体外青蛙小脑兴奋性化学突触传递的钙依赖性

Calcium dependency of excitatory chemical synaptic transmission in the frog cerebellum in vitro.

作者信息

Hackett J T

出版信息

Brain Res. 1976 Sep 10;114(1):35-46. doi: 10.1016/0006-8993(76)91005-2.

Abstract

Chemical synaptic transmission was studied with microelectrode techniques in isolated frog cerebella maintained in vitro. Purkinje cell (PC) EPSPs, elicited by selective monosynaptic electrical stimulation of both the parallel fiber (PF) and climbing fiber (CF) inputs, could be inverted by depolarizing (outward) current injections. Evoked synaptic transmission at both junctions was reduced by lowering the extracellular concentration of calcium ions ([Ca2+]) below 2 mM. Raising [Ca2+] above 2 mM to 8 mM did not further increase synaptic transmission. Mg2+, Sr2+, and Ba2+ did not substitute for Ca2+ in the transmission process.

摘要

采用微电极技术，在体外培养的离体青蛙小脑中研究化学突触传递。通过对平行纤维（PF）和攀缘纤维（CF）输入进行选择性单突触电刺激诱发的浦肯野细胞（PC）兴奋性突触后电位（EPSP），可通过去极化（外向）电流注入使其反转。通过将细胞外钙离子浓度（[Ca2+]）降低至2 mM以下，两个连接处的诱发突触传递均降低。将[Ca2+]提高至2 mM以上至8 mM并未进一步增加突触传递。Mg2+、Sr2+和Ba2+在传递过程中不能替代Ca2+。