Smith S J, Augustine G J, Charlton M P
Proc Natl Acad Sci U S A. 1985 Jan;82(2):622-5. doi: 10.1073/pnas.82.2.622.
Synaptic transmission was studied at the squid giant synapse with voltage clamp control of both presynaptic and postsynaptic cells. Because presynaptic voltage gradients can complicate interpretation of electrophysiological data obtained from this preparation, we used local Ca application to restrict Ca influx and transmitter release to a short and relatively isopotential portion of the elongated presynaptic terminal. Under these conditions, we found that postsynaptic current varies approximately as the third power of presynaptic Ca current. This finding is consistent with the hypothesis that several Ca ions cooperate in triggering secretion of a single transmitter quantum.
在乌贼巨大突触处,利用对突触前和突触后细胞的电压钳控制来研究突触传递。由于突触前电压梯度会使从该标本获得的电生理数据的解释变得复杂,我们采用局部施加钙离子的方法,将钙离子内流和递质释放限制在细长突触前终末的一个短且相对等电位的部分。在这些条件下,我们发现突触后电流大致随突触前钙电流的三次方变化。这一发现与几个钙离子协同触发单个递质量子分泌的假说相一致。