大鼠内侧隔核对齿状回习得性LTP的调制

The Modulation of Medial Septal Nucleus on Learning-Dependent Long-Term Potentiation in The Rat Dentate Gyrus

摘要: 本工作观察到高频刺激(High-frequency stimulation，HFS)自由活动的大鼠内侧隔核(Medial Septal nucleus，MS)，对海马齿状回(dentate gyrus，DG)的群体峰电位(Population spike，PS)有一时性(1-2 h)的抑制作用。在明暗辨别学习中每次训练作业后立即给予MS HFS，导致DG习得性长时程增强，(Long-term potentiation，LTP)的形成显著延缓，并且PS峰值增强的最高水平显著降低(P<0.001)，辨别反应的习得相应延迟，但对DG习得性LTP的保持无影响。表明MS对DG习得性LTP的形成有抑制性作用。提示这可能是隔区参与学习和记忆的机制之一。

Abstract: Population Spike (PS) elicited by perforant path stimulation in the dentate gyrus (DG) of freely moving rats was recorded.Rats were trained on discrimination learning.The results were as follows:(1)High-frequency stimulation (HFS) of the medial septal nucleus (MS) temporarily caused a suppression of PS in DG;(2) HFS of MS following daily training session caused a significant suppression of the development of learning-dependent long-term potentiation (LDLTP),and correspondingly,a prevention of the acquisition of discriminative responding;(3)HFS of MS resulted in a significant decrease (P<0.01) of the maximal level of the potentiation of PS amplitude.These results suggest that MS exerts an inhibitory modulated effects on LDLTP in DG,which mainly affects the development of LDLTP.