Our neurons are particularly vulnerable to a loss of genetic integrity for two basic reasons. First, with very few exceptions, the nervous system cannot generate new, replacement neurons. Thus, if their genome is damaged to such an extent that cell survival becomes impossible the lost cell cannot be replaced. A second compounding problem is that the absence of cell division (DNA replication in particular) excludes an important form of DNA repair known as homologous recombination from taking place. Simply put, each of our neurons gets one set of chromosomes and it must guard each nucleotide carefully. Repair can and does occur, but failure to do so is increasingly recognized as a source of human neurodegenerative diseases – dementias of all types, Parkinson’s, Huntingtons, Amyotrophic lateral sclerosis and many others. The guess research group focused heavily on the mechanisms of DNA repair itself. This Advanced Study Institute extends this perspective and brings in the unique problems that face the brain as it ages. The goal is to bring together individuals who may not be aware of each others work and engage them in conversation and idea exchange over the course of a four day meeting.