The research of the Herrup lab focuses on the cellular and molecular mechanisms behind the neuronal death that is observed in a number of different human diseases. The two diseases that are studied most intensively are Alzheimer’s disease and a rare childhood disorder known as ataxia-telangiectasia. Both conditions have pointed towards the neurons’ inability to suppress their cell cycle activity as a key element in the degenerative process. This has led the lab to focus on two important questions: what are the molecular links between cell cycle and cell death, and what are the factors that drive a neuron to begin a new and ultimately lethal cell cycle. The answers to the first question, the linkage between cell cycle and cell death, remain unknown. One avenue that is under intense scrutiny is the actions of the a-typical cyclin-dependent kinase, Cdk5. Recent results from the lab suggest that this pathway represents an untapped area of potentially valuable therapeutic approaches. The attempts to answer the second question, the factors in the diseased brain that trigger the neurons to attempt cell division, have led to an interest in neuroinflammation, oxidation and DNA damage as inter-related and highly relevant activities. These topics have focused the attention of the lab on the multiple actions of the DNA damage response protein, ATM.