DEVELOPMENT OF ADULT-SPECIFIC BEHAVIOR IN MANDUCA SEXTA

一个重要的和相对较新的概念出现在 关于神经网络功能组织的神经科学 以及这些系统如何产生有节奏的行为。 显著性特征 这一概念的核心是，神经网络具有能力和可塑性， 以生成各种模式化输出，这取决于特定的 神经网络接收的化学和/或突触输入。 重要的是，“保护-调节”策略也可用于 神经系统产生越来越复杂的行为 在以后的发育阶段表达。 人们认为 脊椎动物成年特有的运动行为的发展可能是 基于这样的战略。 这项拟议中的研究将检查发育中的中枢神经系统 全变态虫Manduca sexta， 成人行为的建构似乎是基于 神经回路的神经调节存在于早期发育阶段 阶段 拟议的研究将检查细胞和 成人蜕皮的神经因素的发育方面， 能使昆虫逃脱的有节奏的行为 从它的旧角质层。 先前的实验表明， 蜕皮运动模式可以在成人中被揭露。 保留在 成人被认为是促成新的成人特异性蜕皮的原因 格局 由于神经活动下降的影响，在一些 未知的方式，保守的幼虫蜕皮模式产生电路 产生成虫蜕皮行为。 初步研究 表明在一组大约15对下行的 胸神经元，有必要修改中间神经元， 将幼虫蜕皮运动程序转化为 成人专用1 我建议：（1）审查职能作用， 单个下行的中间神经元在神经元的转化中发挥作用。 幼虫蜕皮模式的成人模式，和（2）检查 下行胸中间神经元的发育历史， 这些神经元与保存的幼虫之间的解剖学联系 成人的电路。 细胞内外电生理 方法将被用来研究下行中间神经元的行动 在确定的蜕皮输出运动神经元和可能的其他 中间神经元 各种细胞示踪剂将被用于研究解剖 下行胸中间神经元，特别是在变性过程中， 发展 这是开发的第一个无脊椎动物模型系统 在细胞水平上研究成年人的行为 由先前表达的运动程序的明显调制引起 参与发展.

An important and relatively recent concept has arisen in the neurosciences regarding the functional organization of neural networks and how such systems generate rhythmic behaviors. The salient feature of this concept is that a neural network has the capacity and plasticity to generate various patterned outputs, depending on the specific chemical and/or synaptic inputs the neural network receives. Importantly, the "conservation-modulation" strategy may also be used by the nervous system for the generation of increasingly complex behaviors expressed at later developmental stages. It is thought that the development of adult-specific locomotor behaviors in vertebrates may be based on such a strategy. The proposed research will examine the developing central nervous system of the holometabolus insect, Manduca sexta, where developmental construction of adult behavior appears to be based on the neuromodulation of neural circuitry present at earlier developmental stages. The proposed research will examine the cellular and developmental aspects of neural elements underlying adult ecdysis, a hormonally activated rhythmic behavior that enables the insect to escape from its old cuticle. Previous experiments indicate that the larval ecdysis motor pattern can be un-masked in the adult. Its retention in the adult is thought to contribute to the novel adult-specific ecdysis pattern. By the influence of descending neural activity, in some unknown way, the conserved larval ecdysis pattern-generating circuitry is acted upon to produce adult ecdysis behavior. Preliminary studies indicate that within a group of approximately 15 pairs of descending thoracic neurons, there are modifying interneurons that are necessary for the transformation of the larval ecdysis motor program into the adult-specific one. I propose to: (1) examine the functional role that individual descending interneurons play in the transformation of the larval ecdysis pattern to that of the adult pattern, and (2) examine the developmental history of descending thoracic interneurons, and the anatomical connections these neurons make with the conserved larval circuitry in the adult. Intra- and extracellular electrophysiological methods will be used to study the actions of the descending interneurons on identified ecdysis out-put motoneurons and possibly other interneurons. Various cell tracers will be used to study the anatomy of the descending thoracic interneurons, especially during metamorphic development. This is the first invertebrate model system developed where it is possible to study, at the cellular level, how adult behavior arises from the apparent modulation of a motor program expressed earlier in development.