The Role of Prostaglandins in Learning and Memory

1. 应用纯化的前列腺素内过氧化物合酶单克隆抗体，研究了前列腺素内过氧化物合酶（PES）在猴海马组织中的免疫组化定位。海马和大脑皮层神经元具有强烈的pes免疫反应性。特别是海马齿状回和阿蒙角的颗粒状和锥体神经元表现出最强烈的免疫反应性。CA3区锥体细胞的顶端树突、近端树突和躯体均呈阳性染色。pg对豚鼠海马CA3神经元长时程增强的影响利用豚鼠海马切片建立了长时程增强的实验装置。前列腺素D2、E2和F2alpha在20mum以内对齿状回强直刺激下CA3神经元的兴奋性突触后电位和长期增强无影响。研究了大鼠脑内磷脂酶A2 （PLA2）的活性，在大鼠脑内的细胞质部分发现了在凝胶过滤柱上具有双峰的活性。低分子量形式（PLAL）在中性pH下具有活性，其活性绝对需要Ca^<2+>。在部分纯化的PLAL和大鼠脑突触体膜的重建系统中，PLAL以Ca^<2+>依赖的方式与膜相关。PGE2对谷氨酸释放的影响通过微透析技术，我们研究了PGE2对谷氨酸释放的影响，其受体在海马中富集，而谷氨酸被认为是海马长期增强的主要触发因素。PGE2增强了大脑几个部分的谷氨酸释放。

1. Localization of prostaglandin endoperoxide synthase in the hippocampusImmunohistochemical localization of Prostaglandin Endoperoxide Synthase (PES) in monkey hippocampus was investigated by the use of monoclonal antibody against purified PES. PES-immunoreactivity was intense in the neurons in the hippocampu and cerebral cortex. Especially, the granular and pyramidal neurons in the dentate gyrus and Ammon's horn of the hippocampus showed the most intense immunoreactivity. In the pyramidal cells in CA3 region, positive staining was seen the apical dendrites as well as the proximal dendrites and somata.2. Effects of PGs on long-term potentiation in the CA3 neurons of guinea pig hippocamp sliceThe experimental set-up for long-term potentiation was established by using hippocampal slices of guinea pig. Prostaglandin (PG) s D2, E2, and F2alpha upto 20 muM ha no effects on excitatory post-synaptic potential and long-term potentiation of CA3 neurons by tetanic stimuli of dentate gyrus.3. Novel cytosolic phospholipase A2 in the rat brain and its translocationWhen phospholipase A2 (PLA2) activities were investigated in the rat brain, some activities with the major two peaks on the gel filtration column were found in the cytosolic fraction of the brain. Low molecular-weight form (PLAL) was active at neutral pH and absolutely required Ca^<2+> for its activity. In the reconstitution syste of partially purified PLAL and synaptosomal membranes from rat brain, PLAL associated with the membranes in a Ca^<2+>-dependent manner.4. Effect of PGE2 on the glutamate releaseBy using microdialysis technique, we investigated the effect of PGE2, whose receptor enriched in the hippocampus, on the release of glutamate which is considered to be major trigger for long-term potentiation in the hippocampus. PGE2 enhanced glutamate release in several portions of the brain.