Hippocampal ripples down-regulate synapses

Science. 2018 Mar 30;359(6383):1524-1527. doi: 10.1126/science.aao0702. Epub 2018 Feb 8.


The specific effects of sleep on synaptic plasticity remain unclear. We report that mouse hippocampal sharp-wave ripple oscillations serve as intrinsic events that trigger long-lasting synaptic depression. Silencing of sharp-wave ripples during slow-wave states prevented the spontaneous down-regulation of net synaptic weights and impaired the learning of new memories. The synaptic down-regulation was dependent on the N-methyl-d-aspartate receptor and selective for a specific input pathway. Thus, our findings are consistent with the role of slow-wave states in refining memory engrams by reducing recent memory-irrelevant neuronal activity and suggest a previously unrecognized function for sharp-wave ripples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Down-Regulation
  • Hippocampus / physiology*
  • Learning / physiology
  • Long-Term Synaptic Depression / physiology*
  • Memory / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Receptors, N-Methyl-D-Aspartate / genetics
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Sleep / physiology
  • Synapses / physiology*


  • Receptors, N-Methyl-D-Aspartate