Characterization of state dependent differences in central complex activity and its influence on motor control in the praying mantis (Tenodera sinensis)

当一只动物在其自然环境中导航时，它必须不断地处理障碍，以寻找目标或避免捕食。这需要在局部控制反射、模式生成器和高级大脑中枢之间产生丰富的相互作用。在脊椎或神经弦水平产生的基本运动模式在大多数情况下不会提供必要的灵活性，使动物能够在所有复杂的地形中导航。为了引导运动，并将它们置于直接存在的内部和外部条件(如光照、温度或饥饿)的背景下，动物依靠复杂的感觉系统。显然，这需要一定程度的多感官整合，而这种整合必须发生在中枢神经系统的某个地方。大量的神经遗传学和电生理学数据表明，在昆虫中，这些功能主要存在于中央复合体(CX)中，CX是所有节肢动物前脑中高度结构的一组相互连接的中线神经毛。CX接收大量关于昆虫周围环境和自身生理状态的感官信息。将多通道四极导线植入被拴或自由行走的蟑螂的CX，显示出单个神经单位的活动与导航决策之间的明确关联。最近对遗传、行为和生理数据的荟萃分析有力地表明，Cx与哺乳动物的基底节同源，后者主要参与行为选择和选择。然而，尽管许多实验室进行了密集的研究，但CX的行为作用尚未得到最终确定。因此，我将研究当昆虫经历其直接环境或内部状态的变化时，Cx回路中的活动如何影响特定的行为。为了实现这一目标，我建议研究螳螂大脑中的多通道四极管记录，使用的技术是为蟑螂CX开发的，但现在已被改装用于密切相关的螳螂大脑。像螳螂这样的捕食性昆虫的使用使我能够准确地预测昆虫在实验操作之前会移动到哪里，或者将神经活动的模式与精确的定向运动联系起来。这也为检验一种假说提供了机会，即与饥饿和饱腹感相关的神经调节剂通过改变Cx回路来改变跟踪行为。我将结合多通道四极管录像和高速视频分析来研究与跟踪和攻击运动相关的中央复合体区域的神经活动模式。我相信，这些研究和由此产生的基于神经的模型将为状态依赖控制的功能提供重要的见解。

When an animal navigates through its natural environment, it must constantly deal with barriers as it seeks out targets or avoids predation. This requires a rich interplay between local control reflexes, pattern generators, and higher brain centers. Basic locomotor patterns that are generated at the spinal or nerve chord level will in most cases not provide the agility necessary to allow the animal to navigate all complex terrain. To guide movements and place them in the context of immediately existing internal and external conditions (e.g. illumination, temperature or hunger) animals rely on sophisticated sensory systems. Clearly this requires a level of multi-sensory integration that must occur somewhere in the central nervous system. A considerable body of neurogenetic and electrophysiological data suggests that in insects these functions reside largely in the central complex (CX), a highly structured group of interconnected midline neuropils in the protocerebrum of all arthropods. The CX receives massive amounts of sensory information regarding the insects surroundings and its own physiological state. Multi-channel tetrode wires implanted in the CX of tethered or freely walking cockroaches demonstrated clear correlations between activity in individual neural units and navigational decisions. A recent meta-analysis of genetic, behavioral and physiological data strongly suggested that the CX is homologous to the mammalian basal ganglia which are primarily involved in behavioral choice and selection. However, despite intense research from many laboratories, the behavioral role of the CX has not been conclusively determined. Therefore I will examine how the activity in CX circuits influences specific behaviors as an insect experiences changes in its immediate surroundings or internal state. To accomplish this goal, I propose to examine multi-channel tetrode recordings in the brain of the praying mantis, using techniques that were developed for cockroach CX but have now been adapted for use in the closely related mantis brain. The use of a predatory insect like the praying mantis enables me to predict exactly where the insect would move to prior to experimental manipulation or relate patterns of neural activity to precise directional movements. It also affords the opportunity to test a hypothesis that neuromodulators associated with hunger and satiety alter stalking behavior through changes in CX circuitry. I will combine multi-channel tetrode recordings with high speed video analysis to examine patterns of neural activity in regions of the central complex associated with stalking and striking movements. I believe that these studies and the resulting neural based models will provide important insights in the functionality of state dependent control.