It's neuroscience’s final frontier. Tiny bubbles will open the blood-brain barrier to sneak drugs into tumours – and we might treat Alzheimer's the same way KULLERVO HYNYNEN is preparing to cross neuroscience's final frontier. In July he will work with a team of doctors in the first attempt to open the blood-brain barrier in humans – the protective layer around blood vessels that shields our most precious organ against threats from the outside world. If successful, the method would be a huge step in the treatment of pernicious brain diseases such as cancer, Parkinson's and Alzheimer's, by allowing drugs to…