The Circuit Logic of Modulation of Locomotion by Odors

即使是简单的自然主义者，我们对回路机制的理解也存在着根本的差距。 2个行为，比如煮一杯咖啡，它们通过子行为的顺序执行来进行。 3这种差距的持续存在是一个重要的问题，因为获得电路层面的理解- 研究复杂的多步骤行为是解开健康大脑功能之谜的必要一步。 5.精神障碍和精神障碍。首要目标是获得对这种自然主义行为的电路层面的理解-- 6IOR。这里的研究目的是在气味的背景下揭开感觉-运动转换的逻辑。 7果蝇的运动调节。核心假设是，就像我们自己的许多日常行为一样， 8运动的气味调制控制是分级的。苍蝇的运动是由更简单的元素构成的，称为 9个运动基元，每个基元持续1-3秒(或10-30步)。气味，而不是对气味采取行动 10个瞬时运动参数，如速度和角速度，作用于这些运动基元和 11更改苍蝇执行给定运动基元的概率。这一假设的形式是-- 12是在前期工作和初步数据的基础上发展起来的。建议进行这项研究的理由是 13理解气味引导的运动--一种复杂的、灵活的行为--在基因易驯化的背景下 14系统将允许精确描述在以下背景下的感应器运动转换的步骤 15.自然主义行为。上面的假设将通过表征调制的电路基础来检验 16使用成像、电生理、定量等技术相结合的食物气味移动 17行为和计算。这项拟议的研究有三个具体目标。1)提取运动基元-- 并验证了气味通过改变苍蝇执行不同任务的时间来调节运动的假说。 19个不同的运动原始人。2)检验假设，不同的ORN类别调节花费在 20个不同的运动原始人。3)阐明侧角在运动气味调制中的作用。再一次- 21搜索是创新的，因为它使用了复杂的统计工具(分层隐马尔可夫模型， 22 HHMM)和尖端实验工具在遗传易驯化的模式生物的背景下获得 23对自然主义行为的洞察。这项拟议的研究具有重要意义，因为它将垂直推进我们的 24了解自然主义行为中的感觉运动过程。来自多个领域的见解 25所有人都得出结论，行为被组织成离散的信息包或行为原语。行动不- 26倍于这些离散分组的顺序招募。研究自然行为的一个关键障碍是 27在大多数情况下，这些离散分组中有足够的可变性，使它们在没有 28借助先进的统计工具。通过部署HHMM，我们克服了这一关键障碍。除了代表- 29在我们对自然主义行为的理解上取得了纵向进展，这是另一个可能的积极结果 30这项研究是对通过不正确的动作顺序发生的神经条件反射的更好诊断。 31 32 33

1 There is a fundamental gap in our understanding of the circuit mechanisms underlying even simple naturalistic 2 behaviors, such as making a cup of coffee, which proceed through a sequential execution of sub-behaviors. 3 Continued existence of this gap represents an important problem because obtaining a circuit-level understand- 4 ing of complex multi-step behaviors is a necessary step toward unlocking the mysteries of healthy brain func- 5 tion and of disorders. The overarching goal is to obtain a circuit-level understanding of such naturalistic behav- 6 ior. The research objective here is to unravel the logic of sensorimotor transformation in the context of odor- 7 modulation of locomotion in Drosophila. The central hypothesis is that, like many of our own everyday actions, 8 control of odor-modulation of locomotion is hierarchical. A fly’s locomotion is built from simpler elements called 9 locomotor primitives, each of which lasts between 1-3 seconds (or 10-30 steps). Odors, instead of acting on 10 instantaneous locomotor parameters such as speed and angular speed, act on these locomotor primitives and 11 change the probability that the fly spends performing a given locomotor primitive. This hypothesis was formu- 12 lated on the basis of our previous work and preliminary data. The rationale for the proposed research is that 13 understanding odor-guided locomotion—a complex, flexible behavior—in the context of a genetically tractable 14 system will allow a precise delineation of the steps that underlie sensorimotor transformation in the context of a 15 naturalistic behavior. The hypothesis above will be tested by characterizing the circuit basis of modulation of 16 locomotion by food odors using a combination of techniques including imaging, electrophysiology, quantitative 17 behavior and computation. The proposed research has three specific aims. 1) To extract the locomotor primi- 18 tives and test the hypothesis that odors modulate locomotion by changing the time a fly spends performing dif- 19 ferent locomotor primitives. 2) To test the hypothesis that different ORN classes modulate the time spent in 20 distinct locomotor primitives. 3) To elucidate the role of lateral horn in odor modulation of locomotion. The re- 21 search is innovative because it employs sophisticated statistical tool (Hierarchical Hidden Markov model, 22 HHMM) and cutting-edge experimental tools in the context of a genetically tractable model organism to obtain 23 insights into naturalistic behaviors. The proposed research is significant because it will vertical advance our 24 understanding of sensorimotor processes involved in naturalistic behaviors. Insights from multiple fields have 25 all come to the conclusion that behavior is organized into discrete packets or behavioral primitives. Actions un- 26 fold by a sequential recruitment of these discrete packets. A critical barrier to the study of natural behavior is 27 that in most cases there is enough variability in these discrete packets to make them unrecognizable without 28 the help of sophisticated statistical tool. By deploying HHMM, we overcome this critical barrier. Besides repre- 29 senting a vertical advance in our understanding of naturalistic behavior, another possible positive outcome of 30 this study is better diagnosis of neurological conditioning that occur through improper sequencing of actions. 31 32 33