Modulation of a Neural Circuit in an Insect During the Molt

该项目旨在识别昆虫血液中的一种化学物质，这种化学物质可以改变昆虫的取食行为。它关注的是六分蛾的额神经节(FG)，这是控制食物摄取的神经系统的一部分。FG驱动肠道的第一部分，即前肠的活动。在毛毛虫体内，前肠不断移动，吸收食物并向下移动到肠道中。破坏FG的功能极大地减少了毛虫或成虫摄取的食物量。在蛾的生活史中的特定时间，前肠的活动会发生变化。例如，当毛虫准备蜕皮时，它会停止觅食，前肠也会在大约16小时内停止运动。一项初步研究发现，这种活动变化是由血液中的一种因素触发的。在目前的研究、实验中，将使用几种生化程序来分离和纯化蜕皮昆虫血液中改变前肠活动的因子(S)。关于该因子(S)如何作用于FG和前肠以改变其活动的进一步研究将被启动。这个项目解决了基本的研究问题，并提供了更多实际应用的潜力。神经生物学中最基本的问题之一是，动物的神经系统是如何改变以产生行为变化的。昆虫的大型可识别神经元和相对简单的行为使研究人员能够对昆虫行为背后的神经回路变化进行详细分析。识别破坏取食行为的关键成分的自然发生因素，可能对开发昆虫取食的特定化学控制是有用的。

This project is designed to identify a chemical in the blood of an insect that alters its feeding behavior. It focuses on the frontal ganglion (FG) of the moth Manduca sexta, a part of the nervous system that controls the ingestion of food. The FG drives the activity of the first part of the gut, the foregut. In the caterpillar, the foregut is constantly moving, taking in food and moving it further down the gut. Disrupting the function of the FG greatly reduces the amount of food ingested by the caterpillar or adult moth. At specific times during the moth's life cycle, the activity of the foregut is altered. For example, when the caterpillar is preparing to molt, it stops feeding and the foregut stops moving for about 16 hours. A preliminary study found that this change in activity is triggered by a factor in the blood. In the current study, experiments, several biochemical procedures will be used to isolate and purify the factor(s) in the blood of molting insects that alters foregut activity. Further studies of how the factor(s) act on the FG and foregut to alter their activities will be initiated. This project addresses basic research questions and provides the potential for more practical applications. One of the most fundamental questions in neurobiology is how an animal's nervous system is modified to produce changes in behavior. The large identifiable neurons and relatively simple behaviors of insects have allowed investigators to carry out detailed analyses of alterations in the neural circuitry underlying insect behaviors. Identification of a naturally occurring factor that disrupts a critical component of feeding behavior may prove useful for the development of specific chemical controls of insect feeding.