Disruption of Oligodendrogenesis Impairs Memory Consolidation in Adult Mice

The generation of myelin-forming oligodendrocytes persists throughout life and is regulated by neural activity. Here we tested whether experience-driven changes in oligodendrogenesis are important for memory consolidation. We found that water maze learning promotes oligodendrogenesis and de novo myelination in the cortex and associated white matter tracts. Preventing these learning-induced increases in oligodendrogenesis without affecting existing oligodendrocytes impaired memory consolidation of water maze, as well as contextual fear, memories. These results suggest that de novo myelination tunes activated circuits, promoting coordinated activity that is important for memory consolidation. Consistent with this, contextual fear learning increased the coupling of hippocampal sharp wave ripples and cortical spindles, and these learning-induced increases in ripple-spindle coupling were blocked when oligodendrogenesis was suppressed. Our results identify a non-neuronal form of plasticity that remodels hippocampal-cortical networks following learning and is required for memory consolidation. [Display omitted] •Spatial learning promotes oligodendrogenesis and de novo myelination in adult mice•Spatial learning promotes hippocampal ripple-cortical spindle coupling•Decreasing adult oligodendrogenesis blocks learning-induced increases in coupling•Decreasing adult oligodendrogenesis impairs spatial memory consolidation Experience-dependent de novo myelination may fine-tune activated circuits by promoting brain synchrony, important for memory consolidation. Steadman et al. find that blocking this form of adaptive myelination prevents learning-induced increases in coordinated activity and impairs memory consolidation.