The authors of this paper make an important point in a very nice and elegant way. Glial progenitors require an additional signal to complete the process of myelination. They showed that a neurotrophin signal is what may be missing, as making a modified progenitor that expresses a neurotrophin capable of binding to multiple receptors can enhance myelination and functional repair.

View all comments by Mahendra Rao

The nanoparticle gene transfer described by Bharali et al. is an exciting new avenue for genetic modification in the brain. The study suggests the organically modified nanoparticles are easy to make, are safe, and provide efficient and widespread transgene expression. The spread of expression after ventricular injections and the live imaging technique were impressive. I would have liked to see if the nanoparticles are more efficient or less toxic than other nonviral systems. The current nanoparticle preparations are probably not as effective for gene transfer as the most efficient viral vectors—as GFP fluorescence was rather weak—but further improvements on the new technology are to be expected. One potential advantage of nonviral techniques is for efficient glial expression, as most viral vectors have a strong tropism for neurons, although glial expression was not demonstrated in this study.

View all comments by Ronald Klein

I think the new applications utilizing D15A looks very promising, but the nanotechnolgy has more broad-based, long-term implications. Showing no toxicity is an amazing leap forward as usually nanotech experiments show similar effects to silicosis. Perhaps a combination of both treatments will show the most therapeutic promise.

View all comments by Jacob Mack