Cingulate-Hippocampus Coherence and Trajectory Coding in a Sequential Choice Task

• Theta oscillations coordinate cingulate cortex and hippocampus in a decision task
• Cingulate and hippocampal neurons accurately encode individual trajectories
• Decreasing frequency of theta coherence underlies increasing trajectory information
• At decision stages, hippocampal spikes precede cingulate spikes and LFP

SummaryInteractions between cortex and hippocampus are believed to play a role in the acquisition and maintenance of memories. Distinct types of coordinated oscillatory activity, namely at theta frequency, are hypothesized to regulate information processing in these structures. We investigated how information processing in cingulate cortex and hippocampus relates to cingulate-hippocampus coordination in a behavioral task in which rats choose from four possible trajectories according to a sequence. We found that the accuracy with which cingulate and hippocampal populations encode individual trajectories changes with the pattern of cingulate-hippocampal theta coherence over the course of a trial. Initial theta coherence at ∼8 Hz during trial onsets lowers by ∼1 Hz as animals enter decision stages. At these stages, hippocampus precedes cingulate in processing increased amounts of task-relevant information. We hypothesize that lower theta frequency coordinates the integration of hippocampal contextual information by cingulate neuronal populations, to inform choices in a task-phase-dependent manner.Video Abstract To view the video inline, enable JavaScript on your browser. However, you can download and view the video by clicking on the icon belowHelp with MP4 filesOptionsDownload video (23192 K)