Modulation of neurotransmission by the catecholamine dopamine (DA) is conserved across phylogeny. In the nematode Caenorhabditis elegans, excess DA signaling triggers Swimming-Induced Paralysis (Swip), a phenotype first described in animals with loss of function mutations in the presynaptic DA transporter (dat-1). Swip has proven to be a phenotype suitable for the identification of novel dat-1 mutations as well as the identification of novel genes that impact DA signaling. Pharmacological manipulations can also induce Swip, though the reagents employed to date lack specificity and potency, limiting their use in evaluation of dat-1 expression and function. Our lab previously established the mammalian norepinephrine transporter (NET) inhibitor nisoxetine to be a potent antagonist of DA uptake conferred by DAT-1 following heterologous expression. Here we demonstrate the ability of low (μM) concentrations of nisoxetine to trigger Swip within minutes of incubation, with paralysis dependent on DA release and signaling, and non-additive with Swip triggered by dat-1 deletion. Using nisoxetine in combination with genetic mutations that impact DA release, we further demonstrate the utility of the drug for demonstrating contributions of presynaptic DA receptors and ion channels to Swip. Together, these findings reveal nisoxetine as a powerful reagent for monitoring multiple dimensions of DA signaling in vivo, thus providing a new resource that can be used to evaluate contributions of dat-1 and other genes linked to DA signaling without the potential for compensations that attend constitutive genetic mutations.

中文翻译：

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哺乳动物去甲肾上腺素转运蛋白抑制剂尼索西汀对秀丽隐杆线虫多巴胺转运蛋白DAT-1的急性阻断揭示了体内多巴胺信号传导基因修饰的影响。

儿茶酚胺多巴胺（DA）对神经传递的调节在整个系统发育中都是保守的。在线虫秀丽隐杆线虫中，过量的DA信号会触发游泳诱发的麻痹（Swip），这是一种在动物中首次描述的具有突触前DA转运蛋白功能缺失（dat-1）的表型。Swip已被证明是适合于鉴定新型dat-1突变以及鉴定影响DA信号的新型基因的表型。尽管迄今为止使用的试剂缺乏特异性和效力，但药理学操作也可以诱导Swip，从而限制了它们在dat-1表达和功能评估中的用途。我们的实验室先前将哺乳动物的去甲肾上腺素转运蛋白（NET）抑制剂尼索西汀确立为异源表达后DAT-1赋予DA吸收的有效拮抗剂。在这里，我们证明了低（μM）浓度的尼索西汀在温育几分钟内触发Swip的能力，而麻痹取决于DA释放和信号传导，而与daip-1缺失触发的Swip无关。尼索西汀与影响DA释放的基因突变结合使用，我们进一步证明了该药物用于证明突触前DA受体和离子通道对Swip的贡献。在一起，这些发现揭示了尼索西汀是一种用于监测体内DA信号的多个维度的有力试剂，从而提供了一种新资源，可用于评估dat-1和与DA信号相关的其他基因的贡献，而没有潜在的补偿组成型遗传突变。