Dopamine neurons in the SNc play a pivotal role in modulating motor behavior via striatum. Here, we show that the same dopamine neuron that targets striatum also sends a direct branch to the optic tectum (superior colliculus). Whenever SNc neurons are activated, both targets will therefore be affected. Visual stimuli (looming or bars) activate the dopamine neurons coding saliency and also elicit distinct motor responses mediated via tectum (eye, orienting or evasive), which are modulated by the dopamine input. Whole-cell recordings from tectal projection neurons and interneurons show that dopamine, released by SNc stimulation, increases or decreases the excitability depending on whether they express the dopamine D1 or the D2 receptor. SNc thus exerts its effects on the visuomotor system through a combined effect directly on tectum and also via striatum. This direct SNc modulation will occur regardless of striatum and represents a novel mode of motor control.

中文翻译：

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SNc的直接多巴胺能投射物调节七Lamp鳗在直肠中的可见运动转换。

SNc中的多巴胺神经元在通过纹状体调节运动行为中起关键作用。在这里，我们显示了以纹状体为靶标的同一多巴胺神经元也向视神经顶盖（上丘）发送了直接分支。每当SNc神经元被激活时，两个目标都将因此受到影响。视觉刺激（若隐若现或条形）激活编码显着性的多巴胺神经元，并引起由顶盖介导的不同运动反应（眼，定向或回避），这些反应由多巴胺输入调节。来自顶盖投射神经元和中间神经元的全细胞记录表明，由SNc刺激释放的多巴胺取决于其表达多巴胺D1或D2受体而增加或减少兴奋性。因此，SNc通过直接作用于皮层和纹状体的综合作用而对视运动系统产生作用。不管纹状体如何，都将发生这种直接的SNc调制，并且代表了一种新型的电机控制模式。