Journal Article

Long-duration hippocampal sharp wave ripples improve memory

Buzsáki, György, Tingley, David, Oliva, Azahara, Rocha-Almeida, Florbela, Fernández-Ruiz, Antonio, de Oliveira, Eliezyer Fermino

2019

Overview

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 sequences. Prolonged ripples recruited new neurons that represented either arm of the maze. Long-duration hippocampal SPW-Rs replaying large parts of planned routes are critical for memory.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Animal behavior / Animal memory / Animals / CA1 Region, Hippocampal - physiology / Cognitive ability / Hippocampus / Male / Maze Learning / Memorization / Memory / Memory Consolidation - physiology / Memory tasks / Neurons / Neurons - physiology / Optogenetics / Prolongation / Pyramidal cells / Rats / Rats, Long-Evans / Ripples / Short term memory / Skewed distributions / Spatial Ability / Spatial analysis / Spatial data / Spatial memory