Slow oscillation of membrane currents mediated by glutamatergic inputs of rat somatosensory cortical neurons:: in vivo patch-clamp analysis
Slow oscillation of membrane currents mediated by glutamatergic inputs of rat somatosensory cortical neurons:: in vivo patch-clamp analysis
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DOI：
10.1111/j.1460-9568.2007.05885.x
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发表时间：
2007-11-01
影响因子：
3.4
通讯作者：
Yoshimura, Megumu
中科院分区：
文献类型：
--
作者：
Doi, Atsushi;Mizuno, Masaharu;Yoshimura, Megumu
使用体内膜片钳技术，在乌拉坦麻醉大鼠的初级体感皮层（SI）神经元中，膜电流的缓慢振荡以其突触性质、与脑电图（EEG）的相关性以及对不同麻醉剂的反应为特征。在超过90%的SI神经元中，在-70 mV的保持膜电位下观察到持续数百毫秒的内向电流（0.1-2.5 Hz）的缓慢振荡。内向电流的反转电位约为0 mV，并且通过应用α-氨基-3-羟基-5-甲基-4-异恶唑丙酸酯(AMPA)受体拮抗剂来抑制。在大多数情况下（> 90%），内向电流与同侧甚至对侧皮质区域记录的表面脑电图的正波同步。挥发性麻醉剂异氟烷（1.5-5.0%）降低了缓慢振荡的频率和持续时间，并且在最高浓度下兴奋性突触后电流（EPSC）几乎被消除。腹腔注射戊巴比妥 (25 mg/kg) 也降低了慢振荡的频率，而不影响短 EPSC。当丘脑局部显微注射蝇蕈醇(3×10(-3)M,1-10μL)激活γ-氨基丁酸A(GABA(A))受体时,慢振荡频率明显降低,但并未完全消除。这些发现表明，内向电流的缓慢振荡是由谷氨酸能 EPSC 的总和产生的，并受到异氟烷和戊巴比妥的不同影响。此外，丘脑中的 GABA 能系统可以影响频率，但本质上与慢振荡的起源无关。
Using in vivo patch-clamp technique, the slow oscillation of membrane currents was characterized by its synaptic nature, correlation with electroencephalogram (EEG) and responses to different anesthetic agents, in primary somatosensory cortex (SI) neurons in urethane-anesthetized rats. In more than 90% of the SI neurons, the slow oscillation of the inward currents (0.1-2.5 Hz) with the duration of several hundreds of a millisecond was observed at the holding membrane potential of -70 mV. The reversal potential of the inward currents was approximately 0 mV and was suppressed by application of an alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor antagonist. In most cases (> 90%) the inward current was synchronized with positive wave of the surface EEG recorded from ipsilateral and even contralateral cortical regions. The frequency as well as duration of the slow oscillation decreased by a volatile anesthetic agent, isoflurane (1.5-5.0%), and excitatory postsynaptic currents (EPSCs) were almost abolished at the highest concentration. Intraperitoneal injection of pentobarbital (25 mg/kg) also decreased the frequency of the slow oscillation without affecting short EPSCs. When gamma-aminobutyric acid A (GABA(A)) receptors were activated by local microinjection of muscimol (3 x 10(-3) M, 1-10 mu L) into the thalamus, the frequency of the slow oscillation markedly decreased, but was not abolished completely. These findings suggest that the slow oscillation of the inward currents is generated by the summation of glutamatergic EPSCs, and affected by isoflurane and pentobarbital differently. In addition, GABAergic system in the thalamus can affect the frequency, but is not essentially implicated in the genesis of the slow oscillation.