Biasing the content of hippocampal replay during sleep

• Published in: Nature neuroscience Vol. 15; no. 10; pp. 1439 - 1444
• Main Authors: Bendor, Daniel, Wilson, Matthew A
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.10.2012; Nature Publishing Group
• Subjects: 631/378/1385/519; 631/378/1595; Acoustic Stimulation - methods; Action Potentials - physiology; Animal Genetics and Genomics; Animals; Association Learning - physiology; Behavioral Sciences; Bias; Binomial distribution; Biological Techniques; Biomedical and Life Sciences; Biomedicine; Cues; Hippocampus (Brain); Hippocampus - physiology; Memory; Memory - physiology; Neurobiology; Neurons - physiology; Neurosciences; Physiological aspects; Rats; Sleep; Sleep - physiology; Sound; United States; United States > US; Massachusetts
• ISSN: 1097-6256; 1546-1726
• DOI: 10.1038/nn.3203

The authors report that, during sleep, a task-related auditory cue biases hippocampal reactivation events towards replaying the spatial memory associated with that cue. These results indicate that sleep replay can be manipulated by external stimulation, and provide further evidence for the role of hippocampal replay in memory consolidation. The hippocampus is essential for encoding self-experienced events into memory. During sleep, neural activity in the hippocampus related to a recent experience has been observed to spontaneously reoccur, and this 'replay' has been postulated to be important for memory consolidation. Task-related cues can enhance memory consolidation when presented during a post-training sleep session, and, if memories are consolidated by hippocampal replay, a specific enhancement for this replay should be observed. To test this, we trained rats on an auditory-spatial association task while recording from neuronal ensembles in the hippocampus. We found that, during sleep, a task-related auditory cue biased reactivation events toward replaying the spatial memory associated with that cue. These results indicate that sleep replay can be manipulated by external stimulation and provide further evidence for the role of hippocampal replay in memory consolidation.