Shimizu N, Akaike N, Oomura Y, Maruhashi J, Klee M R
Jpn J Physiol. 1983;33(3):459-67. doi: 10.2170/jjphysiol.33.459.
Responses of identified single neurons in the isolated right cerebral ganglion of Onchidium to bath applied gamma-aminobutyric acid (GABA) and lioresal (LRS) were measured using conventional intracellular microelectrode techniques under current and voltage clamp conditions. In normal medium the neurons responded to both GABA and LRS. GABA induced two successive hyperpolarizations (phase I and II). Phase I was a short-lasting Cl- permeability increase while phase II was a long-lasting K+ permeability increase. LRS evoked only a long-lasting K+ permeability increase. In Ca2+-free high Mg2+ medium GABA produced only short-lasting hyperpolarization while LRS had no effect. GABA-induced phase I responses behaved as a simple Cl-electrode following changes of external Cl- concentrations. The Hill coefficient obtained from the relation between the relative change in the GABA increase phase in Ca2+-free high Mg2+ medium. These results indicate that GABA has a direct Cl- permeability increase action on the postsynaptic cell membrane of the identified Onchidium neuron while LRS has no such direct action.
在电流钳和电压钳条件下，使用传统的细胞内微电极技术，测量了背角无齿蚌离体右脑神经节中单个已鉴定神经元对浴加γ-氨基丁酸（GABA）和氯苯氨丁酸（LRS）的反应。在正常培养基中，神经元对GABA和LRS均有反应。GABA诱导了两个连续的超极化（I期和II期）。I期是短暂的Cl-通透性增加，而II期是持久的K+通透性增加。LRS仅引起持久的K+通透性增加。在无Ca2+的高Mg2+培养基中，GABA仅产生短暂的超极化，而LRS无作用。GABA诱导的I期反应表现为随着外部Cl-浓度变化的简单Cl-电极反应。从无Ca2+的高Mg2+培养基中GABA增加相的相对变化关系获得的希尔系数。这些结果表明，GABA对已鉴定的背角无齿蚌神经元的突触后细胞膜具有直接的Cl-通透性增加作用，而LRS没有这种直接作用。
