Our current interests include the intrinsic mechanisms of thalamic development and the roles of thalamic input in neocortical development. We extensively use mouse genetics and in vivo gene delivery into developing embryos. Efforts in our lab are directed at two major goals: We are trying to understand how the developing thalamus produces different neuronal populations that later form distinct nuclei. We have characterized the spatial and temporal heterogeneity of progenitor cell populations in the thalamus. We are now trying to reveal molecular mechanisms that regulate such heterogeneity. Some of our recent works have determined the roles of Sonic hedgehog and Wnt signaling in this process, and how these intrinsic patterning mechanisms eventually affect the formation of thalamic nuclei in mice. We are trying to examine the roles of thalamocortical projections in the formation of functionally and anatomically distinct sensory areas in neocortex. To dissect local patterning mechanisms operating within neocortex and extrinsic mechanisms conveyed by the thalamic input, we are analyzing mutant mice in which certain thalamic nuclei are specifically alerted in size or the entire thalamocortical projections are compromised. Using these mice, we will determine the precise roles of thalamic afferents in neocortical development.