Sleep is essential for memory consolidation that stabilizes a memory trace. Memory consolidation includes waves of new gene expression and protein synthesis. Recently, microRNAs (miRNAs) have emerged as critical regulators of memory processes. Previous studies demonstrated that rapid eye movement (REM) sleep deprivation (REM SD) during specific time windows after training in the Morris water maze (MWM) task impairs memory consolidation. Here, we showed that the post-learning REM sleep, extending from 3 to 6 h after last training, is critical for spatial learning in the MWM task. Further, we found that the REM SD after training significantly changes the hippocampal expression of brain-derived neurotrophic factor (BDNF) mRNA; however, it causes minimal difference in the hippocampal expressions of calcium-calmodulin-dependent protein kinase II (CAMKII) and cAMP response-element-binding (CREB). In addition, it considerably affected the hippocampal expressions of miR-132, miR-182, and miR-124. In conclusion, after the MWM task, the post-learning REM sleep during specific time windows can modulate spatial memory consolidation, and its deprivation can impact the hippocampal transcriptional processes including memory-related miRNAs and mRNAs.
Keywords: Hippocampus; Morris water maze; REM sleep deprivation; microRNA.
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