摘要
作者曾证明缰核引起的痛觉改变和心血管活动密切相关。本实验向静脉内冲击式注射新福林（1～2mg／kg）引起动脉血压迅速短暂升高、以刺激压力感受器，用玻璃微电极观察和记录了缰核神经元放电对压力感受性刺激和伤害性刺激的反应。证明缰核一些神经元可接受压力感受性刺激和伤害性刺激，并且两者之间有密切联系。对伤害性刺激反应的单位，多对压力感受性刺激也有反应。即痛敏单位对压力感受性刺激主要呈兴奋反应（75％）,而抑制单位对其呈抑制反应（63％）。侧脑室注入吗啡后，缰核神经元对伤害性刺激的反应发生明显改变，同时对压力感受性刺激反应也改变。压力感受性兴奋单位或抑制单位对压力感受性刺激反应均增强，并伴有血压降低。提示吗啡加强缰核心血管反应神经元的活动与血压降低有关。说明缰核神经元可汇聚这两种不同性质刺激的传入信息，同时表明这种与痛和心血管反应有关神经元可能参与防御性心血管反应过程。
Recently, we reported that excitatory stimulation of habenular nucleus (Hb) resulted in a parallel changes in both blood pressure and pain threshold. The present study was designed to observe the effects of baroreceptive and noxious stimulation on neuronal discharges of Hb recorded extracellullary by glass microelectrodes in anesthetized rats. The baroreceptor was stimulated by intravenous injection of phenylaphrine (1～2 mg/kg b. w. ). The results showed that 75% pain-excitatory units were excited, whereas 63% pain-inhibitory units were inhibited by baroreceptive stimulation, suggesting that most of the Hb neurons receive information from both peripheral nociceptive and baroreceptive afferents. After intracerebroventricular administration of morphine, the spontaneous and evoked discharges of Hb neurons in response to both noxious and baroreceptive stimulation were obviously changed. The responsiveness of baroreceptor-excited units were enhanced, whereas that of baroreceptor-inhibited units were reduced respectively in parallel with the decrease in blood pressure. The present results indicated that morphine may strengthen the activities of Hb neurons in response to changes in blood pressure, and the correlative changes in pain threshold and blood pressure may be involved in the processing of defence cardiovascular reaction.
出处
《神经解剖学杂志》
CAS
CSCD
北大核心
1998年第2期179-182,共4页
Chinese Journal of Neuroanatomy
关键词
单位放电
压力感受性刺激
伤害性刺激
缰核
大鼠
unit discharge, baroreceptive stimulation, noxious stimulation, habenular nucleus, rat
