头孢呋辛钠影响幼鼠平行纤维-浦肯野细胞的突触可塑性

Influence of cefuroxime sodium on synaptic plasticity of parallel fiber-Purkinje cells in young rats

摘要:

目的 探讨头孢呋辛钠(CS)对Sprague-Dawley(SD)大鼠小脑浦肯野细胞(PCs)电生理功能的影响。方法 将7 d龄(P7)SD大鼠分为早期用药Ⅰ组、Ⅱ组(P7~P14给药)和晚期用药组(P14~P21给药),均腹腔注射CS;以及早期用药对照组和晚期用药对照组,腹腔注射等容积的生理盐水(NS)。每组均10只。早期用药Ⅰ组及早期对照组于P15处死,早期用药Ⅱ组、晚期用药及晚期对照组于P22处死。采用全细胞膜片钳记录法,在小脑脑片上记录PCs的内向电流和动作电位,以及低频刺激平行纤维(PF)诱发的PCs兴奋性突触后电流(EPSC)的长时程抑制(LTD)现象。结果 早期用药组和晚期用药组PCs内向电流幅值和动作电位峰值均略大于相应对照组,差异无统计学意义 (P > 0.05);用药组的EPSC抑制程度均大于对照组 (P < 0.01),但早期用药Ⅱ组的抑制程度较晚期用药组更大 (P < 0.01)。结论 生后早期CS暴露影响幼鼠小脑平行纤维PC 的突触可塑性,这种影响在停药后仍持续存在。

Abstract:

Objective To investigate the influence of cefuroxime sodium (CS) on the electrophysiological function of cerebellar Purkinje cells (PCs) in Sprague-Dawley rats. Methods Postnatal day 7 (P7) Sprague-Dawley rats were divided into early administration I and II groups (administered from P7 to P14) and late administration group (administered from P14 to P21), and all the groups received intraperitoneally injected CS. The control groups for early and late administration groups were also established and treated with intraperitoneally injected normal saline of the same volume. There were 10 rats in each group. The rats in the early administration I group and early administration control group were sacrificed on P15, and those in the early administration II group, late administration group, and late administration control group were sacrificed on P22. The whole-cell patch-clamp technique was used to record inward current and action potential of PCs on cerebellar slices, as well as the long-term depression (LTD) of excitatory postsynaptic current (EPSC) in PCs induced by low-frequency stimulation of parallel fiber (PF). Results Compared with the control groups, the early and late administration groups had a slightly higher magnitude of inward current and a slightly higher amplitude of action potential of PCs (P > 0.05). All administration groups had a significantly higher degree of EPSC inhibition than the control groups (P < 0.01), and the early administration II group had a significantly greater degree of EPSC inhibition than the late administration group (P < 0.01). Conclusions Early CS exposure after birth affects the synaptic plasticity of PF-PCs in the cerebellum of young rats, which persists after drug withdrawal.