Hasuo H, Akasu T
Department of Physiology, Kurume University School of Medicine, Japan.
Pflugers Arch. 1988 Dec;413(2):206-8. doi: 10.1007/BF00582532.
Intracellular recordings were made from sympathetic B neurons to investigate an interaction between peptidergic and cholinergic responses in bullfrog sympathetic ganglia. Simultaneous stimulations of 3rd-5th and 8th spinal nerves evoked the fast excitatory postsynaptic potential (EPSP) superimposed with the late slow EPSP at the same sympathetic neuron. The amplitude of fast EPSPs was reduced during the course of the late slow EPSP in a majority of sympathetic neurons. A nicotinic depolarization produced by an ionophoretic application of ACh (ACh potential) was not significantly affected during the late slow EPSP. The quantal content of the fast EPSP calculated by the variance method was depressed during the late slow EPSP. Luteinizing hormone-releasing hormone (LH-RH), a putative transmitter for the late slow EPSP decreased the amplitude and the quantal content of the fast EPSP. [D-Phe2,6, Pro3]-LH-RH, and [D-pGlu1, D-Phe2, D-Trp3,6]-LH-RH, antagonists for LH-RH receptors prevented the inhibition of the fast EPSP induced by the late slow EPSP and LH-RH. These results suggest that cholinergic nicotinic transmission is inhibited during the late slow EPSP by a decreased ACh-release from nerve terminals in bullfrog sympathetic ganglia.
通过对交感神经B神经元进行细胞内记录，以研究牛蛙交感神经节中肽能反应与胆碱能反应之间的相互作用。同时刺激第3 - 5对和第8对脊神经，在同一个交感神经元上诱发了快速兴奋性突触后电位（EPSP）叠加晚期缓慢EPSP。在大多数交感神经元中，快速EPSP的幅度在晚期缓慢EPSP过程中降低。离子电泳施加乙酰胆碱（ACh）产生的烟碱样去极化（ACh电位）在晚期缓慢EPSP期间没有受到显著影响。通过方差法计算的快速EPSP的量子含量在晚期缓慢EPSP期间降低。促黄体生成素释放激素（LH - RH），一种假定的晚期缓慢EPSP的递质，降低了快速EPSP的幅度和量子含量。LH - RH受体拮抗剂[D - Phe2,6, Pro3] - LH - RH和[D - pGlu1, D - Phe2, D - Trp3,6] - LH - RH可阻止晚期缓慢EPSP和LH - RH诱导的快速EPSP的抑制。这些结果表明，在牛蛙交感神经节中，晚期缓慢EPSP期间胆碱能烟碱样传递因神经末梢ACh释放减少而受到抑制。
