蓝斑神经元去甲肾上腺素量子化释放的长潜伏期：大鼠脑片膜片钳-电化学联合记录研究

发布时间：2018-05-19 21:02

本文选题：蓝斑神经元 + 脑片　；参考：《中国科学院研究生院（上海生命科学研究院）》2007年博士论文

【摘要】： 蓝斑(Locus Coeruleus, LC)核团主要含有去甲肾上腺素(NA)神经元并且投射到中枢神经系统的大部分区域。然而,有关NA如何从蓝斑神经元释放却知之甚少。本学位工作联合电化学记录和膜片钳测量技术发现:去极化刺激蓝斑神经元可以记录到被诱发的尖峰(spike)信号(Iamp),每个尖峰代表一个量子化的递质释放;去极化脉冲诱发的量子化NA分泌信号的平均潜伏期是1870ms;而蓝斑神经元谷氨酸介导的兴奋性突触后电位的平均潜伏期只有1.6ms;这些量子化安培信号的释放是依赖钙离子的,去除细胞外的钙离子可以阻断释放; TTX不能阻断去极化脉冲诱发的蓝斑神经元的递质释放,在急性游离的蓝斑神经元胞体部位可以记录到去极化刺激诱发的尖峰信号和膜电容的增加,说明有一部分递质释放来自胞体;相对于谷氨酸能的快速EPSC,脑片上蓝斑神经元的儿茶酚胺的分泌更易受到动作电位频率的调节(0.5-50 Hz),神经元在自发放电状态下,胞体释放量很少,而在受到刺激后,放电频率增加时,胞体释放也增多;蓝斑核团内神经元兴奋性增强时,使胞体树突区域的NA释放,继而抑制胞体本身的放电和NA的释放,这种作用与胞体上α2肾上腺素能受体有关。综上所述,与经典的突触递质释放相比,蓝斑胞体部位的NA的量子化释放具有潜伏期长,对动作电位模式高度敏感的特点。
[Abstract]:The nucleus of Locus Coeruleus (LC) mainly contains norepinephrine (NAN) neurons and projects to most areas of the central nervous system (CNS). However, little is known about how na is released from locus coeruleus neurons. In combination with electrochemical recording and patch clamp measurement, it was found that depolarization-stimulated locus coeruleus neurons could record evoked spike-spike signals, each peak representing a quantized release of a transmitter; The average latency of quantized na secreting signals induced by depolarization pulses was 1870 Ms, while that of glutamate mediated excitatory postsynaptic potentials in locus coeruleus neurons was only 1.6 Ms. Removal of extracellular calcium ions could block release, TTX could not block the release of neurotransmitters from locus coeruleus neurons induced by depolarization pulse. The spike signal and the increase of membrane capacitance induced by depolarization stimulation could be recorded in the acute free locus coeruleus neurons, indicating that some of the transmitters were released from the cell body. The catecholamine secretion of locus coeruleus neurons was more likely to be regulated by the frequency of action potential 0.5-50 Hz than that of glutaminergic EPSC.When the neurons were spontaneously discharges, the release of catecholamine from the neurons was very small, but after stimulation, the secretion of catecholamine was more likely to be regulated by the action potential frequency. When the frequency of discharge increased, the release of the cell body increased, and when the excitability of neurons in the locus coeruleus increased, the na release in the dendritic region of the cell body was released, which in turn inhibited the discharge of the cell body itself and the release of na. This action is related to 伪 2 adrenoceptor on the cell body. In conclusion, compared with the classical synaptic transmitter release, the quantized release of na in the locus of locus coeruleus has long latency and is highly sensitive to the action potential pattern.
【学位授予单位】：中国科学院研究生院（上海生命科学研究院）
【学位级别】：博士
【学位授予年份】：2007
【分类号】：R338

【共引文献】