Research in the Chiang Lab is focused on Sonic hedgehog (Shh) signaling in development and cancer. They study how the distribution of Shh protein is regulated and how this regulation affects the identity and number of neural progenitors/stem cells in the central nervous system. The lab utilizes the vertebrate system to address these questions, with emphasis on neural progenitors involved in the establishment of the cerebellum circuitry or the generation of tumors.
The cerebellar circuitry is comprised of a limited number of excitatory and inhibitory neurons that are important for motor coordination and cognitive function. Excitatory neurons use glutamate as the neurotransmitter and are generated from the rhombic lip, a distinct proliferative germinal zone situated at the outer layer of the cerebellar anlage, whereas inhibitory neurons use GABA as their neurotransmitter and are generated from the ventricular germinal zone of the inner layer of the cerebellar anlage. The lab's hopes to elucidate the signaling pathways regulating the expansion and diversification of neuronal subtypes generated in the two distinct cerebellar germinal layers. This is a crucial area of study as deregulation of signaling pathways such as Shh and Wnt in the cerebellum has been associated with medulloblastoma, the most common pediatric central nervous system tumor.