Transplantation of GABAergic neurons into adult mouse neocortex

GABAergic neurons in the neocortex contribute to various brain functions by regulating cortical pyramidal neurons. A deficiency of GABAergic neurons in the neocortex leads to the dysregulation of cortical neuronal circuits, but this can be overcome by cell transplantation, which provides a practical approach to repair damaged neuronal circuits. Here, we focused on the transplantation of committed neuronal progenitor cells. Because neuronal differentiation is considerably suppressed in the adult neocortex, we transfected proneural bHLH transcription factors into neural precursor cells to commit them to a neuronal lineage prior to the cell transplantation. We show that ventral neural stem cells transfected with Ngn1 are integrated as GABAergic neurons within a few days of transplantation into the adult mouse neocortex. These results demonstrate that the transplantation of committed neuronal progenitor cells is an effective method for brain repair.