Rhythmic coordination of hippocampal neurons during associative memory processing Rangel Rueckemann Riviere Keefe Porter Heimbuch Budlong Eichenbaum

Rhythmic coordination of hippocampal neurons during associative memory processing Rangel Rueckemann Riviere Keefe Porter Heimbuch Budlong Eichenbaum

Rhythmic coordination of hippocampal neurons during associative memory processing Rangel Rueckemann Riviere Keefe Porter Heimbuch Budlong Eichenbaum 2016 Hippocampal oscillations are dynamic, with unique oscillatory frequencies present
during different behavioral states. To examine the extent to which these oscillations reflect neuron
engagement in distinct local circuit processes that are important for memory, we recorded single
cell and local field potential activity from the CA1 region of the hippocampus as rats performed a
context-guided odor-reward association task. We found that theta (4–12 Hz), beta (15–35 Hz), low
gamma (35–55 Hz), and high gamma (65–90 Hz) frequencies exhibited dynamic amplitude profiles
as rats sampled odor cues. Interneurons and principal cells exhibited unique engagement in each of
the four rhythmic circuits in a manner that related to successful performance of the task. Moreover,
principal cells coherent to each rhythm differentially represented task dimensions. These results
demonstrate that distinct processing states arise from the engagement of rhythmically identifiable
circuits, which have unique roles in organizing task-relevant processing in the hippocampus