Slow synchronized bursts of inhibitory postsynaptic currents (0.1-0.3 Hz) by cholinergic stimulation in the rat frontal cortex in vitro
Slow synchronized bursts of inhibitory postsynaptic currents (0.1-0.3 Hz) by cholinergic stimulation in the rat frontal cortex in vitro
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DOI：
10.1016/s0306-4522(01)00388-8
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发表时间：
2001-01-01
期刊：
影响因子：
3.3
通讯作者：
Kawaguchi, Y
中科院分区：
文献类型：
--
作者：
Kondo, S;Kawaguchi, Y
从基底前脑到大脑皮层的胆碱能输入对大脑皮层活动产生深远的影响，如节律性同步。对于这些调节作用，抑制性中间神经元可能在大脑皮层回路中发挥关键作用。研究胆碱能对GABA介导的抑制作用的调节作用。我们在大鼠额叶皮质记录了应用胆碱能激动剂时的抑制性突触后电流(IPSC)。卡巴胆碱和毒扁豆碱都在锥体细胞和抑制性中间神经元引起两种不同的IPSC调制模式：强直或周期性地增加GABA-A受体介导的抑制。强直模式表现为IPSC频率的持续增加，而周期性增加表现为IPSC的节律性(0.1-0.3 Hz，平均0.2 Hz)爆发(频率：6-69 Hz，平均24 Hz)。爆发持续时间：S 1.2-4.3%，平均2.2 S)。这两种类型的增加都被毒碱受体拮抗剂阿托品或哌仑西平抑制。离子型谷氨酸受体拮抗剂不影响IPSC的周期性爆发。在胆碱能刺激后，邻近细胞的周期性IPSC爆发作为一个整体是同步的，但爆发内的单个抑制事件并不总是在时间上相关，这表明几个突触前神经元之间的去极化是同步的。已有研究表明，伴随着放电的慢节奏去极化可以在皮质内产生。除了皮质环路的这种周期性兴奋外，这些结果表明，皮质抑制性中间神经元有自己的乙酰胆碱依赖机制，产生不依赖于兴奋环路的慢节奏。(C)2001年IBRO。爱思唯尔科学有限公司出版。版权所有。
Cholinergic inputs from the basal forebrain to cortex exert profound effects on cortical activities, such as a rhythmic synchronization. For these modulatory effects inhibitory interneurons could play crucial roles within the cortical circuitry. To study cholinergic modulation of GABA-mediated inhibition. we recorded inhibitory postsynaptic current (IPSC) during application of cholinergic agonists, in the rat frontal cortex in vitro. Both carbachol and muscarine caused two temporally different patterns of IPSC modulation in both pyramidal cells and inhibitory interneurons: tonic or periodic increase of GABA-A receptor-mediated inhibition. The tonic pattern showed a continuous increase of IPSC frequency, while the periodic increase manifested itself as rhythmic (0.1-0.3 Hz, mean 0.2 Hz) bursts of IPSC (frequency: 6-69 Hz, mean 24 Hz. burst duration: 1.2-4.3 s, mean 2.2 s). Both types of increase were suppressed by atropine or pirenzepine, muscarinic-receptor antagonists. The periodical IPSC bursts were not affected by antagonists for ionotropic glutamate receptors. Following cholinergic stimulation, periodic IPSC bursts in nearby cells were synchronized as a whole, but individual inhibitory events within the bursts were not always temporally correlated, suggesting synchronized depolarizations of several presynaptic interneurons.It has been revealed that slow rhythmic depolarizations accompanying spike firing can be generated within the cortex. In addition to this periodic excitation of cortical circuits, these results indicate that cortical inhibitory interneurons have their own acetylcholine-dependent mechanism generating the slow rhythm independent of the excitatory circuits. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.