前连合及其吻侧区域后，这些反应消失。这些结果表明，前POAH的左右两侧之间有大量的多突触联系。较少

The present study explored the laterality of central nervous thermoregulatory control in anesthetized rats by measuring paw skin vasomotor activity and cold-induced shivering in hind leg muscles during unilateral POAH warming and electrical stimulation or during unilateral thermal stimulation of abdominal skin. Unilateral POAH warming produced vasodilation on both sides of the body, but vasodilation on the ipsilateral side always either occurred at a lower threshold hypothalamic temperature or was stronger than on the contralateral side. In a cold environment(5ﾟC), shivering was suppressed simultaneously in both hind legs when one side of the POAH was warmed, and shivering reappeared simultaneously on both sides when POAH warming stopped. These results suggest that different thermoregtilarory effectors are regulated in a different way by each side of the POAH. In the next series of experiments, the possibility of direct exchange of thermoregulatory control information between the left … More and right sides of the preoptic area and anterior hypothalamus(POAH)was tested by extracellularly recording single unit activity in the POAH of urethane-anaesthetized rats during local temperature changes and electrical stimulation of the contralateral POAH. Twenty-four of 123 neurons were facilitated and 20 inhibited by contralateral stimulation ; none were antidromically activated. Twenty-seven of the 82 of these neurons tested for thermosensitivity were warm-sensitive, and 20 were cold-sensitive : a neuron's thermosensitivity was not significantly correlated with its response to contralateral stimulation. The highest incidence of response to contralateral stimulation(60%)was found when stimulation and recording sites were both in the anterior half of the POAH. These responses were absent after midsagittal transection of the anterior commissure and its rostral area. These results indicate plentiful and predominantly polysynaptic connections between the right and left sides of the anterior POAH. Less