EXCITATORY AMINO-ACIDS IN SYNAPTIC TRANSMISSION IN THE SCHAFFER COLLATERAL COMMISSURAL PATHWAY OF THE RAT HIPPOCAMPUS
EXCITATORY AMINO-ACIDS IN SYNAPTIC TRANSMISSION IN THE SCHAFFER COLLATERAL COMMISSURAL PATHWAY OF THE RAT HIPPOCAMPUS
复制标题
DOI：
10.1113/jphysiol.1983.sp014478
复制
发表时间：
1983-01-01
影响因子：
5.5
通讯作者：
MCLENNAN, H
中科院分区：
文献类型：
--
作者：
COLLINGRIDGE, GL;KEHL, SJ;MCLENNAN, H
本实验观察了兴奋性氨基酸和某些拮抗剂对大鼠海马脑片CA_1区放射层的影响，并对刺激Schaffer侧支-连合投射诱发的兴奋性突触后电位进行了局部记录。L-谷氨酸，L-天冬氨酸和更有效的和选择性的兴奋性氨基酸使君子酸，红藻氨酸和N-甲基-DL-天冬氨酸（NMA）可能通过去极化和/或膜电导的变化抑制epsp。红藻氨酸引起的抑郁症相当持久的喷射期，而NMA抑郁症是迅速可逆的，往往其次是增强的epsp。在较高剂量的NMA也抑制突触前纤维齐射。这些影响可能参与神经毒性和突触可塑性的提高。选择性NMR拮抗剂DL-2-amino-5-phosphonovalerate（APV）的应用剂量可以消除对NMA的反应，但对epsp没有影响，但可以阻止由高频刺激Schaffer侧支-连合通路诱发的突触传递的长时程增强（ltp）。对正常突触传递几乎没有或没有影响的其它拮抗剂包括D-α-氨基己二酸酯（DAA）、2-氨基-4-膦酰基丁酸酯（APB）和L-谷氨酸二乙酯（GDEE）的光学异构体。γ- D-谷氨酰甘氨酸（DGG），应用的数量，影响quisqualate和红藻氨酸的行动，以及那些NMA，是一个有效的突触拮抗剂，而对突触前纤维凌空没有影响。Schaffer侧支-连合通路中的突触受体可以是红藻氨酸或使君子氨酸类型。虽然NMA受体似乎不参与该通路中的正常突触传递，但它们可能在突触可塑性中发挥作用。讨论了L-谷氨酸和L-天冬氨酸与这些受体的相互作用。
The effects of excitatory amino acids and some antagonists applied by ionophoresis to stratum radiatum in the CA1 region of rat hippocampal slices were examined on the locally recorded field epsp [excitatory postsynaptic potential] evoked by stimulation of the Schaffer collateral-commissural projection. L-Glutamate, L-aspartate and the more potent and selective excitatory amino acids quisqualate, kainate and N-methyl-DL-aspartate (NMA) depressed the epsp presumably through depolarization and/or a change in membrane conductance. The depression induced by kainate considerably outlasted the period of ejection, whereas NMA depressions were rapidly reversible and were often followed by a potentiation of the epsp. In higher doses NMA also depressed the presynaptic fiber volley. The possible involvement of these effects in neurotoxicity and synaptic plasticity is raised. The selective NMR antagonist, DL-2-amino-5-phosphonovalerate (APV) applied in doses which abolished responses to NMA, had no effect on the epsp, but prevented long term potentiation (ltp) of synaptic transmission evoked by high frequency stimulation of the Schaffer collateral-commissural pathway. Other antagonists which had little or no effect on normal synaptic transmission included D-.alpha.-aminoadipate (DAA), the optical isomers of 2-amino-4-phosphonobutyrate (APB) and L-glutamate diethylester (GDEE). .gamma.-D-Glutamylglycine (DGG), applied in amounts which affected quisqualate and kainate actions as well as those of NMA, was an effective synaptic antagonist while having no effect on the presynaptic fiber volley. The synaptic receptor in the Schaffer collateral-commissural pathway may be of the kainate or quisqualate type. Although NMA receptors do not appear to be involved in normal synaptic transmission in this pathway, they may play a role in synaptic plasticity. The interaction of L-glutamate and L-aspartate with these receptors is discussed.