Luo Dong Gen, Yang Xiong Li
Institute of Neurobiology, Fudan University, 220 Han-Dan Road, 200433, Shanghai, China.
Brain Res. 2002 Dec 20;958(1):222-6. doi: 10.1016/s0006-8993(02)03598-9.
Modulation by Zn(2+) of ON and OFF responses of transient amacrine cells driven by red- and green-sensitive cones was investigated in isolated, superfused carp retina, using intracellular recording techniques. Zn(2+) selectively abolished the OFF response to red flash of the transient amacrine cells. This Zn(2+) effect was mimicked by GABA application and was blocked by bicuculline, indicating the involvement of GABA(A) receptors. Such differential modulation was observable neither in bipolar cells nor in sustained OFF amacrine cells. It is suggested that the Zn(2+) effect reported here might be due to a direct action of Zn(2+) on GABA(A) receptors of the transient amacrine cells.
利用细胞内记录技术，在分离的、经灌流的鲤鱼视网膜中，研究了锌离子（Zn(2+)）对由红敏和绿敏视锥细胞驱动的瞬态无长突细胞的开反应和关反应的调节作用。锌离子选择性地消除了瞬态无长突细胞对红色闪光的关反应。这种锌离子效应可被应用γ-氨基丁酸（GABA）模拟，并被荷包牡丹碱阻断，表明γ-氨基丁酸A（GABA(A)）受体参与其中。在双极细胞和持续型关无长突细胞中均未观察到这种差异调节。提示此处报道的锌离子效应可能是由于锌离子对瞬态无长突细胞的GABA(A)受体的直接作用。
