So, what do we mean by dementia? It’s an umbrella term for diseases typified by brain cell degeneration beyond what is expected for a certain age group, due to damage or disease.  Dementias that affect the cortex region of the brain – the outer region that is densely packed with nerve cells, or neurons – include Alzheimer’s, and Creutzfeldt-Jakob Disease (CJD), the human equivalent of BSE. Memory loss and learning difficulties are the major consequences of these diseases. If we could look inside the brain, we would witness abnormal protein deposits, brain cells dying, and a reduction in new cell growth, which all contribute to brain circuit damage. Parkinson’s and Huntingdon’s disease affect the regions of the brain just below the outer cortex, and cause motor symptoms such as involuntary movements. So, how can we halt brain cell destruction? And how do we repair it?