Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.
J Neurosci. 2010 Jan 20;30(3):1003-14. doi: 10.1523/JNEUROSCI.4516-09.2010.
The primary function of a brain is to produce adaptive behavioral choices by selecting the right action at the right time. In humans, attention determines action selection as well as memory formation, whereas memories also guide which external stimuli should be attended to (Chun and Turk-Browne, 2007). The complex codependence of attention, memory, and action selection makes approaching the neurobiological basis of these interactions difficult in higher animals. Therefore, a successful reductionist approach is to turn to simpler systems for unraveling such complex biological problems. In a constantly changing environment, even simple animals have evolved attention-like processes to effectively filter incoming sensory stimuli. These processes can be studied in the fruit fly, Drosophila melanogaster, by a variety of behavioral and electrophysiological techniques. Recent work has shown that mutations affecting olfactory memory formation in Drosophila also produce distinct defects in visual attention-like behavior (van Swinderen, 2007; van Swinderen et al., 2009). In this study, we extend those results to describe visual attention-like defects in the Drosophila memory consolidation mutant radish(1). In both behavioral and brain-recording assays, radish mutant flies consistently displayed responses characteristic of a reduced attention span, with more frequent perceptual alternations and more random behavior compared with wild-type flies. Some attention-like defects were successfully rescued by administering a drug commonly used to treat attention-deficit hyperactivity disorder in humans, methylphenidate. Our results suggest that a balance between persistence and flexibility is crucial for adaptive action selection in flies and that this balance requires radish gene function.
大脑的主要功能是通过在正确的时间选择正确的行动来产生适应性的行为选择。在人类中，注意力决定了行为选择以及记忆的形成，而记忆也指导着应该注意哪些外部刺激（Chun 和 Turk-Browne，2007）。注意力、记忆和行为选择的复杂相互依存关系使得在高等动物中研究这些相互作用的神经生物学基础变得困难。因此，一种成功的还原方法是转向更简单的系统来解决这些复杂的生物学问题。在不断变化的环境中，即使是简单的动物也进化出了类似于注意力的过程，以有效地过滤传入的感觉刺激。这些过程可以通过各种行为和电生理技术在果蝇，黑腹果蝇中进行研究。最近的工作表明，影响果蝇嗅觉记忆形成的突变也会导致类似于视觉注意力的行为出现明显缺陷（van Swinderen，2007；van Swinderen 等人，2009）。在这项研究中，我们扩展了这些结果，描述了果蝇记忆巩固突变体 radish(1) 中的类似于视觉注意力的缺陷。在行为和大脑记录测定中，radish 突变体果蝇的反应表现出注意力持续时间缩短的特征，与野生型果蝇相比，它们更频繁地进行感知交替，行为更随机。一些类似于注意力的缺陷可以通过服用一种常用于治疗人类注意力缺陷多动障碍的药物利他林来成功挽救。我们的结果表明，在果蝇中，持久性和灵活性之间的平衡对于适应性的行为选择至关重要，而这种平衡需要 radish 基因的功能。
