What does sleep do for the transfer of memories to the cortex? · Grey Matter

In deep sleep the hippocampus replays the activity of the day: cells that fired together while a rat ran a track fire together again, in the same order and compressed in time, during brief bursts called sharp-wave ripples.

What does sleep do for the transfer of memories to the cortex?

In deep sleep the hippocampus replays the activity of the day: cells that fired together while a rat ran a track fire together again, in the same order and compressed in time, during brief bursts called sharp-wave ripples. These bursts tend to coincide with the slow waves and spindles of the cortex, a timing thought to let the cortex strengthen the links between the pieces the hippocampus is replaying. In rats, disrupting the ripples after learning impairs the memory, and in humans a night of sleep after learning improves retention compared with the same hours awake.