Dopamine-mediated reinforcement and behavioral adaptation is essential to survival. Here, we test the effects of food restriction on dopamine-mediated learning and reinforcement using optical intracranial self-stimulation (oICSS), an optogenetic version of conventional electrical ICSS (also known as brain stimulation reward, BSR). Using mouse genetic lines to express channelrhodopsin selectively in midbrain dopamine neurons, we demonstrate that genetically expressed channelrhodopsin can mediate optically evoked dopamine release and support self-stimulation in a lever-pressing paradigm. Using this midbrain dopamine oICSS preparation, we compare acquisition and rate of pressing in ad libitum versus food restricted mice. Food restriction facilitated both more rapid acquisition of self-stimulation behavior and higher rates of responding; reversing food status after acquisition modulated response vigor in already established behavior. These data suggest that food restriction enhances both the acquisition and expression of dopamine-reinforced self-stimulation responding. These data demonstrate the utility of oICSS for examining changes in reinforcement learning concomitant to neuroadaptations induced in dopamine signaling by experimental manipulations such as food restriction.

中文翻译：

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长期食物限制会增强多巴胺介导的颅内自我刺激。

多巴胺介导的强化和行为适应对于生存至关重要。在这里，我们使用光学颅内自刺激（oICSS）来测试食物限制对多巴胺介导的学习和强化的影响，oICSS是传统电ICSS（也称为脑刺激奖励，BSR）的光遗传学版本。使用小鼠遗传系在中脑多巴胺神经元中选择性表达视紫红质通道蛋白，我们证明遗传表达的视紫红质通道蛋白可以介导光学诱发的多巴胺释放并支持杠杆按压范式中的自我刺激。使用这种中脑多巴胺 oICSS 制剂，我们比较了随意与食物限制小鼠的按压获取和速率。食物限制有助于更快地获得自我刺激行为和更高的反应率；获得后逆转食物状态调节已经建立的行为的反应活力。这些数据表明，食物限制增强了多巴胺增强的自我刺激反应的获得和表达。这些数据证明了 oICSS 用于检查强化学习的变化，以及通过食物限制等实验操作在多巴胺信号传导中诱导的神经适应的变化。