Topic: ripple oscillations

The hippocampus is thought to form the brain substrate of a cognitive map. While the spatial component of this map involves hippocampal ‘place’ cells, non-spatial features may require coupling with other brain areas. This could involve ‘hippocampal sequences’, endogenous activations of successive place cells representing entire trajectories at a highly accelerated rate. These sequences are paced by theta or ripple oscillations, and could participate in learning and memory, as well as goal-directed decision making. However, the association between hippocampal sequences and reward- and goal-rela

The deep layers (V/VI) of the entorhinal cortex constitute a major relay station for routing neuronal activity from the hippocampus to downstream networks. To identify contributing pathways, we recently investigated the structural and functional organization of hippocampal projections to layer V (LV) of the medial entorhinal cortex (MEC) (Ohara, Rannap et al., Cell Rep. 2023). Here, we performed whole-cell patch-clamp recordings from MEC-LVI neurons combined with field potential recordings from hippocampal area CA1 in horizontal mouse brain slices. We found that a spontaneously occurring hippo