Blockade of amino acid‐induced depolarizations and inhibition of excitatory post‐synaptic potentials in rat dentate gyrus.
Blockade of amino acid‐induced depolarizations and inhibition of excitatory post‐synaptic potentials in rat dentate gyrus.
复制标题
阻断氨基酸诱导的去极化和抑制大鼠齿状回兴奋性突触后电位。
DOI：
10.1113/jphysiol.1983.sp014829
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
J. Kelly
中科院分区：
文献类型：
--
作者：
V. Crunelli;S. Forda;J. Kelly
在制备的大鼠海马切片中，记录了由内侧穿通通路刺激引起的兴奋性突触后电位和由兴奋性氨基酸诱导的去极化。比较了兴奋性氨基酸拮抗剂（+/‐）‐2‐氨基‐5‐磷酸戊酸酯（APV）、γ‐D‐谷氨酰甘氨酸（gamma DGG）和顺式2,3‐哌啶二羧酸酯（PDA）对这些现象的影响。伽马DGG是最有效的e.p.s.p拮抗剂，其作用是可逆的，与颗粒细胞的被动膜特性或e.p.s.p的明显逆转电位的任何变化无关。量子分析表明，e.p.s.p的减少与量子大小的减少而不是量子含量的减少平行，证实了伽马DGG作用的突触后位点。γ - DGG对外源性激动剂的效价为N -甲基- D -天冬氨酸大于海因酸盐大于或等于准质酸盐。APV对e.p.s.p.的影响很小，但它是N -甲基- D -天冬氨酸诱导的去极化的选择性拮抗剂。PDA使颗粒细胞去极化，增加其膜输入电阻。虽然γ - DGG是谷氨酸和天冬氨酸诱导的去极化的有效拮抗剂，但没有发现明确的特异性模式。谷氨酸的作用不受APV的影响。这些结果表明，在与颗粒细胞穿孔通路的纤维形成的突触上的递质受体是准质和/或盐酸盐型的。目前的数据与生化证据一致，谷氨酸可能是他突触的内源性递质。
Excitatory post‐synaptic potentials (e.p.s.p.s) evoked by stimulation of the medial perforant path and depolarizations induced by excitatory amino acids were recorded from granule cells in the preparation of the hippocampal slice from the rat. The effects of (+/‐)‐2‐amino‐5‐phosphonovalerate (APV), gamma‐D‐glutamylglycine (gamma DGG) and cis‐2,3‐piperidinedicarboxylate (PDA), antagonists of excitatory amino acids on these phenomena were compared. gamma DGG was the most effective antagonist of the e.p.s.p. Its action was reversible and not associated with any change in the passive membrane properties of the granule cells or in the apparent reversal potential of the e.p.s.p. Quantal analysis showed that the reduction in the e.p.s.p. paralleled the decrease in quantal size rather than quantal content, confirming a post‐synaptic site of the action of gamma DGG. The potency of gamma DGG against the exogenous agonists was N‐methyl‐D‐aspartate greater than kainate greater than or equal to quisqualate. APV had very little effect on the e.p.s.p. but was a selective antagonist of N‐methyl‐D‐aspartate‐induced depolarizations. PDA depolarized granule cells and increased their membrane input resistance. Although gamma DGG was a potent antagonist of both glutamate‐ and aspartate‐induced depolarizations, no clear pattern of specificity could be found. The action of glutamate was unaffected by APV. These results indicate that the receptor for the transmitter at the synapses formed by the fibres of the perforant path with the granule cells is of the quisqualate and/or kainate type. The present data are consistent with the biochemical evidence that glutamate may be the endogenous transmitter at his synapse.
影响因子：
2.5
作者：
T. H. Brown;R. Fricke;D. Perkel
通讯作者：
T. H. Brown;R. Fricke;D. Perkel