Mesolimbic dopamine activity occasionally exhibits ramping dynamics, reigniting debate on theories of dopamine signaling. This debate is ongoing partly because the experimental conditions under which dopamine ramps emerge remain poorly understood. Here, we show that during Pavlovian and instrumental conditioning, mesolimbic dopamine ramps are only observed when the inter-trial interval is short relative to the trial period. These results constrain theories of dopamine signaling and identify a critical variable determining the emergence of dopamine ramps.

中文翻译：

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中脑边缘多巴胺斜坡反映环境时间尺度

中脑边缘多巴胺活动偶尔会表现出急剧的动态变化，重新引发关于多巴胺信号传导理论的争论。这场争论仍在继续，部分原因是多巴胺斜坡出现的实验条件仍然知之甚少。在这里，我们表明，在巴甫洛夫和仪器条件作用期间，仅当试验间间隔相对于试验期较短时才观察到中脑边缘多巴胺斜坡。这些结果限制了多巴胺信号传导理论，并确定了决定多巴胺斜坡出现的关键变量。