GABAA receptor-mediated tonic currents in substantia gelatinosa neurons of rat spinal trigeminal nucleus pars caudalis
GABAA receptor-mediated tonic currents in substantia gelatinosa neurons of rat spinal trigeminal nucleus pars caudalis
复制标题
DOI：
10.1016/j.neulet.2008.06.048
复制
发表时间：
2008-08-29
影响因子：
2.5
通讯作者：
Youn, Dong-ho
中科院分区：
文献类型：
--
作者：
Han, Sang-mi;Youn, Dong-ho
在本研究中，我们描述了大鼠三叉神经脊束核尾侧核胶状质(SG)区GABA(A)受体介导的紧张性抑制电流。用GABA(A)受体拮抗剂印防己毒素(1 MM)、SR95531(100 MU M)和双核(100 MU M)浸浴，鉴定GABA(A)受体介导的紧张性电流。三种拮抗剂均可完全阻断突触后自发外向抑制电流，但只有印防己毒素和荷包牡丹碱可使60-70%的SG神经元在保持电位(VH)为0 mV时引起明显的(>；5pA)抑制电流内移，提示紧张性外向电流的存在。紧张性电流对甘氨酸受体或谷氨酸受体和电压依赖性钠通道以外的受体有进一步的阻断作用。应激相关神经类固醇THDOC(0.1mM)的急性沐浴确实增强了紧张性电流，但仅在一小部分SG神经元上。此外，与THDOC孵育30min的脑片增加了具有显著紧张性电流的神经元的概率。本研究显示GABA能的紧张性抑制可能在Vc的感觉处理系统中起重要作用。(C)2008爱思唯尔爱尔兰有限公司。保留所有权利。
In the present study, we describe GABA(A) receptor-mediated tonic inhibitory currents in the substantia gelatinosa (SG) region of rat spinal trigeminal nucleus pars caudalis (Vc). The GABA(A) receptor-mediated tonic currents were identified by bath-application of the GABA(A) receptor antagonists, picrotoxin (1 mM), SR95531 (100 mu M) and bicucullme (100 mu M). All three antagonists completely blocked outward spontaneous (phasic) inhibitory postsynaptic currents, but only picrotoxin and bicuculline induced a significant (> 5 pA) inward shift of holding currents at a holding potential (Vh) of 0 mV in 60-70% of SG neurons, revealing the existence of tonic outward currents. The tonic currents were resistant to further the blockades of glycine receptors or those in addition to glutamate receptors and voltage-dependent sodium channels. An acute bath-application of THDOC (0.1 mu M), the stress-related neurosteroid, did enhance tonic currents, but only in a small population of SG neurons. In addition, slices incubated with THDOC for 30 min increased the probability of neurons with significant tonic currents. The GABAergic tonic inhibition demonstrated in this study may play a significant role in the sensory processing system of the Vc. (c) 2008 Elsevier Ireland Ltd. All rights reserved.