Effects of the inhibitory pathway(s) on the dual-peak response in mouse retinal ganglion cells

【作者】 严汝佳； 张溥明； 梁培基；

【机构】 上海交通大学生物医学工程学院；

【摘要】 Objective Dual-peak response of retinal ganglion cells(RGCs)has been observed in mouse,and previous researches suggested that both response peaks were involved in retinal information coding.The underlying mechanism for the generation of the dual-peak response was suggested to involve inhibitory pathway(s).The present study is to investigate the possible contribution of the inhibitory input mediated by GABAergic and/or glycinergic pathway(s)to the dual-peak response pattern of mouse RGCs.Methods Mouse(between 2 and 3 months of age)retinal ganglion cells’firing activities were recorded using multi-electrode arrays.Visual stimulus was generated from a computer monitor and projected onto retina via a lens focus system.Stimulus consisting of full-field white light with duration of 1 s and dark interval of1 s was given repeatedly for 100 times.In pharmacological experiments,GABA(250μM),picrotoxin(40μM),glycine(100μM)and strychnine(5μM)were applied.Results(1)Exogenous GABA or glycine greatly suppressed or even eliminated the second peak of the cells’firing activities,while keeping the first peak basically unaltered.Co-application of glycine and GABA completely eliminated the second peak in the dual-peak responses recorded.(2)Application of picrotoxin or strychnine induced dual-peak responses in some cells with transient response by unmasking a second response phase.Conclusion The generations of the two response peaks in the dual-peak response involve separated mechanisms,and arise from distinct pathways and converge on the ganglion cells;both GABAergic and glycinergic pathway(s)are involved in mediating the properties of the dual-peak response of the mouse RGCs.更多还原

【Abstract】 Objective Dual-peak response of retinal ganglion cells(RGCs) has been observed in mouse,and previous researches suggested that both response peaks were involved in retinal information coding.The underlying mechanism for the generation of the dual-peak response was suggested to involve inhibitory pathway(s).The present study is to investigate the possible contribution of the inhibitory input mediated by GABAergic and/or glycinergic pathway(s) to the dual-peak response pattern of mouse RGCs.Methods Mouse(between 2 and 3 months of age) retinal ganglion cells’ firing activities were recorded using multi-electrode arrays.Visual stimulus was generated from a computer monitor and projected onto retina via a lens focus system.Stimulus consisting of full-field white light with duration of 1 s and dark interval of 1 s was given repeatedly for 100 times.In pharmacological experiments,GABA(250 μM),picrotoxin(40 μM),glycine(100 μM) and strychnine(5 μM) were applied.Results(1) Exogenous GABA or glycine greatly suppressed or even eliminated the second peak of the cells’ firing activities,while keeping the first peak basically unaltered.Co-application of glycine and GABA completely eliminated the second peak in the dual-peak responses recorded.(2) Application of picrotoxin or strychnine induced dual-peak responses in some cells with transient response by unmasking a second response phase.Conclusion The generations of the two response peaks in the dual-peak response involve separated mechanisms,and arise from distinct pathways and converge on the ganglion cells;both GABAergic and glycinergic pathway(s) are involved in mediating the properties of the dual-peak response of the mouse RGCs.更多还原