葡萄糖浓度降低对幼龄鼠及成年鼠海马长时程增强的影响

Effects of low-glucose on long-term potentiation in the hippocampal slices of immature and adult rats

目的 :观察葡萄糖浓度降低对幼龄鼠 1 5 - 1 6日龄及成年鼠 56 - 63日龄海马CA1区长时程增强(LTP)诱发的影响。方法 :采用脑片灌流及电生理学技术 ,以场兴奋性突触后电位的初始斜率 (S -EPSP)为观测指标。结果 :当将灌流液中葡萄糖浓度降为 3或 1 5mmol/L时 ,S -EPSP显著减小。在葡萄糖浓度为 3或 1 5mmol/L的介质中 ,以高频刺激 (HFS)作用于成年鼠脑片仅出现短时程增强反应 ;但在葡萄糖浓度为 3mmol/L的介质中 ,HFS仍可在幼龄鼠脑片上诱导出LTP。结论 :低糖可使突触的传递活动减弱 ;在突触可塑性方面 ,幼龄鼠对低糖的耐受性要强于成年鼠。

AIM: The effects of low-glucose on long-term potentiation (LTP) in the CA1 region of hippocapal slices of immature (15-16 days old) and adult (56-63 days old) rats were examined. METHODS: The technique of electrophysiology was used, and the slopes of the field excitatory postsynaptic potentials (S-EPSP) were measured. RESULTS: When slices were exposed to glucose medium at concentrations of 3 or 1.5 mmol/L, S-EPSP decreased significantly. In the slices from adult rats, only short-term potentiation was elicited by high frequency stimulation in the medium of 3 or 1.5 mmol/L glucose. However, in the slices from immature rats, LTP was still induced in the medium of 3 mmol/L glucose. CONCLUSION: Low-glucose medium depressed the synaptic transmission. In terms of the synaptic plasticity, the low-glucose endurance in immature rats was stronger than that in adult rats.