Rhythmic coordination of hippocampal-prefrontal ensembles for odor-place associative memory and decision making

Memory-guided decision making involves long-range coordination across sensory and cognitive brain networks, with key roles for the hippocampus and prefrontal cortex (PFC). To investigate coordination mechanisms that mediate sensory-cued decision making based on learned associations, we monitored activity in hippocampus (CA1), PFC, and olfactory bulb in rats performing an odor-place associative memory and decision task on a T-maze. During odor sampling, the beta (15-30 Hz) and respiratory (7-8 Hz) rhythms (RR) were prominent and coherent across the three regions, with beta specifically linked to fast decisions. Single neurons and ensembles in both CA1 and PFC encoded and predicted animals9 upcoming choices, with choice-encoding dynamics linked specifically with beta rhythm coordination. Beta phase modulation of CA1 interneuron activity was linked to accurate decisions, suggesting a mechanism for enabling temporal coordination. Our findings indicate that beta rhythm coordination within the hippocampal-prefrontal network supports utilization of odor cues for memory-guided decision making.