Lay Abstract PI: Givens, Bennet Proposal Number: IBN-9723513 The hippocampus is a structure in the brain known top be important for memory formation, but the precise mechanism by which new information is acquired by the hippocampus is unknown. The electrical activity of the hippocampus occasionally oscillates in a rhythmic fashion, and this oscillation, called the theta rhythm, synchronizes with the arrival of new information. One hypothesis for memory formation is that this synchronization is important for stamping in new information. This project examines both the behavioral determinates of the theta rhythm synchronization and the neural systems that generate and control the rhythmic activity in order to establish the mechanism by which the hippocampus encodes new information. The results from this project significantly advance the understanding of how information is processed and stored in the brain.