权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

本项目旨在阐明冷寒战是否由中脑温度控制。在电损毁双侧视前区和下丘脑前部以消除震颤的高级中枢影响的大鼠标本中分离出单个γ传出神经，并通过水灌注热电极观察中脑冷却或加温时放电活动的变化。在正常中脑温度下，36%的64个γ纤维分离出的自发放电表现出周期性波动，而其余的持续自发放电。38个伽马纤维，包括这两种类型的纤维，检查其热反应性，71%产生的放电频率的增加或减少，以低于或高于正常的中脑温度，分别下降或上升。在低于37.5 ° C（-1.5 <plus-minus>0.1 imp./ sec/℃灌注温度） ...更多信息小于37.5 ℃以上范围内的温度（2.8 <plus-minus>± 0.5 imp./ sec/sec C）。γ活动的这种行为与维持热平衡所涉及的体温调节反应的一般模式相似，例如，产热在低体温范围内是促进的，而在高体温范围内是抑制的。在中脑降温或升温过程中，通过测量每次牵拉反应的峰值频率、静态频率和动态指数，分析了腹楔肌和比目鱼肌肌梭初级终末（43个）和次级终末（7个）对肌肉牵拉的传入反应。结果发现，中脑冷却不仅产生动态伽马激活，而且产生静态伽马激活，前者（63%）的患病率高于后者（29%）。这些结果表明，来自中脑温度敏感结构的下行信号也会影响γ运动活动，这表明颤抖阈值可以通过治疗改变。