ON-pathway-dominant glycinergic regulation of cholinergic amacrine cells in the mouse retina
ON-pathway-dominant glycinergic regulation of cholinergic amacrine cells in the mouse retina
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DOI：
10.1113/jphysiol.2014.271148
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发表时间：
2014-10-01
影响因子：
5.5
通讯作者：
Kaneda, Makoto
中科院分区：
文献类型：
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作者：
Ishii, Toshiyuki;Kaneda, Makoto
视网膜的方向选择性作为神经回路树突计算的模型已经被研究。星爆无长突细胞（SACs）已被视为树突计算的模型系统，因为它们在方向选择性的形成中起着关键作用。由于视网膜内解剖位置的差异使ON-SAC成为更容易记录的目标，因此ON-SAC的生物物理特性已被用于预测OFF-SAC的生物物理特性。在这项研究中，我们系统地比较了两个主要的神经递质，甘氨酸和谷氨酸的ON和OFF-SAC的反应。我们发现，甘氨酸的反应显着大于在ON-SAC比OFF-SAC。相比之下，ON-和OFF-SAC对谷氨酸的反应相似。在ON-SACs的甘氨酸反应的幅度增加后，眼睛睁开，并观察到在出生后第28天的最大幅度。另一方面，直到出生后第28天才观察到OFF-SAC中甘氨酸反应幅度的增加。甘氨酸诱发的电流被抑制士的宁的应用。谷氨酸诱发的电流模拟AMPA或红藻氨酸的应用程序，并观察到的N-甲基-D-天冬氨酸的Mg 2+块的情况下的反应。谷氨酸诱发的电流产生的GABA能抑制性突触后电流的频率增加。我们的研究结果表明，在ON-SAC的信号处理不能直接用于理解OFF-SAC的属性。因此，完全定义OFF-SAC的生理特性对于理解和建模视网膜中的方向选择性至关重要。
Direction selectivity in the retina has been studied as a model of dendritic computation of neural circuits. Starburst amacrine cells (SACs) have been examined as a model system of dendritic computation as they play a pivotal role in the formation of direction selectivity. Because the difference of anatomical location inside the retina made ON-SACs an easier target to record, the biophysical properties of ON-SACs have been used to predict those of OFF-SACs. In this study, we systematically compared the responses of ON-and OFF-SACs to the two principal neurotransmitters, glycine and glutamate. We found that responses to glycine were significantly larger in ON-SACs than in OFF-SACs. In contrast, ON-and OFF-SACs responded similarly to glutamate. The amplitude of glycine responses in ON-SACs increased after eye opening and the largest amplitude was observed at postnatal day 28. On the other hand, no increase in the amplitude of glycine responses in OFF-SACs was observed until postnatal day 28. Glycine-evoked currents were inhibited by the application of strychnine. Glutamate-evoked currents were mimicked by the application of AMPA or kainite, and responses to N-methyl-D-aspartate were observed in the absence of Mg2+ block. Glutamate-evoked currents produced an increase in the frequency of GABAergic inhibitory postsynaptic currents. Our results suggest that signal processing in ON-SACs cannot be directly used to understand the properties of OFF-SACs. Therefore fully defining the physiological properties of OFF-SACs will be critical to understanding and modelling direction selectivity in the retina.