GABA AS AN INHIBITORY NEUROTRANSMITTER IN HUMAN CEREBRAL-CORTEX
GABA AS AN INHIBITORY NEUROTRANSMITTER IN HUMAN CEREBRAL-CORTEX
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DOI：
10.1152/jn.1989.62.5.1018
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发表时间：
1989-11-01
影响因子：
2.5
通讯作者：
MCCORMICK, DA
中科院分区：
文献类型：
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作者：
MCCORMICK, DA
1. 利用体外保存的新皮层切片的细胞内记录，研究了γ -氨基丁酸（GABA）作为一种抑制性神经递质在人类大脑皮层中的可能作用。2. 电刺激传入锥体细胞导致初始兴奋性突触后电位（EPSP），随后是快速和缓慢抑制性突触后电位（ipsp）。早期IPSP的平均逆转电位为-68 mV，膜电导平均增加67 ns，被GABAA拮抗剂双库兰降低，对细胞内注射Cl-敏感，并被GABAA激动剂muscimol模拟。3. 相比之下，晚期IPSP的平均逆转电位为-95 mV，膜电导平均增加12 ns，被GABAB拮抗剂苯氯芬降低，并被GABAB拮抗剂巴氯芬模拟。4. 二胡碱或微毒素阻断早期IPSP可产生阵发性癫痫样活性，晚期IPSP的减少可进一步增强这种活性。5. 这些数据有力地支持了GABA是人类大脑皮层中一种主要的抑制性神经递质，GABA能ipsp在控制皮层神经元的兴奋性和反应性中发挥重要作用的假设。
1. The possible role of gamma-aminobutyric acid (GABA) as an inhibitory neurotransmitter in the human cerebral cortex was investigated with the use of intracellular recordings from neocortical slices maintained in vitro. 2. Electrical stimulation of afferents to presumed pyramidal cells resulted in an initial excitatory postsynaptic potential (EPSP) followed by fast and slow inhibitory postsynaptic potentials (IPSPs). The early IPSP had an average reversal potential of -68 mV, was associated with a mean 67-nS increase in membrane conductance, was reduced by the GABAA antagonist bicuculline, was sensitive to the intracellular injection of Cl-, and was mimicked by the GABAA agonist muscimol. 3. The late IPSP, in contrast, had an average reversal potential of -95 mV, was associated with a mean 12-nS increase in membrane conductance, was reduced by the GABAB antagonist phaclofen, and was mimicked by the GABAB agonist baclofen. 4. Block of the early IPSP by bicuculline or picrotoxin led to the generation of paroxysmal epileptiform activity, which could be further enhanced by reduction of the late IPSP. 5. These data strongly support the hypothesis that GABA is a major inhibitory neurotransmitter in the human cerebral cortex and that GABAergic IPSPs play an important role in controlling the excitability and responsiveness of cortical neurons.