Suppression of sustained and transient ON signals of amacrine cells by GABA is mediated by different receptor subtypes  

作　　者：张道启 杨如 杨雄里 

出　　处：《Science China(Life Sciences)》1999年第4期395-400,共6页中国科学（生命科学英文版）

基　　金：Project supported by the State Commission of Science and Technology of China (Climbing Project);the National Natural Science Foundation of China (Grant Nos. 39670253 and 39770256);the National Research Center of Life Science of China (Shanghai)

摘　　要：Intracellular recordings were made from amacrine cells in the isolated, superfused carp retina, and the effects of γ-aminobutyric acid (GABA) on sustained and transient ON signals of these cells were studied. Exogenous GABA application partially suppressed the sustained response of ON amacrine cells, which could be completely reversed by picrotoxin (PTX), a chloride channel blocker, and by bicuculline (BCC), a specific GABA_A receptor antagonist. On the other hand, suppression by GABA of the ON response which was predominantly driven by rod signals in a certain portion of transient ON-OFF amacrine cells was completely blocked by PTX, but not by BCC, indicating that GABA_C receptors may be involved in the effect. These results suggest that GABA_A and GABA_C receptors may be respectively involved in mediating the transmission of sustained and transient signals in the carp inner retina.Intracellular recordings were made from amacrine cells in the isolated, superfused carp retina, and the effects of γ-aminobutyric acid (GABA) on sustained and transient ON signals of these cells were studied. Exogenous GA-BA application partially suppressed the sustained response of ON amacrine cells, which could be completely reversed by picrotoxin (PTX) , a chloride channel blocker, and by bicuculline (BCC) , a specific GABAA receptor antagonist. On the other hand, suppression by GABA of the ON response which was predominantly driven by rod signals in a certain portion of transient ON-OFF amacrine cells was completely blocked by PTX, but not by BCC, indicating that GABAC receptors may be involved in the effect. These results suggest that GABAA and GABAC receptors may be respectively involved in mediating the transmission of sustained and transient signals in the carp inner retina.

关 键 词：γ-aminobutyric acid (GABA ) GABAA RECEPTOR GABAc RECEPTOR SUSTAINED and transient SIGNALS CARP inner retina. 

分 类 号：Q42[生物学—神经生物学]