Gustatory plasticity in C-elegans involves integration of negative cues and NaCl taste mediated by serotonin, dopamine, and glutamate
Gustatory plasticity in C-elegans involves integration of negative cues and NaCl taste mediated by serotonin, dopamine, and glutamate
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DOI：
10.1101/lm.994408
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发表时间：
2008-11-01
影响因子：
2
通讯作者：
Jansen, Gert
中科院分区：
文献类型：
--
作者：
Hukema, Renate K.;Rademakers, Suzanne;Jansen, Gert
虽然幼稚的秀丽隐杆线虫个体被 0.1-200 mM NaCl 所吸引，但在长时间暴露于 100 mM NaCl 后，它们会对这些 NaCl 浓度产生强烈排斥。我们将这种行为称为味觉可塑性。在这里，我们表明，只有当预先暴露于 NaCl 并结合负面刺激（例如，刺激）时，线虫才会表现出对低 NaCl 浓度的回避。例如，驱虫剂，或在没有食物的情况下。通过测试血清素和/或多巴胺信号突变体并通过外源供应这些神经递质进行救援，我们发现血清素和多巴胺在可塑性反应中发挥作用，而在发育过程中也需要血清素。此外，我们还表明，谷氨酸在对氯化钠的反应中发挥着重要作用，无论是在氯化钠的化学吸引力还是味觉可塑性方面。因此，线虫可以利用多巴胺能、血清素能和谷氨酸能神经传递将 NaCl 与负面刺激联系起来。最后，我们发现，长时间饥饿会增强味觉可塑性，并且可以在大多数测试的味觉可塑性突变体中诱导避免氯化钠。只有谷氨酸门控 Cl 通道基因 avr-15 的突变影响饥饿增强的味觉可塑性。这些结果表明，饥饿会导致对氯化钠的回避，这在很大程度上与正常的味觉可塑性机制无关。
While naive Caenorhabditis elegans individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that C. elegans displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined with a negative stimulus, e. g., a repellent, or in the absence of food. By testing serotonin and/or dopamine signaling mutants and rescue by exogenously supplying these neurotransmitters, we found that serotonin and dopamine play a role during the plasticity response, while serotonin is also required during development. In addition, we also show that glutamate plays an important role in the response to NaCl, both in chemoattraction to NaCl and in gustatory plasticity. Thus, C. elegans can associate NaCl with negative stimuli using dopaminergic, serotonergic, and glutamatergic neurotransmission. Finally, we show that prolonged starvation enhances gustatory plasticity and can induce avoidance of NaCl in most gustatory plasticity mutants tested. Only mutation of the glutamate-gated Cl-channel gene avr-15 affected starvation-enhanced gustatory plasticity. These results suggest that starvation induces avoidance of NaCl largely independent of the normal gustatory plasticity mechanism.