Neural circuits underlying sensorimotor behaviors in C. elegans

所有动物都进化出了特定的行为，使它们能够找到资源并避免伤害。反射等固定的先天行为的产生，取决于专用神经回路的功能。然而，行为也必须灵活，并适应新的条件。神经回路也调节这些更复杂的行为。这些回路的结构和功能特性是由特定大脑发育的基因确定的，并由经验进一步塑造和调节。通过在广泛的动物和许多行为环境中研究神经回路，我们可以了解神经系统处理信息和产生行为的基本机制。 我们研究了一种简单动物--秀丽线虫的神经回路和行为。线虫是一种一毫米长的蛔虫。线虫只有302个神经细胞，但它的行为很复杂，既表现出天生的行为，又适应了它的环境和经历。由于线虫是盲人，它主要依靠类似于嗅觉和味觉的化学感官来导航环境。我们正在研究允许蠕虫检测和定位(或避免)其环境中的关键资源或危险的神经电路。线虫有三个关键属性，使其成为一种有吸引力的动物，以这种方式进行研究：1)它是唯一一种描述了其所有神经元之间的完整连接的动物--称为“接线图”；2)它的导航行为可以通过视频分析轻松和定量地描述；3)它是透明的，使用遗传方法，我们可以用荧光分子标记它的神经元，使我们能够监测行为任务中每个神经元的活动。总而言之，这项工作是一个机会，从单个细胞到相互作用的神经元网络，再到由此产生的生物体水平的行为，这是一个跨越生物组织规模的机会。这样一个综合的观点对于理解行为、它的变化和它的进化是必不可少的。

All animals have evolved specific behaviors that allow them to find resources and avoid harm. The production of fixed, innate behaviors such as reflexes, depends on the function of dedicate neural circuits. However, behavior must also be flexible and adapt to new conditions. Neural circuits also mediate these more complex behaviors. The structural and functional properties of these circuits are established by genes that specify the development of the brain, and are further shaped and modulated by experience. By studying neural circuits in a wide range of animals and in many behavioral contexts, we can gain understanding of the fundamental mechanisms by which nervous systems process information and produce behavior. We study neural circuits and behavior in a simple animal, Caenorhabditis elegans, a one millimeter long roundworm. C. elegans has just 302 nerve cells, or neurons, yet it is behaviorally complex, exhibiting both innate behaviors and adapting to its environment and experiences. Because C. elegans is blind, it relies principally on chemical senses, similar to smell and taste, to navigate its environment. We are studying the neural circuits that allow worms to detect and locate (or avoid) critical resources or dangers in its environment. There are three key attributes of C. elegans that make it an attractive animals to study in this manner: 1) It is the only animal in which the complete set of connections between all of its neurons—referred to as the “wiring diagram”—has been describe; 2) Its navigation behaviors can be easily and quantitatively described with video analysis; and 3) It is transparent, and using genetic methods we can label its neurons with fluorescent molecules that allow us to monitor the activity of each neuron during behavioral tasks. Together, this work is an opportunity to look across scales of biological organization, from individual cells, to networks of interacting neurons, to the organism-level behaviors that result. Such an integrative view is essential to understanding behavior, its variation, and its evolution.