The Development of V3 interneurons in the mouse spinal cord

Abstract

V3 interneurons in the spinal cord are a group of excitatory commissural interneurons that play an important role in producing balanced and stable gaits in animals. We discovered that Sim1-expressing V3 interneurons arise from the ventral-most progenitor domain in the developing neural tube and migrate in a dorso-lateral trajectory to settle into three distinct subpopulations. The most ventral subpopulation projects axons in both an rostral and caudal direction, while the intermediate and dorsal subpopulations are mostly rostrally-projecting. The role of Sim1 as a transcription factor was shown to play a role both in the proper migration and axon projection of V3 interneurons.