Peter Baracskay

Results We performed 128-channel wireless recordings in the dorsal CA1 region in three Long-Evans rats using bilaterally implanted 32-tetrode microdrives. Continuous recordings were performed for a period of approximately 24 h, covering the learning of a novel set of goal locations on a cheeseboard maze,9 an interleaved, extended rest period at the home cage, and the recall of the previously learned goal locations (Figure 1A).

Highlights • CCKI silencing triggers broad disinhibitory network effects and enhances burst firing • CCKIs are involved in theta phase precession-mediated temporal coding • Disruption of theta phase precession did not prevent subsequent sleep replay • CCKI activity regulates the magnitude of contextual fear-memory recall Summary Cholecystokinin-expressing interneurons (CCKIs) are hypothesized to shape pyramidal cell-firing patterns and regulate network oscillations and related network state...

Abstract Hippocampal reactivation of waking neuronal assemblies in sleep is a key initial step of systems consolidation. Nevertheless, it is unclear whether reactivated assemblies are static or whether they reorganize gradually over prolonged sleep. Here, we tracked reactivated CA1 assembly patterns over ~20 hours of sleep/rest periods and related them to assemblies seen before or after in a spatial learning paradigm.