Test tube brains may sound like something out of a dystopian science fiction or horror movie, but scientists are using them to understand Alzheimer's disease, Parkinson's disease, and traumatic brain injuries, and even detect these conditions early.

Now, according to research published in the American Chemical Society's Biomaterials Science & Engineering journal this month, these mini-brains can survive for at least nine months when grown in a mixture of protein from silk and stem cells from patients with diseases like Alzheimer's and Parkinson's. Artificial mini-brains typically have a short life span, but these long-lasting brains allow scientists to observe the progression of neurological diseases in groups of cells over time so that they can pin down the earliest signs of disease onset.