Nemargut Joseph P, Zhu Junling, Savoie Brian T, Wang Guo-Yong
Department of Structural and Cellular Biology, School of Medicine, Tulane University, New Orleans, LA 70112, USA.
Vision Res. 2009 Feb;49(3):388-97. doi: 10.1016/j.visres.2008.11.008. Epub 2008 Dec 30.
Patch-clamp recordings were made from retinal ganglion cells in the mouse retina. Under dark adaptation, blockage of BK(Ca) channels increases the spontaneous excitatory postsynaptic currents (EPSCs) and light-evoked On-EPSCs, while it decreases the light-evoked Off inhibitory postsynaptic currents (IPSCs). However, under light adaptation it decreases the light-evoked On-EPSCs, the spontaneous IPSCs and the light-evoked On- and Off-IPSCs. Blockage of BK(Ca) channels significantly altered the outputs of RGCs by changing their light-evoked responses into a bursting pattern and increasing the light-evoked depolarization of the membrane potentials, while it did not significantly change the peak firing rates of light-evoked responses.
在小鼠视网膜的视网膜神经节细胞上进行了膜片钳记录。在暗适应条件下，BK（Ca）通道的阻断增加了自发兴奋性突触后电流（EPSC）和光诱发的开反应EPSC，同时减少了光诱发的关反应抑制性突触后电流（IPSC）。然而，在光适应条件下，它减少了光诱发的开反应EPSC、自发IPSC以及光诱发的开反应和关反应IPSC。BK（Ca）通道的阻断通过将光诱发反应转变为爆发模式并增加光诱发的膜电位去极化，显著改变了视网膜神经节细胞的输出，而它并未显著改变光诱发反应的峰值放电频率。
