--We continued our studies of the CA2 region of the hippocampus where the oxytocin receptor (Oxtr) and vasopressin 1b receptor (Avpr1b) are located. The CA2 area is an important, although relatively unexplored, component of the hippocampus. We are studying the role of the CA2 in learning and memory using a Avpr1b-cre expressing line we made. We are expressing a calcium sensor in the Avpr1b neurons and monitoring their activities during behaviors. --We are continuing to use optogenetics and electrophysiology to study the role of the CA2 in behavior. We are examining the input to CA2 from other regions as well.