This is my first post to this blog. I’ll post brief reviews about papers which interest me. The first paper is
Awake replay of remote experiences in the hippocampus.
Karlsson MP, Frank LM. 2009, Nat Neurosci.
Replay events of place cells firing sequences are separated in two categories; one occurs during experience, and the other occurs following experience. An awake replay was thought to be depend on sensory inputs, thus it didn’t contain a later type of a replay event. However, this paper shows that both types of replay occur during waking state (figure 2 and 4). In addition, the paper shows firing rate during SWRs are lower in awake state than in quiescent state (figure 3) but replay pattern is more robust in awake state than in quiescent state (figure 3 and 4). I think the paper indicate awake replay has a role for memory consolidation, and the role might be different from that of replay during sleep.
First, I thought the difference of robustness of replay sequence might correlate with that dream is obscurer and more fragmentized than recalling during waking. But now I don’t think it is such simple because human dreams during REM sleep during which sharp-wave ripple isn’t observed. There are many discussions about correlation between memory consolidation and dream. They may be complicated, but interesting.