Studying stem cell-based therapies by applying advanced in vivo physiological and imaging methods to transplanted human neural populations in mice

Project Summary/Abstract Stem cell transplantation therapies are emerging as some of the most promising methods for treating an array of neurological and neurodegenerative disorders where the primary cause of pathology is cell death. Among the most exciting of these approaches is the transplantation of human Neural Precursor Cells (hNPCs) that are derived from human induced Pluripotent Stem Cells (hiPSCs) to replace neuronal loss. For targeted stem cell therapies to be successful, programmed hNPCs must undergo a complex and dynamic set of processes in vivo after transplantation, including proliferation, migration, and integration into the existing circuit. Although it is accepted that all of these processes are critical to the success of hNPC transplantation therapies very little is known about their dynamics, either in patients or in animal models. The ability to track the changes that hNPCs undergo once in the neocortex, in vivo over the lifetime of the animal, will provide key insights into the mechanisms governing transplant integration, as well as the functional impact that transplants have on existing circuits. The goal of this proposal is thus to develop cutting edge methods for in vivo imaging and neurophysiology to study the structural dynamics and functional impact of hNPC transplantation in adult cortical circuits in the mouse. We are ideally suited to accomplish this goal as we have shown that hNPCs derived from hiPSCs transplanted into the juvenile mouse integrate into mouse cortical and hippocampal circuits. Furthermore, we have pioneered multiphoton in vivo imaging and neurophysiology methods in the mouse that will support the innovations proposed for tracking the structural and functional dynamics of transplanted hNPCs. Using this expertise, we will accomplish the goal of this project via the following 3 aims. In aim 1, we will determine the structural maturation of human NPCs transplanted into the adult mouse using lifetime in vivo 2-photon imaging. In aim 2, we will determine the molecular and cellular identity and characterize the intrinsic biophysical properties of NPCs engrafted into the adult mouse. In aim 3, we will characterize the functional properties of neurons differentiated from transplanted hNPCs in the visual cortex of awake behaving mice.