The paper "Awake Hippocampal Sharp-Wave Ripples Support Spatial Memory", by Shantanu Jadhav, Caleb Kemere, Walter German, and Loren Frank is now availble at Science! The ripple disruption system employed by Jadhav in this paper (and developed by Kemere and Frank) is one of the tools being employed in further experiments here in the Rice Neuroengineering lab.
Abstract: The hippocampus is critical for spatial learning and memory. Hippocampal neurons in awake animals exhibit place field activity that encodes current location, and sharp-wave ripple (SWR) activity during which representations based on past experiences are often replayed. The relationship between these patterns of activity and the memory functions of the hippocampus is poorly understood. We interrupted awake SWRs in animals learning a spatial alternation task. We observed a specific learning and performance deficit that persisted throughout training. This deficit was associated with awake SWR activity as SWR interruption left place field activity and post-experience SWR reactivation intact. These results provide a link between awake SWRs and hippocampal memory processes, and suggest that awake replay of memory-related information during SWRs supports learning and memory-guided decision-making.