In vivo patch clamp analysis of pain transmission in the spinal dorsal horn

脊髓背角疼痛传递的体内膜片钳分析

基本信息

批准号：
10680766
负责人：
YOSHIMURA Megumu
金额：
$ 2.24万
依托单位：
Saga Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

In vivo patch-clamp recording technique has been developed to analyze synaptic responses evoked by noxious or non-noxious stimuli applied to the skin. Under artificial ventilation of rats anesthetized with urethane and monitoring the blood pressure and temperature, L4 or L5 lumbar spinal cord was exposed by laminectomy and then the rat was placed on a stereotoxic apparatus. Using a micromanipulator, recording electrodes were inserted into the dorsal horn and giga-ohm sealing was established. Patch-clamp recordings were obtained from neurons located in substantia gelatinosa (SG, lamina II), which had a resting membrane potential of -50〜-75 mV and an input membrane resistance of 250〜600 MΩ. Under a voltage-clamp condition, they exhibited spontaneous fast excitatory postsynaptic currents (EPSCs) at holding potential of -70 mV and inhibitory postsynaptic currents (IPSCs) at 0 mV. Pinch and air stimuli applied to the ipsilateral hind limb increased the fast EPSCs in frequency and amplitude … More in all SG neurons tested, some of which initiated an actin potential under a current clamp condition. In contrast, all SG neurons examined, did not respond to noxious heat stimuli. To know where the noxious heat information is transmitted, patch-clamp recordings were made from deeper neurons. The deep dorsal horn neurons responded to noxious heat stimuli with increasing fast EPSCs in frequency and amplitude. The responses were, however, mediated solely by glutamatergic fast EPSCs, and no slow responses, supposed to be mediated by peptides, were detected in all neurons tested. These observations suggest that SG neurons receive nociceptive and non-nociceptive mechanical, but not noxious thermal inputs. The mechanical information may be transmitted by Aδ and C primary afferent fibers through an activation of non-NMDA receptor. Whereas, the noxious heat information is transmitted to the deeper laminae through activating glutamatergic receptors. Mechanisms of peptidergic transmission are required to be clarified. Less

已经开发了体内贴片钳记录技术来分析因在皮肤上应用有害或无毒性刺激引起的突触反应。在用氨基甲酸酯麻醉的大鼠人工通气并监测血压和温度，L4或L5腰脊髓通过椎板切除术暴露于脊髓，然后将大鼠放在立体毒性设备上。使用微型操纵器，将记录电极插入后角，并建立了千兆ohm密封。斑板钳记录是从位于质明明胶（SG，Lamina II）的神经元中获得的，该神经元的静息膜电位为-50至-75 mV，输入膜电阻为250至600MΩ。在电压钳状态下，它们在保持-70 mV的电位和抑制性突触后电流（IPSC）处表现出赞助者 - 狂热的突触后电流（EPSC），在0 mV处表现出抑制性的突触后电流（IPSC）。应用于同侧后肢的捏和空气刺激增加了频率和放大器的快速EPSC…在所有测试的SG神经元中，更多的是在当前夹具条件下启动肌动蛋白电位。相比之下，所有检查的SG神经元对有害的热刺激没有反应。为了知道有害的热信息在何处传播，贴片钳记录是由更深的神经元进行的。深层角神经元对有害的热刺激反应，随着频率和放大器的快速EPSC的增加。但是，这些反应仅由谷氨酸能快速EPSC介导，并且在所有测试的神经元中检测到了预计将被胡椒剂介导的缓慢反应。这些观察结果表明，SG神经元会受到伤害和非吸引人的机械性机械，但不是有害的热输入。机械信息可以通过非NMDA受体的激活来通过Aδ和C主要传入纤维传输。鉴于，有害的热信息通过激活谷氨酸能受体传播到更深的薄片。需要澄清胡椒传播的机制。较少的