产前应激对子代大鼠海马CA3区神经元高电压激活Ca^(2+)通道动力学特征的影响

Effects of prenatal stress on kinetic properties of high-voltage-activated Ca^(2+) channel in freshly isolated offspring rat hippocampal CA3 pyramidal neurons

目的探讨产前应激对子代大鼠海马CA3神经元高电压激活(HVA)钙通道动力学特征的影响。方法给予孕鼠束缚应激,急性分离子代海马CA3神经元,应用全细胞膜片钳技术,研究产前应激对子代大鼠海马CA3区神经元高电压激活Ca2+通道的影响。结果产前应激增加了子代海马CA3神经元高电压激活钙电流幅值、电流面积,而未改变其电导-电压关系、稳态失活动力学、时间到峰等指标。对照组和产前应激组子代海马CA3神经元高电压激活最大钙电流幅值分别为(-40.89±0.31)pA/pF和(-49.44±0.37)pA/pF(P<0.01)。最大电流面积分别为(106.81±4.20)nA*ms和(133.49±2.59)nA*ms(P<0.01)。结论在胎儿发育的关键时期,给予母体应激,对子代海马神经元离子通道产生持续的影响。

Objective To investigate the effects of prenatal stress （PNS） on kinetic properties of high-voltage-activated （HVA） Ca^2＋ channel in freshly isolated offspring rat hippocampal CA3 pyramidal neurons, Methods The pregnant rats were exposed to restraint stress, and the hippocampal CA3 pyramidal neurons were freshly isolated from the offspring rats to record voltage-gate Ca^2＋ channel currents in these neurons using whole-cell configuration of patch-clamp technique. Results PNS significantly increased HVA calcium current density and integral current but did not alter the steady-state activation and steady-state inactivation properties of HVA Ca^2＋ channel in the offspring rat CA3 neurons.. The maximal HVA calcium current density was -40.89±0.31 pA/pF in the control group （n=10） and -49.44±0.37 pA/pF in PNS group （tF8, P〈0.01）. The maximal integral current of the HVA Ca^2＋ channel was 106.81±4.20 hA＊ms in the control group （n=10） and 133.49±2.59 nA＊ms in the PNS group （n=8, P〈0.01）. Conclusion Maternal exposure to stress during the critical phase of pregnancy may result in long-lasting effects on the ion channels of the hippocampal neurons in the offspring rats.