Dopamine modulates the optomotor response to unreliable visual stimuli in Drosophila melanogaster
Dopamine modulates the optomotor response to unreliable visual stimuli in Drosophila melanogaster
复制标题
DOI：
10.1111/ejn.14648
复制
发表时间：
2019-12-30
影响因子：
3.4
通讯作者：
Morimoto, Takako
中科院分区：
文献类型：
--
作者：
Akiba, Masumi;Sugimoto, Kentaro;Morimoto, Takako
感觉系统的状态依赖性调节已经在许多生物体中进行了研究，并且可能通过单胺类神经递质等神经调节剂介导。其中，多巴胺参与动物行为的许多方面，包括运动控制、注意力、动机和认知。然而，感官刺激引起的多巴胺能调节行为的精确神经机制仍然知之甚少。在这里，我们用黑腹果蝇来证明多巴胺可以调节对包括噪音在内的移动视觉刺激的视运动反应。视动反应是对移动物体的头部转动反应，在大多数依赖视觉的动物（包括哺乳动物和昆虫）中都可以观察到。首先，在多巴胺受体D1R1或D1R2缺失的突变果蝇中，研究了多巴胺系统对光运动反应的影响，这些受体参与果蝇睡眠唤醒的调节。我们检测了D1R1基因敲除（D1R1 KO）和D1R2基因敲除（D1R2 KO）果蝇的视运动反应，发现D1R1 KO果蝇的视运动反应不受影响；然而，与野生型相比，D1R2 KO果蝇的基因表达明显减少。利用D1R2 RNA干扰构建体的细胞类型特异性表达，我们确定了扇形体，这是中心复合体的一部分，负责多巴胺介导的视运动反应调节。特别是，扇形体中的脑桥细胞在光运动反应的调节中似乎很重要，它们的神经活动是光运动反应所必需的。这些结果表明，中枢复合体在调节基于感觉刺激处理的行为中发挥了新的作用。
State-dependent modulation of sensory systems has been studied in many organisms and is possibly mediated through neuromodulators such as monoamine neurotransmitters. Among these, dopamine is involved in many aspects of animal behaviour, including movement control, attention, motivation and cognition. However, the precise neural mechanism underlying dopaminergic modulation of behaviour induced by sensory stimuli remains poorly understood. Here, we used Drosophila melanogaster to show that dopamine can modulate the optomotor response to moving visual stimuli including noise. The optomotor response is the head-turning response to moving objects, which is observed in most sight-reliant animals including mammals and insects. First, the effects of the dopamine system on the optomotor response were investigated in mutant flies deficient in dopamine receptors D1R1 or D1R2, which are involved in the modulation of sleep-arousal in flies. We examined the optomotor response in D1R1 knockout (D1R1 KO) and D1R2 knockout (D1R2 KO) flies and found that it was not affected in D1R1 KO flies; however, it was significantly reduced in D1R2 KO flies compared with the wild type. Using cell-type-specific expression of an RNA interference construct of D1R2, we identified the fan-shaped body, a part of the central complex, responsible for dopamine-mediated modulation of the optomotor response. In particular, pontine cells in the fan-shaped body seemed important in the modulation of the optomotor response, and their neural activity was required for the optomotor response. These results suggest a novel role of the central complex in the modulation of a behaviour based on the processing of sensory stimulations.