去除感觉神经细胞体对突触长时程易化效应的影响

目的去除感觉神经细胞的体部,研究离体培养突触长时程易化效应的变化。方法体外培养多组由无脊椎海生动物海兔(Ap lysia)的感觉神经元(SN)和运动神经元(L7,MN)互相接触而形成的突触模型,培养到第4 d时,将部分感觉神经细胞体去除(SN/L7,-CB),其余仍保留细胞体部(SN/L7,+CB),应用5-HT处理上述突触模型,之后将处理后的模型继续培养,在此后24 h和48 h,分别检测去除和保留感觉神经细胞体突触模型的长时程易化(LTF)效应。结果在应用5-HT后24 h,去除胞体组突触的LTF明显高于保留胞体组;而在应用5-HT后48 h,去除细胞体组突触的LTF呈明显下降,与保留细胞体组无明显差异;应用5-HT后24 h和48 h保留感觉神经细胞体组突触的LTF水平无明显变化。结论去除感觉神经细胞体在较短的时程内(24 h)可以提高突触LTF表达水平,而这种高水平的LTF无法长时间维持(48 h),保留感觉神经细胞体突触的LTF在一定时程内(48 h)可以在一定水平上稳定表达。

Removal of Sensory Cell Body Enhances the Long-Term Facilitation at Isolated Synapses of Aplysia

Objective To study the effect of vemoval of sensony cell body on long-term facilitation(LTF) induced by 5-HT applicaion at isolated synapses of aplysia.Methods Culture model of isolated synapses was established by using sensory neuron and motor neuron(L7) of aplysia,when the isolated synaptic model was cultured up to 4 days,some sensory cell bodies were cut for experiment,and rest of the cell bodies without cutting for control.Then a EPSP of isolated synapses was determined,and 5-HT was applied to the cultures,the cultures were kept in same method immediately after 5-HT application.The LTF at isolated synapse was evoked separately 24h and 48h after 5-HT treatment.Result Compared with control group witout cutting of cell body,LTF at isolated synapses of cutting group increased significantly 24h after 5-HT application,but decreased significantly and rapidly 48h after 5-HT treatment.Conclusion Removing sensory cell body facilitates the LTF at isolated synapses significantly 24h after 5-HT application,and decreased rapidly 48h.