Dr. David Chen
Research Fellow, NYU
PI: Prof. Ted Erclik
February 14, 2025
12 to 1 PM
IB140
Title: “Building the Blueprint of the Brain: Genetic and Molecular Strategies for Unraveling Sensory Circuit Development"
Abstract: During neuronal development, sensory neurons are specified into correct cell fates and connect to proper partners. The formation of functional circuits is essential for animals to detect environmental inputs and thus drive behaviors. Dissecting the molecular logic for establishing sensory circuits in higher-order organisms has been challenging to study partly due to the extreme complexity and diversity of their nervous systems. While Drosophila has been a powerhouse model system with many genetic tools for studying the fundamental principles of neuronal development and function, progress on understanding the development of neuronal circuits has been dramatically limited by the lack of tools manipulating developmental neurons. Although genetic lines exist that target specific neurons in the adult Drosophila brain, very few target the same cells during development. In the first part of the seminar, I will introduce the method I developed to target any neurons of interest from early development to adult. This toolkit provides a unique angle to uncovering the emergent principles that developing neurons use to generate and maintain the right neuronal connectivity.
In the second part of the seminar, I will discuss how the coordination between neuronal specification and specific connectivity patterns, especially when two synaptic partners undergo two different modes of cell specification (stochastic vs. deterministic). In the fly retina, pale (p) and yellow (y) subtypes of color photoreceptors (R7 and R8) are stochastically specified, whereas their synaptic partners in the optic lobe are produced through highly deterministic programs. How do stochastically determined p vs. y R7 and R8 find their respective targets that are deterministically specified in the optic lobes?
Previous work from our lab identified one pair of Dprs and DIPs, members of an interacting network of immunoglobulin superfamily proteins, is important for the synaptic connection between yR7 and its downstream target. I therefore hypothesize that different pairs of cell adhesion molecules can mediate the matching of other synaptic partners. By using advanced single-cell RNA sequencing technology, CRISPR gene editing, and sophisticated genetic manipulation in the Drosophila color vision circuit, I have identified candidates of cell adhesion molecules for synaptic partner matching. I will be presenting the molecular logic for coordinating between cell-type specification and the synaptic connectivity at the system level. Overall, our work has uncovered novel molecular mechanisms regulating synaptic pairing and probes the fundamental principles underlying the propagation of stochastic cell fate choices during circuit assembly.
Visit Dr. Chen's website to learn more about him and his research!