Methods for producing new neurons in the brain in vivo are provided according to aspects of the present invention which include introducing NeuroD1 into a glial cell, particularly into a reactive astrocyte or NG2 cell, thereby “converting” the reactive glial cell to a neuron. Methods of producing a neuronal phenotype in a glial cell are provided according to aspects of the present invention which include expressing exogenous NeuroD1 in the glial cell, wherein expressing exogenous NeuroD1 includes delivering an expression vector, such as a viral expression vector, including a nucleic acid encoding the exogenous NeuroD1 to the glial cell.
