Multiple cone pathways are involved in photic regulation of retinal dopamine.
Multiple cone pathways are involved in photic regulation of retinal dopamine.
复制标题
多个视锥细胞通路参与视网膜多巴胺的光调节
DOI：
10.1038/srep28916
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发表时间：
2016-06-30
影响因子：
4.6
通讯作者：
Zhang DQ
中科院分区：
文献类型：
--
作者：
Qiao SN;Zhang Z;Ribelayga CP;Zhong YM;Zhang DQ
多巴胺是视网膜中的一种关键神经递质，在视觉系统的光适应过程中发挥着核心作用。视网膜多巴胺的唯一来源是多巴胺能无长突细胞（DAC）。我们和其他人之前已经证明，DAC 在光照下被视杆细胞、视锥细胞和固有光敏视网膜神经节细胞 (ipRGC) 激活。然而，目前尚不清楚每一类光敏细胞如何在 DAC 中产生光响应。我们对小鼠的视锥细胞功能进行了基因分离，以专门检查 DAC 及其神经通路的视锥细胞介导的反应。除了已报道的光增量 (ON) 双极细胞对 DAC 的兴奋性输入外，我们还发现视锥细胞通过 ipRGC 的逆行信号通路向 DAC 发送信号。视锥细胞还在 DAC 中产生 ON 和光减 (OFF) 抑制反应，这些反应由其他无长突细胞介导，可能分别由 1 型和 2/3a 型 OFF 双极细胞驱动。染料注射表明 DAC 具有相似的形态特征，有或没有 ON/OFF 抑制。我们的数据表明，视锥细胞利用特定的并行兴奋和抑制电路来调节 DAC 活性，并有效调节多巴胺释放和视网膜的光适应状态。
Dopamine is a key neurotransmitter in the retina and plays a central role in the light adaptive processes of the visual system. The sole source of retinal dopamine is dopaminergic amacrine cells (DACs). We and others have previously demonstrated that DACs are activated by rods, cones and intrinsically photosensitive retinal ganglion cells (ipRGCs) upon illumination. However, it is still not clear how each class of photosensitive cells generates light responses in DACs. We genetically isolated cone function in mice to specifically examine the cone-mediated responses of DACs and their neural pathways. In addition to the reported excitatory input to DACs from light-increment (ON) bipolar cells, we found that cones alternatively signal to DACs via a retrograde signalling pathway from ipRGCs. Cones also produce ON and light-decrement (OFF) inhibitory responses in DACs, which are mediated by other amacrine cells, likely driven by type 1 and type 2/3a OFF bipolar cells, respectively. Dye injections indicated that DACs had similar morphological profiles with or without ON/OFF inhibition. Our data demonstrate that cones utilize specific parallel excitatory and inhibitory circuits to modulate DAC activity and efficiently regulate dopamine release and the light-adaptive state of the retina.