Laboratory of Cellular Neurobiology, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Kyoto University, Kyoto, Japan.
Dev Neurosci. 2012;34(6):533-42. doi: 10.1159/000346266. Epub 2013 Feb 12.
Experience in early life can affect the development of the nervous system. There is now evidence that experience-dependent plasticity exists in adult insects. To uncover the molecular basis of plasticity, an invertebrate model, such as Drosophila melanogaster, is a powerful tool, as many established genetic and molecular methods can be applied. To establish a model system in which behavioral plasticity can be examined, we investigated the optomotor response, a behavior common to most sight-reliant animals, in Drosophila and found that the response could be modified by the level of light during rearing. The angle turned by the head in response to a moving stimulus was used to quantify the response. Deprivation of light increased the response to low-contrast stimuli in wild-type Drosophila at 4 days after eclosion and this plastic change did not appear in rutabaga, a known mutant defective in short-term memory. In addition, the change was transient and was markedly decreased at 6 days after eclosion. Further, we found that Dark-flies, which have been kept in constant darkness for more than 50 years, showed a higher response to low-contrast stimuli even at 6 days after eclosion compared to wild type and this characteristic was not lost in Dark-flies placed in a normal light environment for 2 generations, suggesting that this high response has a hereditary nature. Thus, our model system can be used to examine how the environment affects behaviors.
早期的生活经历会影响神经系统的发育。现在有证据表明，成年昆虫中存在依赖经验的可塑性。为了揭示可塑性的分子基础，像 Drosophila melanogaster 这样的无脊椎动物模型是一种强大的工具，因为可以应用许多已建立的遗传和分子方法。为了建立一个可以研究行为可塑性的模型系统，我们研究了光感受器反应，这是大多数依赖视觉的动物共有的一种行为，发现光感受器反应可以通过饲养期间的光水平来修饰。头部对运动刺激的转动角度用于量化反应。在羽化后 4 天，剥夺光会增加野生型果蝇对低对比度刺激的反应，而 rutabaga（一种已知的短期记忆缺陷突变体）中不会出现这种可塑性变化。此外，这种变化是短暂的，在羽化后 6 天明显减少。此外，我们发现，已经在黑暗中饲养超过 50 年的 Dark-flies 即使在羽化后 6 天，对低对比度刺激的反应也更高，与野生型相比，这种特征在将 Dark-flies 放置在正常光照环境中两代后不会丧失，表明这种高反应具有遗传性。因此，我们的模型系统可用于研究环境如何影响行为。
