神经肽Y对海马神经元“癫痫样”动作电位的影响

目的探讨神经肽Y(neuropeptide Y,NPY)对海马神经元"癫痫样"动作电位的影响。方法用无镁细胞外液处理原代培养12 d的海马神经元3 h,诱导海马神经元癫痫样放电,建立海马神经元癫痫样放电模型;用全细胞膜片钳电流钳模式检测神经元动作电位,分别给予0.1μmol/L和1μmol/L NPY各1μL,给药时间10 s,观察其对神经元动作电位频率及波幅的影响。结果无镁细胞外液处理神经元3 h,可以形成稳定的海马神经元癫痫样放电模型,频率16～23 Hz,波幅75～96 mV。模型组神经元动作电位频率为(18.00±2.32)Hz,而0.1μmol/L和1μmol/L NPY组分别为(4.75±1.04)Hz和(1.50±0.75)Hz。与模型组相比较,两种浓度NPY组均降低了动作电位发放的频率(P<0.05)。模型组神经元动作电位波幅为(82.25±5.17)mV,而0.1μmol/L和1μmol/L NPY组分别为(49.75±2.49)mV和(40.00±2.20)mV。与模型组相比较,两种浓度NPY组均降低了动作电位发放的波幅(P<0.05)。两种浓度NPY之间相比较,也有统计学差异(P<0.05)。1μmol/LNPY明显抑制了动作电位发放的频率和波幅。结论 NPY能够抑制无镁细胞外液诱发的神经元癫痫样电活动,为应用NPY抑制癫痫发作提供了细胞电生理学证据。

The expression of neuropeptide Y on action potential in hippocampal epileptic neurons

Objective To investigate the effects of NPY on action potential of the hippocampal epileptic neurons in rats.Methods E12 rat primary hippocampal neurons were exposed to magnesium-free solution for 3 h to establish the model of "epileptic neuron.Whole cell current clamp was used to detect action potentials of the hippocampal epileptic neurons.The frequency and amplitude of neuronal action potential were recorded following treatment with 0.1 μM and 1 μM NPY for 10 s.Results A stable model of epileptiform discharges at frequency 16 ～ 23 Hz and amplitude 75 ～ 96 mV was successfully created by exposure of the hippocampal neurons to magnesium-free extracellular fluid for 3 h.The frequency of action potential was 18.00±2.32 Hz in the model group,4.75±1.04 Hz in the 0.1μmol/L NPY group and 1.50±0.75 Hz in the 1μmol/L NPY group,respectively.Compared with the model group,the frequency of action potential was significantly decreased in both NPY groups(P<0.05).The amplitude of action potential in the model group was 82.25±5.17 mV in the model group,49.75±2.49 mV in the 0.1 μmol/L NPY group and 40.00±2.20 mV in the 1 μmol/L NPY group,respectively.Compared with the model group,the amplitude of action potential was significantly decreased in both NPY groups(P<0.05).The inhibitory effects on the frequency and amplitude of action potential were more pronounced in 1 μmol/L NPY group than in 0.1 μmol/L NPY group(P<0.05).Conclusion NPY can inhibit neuronal epileptiform activity induced by magnesium-free extracellular solution,which provides evidence of cell electrophysiology for NPY application in treatment of seizures.