Quan Yuan, Ph.D.

Proper functions of neuronal circuits rely on the fidelity of their assembly, while adaptive modifications are also essential. Our research objectives are to understand how the balance of reliability and flexibility is achieved and regulated in neural circuits, and its functional implications in physiological and pathological conditions.

The discovery of a surprising degree of wiring plasticity in the Drosophila larval visual system provides us opportunities to study the experience-dependent plasticity in a simple yet powerful system. We observed large scale homeostatic modification of the dendritic arbor of ventral lateral neurons (LNvs) by visual experience during larval development. This structural plasticity is accompanied by the changes in synapse number and physiological response to light. Our genetic analyses have uncovered novel molecules involved in the regulation of activity-dependent structural modification, with connections to functional plasticity such as learning and memory.

The Drosophila system allows rapid identification of genetic components and systematic studies using anatomical, physiological and behavioral approaches. We are currently carrying out projects to: identify molecular components underlying structural plasticity in the fly larval visual circuit; determine cellular mechanisms regulating light-mediated behaviors in Drosophila larvae; and investigate the functional consequences of deficits in homeostatic neuronal plasticity.