Extended Data Fig. 4: Remote 3-week OPR testing.
From: The hippocampus is crucial for forming non-hippocampal long-term memory during sleep
OPR memory was tested in n = 6 rats, 3 weeks after a 2-h post-encoding sleep interval. These supplementary experiments followed the same procedures as described for the 1-week sleep condition on the OPR task, but included sleep EEG recordings. a, OPR memory is indicated by the mean ± s.e.m. discrimination ratio during the first 1 min and 3 min of exploration. +P = 0.034, for one-sample t-test against chance level. Rats displayed significant OPR memory after 3 min (as well as for the whole 5-min exploration period). b, OPR performance (discrimination ratio at 1 min) at the 3-week retrieval test was correlated with sleep spindle duration during the first 30 min of post-encoding sleep (*P = 0.029, Pearson’s product–moment correlation). A similar correlation with NOR performance at the 3-week retrieval (Fig. 3a) points towards a similar mechanism underlying the formation of long-term NOR and OPR memory during sleep.
