A strong defense system allows what the brain needs in and keeps out toxins and pathogens. It's a vital function that also stops promising drugs from reaching their target (think: a tumor) and prevents neuroscientists from probing how the brain works. Scientists at Caltech have now engineered viruses that can bypass this barrier in mice and deliver genes to many different types of cells.
Why it matters: In the past few decades, a wealth of tools have been created to study the brain — neurons can be individually labeled and imaged, genes can conceivably be edited, and the brain's cells can be manipulated with light in order to see what effect it has on functions like memory. But that all hinges on getting into the brain. This new work opens up the brain's intricacies for unprecedented study and possibly treatment of neural disorders (like Parkinson's and Huntington's diseases), brain cancers, and Friedreich's ataxia and other peripheral nervous system diseases.