Long-duration hippocampal sharp wave ripples improve memory

Hippocampal sharp wave ripples (SPW-Rs) have been hypothesized as a mechanism for memory consolidation and action planning. The duration of ripples shows a skewed distribution with a minority of long-duration events. We discovered that long-duration ripples are increased in situations demanding memory in rats. Prolongation of spontaneously occurring ripples by optogenetic stimulation, but not randomly induced ripples, increased memory during maze learning. The neuronal content of randomly induced ripples was similar to short-duration spontaneous ripples and contained little spatial information. The spike content of the optogenetically prolonged ripples was biased by the ongoing, naturally initiated neuronal…

• NS
  National Science Foundation

  Award: 1707316
• FD
  Fundação de Amparo à Pesquisa do Estado de São Paulo

  Award: 2017/03729-2
• NI
  National Institutes of Health

  Awards: MH107396, NS074015, U19NS104590