Functional roles of co-transmitters in brainsten cholinergic neurons

脑胆碱能神经元中共递质的功能作用

基本信息

批准号：
05680725
负责人：
KAYAMA Yukihiko
金额：
$ 1.34万
依托单位：
Fukushima Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680725/
关键词：
laterodorsal tegmental nucleus acetylcholine substance P nitric oxide co-transmitters thalamus cerebral blood flow ascending activating system 外側膝状核レーザードプラ血流計

项目摘要

Cholinergic neurons gathering tightly in the laterodorsal tegmental nucleus (LDT) of the brainstem have nitric oxide (NO) and/or substance P (SP) as co-transmitters. The present study examined whether these co-transmitters released from axon terminals or varicosities, and what effects they gave to postsynaptic targets.In the previous study we had shown that LDT stimulation produced excitation of thalamic relay neurons which received direct projection of the cholinergic neurons. We examined in urethane-anesthetized rats, using a laser-Doppler flow meter, how the same LDT stimulation affected cerebral blood flow in the thalamus, since the co-transmitters have strong action on the blood vessels. An increase of the blood flow was observed consistently starting within several seconds after the onset of LDT stimulation and continuing about 1 minute after the stimulation. The increase was reduced by administration of scopolamine, a muscarinic antagonist, but the treatment did not block it com … More pletely.Whether NO concentration in the thalamus increased after the LDT stimulation was also examined in urethane-anesthetized rats, using electrochemical electrode sensitive specifically to NO (developed in Shionogi Research Laboratories) . The NO concentration increased transiently just after the stimulation only when the stimulating electrode was inserted in the LDT ; the stronger stimulation produced the stronger increase. The results show that NO is released from the axon terminals and/or varicosities by the excitation of LDT neurons.Postsynaptic actions of the co-transmitters were examined in in vitro slice preparations of the rat thalamus. Most thalamic neurons were depolarized by application of acetylcholine (ACh) . When SP was applied simultaneously with ACh, the depolarization was increased in some neurons, but was cancelled to produce no resting potential change in others. It is thus suggested that SP as a co-transmitter modifies the action of main transmitter ACh, but tha modification differs from neuron to neuron. Actions of NO was not demonstrated clearly. Less

在脑干的后期核能（LDT）中紧密聚集的胆碱能神经元具有一氧化氮（NO）和/或物质P（SP）作为co递传中。本研究检查了这些co弹器是否是从轴突末端或静脉曲张中释放出来的，以及它们对突触后靶标产生的影响。在先前的研究中，我们表明，LDT刺激会刺激丘脑中继神经元获得胆碱能神经元的直接投射。我们使用激光多普勒流量计检查了氨基甲酸酯麻醉的大鼠，因为副传播者对血管具有很强的作用，因此相同的LDT刺激如何影响丘脑中的大脑血流。在LDT刺激开始后的几秒钟内，观察到血流的增加，并在刺激后持续约1分钟。通过给药（一种毒蕈碱拮抗剂）施用Scopolamine，但这种治疗方法并没有阻止其com。仅当刺激电极插入LDT之后，无浓度就会暂时增加。更强的刺激产生了更强的增加。结果表明，在大鼠Thalamus的体外片剂中检查了co骨传播者的兴奋性，从轴突末端释放了NO和/或静脉曲张。大多数丘脑神经元是通过应用乙酰胆碱（ACH）部署的。当SP仅用ACH应用时，某些神经元中的沉积增加，但被取消以在其他神经元中产生静止的潜在变化。因此，建议SP作为共晶剂会修饰主发射器ACH的作用，但是从神经元到神经元的修饰差异。 NO的动作尚未清楚地证明。较少的