Midbrain Control of Cold Shivering

这个项目的目标是澄清由midbrain温度控制的冷转移。单伽马效应是孤立的，在对大鼠的双手性预光学和非手性hypotharamus的准备中，通过电方式消除较高中心对振荡的影响，并在放电活动中发生的变化，而在测试的同时，中脑是冷却或加热的，这意味着水性能热模式。在正常的中频温度下，64伽马纤维隔离的暴露的周期性通量占36%，当剩余的持续的自发性放电时。在38种伽马纤维中，包括两种类型的纤维，对它们的热反应性进行了调查，71%产生了在放电频率下的增加或减少，导致在正常的中频温度下或上升，适当地。在低于37.5 ° C的范围内产生的电荷频率的温度依赖性（-1.5<加减>0.1英寸）。灌注温度下的秒/秒C是 ... More 比37.5 ° C以上范围小的一个（2.8<加减>0.5英寸）。sec/C）。这一行为的伽马活动的类比揭示了热调节反应的一般模式，并使之保持热平衡，例如，热量的产生是在超热范围内形成的，在超热范围内被抑制。从麝香螺旋的主要（43）和第二结尾（7）中，在Gastrocunemius和soleus中，重复应用于在midbrain冷却或变暖期间通过测量峰值频率、静态频率和动态指数在每个拉伸响应中被动态指数所分析。发现的是，脑中分泌冷却不仅产生了动态伽马激活，而且还具有静态伽马激活，而且具有较强的成型机（63%）和较低的成型机（29%）。这些结果表明，从中间脑中的热敏性结构中衍生出的下降信号也影响了伽马马达活动，建议降低阈值可能会改变更少的热敏分子

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