PAF受体在铝抑制海马CA3区长时程增强中的作用

INFLUENCE OF PAF RECEPTORS ON LONG TERM POTENTIATION ATTENUATED BY ALUMINIUM IN HIPPOCAMPAL CA3 AREA OF RATS

目的 :观察PAF受体在铝抑制海马CA3区长时程增强 (longtermpotentiation ,LTP)中的作用。 方法 :应用细胞外电生理记录方法 ,通过向海马CA3区分别微量注射血小板活化因子 (PlateletactivatingfactorPAF)受体拮抗剂银杏内酯B(GinkgolideB)和激动剂mc PAF ,以群体锋电位 (populationspikesPS)幅度为指标 ,观察PP CA3通路的LTP变化。结果 :① 0 .2 μmol/L的银杏内酯B对CA3区的诱发电位无影响 ,但可抑制CA3区的LTP。② 0 .2 5mol/L的三氯化铝不影响CA3区LTP ,但可加强银杏内酯B的抑制作用。③ 4 0 μmol/Lmc PAF对强直刺激引起的LTP无影响 ,却可减轻 0 .5mol/L三氯化铝的对LTP的抑制作用。结论 :PAF受体在刺激PP诱发的CA3区LTP中起作用 ,而金属铝对CA3区LTP的抑制作用至少部分与PAF受体有关。

Aim: To investigate the influence of platelet-activating factor(PAF) receptor on long-term potentiation(LTP) attenuated by aluminium. Methods: The method of extracellular recording was used to investigate the effect of PAF receptors on PP-CA3 LTP by microinjection of PAF receptor antagonist Ginkgolide B or agonist mc-PAF into CA3 area. Results: ① Amplitude of population spikes(PS) of evoked potential was not affected but LTP induction was blocked by 0.2 μmol/L ginkgolide B in CA3 area. ② LTP induction was not influenced by 0.25 mol/L aluminium chloride, however, it could be blocked when aluminium was coapplicated with ginkgolide B. ③ LTP induction was influenced slightly by 40 μmol/L mc-PAF but it has no difference in statistic. LTP induction could be blocked completely by 0.5 mol/L aluminium, but when aluminium was coapplicated with mc-PAF, this effect could be relieved. Conclusion: These results indicate that PAF receptors are involved in induction of LTP in CA3 area by stimulating perforant path. The inhibitory effect of aluminium on LTP is partly related to PAF receptors.