Effects of norepinephrine on spontaneous firing activity of cerebellar Purkinje cells in vivo in mice
Effects of norepinephrine on spontaneous firing activity of cerebellar Purkinje cells in vivo in mice
复制标题
去甲肾上腺素对小鼠体内小脑浦肯野细胞自发放电活性的影响
DOI：
10.1016/j.neulet.2016.06.058
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发表时间：
2016-08-26
影响因子：
2.5
通讯作者：
Chu, Chun-Ping
中科院分区：
文献类型：
--
作者：
Guo, Ao;Feng, Jun-Yang;Chu, Chun-Ping
来自蓝斑的去甲肾上腺素（NE）通过肾上腺素受体影响小脑皮层GABA能系统和平行纤维（PF）-浦肯野细胞（PC）突触传递。然而，NE对活体小鼠小脑前体细胞自发放电的影响尚未完全清楚。本文用电生理和药理学方法研究了去甲肾上腺素（NE）对乌拉坦麻醉小鼠PC自发活动的影响。小脑表面应用NE（2.5-25 μ M）以剂量依赖性方式降低PC简单锋电位（SS）放电率。半抑制浓度（1050）为5.97 μ M。与此相反，NE显著增加分子层中间神经元（MLI）的自发放电频率。应用GABA（A）受体拮抗剂gabazine（SR 95531，20 μ M）不仅能阻断NE对PC SS放电的抑制，而且还能显示NE对小脑PC的兴奋。阻断AMPA受体活性增强NE对PC自发活动的抑制。同时阻断GABA（A）和AMPA受体活性，可消除NE对PC自发活动的影响。这些结果表明NE通过增强MLI的抑制性输入和平行纤维的兴奋性输入双向调节PC的自发活动，但在体内NE诱导的抑制性输入的增强超过了兴奋性输入。(C)2016爱思唯尔爱尔兰有限公司版权所有。
Norepinephrine (NE), from the locus coeruleus (LC), has been supported to affect GABAergic system and parallel fiber (PF)-Purkinje cell (PC) synaptic transmission via adrenoceptor in cerebellum cortex. However, the effects of NE on the spontaneous spike activity of cerebellar PCs in living mouse have not yet been fully understood. We here examined the effects of NE on the spontaneous activity of PC in urethane anesthetized mice by electrophysiological and pharmacological methods. Cerebellar surface application of NE (2.5-25 mu M) reduced the PC simple spike (SS) firing rate in a dose-dependent manner. The half inhibitory concentration (1050) was 5.97 mu M. In contrast, NE significantly increased the spontaneous firing rate of molecular layer interneuron (MLI). Application of GABA(A) receptor antagonist, gabazine (SR95531, 20 mu M) not only blocked the NE-induced inhibition of PC SS firing but also revealed NE-induced excitation of cerebellar PC. Blocking AMPA receptors activity enhanced NE-induced inhibition of PC spontaneous activity. Moreover, the effects of NE on PC spontaneous activity were abolished by simultaneously blocking GABA(A) and AMPA receptors activity. These results indicated that NE bidirectional modulated the spontaneous activity of PCs via enhancing both inhibitory inputs from MLIs and excitatory inputs of parallel fibers, but NE-induced enhance of inhibitory inputs overwhelmed the excitatory inputs under in vivo conditions. (C) 2016 Elsevier Ireland Ltd. All rights reserved.