The Theta Rhythm of the Hippocampus: From Neuronal and Circuit Mechanisms to Behavior

This review focuses on the neuronal and circuit mechanisms involved in the generation of the theta (theta) rhythm and of its participation in behavior. Data have accumulated indicating that theta arises from interactions between medial septum-diagonal band of Broca (MS-DbB) and intra-hippocampal circuits. The intrinsic properties of MS-DbB and hippocampal neurons have also been shown to play a key role in theta generation. A growing number of studies suggest that theta may represent a timing mechanism to temporally organize movement sequences, memory encoding, or planned trajectories for spatial navigation. To accomplish those functions, theta and gamma (gamma) oscillations interact during the awake state and REM sleep, which are considered to be critical for learning and memory processes. Further, we discuss that the loss of this interaction is at the base of various neurophatological conditions.

Automated summary

The generation of theta rhythm involves interactions between the medial septum-diagonal band of Broca and intra-hippocampal circuits, as well as the intrinsic properties of neurons in these regions. Theta may serve as a timing mechanism to organize movement sequences, memory encoding, and spatial navigation trajectories, with interactions with gamma oscillations being critical for learning and memory processes. The disruption of this interaction is believed to underlie various neurophatological conditions.