Involvement of G-protein in the synaptic transmission at the lobster neuromuscular junction

G 蛋白参与龙虾神经肌肉接头的突触传递

• 批准号: 63570075
• 负责人: MIWA Akiko
• 金额: $ 1.22万
• 依托单位: TOKYO METROPOLITAN INSTITUTE FOR NEUROSCIENCES
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63570075/
• 关键词: Nerve terminal; L-Glutamic acid; G-protein; GTPgammaS; Glutamate_B receptor; Neuromuscular junction; Gーprotein; シナプス前神経; GABA; シナプス後電位; イセエビ歩脚

The role of GTP binding protein in the presynaptic membrane was investigated by use of intra-axonal recording near the nerve terminal of lobster neuromuscular synapse. L-glutamate activated the presynaptic glutamate receptor. (glutamate B receptor), inducing a hyperpolarizing current carried by K ion. This presynaptic glutamate potential was effectively blocked by pertussis toxin (IAP), indicating mediation by GTP-protein. Injection of GTPYS, a non-hydrolysable analog of GTP, hyperpolarized the presynaptic membrane and mimicked the presynaptic glutamte potential.The effect of GTP_<gamma>S injection on synaptic transmission was studied by recording the excitatory postsynaptic current (EPSC) with macro-patch recording. After injection GTP_<gamma>S in the presynaptic axon, the amplitude of the EPSC was gradually and irreversively diminished. Quantal analysis of EPSCs revealed that after GTP_<gamma>S injection quantal content was much reduced, whereas unit quantal size was unchanged.The results suggest that glutamate B receptor in the presynaptic membrane gives rise to a presynaptic inhibitory effect on transmitter release by activating GTP-binding protein.

在龙虾神经肌肉突触神经末梢附近的轴突内记录，研究了GTP结合蛋白在突触前膜中的作用。L-谷氨酸激活突触前谷氨酸受体。(谷氨酸B受体)，诱导K离子携带的超极化电流。这种突触前谷氨酸电位可被百日咳毒素(IAP)有效阻断，提示GTP蛋白参与了这一过程。注射GTP的非水解性类似物GTPYS可使突触前膜超极化，模拟突触前谷氨酸电位。采用大片片记录兴奋性突触后电流的方法，研究了GTP_1、GT、GT、S对突触传递的影响。突触前轴突注射GTP_(lt；)γ&gt；S后，EPSC的波幅逐渐降低，且不可逆。突触前膜谷氨酸B受体通过激活GTP结合蛋白对递质释放产生突触前抑制作用。

项目成果

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NOBUFUMI KAWAI, AKIKO MIWA, YUICHI HASHIMOTO, KOICHI SHUDO, TAIJI ASAMI and TERUMI NAKAJIMA: "Zinc ion enhances the blocking potency of synthetic analogs of spider toxin (JSTX) on the glutamate receptor" Neurosci. Res., vol.6, 358-362, 1989.

NOBUFUMI KAWAI、AKIKO MIWA、YUichi Hashimoto、KOICHI SHUDO、TAIJI ASAMI 和 TERUMI NAKAJIMA：“锌离子增强蜘蛛毒素 (JSTX) 合成类似物对谷氨酸受体的阻断效力” Neurosci。

N.Kawai et al.: "Zinc ion enhances the blocking potency of synthetic analogs of spider toxin(JSTX)on the glutamate receptor." Neuroscience Research. 6. 358-362 (1989)

N.Kawai 等人：“锌离子增强了蜘蛛毒素 (JSTX) 合成类似物对谷氨酸受体的阻断效力。”

M.Saito et al.: "Effects of a spider toxin(JSTX)on hippocampal CA1 neurons in vitro." Brain Research. 481. 16-24 (1989)

M.Saito 等人：“蜘蛛毒素 (JSTX) 对海马 CA1 神经元的体外影响。”

T,Abe,et al.,: "Blocking of repetitive response form a neuromuscular preparation of tenebrio Molitor by phosphotriesters" Comp.Biochoem.Physiol.92C. 309-313 (1989)

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