Abstract: A method of treating increased non-LTR retrotransposition in a cell. The method includes exposing a neural cell to a retrotransposition inhibitor in an amount sufficient to decrease the non-LTR retrotransposition in the neural cell or a progeny of the neural cell. In various embodiments, the non-LTR retrotransposition involves at least one L1 retrotransposon. Also provided is a method of assaying retrotransposition in neural cells. The method includes sorting synchronized neural cells of the same genetic background into single neural cells, and subjecting one or more of the sorted single neural cells to quantitative polymerase chain reaction amplification of at least one retrotransposon. In addition, a method of identifying an inhibitor of retrotransposition and a identifying a neural condition associated with non-LTR retrotransposition are provided.