Optogenetically-initiated low frequency dorsal hippocampal activity enhances resting-state fMRI connectivity and visual memory retrieval performance

Abstract

Our recent study demonstrated that low frequency optogenetically-initiated hippocampal activities enhances brain-wide resting-state fMRI connectivity. However, the behavioral consequence of such connectivity enhancement remains unknown. Since hippocampus is known to play a prominent role in memory, we assessed the effects of such connectivity enhancement on short-term and long-term memory. Our experimental results demonstrated that, while low frequency dorsal hippocampus stimulation enhanced interhemispheric fMRI connectivity (in hippocampus, V1, A1 and S1), it also improved the long-term visual memory by enhancing memory retrieval (in contrast to memory encoding) performance.