Characterizing neuronal circuit assembly of the pharyngeal nervous system during C. elegans embryogenesis

A functional nervous system requires neurons to be connected in very specific ways to allow animals to move, sense the environment, and form memories. Here, we use a transparent microscopic round worm, Caenorhabditis elegans, as a model organism to study the nervous system. While the nervous system of other organisms, such as mammals are far more complex, many of the fundamental aspects their molecular and cellular mechanisms are conserved. The entire nervous system of C. elegans is simple and well-characterized: a hermaphrodite worm has a total of 302 neurons, and how they connect to each other has been mapped out. In particular, 20 neurons are precisely interconnected to form a small but functional nervous system in the C. elegans pharynx to coordinate pumping of the organ and allow the animal to take in food. Our project aims to studying how this simple nervous system is assembled in the embryo. We will use fluorescent labels to mark neurons in the pharynx, and live microscopic imaging of a developing embryo to capture the process of how neurons form connections to make a functional neuronal network. Moreover, genetic mutations have been found to disrupt proper formation of the pharyngeal nervous system. We aim to study what goes wrong in the embryo in these mutants. Since many genes and regulatory mechanisms are shared across animals. By studying how a simple nervous system is wired together in the worm, we may also begin to understand the genetic and molecular mechanisms for putting together more complex nervous system, such as in humans, and what goes wrong when these mechanisms fail in the case of genetic mutations.