Neurodegeneration is a process involved in several serious and debilitating diseases, for which there is often no cure. One of the first steps on the journey towards a treatment to stop neurons dying is understanding how and why they do so. Now, scientists from Cambridge University and the University of Toronto have announced a mechanism that explains how neurons die in two diseases, motor neurone disease and a type of dementia called fronto-temporal dementia. Georgia Mills spoke to Cambridge University chemist Michele Vendruscolo. First, Georgia asked, what actually are neurons?