Optical responses evoked by single-pulse stimulation to the dorsal root in the rat spinal dorsal horn in slice
Optical responses evoked by single-pulse stimulation to the dorsal root in the rat spinal dorsal horn in slice
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DOI：
10.1016/s0006-8993(98)00928-7
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发表时间：
1998-11-23
期刊：
影响因子：
2.9
通讯作者：
Murase, K
中科院分区：
文献类型：
--
作者：
Ikeda, H;Ryu, PD;Murase, K
用高分辨率光学成像技术观察了电刺激大鼠脊髓背角（DH）背根（DR）诱发的神经元兴奋，并探讨了其传播机制。从2-4周龄大鼠获得脊髓横切片，并用电压敏感染料RH-482染色。单脉冲刺激与切片相连的DR中的初级传入A纤维在I和III-V层诱发了弱的、短暂的（< 10 ms）兴奋性光学反应。当刺激强度和持续时间增加以激活A和C纤维时，（> 100 ms）的兴奋性反应在I-III层中产生，在II层中最强烈。兴奋性氨基酸（EAA）拮抗剂，DL-2-氨基-5-膦酰基戊酸和6-氰基-7-硝基喹喔啉-2，3-二酮的治疗，显着降低的振幅和持续时间的反应在板层II。在拮抗剂的解决方案中的光学响应是非常相似的记录在一个无钙的解决方案，阻止传入突触传递。然而，晚期分量（> 10 ms）略大于无Ca 2+溶液中的晚期分量。治疗与ATP受体拮抗剂，苏拉明，有一个最小的影响，在EAA拮抗剂的存在下的反应。这些结果表明，DR刺激引起的兴奋的传播主要是由EAA受体，但也由其他受体在很小程度上。(C)1998 Elsevier Science B. V.保留所有权利。
Neuronal excitation evoked after dorsal-root (DR) stimulation in the spinal dorsal horn (DH) of rats was visualized with a high-resolution optical-imaging method, and the propagation mechanism was studied. Transverse slices of the spinal cord were obtained from 2-4 week-old rats and stained with the voltage-sensitive dye RH-482. Single-pulse stimulation to the primary-afferent A fibers in the DR attached to the slice evoked a weak, brief (< 10 ms) excitatory optical response in the laminae I and III-V. When the stimulus intensity and duration were increased to activate both A and C fibers, an additional, much greater, and longer-lasting (> 100 ms) excitatory response was generated in the laminae I-III, most intensely in the lamina II. A treatment with excitatory amino acid (EAA) antagonists, DL-2-amino-5-phosphonovaleric acid and 6-cyano-7-nitroquinoxaline-2,3-dione, significantly reduced the amplitude and duration of the response in the lamina II. The optical response in the antagonists-containing solution was quite similar to that recorded in a Ca2+-free solution that blocked afferent synaptic transmission. The late component(> 10 ms) was, however, slightly greater than that in the Ca2+-free solution. Treatment with the ATP-receptor antagonist, suramin, had a minimal effect on the response in the presence of EAA antagonists. These results suggested that the propagation of the DR-stimulus-elicited excitation was contributed largely by EAA receptors, but also by other receptors to a much lesser extent. (C) 1998 Elsevier Science B.V. All rights reserved.