Control of dopamine release in the retina: A transgenic approach to neural networks
Control of dopamine release in the retina: A transgenic approach to neural networks
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DOI：
10.1016/s0896-6273(00)80313-x
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发表时间：
1997-05-01
期刊：
影响因子：
16.2
通讯作者：
Raviola, E
中科院分区：
文献类型：
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作者：
Gustincich, S;Feigenspan, A;Raviola, E
多巴胺能，interplexiform无长突（DA细胞）标记的转基因小鼠与人类胎盘碱性磷酸酶，一种酶，驻留在细胞膜的外表面。因此，有可能在视网膜分离后，用全细胞电流和电压钳，以及在完整的视网膜与电子显微镜的连接，在体外研究他们的活动。DA细胞即使在没有突触输入的情况下也能产生动作电位。这种活性被无长突细胞递质GABA和甘氨酸消除，它们诱导由氯离子携带的内向电流，并被红藻氨酸刺激，红藻氨酸是双极细胞递质谷氨酸受体的激动剂，它打开非选择性阳离子通道。由于DA细胞是突触后的无长突和双极细胞，我们认为，DA细胞的自发放电被抑制在黑暗中的GABA能无长突，收到他们的输入从关闭双极。在照明时，GABA抑制被去除，DA细胞产生动作电位，并且它们的放电由从非双极接收的激发来调制。
Dopaminergic, interplexiform amacrines (DA cells) were labeled in transgenic mice with human placental alkaline phosphatase, an enzyme that resides on the outer surface of the cell membrane. It was therefore possible to investigate their activity in vitro after dissociation of the retina with whole-cell current and voltage clamp, as well as their connections in the intact retina with the electron microscope. DA cells generate action potentials even in the absence of synaptic inputs. This activity is abolished by the amacrine cell transmitters GABA and glycine, which induce an inward current carried by chloride ions, and is stimulated by kainate, an agonist at the receptor for the bipolar cell transmitter glutamate, which opens nonselective cation channels. Since DA cells are postsynaptic to amacrine and bipolar cells, we suggest that the spontaneous discharge of DA cells is inhibited in the dark by GABAergic amacrines that receive their input from off-bipolars. Upon illumination, the GABA-inhibition is removed, DA cells generate action potentials, and their firing is modulated by the excitation received from on-bipolars.