豚鼠离体腹腔神经节神经元自发f-EPSP和AP

Spontaneous Fast-excitatory Postsynaptic Potential and Action Potential in the Celiac Ganglion Neurons of Guinea-pig in Vitro

应用细胞内生物电记录技术观察豚鼠腹腔神经节(CG)神经元自发快兴奋性突触后电位(f-EPSP)和动作电位(AP)的特征,分析其形成的可能机制。发现在豚鼠离体CG上存在自发f-EPSP和AP,发放频率不同。自发f-EPSP的幅度(5.67±2.66)mV(n=26),明显低于刺激内脏大神经诱发f-EPSP的幅度(13.26±6.74)mV(n=34,P<0.01),而自发的AP后超极化幅度(AHPA)(13.86±4.24)mV(n=30),明显高于刺激内脏大神经诱发的AHPA(8.99±2.79)mV(n=54,P<0.01)。六烃季铵或低Ca2+/高Mg2+Krebs液能完全阻断自发的AP,但自发的f-EPSP则不被完全阻断。结果提示豚鼠离体CG神经元有自发性电活动,这除与突触前膜ACh的随机释放有关以外,可能还有对Ca2+不敏感的其他递质介导。

The in vitro spontaneous fast-excitatory postsynaptic potential（f-EPSP）and spontaneous action potential （AP） were recorded in the celiac ganglion （CG） neurons of Guinea-pig by the intracellular recording technique and the related possible mechanism was analyzed. The spontaneous f-EPSP and AP had different frequencies in the CG neurons. Amplitudes of f-EPSP （13.26± 6.74） mV（ n = 34） and spontaneous f-EPSP （5.67 ± 2.66）mV（ n = 26） were significantly different （P 〈 0.01 ）. Amplitudes of AHP （8.99 ± 2.79） mV（ n = 54）and spontaneous AHP （13.86 ± 4.24）mV（ n = 30） were also significantly different （P 〈 0.01 ）. Spontaneous AP could be blocked by hexamethonium or low Ca^2＋/high Mg^2 ＋ Krebs solution, whereas spontaneous f-EPSP could be partly blocked by the same treatment. The results indicate that spontaneous bioelectricity exists in isolated CG neurons, and this may be induced by ACh and other calcium-independent neurotransmitters.