NMDA受体在海马CA3区习得性TP保持中的作用

The effect of microinjection of 2-amino-5-phosphonovaleric acid (APV), a selective NMDA receptor antagonist, into the rat hippocampal CA3 area on the synaptic efficacy and related conditioned behavior during the acquisition and consolidation of discrimination learning behavior was examined. The results showed: (1) After population spike (PS) amplitude had just increased to the maximum through training i.e. learning-dependent LTP had just formed, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block. The result demonstrated that the PS amplitude could not be maintained at the highest level but decreased to the pre-experiment level after 8 blocks. Correct response percentage of rats could not be consolidated with further training but decreased to less than 10%. (2) After the PS amplitude had kept up at the highest level, APV 1 microliter (2 mmol/L) was injected into CA3 area, then the rats were trained during the time of efficacy of the drug in every experimental block, in which case the PS amplitude also could not be maintained at the highest level but decreased to the pre-experiment level after 14 blocks. Correlatively, when the correct response percentage of rats decreased gradually to less than 10%, the conditioned response of the animals extinguished, but its extinction speed was slower than it was in result (1). These results suggest that the NMDA receptor in CA3 area plays an important role in the maintenance of the learning-dependent long-term potentiation.     

NMDA受体在海马CA_3区习得性LTP保持中的作用

在大鼠明暗分辨学习的建立和巩固过程中,通过与记录电极一起慢性埋植于海马CA_3区的注药管微量注射NMDA受体的特异性拮抗剂2-amino-5-phosphonovaleric acid(APV),观察对海马CA_3区突触效应及与之相关的习得性行为的影响。结果如下:(1)在动物经训练PS峰幅值刚增大至最高水平后,即在习得性LTP刚好形成后,每实验单元先于CA_3区注射AFV 1μl(2mmol/L),然后在药物有效作用时间内再进行训练,则PS峰值不能随训练而保持在最高水平,相反经8个实验单元,PS峰值降至实验前水平;相应地动物的正确反应率不能随训练而巩固,反而下降至10％以下。(2)在动物习得性LTP已形成并经一单元训练PS保持在最高水平后,于每实验单元训练前注射APV 1μl(2mmol/L),PS峰值同样不会随训练而保持在最高水平,经14个实验单元注药和训练,PS峰值逐渐降至实验前水平,相应地动物行为的正确反应率也降至10％以下,习得性行为消退,不过其消退速度比前一情况的动物为慢,说明习得性LTP发展情况不同,APV的作用效率有差别。结果表明:NMDA受体在习得性LTP的巩固中起着重要作用。     

芦苇苗期高粱长蝽若虫空间分布型及抽样技术

<正> 高梁长蝽Dimorphopterus spinolae(Si-gnoret)是湘鄂两省湖区重要的芦苇害虫,以芦苇苗期受害最烈,长势衰弱,枯黄死亡,对苇株生长和产量都有严重影响。空间分布型可以     

以突触前排放的消失设定海马脑片缺氧损伤时间及应用实例

刺激Schaffer侧支,记录大鼠海马脑片CA_1区的突触前排放(presynaptic volley,PV)和突触后群锋电位(population spikes,PS),观察缺氧后PS和PV的变化及复氧30min后脑片PS的恢复,缺氧持续到PV消失1,2,3或4min,复氧后脑片恢复率分别为100％,11.5％,0％,0％。可见,缺氧后 PV 消失2min为损伤的关键时刻。提前1min终止缺氧,全部脑片的PS可以恢复,延迟1min终止缺氧,则全部脑片的PS不能恢复。这种方法是根据每个脑片的电反应确定其总的缺氧时间,故每个脑片的缺氧时间略有变动。与每次采用相同缺氧时间的传统方法相比,此方法脑片恢复率的稳定性与重复性均较好。用此方法发现美西律10和100μmol/L能增加复氧后PS恢复率,对突触功能的缺氧损伤具有保护作用。     

立地性日照长短与甜橙生长发育的相关性

甜橙[Citrus sinensis(L.)Osbesk,本文中均指雪柑(Citrus sinensis var.sekkan)]对日照的需要量,比温州蜜柑(Citrus reticulata var.unshiu)等桔类要少些,即温州蜜柑比甜橙和杂柑类的耐荫性稍弱。然而,究竟可少到什么临界值呢?同一果园,同一管理水平,同一树龄,由于坡向、地形等的不同,而     

慢性粒细胞白血病细胞选择性培养和净化

近年来,随着体外净化方法的不断发展和完善,以及家庭的日益小型化,使得自体骨髓移植在治疗急性白血病方面越来越受到重视。但对慢性粒细胞性白血病(CML)至今仍未找到理想的净化骨髓的方法,从而使自体骨髓移植在CML中的应用受到很大的限制。 CML是起源于多能干细胞的肿瘤性疾病,疾病的发生、发展、转归、细胞生物学及分子生物学变化     

水葫芦对含氰废水的净化、抗性及生理反应的初步研究

经水葫芦对含氰(CN~-)模拟废水的净化、抗性及生理反应的研究表明,水葫芦对含CN~-废水不仅具有显著的净化作用,且具有较高的抗性,但是当CN~-浓度达到5mg/L时,将开始危害水葫芦的正常生长。