Methods are disclosed for transducing neurons with heterologous genes using retrograde viral transport. The methods disclosed employ substantially non-toxic vectors, such as adeno-associated virus vectors, that are capable of retrograde axonal transport to introduce and express genes in the neurons. This method has applications in the mapping of neural pathways, in stimulating or inhibiting the growth of neurons, and in the treatment of various neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.