Kato K, Zorumski C F
Section of Neurosurgery, Yale University School of Medicine, New Haven CT 06520, USA.
J Lipid Mediat Cell Signal. 1996 Sep;14(1-3):341-8. doi: 10.1016/0929-7855(96)00543-3.
Previously the involvement of platelet-activating factor (PAF) as a retrograde messenger in the induction of long-term potentiation (LTP) in CA1 region of rat hippocampus has been reported (Kato, K. et al. (1994) Nature 367, 175-179). In this report, the effect of PAF receptor antagonist on LTP in the dentate gyrus has been demonstrated and suggests the existence of common mechanisms of LTP in Ca1 and dentate gyrus. The site responsible for the expression of LTP induced by PAF has also been examined. The frequency of miniature EPSCs were enhanced by application of a PAF analog, but median amplitude were unaffected, suggesting that PAF preferentially affects presynaptic sites. Evoked synaptic responses were also monitored and the potentiation by the PAF analog was observed. Interestingly, there is a discrepancy between the results observed in the miniature and evoked potential studies in terms of dose effect of PAF. This discrepancy could have resulted from repeated synaptic stimulations required for studying evoked responses. The requirement for a monitoring stimulation in the evoked response measurement could activate additional biological process that enhance LTP expression.
此前有报道称，血小板活化因子（PAF）作为逆行信使参与大鼠海马CA1区长期增强（LTP）的诱导（Kato, K.等人，（1994年）《自然》367卷，第175 - 179页）。在本报告中，已证明PAF受体拮抗剂对齿状回LTP的影响，并提示CA1区和齿状回中存在LTP的共同机制。还研究了PAF诱导LTP表达的位点。应用PAF类似物可增强微小兴奋性突触后电流（mEPSCs）的频率，但中位幅度不受影响，这表明PAF优先影响突触前位点。还监测了诱发的突触反应，并观察到PAF类似物的增强作用。有趣的是，在微小和诱发电位研究中观察到的结果在PAF的剂量效应方面存在差异。这种差异可能是由于研究诱发反应需要重复的突触刺激所致。在诱发反应测量中进行监测刺激的要求可能会激活额外的生物过程，从而增强LTP表达。
