大鼠海马齿状回外侧支的再可塑性  

Metaplasticity in the Perforant Path of Hippocampal Slice in Rats

作　　者：张炼[1] 肖鸿美[2] 周艳霞[1] 罗小平[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院儿科,武汉430030 [2]华中科技大学同济医学院基础医学院生理学系,武汉430030

出　　处：《华中科技大学学报（医学版）》2007年第4期500-503,共4页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

摘　　要：目的中枢神经系统呈现长时程增强(LTP)和长时程抑制(LTD)的能力与其早期的突触活性有关,这种更高形式的可塑性称为再可塑性。探究预先刺激是否对齿状回外侧支的突触可塑性产生调节。方法用各种预先刺激和条件刺激对脑切片的场电位进行记录。结果不影响基本突触传递的10 Hz预先刺激能使外侧支随后的LTP明显减弱,而不影响LTD。这种作用在体外能维持2 h以上。当预先刺激作用于苔状纤维进行反向刺激时,外侧支的LTP也被抑制。结论在生理条件下常见的10 Hz预先刺激能导致长时间的LTP而非LTD减弱。这种形式的再可塑性有助于深入了解齿状回突触活动调节的复杂性。Objective To examine the plasticity and metaplasticity in the lateral perforant path of rats. Methods Field potential was measured with different priming and conditioning stimulation protocols. Results Ten-Hz priming, which does not affect basal synaptic transmission, caused a dramatic reduction in subsequent long term potentiation （LTP） at lateral perforant path synapses in vitro, and the reduced LTP lasted for at least 2 h. The long term depression （LTD） was unaffected. The reduction of LTP in the lateral perforant path was also readily induced by applying priming antidromically at the mossy fibers. Conclusion Priming with 10 Hz, which is within a frequency range observed during physiological activity, can cause potent, long-lasting inhibition of LTP, but not LTD. This form of metaplasticity adds a layer of complexity to the activity-dependent modification of synapses within the dentate gyrus.

关 键 词：海马 突触可塑性 预先刺激 

分 类 号：R238.2[医药卫生—中医学]