Midbrain Control of Cold Shivering

中脑控制冷颤

基本信息

批准号：
61570087
负责人：
SATO Haruhiko
金额：
$ 1.22万
依托单位：
Nagoya City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

This project was aimed to clarify whether cold shivering is controlled by midbrain temperature or not. Single gamma efferents were isolated in the preparations of rat whose bilateral preoptic and anterior hypothalamus were electrolytically lesioned to eliminate the influences from the higher center for shivering, and changes in the discharge activity were examined while the midbrain was cooled or warmed by means of a water perfused thermode. Under the normal midbrain temperature, 36% of 64 gamma fibers isolated exhibited periodic fluctuations in spontaneous discharge whereas the rest sustained spontaneous discharge. Of 38 gamma fibers, including both type of fibers, examined for thier thermal reactiveness, 71% produced an increase or a decrease in discharge frequency to a fall below or a rise above the normal midbrain temperature, respectively. Temperature dependency of discharge frequency obtained in the range below 37.5゜C(-1.5<plus-minus>0.1 imp./sec/゜C in perfusion temperature) was … More smaller than the one in the range above 37.5゜C(2.8<plus-minus>0.5 imp./sec/゜C). This behaviour of gamma activity parallels the general pattern of thermoregulatory responses involved inmaintaining a heat balance, e.g., heat production is facilitation in the hypothermic range and suppressed in hyperthermic range. The afferent responses from the muscle spindle primary(43) and secondary endings(7) in the gastrocunemius et soleus to stretches of the muscle which were repeatedly applied during midbrain cooling or warming were analyzed by measuring peak frequency, static frequency and the dynamic index in each stretch response. It was found that midbrain cooling produced not only dynamic gamma activation but also static gamma activation, with the prevalence of former(63%) over the latter(29%). These results indicate that the descending signals derived from the thermosensitive structures in the midbrain also influence gamma motor activities, suggesting that shivering threshold could be altered therpmen Less

该项目的目的是阐明冷颤抖是否受中脑温度控制。在大鼠的制备中分离出单个伽马有效性，将双侧前和下丘脑的前后下丘脑进行电解病变，以消除较高的颤抖中心的影响，并检查中脑的变化，而中间脑的变化是通过水灌注的热层冷却或温暖的。在正常的中脑温度下，有64个伽马纤维中有36％的人在发起人的发电液中分离出裸露的周期性波动，而其余的则持续持续的赞助放电。在38个伽马纤维（包括两种类型的纤维）中，检查了其热反应性，71％的伽马纤维产生的增加或降低频率下降到下降至低于正常中脑温度或高于正常的中脑温度。在灌注温度下以低于37.5゜c（-1.5 <plus-minus> 0.1 Imp./sec/ c c）获得的排放频率的温度依赖性比37.5 c（2.8 <plus-minus> 0.5 imp./sec/sec/sec/ c）的范围更小。伽马活性的这种行为与侵入热平衡涉及的热调节反应的一般模式相似，例如，热量产生是在低温范围内的设施，并且在高温范围内被抑制。通过测量峰值，静态频率，静态频率和每个拉伸响应的动态指数，分析了胃纺锤纺丝原发性（43）和次级末端（7）的传入术中对肌肉伸展的传入（7）。发现中脑冷却不仅产生了动态伽马活化，而且还产生了静态伽马活化，而后者的患病率在后来的（63％）（29％）。这些结果表明，中脑的热敏性结构得出的下降信号也会影响伽马运动活动，这表明可以改变颤抖的阈值。