Extracellular electrical recordings of region CA1 display different types of oscillatory activity related to behavioral states. One of the most prominent and well-studied is the theta rhythm, a 4-12 Hz regular oscillation that occurs during locomotion and rapid eye movement (REM) sleep. Theta rhythms are believed to coordinate the encoding and retrieval of episodic memory during spatial navigation. Here, we report on phases and rates of spiking during network theta rhythmic activity.